back to indexDr. Matthew Walker: The Science & Practice of Perfecting Your Sleep | Huberman Lab Podcast #31
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Welcome to the Huberman Lab Podcast,
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where we discuss science and science-based tools
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for everyday life.
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I'm Andrew Huberman,
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and I'm a professor of neurobiology and ophthalmology
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at Stanford School of Medicine.
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Today, I have the pleasure of introducing Dr. Matthew Walker
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as our guest on the Huberman Lab Podcast.
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Dr. Walker is a professor of neuroscience and psychology
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at the University of California, Berkeley.
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There, his laboratory studies sleep.
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They study why we sleep, what occurs during sleep,
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such as dreams and why we dream, learning during sleep,
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as well as the consequences of getting insufficient
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or poor quality sleep on waking states.
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Dr. Walker is also the author
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of the international bestselling book, Why We Sleep.
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Our discussion today is an absolutely fascinating one
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for anyone that's interested in sleep, learning,
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or human performance of any kind.
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Dr. Walker teaches us how to get better at sleeping.
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He also discusses naps,
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whether or not we should or should not nap,
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whether or not we can compensate for lost sleep,
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and if so, how to best do that.
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We discuss behavioral protocols and interactions
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with light, temperature, supplementation, food,
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exercise, sex, all the variables that can impact
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this incredible state of mind and body that we call sleep.
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During my scientific career,
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I've read many papers about sleep
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and attended many seminars about sleep.
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Yet, my discussion with Dr. Walker today
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revealed to me more about sleep, sleep science,
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and how to get better at sleeping
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than all of those papers and seminars combined.
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I'm also delighted to share
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that Dr. Walker has started a podcast.
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That podcast, entitled The Matt Walker Podcast,
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releases its first episode this month
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and is going to teach all about sleep
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and how to get better at sleeping.
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So be sure to check out The Matt Walker Podcast
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on Apple, Spotify, or wherever you listen to podcasts.
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Before we begin, I'd like to mention that this podcast
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is separate from my teaching and research roles at Stanford.
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It is, however, part of my desire and effort
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to bring zero cost to consumer information
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about science and science-related tools
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to the general public.
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In keeping with that theme,
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I'd like to thank the sponsors of today's podcast.
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Our first sponsor is Roca.
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Roca makes sunglasses and eyeglasses
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that are of the absolutely highest quality.
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The company was founded by two all-American swimmers
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from Stanford, and everything about the design
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of their glasses is with performance in mind.
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I've spent my career studying the visual system
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and how it works, and I can tell you that Roca glasses
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take into account the science of the visual system,
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such that whether or not you're wearing them
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on a very bright day or you walk into a shadowed area
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or there's cloud cover,
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you can still see everything with perfect clarity.
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That also reflects the fact that the lenses that they use
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The other terrific thing about Roca sunglasses and eyeglasses
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You can use them while running, while cycling.
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Even if you get sweaty, they won't slip off,
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and they look great.
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One problem I have with a lot of so-called
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performance eyeglasses and sunglasses out there
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is that they look crazy.
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They make people look like cyborgs.
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Roca glasses have a terrific aesthetic.
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You can wear them to dinner, you can wear them at work,
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and you can wear them in all sorts of sports activities.
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If you'd like to try Roca glasses,
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you can go to Roca, that's R-O-K-A.com,
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and enter the code Huberman to save 20% off your first order.
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That's Roca, R-O-K-A.com,
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Today's podcast is also brought to us by Inside Tracker.
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Today's episode is also brought to us by Belcampo.
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Belcampo is a regenerative farm in Northern California
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that raises organic, grass-fed,
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and finished certified humane meats.
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I don't eat a lot of meat.
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I eat meat about once a day,
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but when I do, I make sure that it's high quality
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and both humanely and sustainably raised.
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Conventionally raised animals are confined to feedlots
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and eat a diet of inflammatory grains,
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but Belcampo's animals graze on open pastures
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And I've talked many times before on this podcast
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I eat those pretty much once a day.
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and it's belcampo.com slash Huberman for 20% off your order.
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And now my discussion with Dr. Matt Walker.
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Great to finally meet you in person.
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Wonderful to connect.
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I mean, it's been too long,
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but I suspect it would have been a shorter time
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before we'd met, lest the pandemic.
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Yeah, I'm delighted that we're finally
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sitting down face to face.
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I've been tracking your work, both in the internet sphere,
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and I read your book and loved it.
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And also from the perspective of science,
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you actually came to Stanford a couple of years ago
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and gave a lecture for brain mind.
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Oh yeah, yeah, yeah, yeah.
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And there, of course, you talked about sleep
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and its utility and its challenges
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and how to conquer it, so to speak.
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Let's start off very basic.
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Sleep is probably the single most effective thing
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you can do to reset your brain and body health.
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So that's a functional answer in terms of,
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you know, what is sleep in terms of its benefits.
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Sleep as a process, though,
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is an incredibly complex physiological ballet.
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And if you were to recognize or see what happens
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to your brain and your body at night during sleep,
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you would be blown away.
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And the paradox is that most of us,
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and I would think this too, you know,
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if I wasn't a sleep scientist,
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we go to bed, we lose consciousness for seven to nine hours,
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and then we sort of wake up in the morning
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and we generally feel better.
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And in some ways that denies the physiological
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and biological beauty of sleep.
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So upstairs in your brain,
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when you're going through these different stages of sleep,
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the changes in brainwave activity are far more dramatic
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than those that we see when we're awake.
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And we can speak about deep sleep and what happens there.
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REM sleep is a fascinating time,
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which is another stage of sleep often called dream sleep,
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which is rapid eye movement sleep.
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That stage of sleep, some parts of your brain
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are up to 30% more active than when you're awake.
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So again, it's kind of violating this idea
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that our mind is dormant
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and our body is just simply quiescent and resting.
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So I would happy to just sort of double click
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on either one of those
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and also what changes in the body as well.
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But it is an intense evolutionary adaptive benefit
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I would almost push back against an evolved system
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when we think about the question of sleep
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and what sleep is.
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Our assumption has always been that we evolved to sleep.
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And I've actually questioned that
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and I have no way to get in a time capsule
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and go back and prove this.
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But what if we started off sleeping
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and it was from sleep that wakefulness emerged?
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Why do we assume that it's the other way around?
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And I think there's probably some really good evidence
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that sleep may have been the proto state,
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that it was the basic fundamental living state.
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And when we became awake, as it were,
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we always had to return to sleep.
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In some ways at that point,
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sleep was the price that we paid for wakefulness.
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And that's another way of describing what sleep is.
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But again, I think it sort of denies
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that the active state of sleep,
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it's not a passive state of sleep either.
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And then finally you can say,
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what is sleep across different species?
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And in us human beings and in all mammalian species
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and avian species as well,
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sleep is broadly separated into these two main types.
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And we've got non-rapid eye movement sleep on the one hand,
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and then we've got rapid eye movement sleep on the other.
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And we can speak about how they unfold across a night
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and their architecture,
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because it's not just intellectually interesting
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from the perspective of what sleep is.
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It's also practically impactful for our daily lives.
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And I'd love to sort of go down that route too,
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but you navigate, you tell me I can-
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Let's definitely go down that route.
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So you mentioned how active the brain is
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during certain phases of sleep.
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When I was coming up in science,
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REM sleep, rapid eye movement sleep,
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was referred to as paradoxical sleep.
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Is that still a good way to think about it?
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Paradoxical because the brain is so active
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and yet we are essentially paralyzed, correct?
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Yeah, it really is a paradox.
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And where that came from
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was simply the brainwave recordings.
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That if all I'm measuring about you
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is your brainwave activity,
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it's very difficult for me
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sitting outside of the sleep laboratory room
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to figure out, are you awake or are you in REM sleep?
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Because those two patterns of brain activity
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are so close to one another,
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you can't discriminate between them.
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Yet the paradox is that when you are awake,
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I go in there and you're sort of sitting up,
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you're clearly conscious and awake.
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But yet when you go into REM sleep,
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you are completely paralyzed.
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And that's one of the,
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I think that's part of the paradox,
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but the paradox really just comes down
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to two dramatically different conscious states.
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Yet brain activity is dramatically
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more similar than different.
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And the way I can figure out which of the two you are in
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is by measuring two other signals,
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the activity from your eyes
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and the activity from your muscles.
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So when we're awake,
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we will occasionally have these blinks
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and we'll have sort of saccades.
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But during REM sleep,
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you have these really bizarre horizontal
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shuttling eye movements that occur.
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And that's where the name comes from, rapid eye movements.
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Are they always horizontal?
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Mostly they are horizontal.
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And that's one of the ways that we can differentiate them
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from other waking eye movement activity.
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Because it's not always, it can be sometimes horizontal,
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but can also have diagonal and also vertical in that plane.
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But then the muscle activity is the real dead giveaway.
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Just before you enter REM sleep,
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your brainstem, which is where the dynamics of non-REM
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and REM are essentially played out
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and then expressed upstairs in the cortex
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and downstairs in the body.
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When we go into REM sleep
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and just a few seconds before that happens,
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the brainstem sends a signal
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all the way down the spinal cord.
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And it communicates with what are called
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the alpha motor neurons in the spinal cord,
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which control of voluntary skeletal muscles.
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And it's a signal of paralysis.
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And when you go into dream sleep,
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you are locked into a physical incarceration
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You know, why would mother nature do such a thing?
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And it's in some ways very simple.
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The brain paralyzes the body
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so that the mind can dream safely.
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Because think about how quickly
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we would have all been popped out of the gene pool.
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You know, if I think I'm one of the best skydivers
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who can just simply fly,
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and I've had sometimes those dreams too,
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and I get up on my apartment window and I leap out.
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So that's one of the sort of,
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that's part of the paradox of REM sleep,
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both its brain activity similarity,
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despite the behavioral state being so different,
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and this bizarre lockdown of the sort of brain
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of the body itself.
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Now, of course, the involuntary muscles,
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thankfully, aren't paralyzed.
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So you keep breathing, your heart keeps beating.
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Is this why men have erections during REM sleep
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and women have vaginal lubrication during sleep?
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That's one of the reasons.
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Part of the other reason, though,
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that is because of the autonomic activity.
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So there is a part of our nervous system
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called the autonomic nervous system,
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and it controls many of the automatic behaviors.
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And some of those are aspects of our reproductive facilities.
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During REM sleep, what we later discovered
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is that you go through these bizarre,
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what we call autonomic storms, which sounds dramatic,
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but it actually is when you measure them,
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that you'll go through periods
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where your heart rate decelerates and drops
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and your blood pressure goes down,
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and then utterly randomly,
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your heart rate accelerates dramatically
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and what we call the fight or flight branch
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of the autonomic nervous system
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or the sympathetic nervous system,
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a badly named because it's anything but sympathetic,
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it's very aggravating,
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that all of a sudden fires up and then it shuts down again.
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And it's not in any regular way.
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And it's when you get those autonomic storms,
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you get very activated from a physiological perspective,
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that you can have these erections
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and you have vaginal discharge, et cetera.
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But you're totally paralyzed.
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But you are still paralyzed.
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There are only two voluntary muscle groups
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that are spurred from the paralysis, bizarre.
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One, your extra ocular muscles,
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because if they were paralyzed,
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you wouldn't be able to have rapid eye movements.
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And the other that we later discovered
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was the inner ear muscle.
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And we've got no good understanding
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as to why those two muscle groups
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are spurred from the paralysis.
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It may have something to do with cranial nerve,
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but I don't think it's that.
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I think it's perhaps something more sensory related.
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Some people have argued that the reason the eyeballs
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are spurred from the paralysis
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is because if your eyeballs are left
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for long periods of time inactive,
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you may get things such as oxygen sort of issues
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in the aqueous or vitreous humor.
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And so the eyeballs have to keep moving in some way.
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The drainage systems of the anterior eye
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are made to require movement.
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People with glaucoma have deficits in drainage
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through the anterior chamber, but there I'm speculating.
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I'm also speculating when I asked this.
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I would imagine that there are states in waking
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that also resemble slow wave sleep,
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or rather that there are states that slow wave sleep
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also resembles waking states.
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You've beautifully illustrated how REM sleep
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can mimic some of the more active brain states
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that we achieve in waking.
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What sort of waking state that I might've experienced
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or experienced on a daily basis might look similar
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to slow wave sleep, non-REM sleep, if any?
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It's a genius way of thinking about it.
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Turns the tables, I love it.
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We almost never see anything like the true ultra slow waves
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of deep non-REM sleep.
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So we spoke about these two stages, non-REM and REM.
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Non-REM is further subdivided into four separate stages,
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stages one through four, increasing in the depth of sleep.
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So stages three and four,
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that's what we typically call deep non-REM sleep,
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stages one and two.
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So maybe take me through the arc of a night,
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just so that, so I put my head down.
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Well, for you, what time do you normally go to sleep?
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So I'm usually sort of around about a 10.30 PM guy,
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and usually I'll naturally wake up
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sort of a little bit before seven,
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sometimes before 6.45 or seven.
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I have an alarm set for 7.04 AM.
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You heard it here, folks.
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Matt Walker does use an alarm clock.
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I really, really, I'm usually-
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He doesn't recommend it, but he does use it.
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You're human after all.
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Oh, I am so human.
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And I've had my sleep issues
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and I'd love to speak about that too,
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but it's only just in the event that,
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cause I like to keep regularity too,
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you've got to keep those two things in balance.
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And 7.04, just because, you know, why not be idiosyncratic?
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I don't know why we always set things on these hard numbers.
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So you go to sleep around 10.30,
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so using you as an example,
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because I imagine a number of people go to sleep
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at different times, but 10.30 is about
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when I go sleep, 11 is for me,
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but so you go to sleep at 10.30.
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So for that first, let's say three hours of sleep,
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what is the architecture of that sleep look like
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as compared to the last three hours of your sleep
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Yeah, so I should note that that sort of,
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you know, 10.30 to seven,
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that's just based on my chronotype and my preferential.
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It's different for different people.
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I'm not suggesting that that's the perfect sweet spot
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for humanity's sleep.
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But I imagine most people probably go to sleep
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somewhere between 10 and PM and midnight.
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And most probably wake up between 5 AM and 7 AM
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Yeah, yeah, at least in,
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if you look at sort of first world nations,
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that's a typical sleep profile.
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So when I first fall asleep,
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I'll go into the light stages of non-REM sleep,
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stages one and two of non-REM,
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and then I'll start to descend down
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into the deeper stages of non-REM sleep.
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So after about maybe 20 minutes,
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I'm starting to head down into stage three non-REM
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and then into stage four non-REM sleep.
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And as I'm starting to fall asleep,
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as I've cast off from the usually with me
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murky waters of wakefulness,
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and I'm in the shallows of sleep stages one and two,
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my heart rate starts to drop a little bit,
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and then my brainwave pattern activity starts to slow down.
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Normally when I'm awake,
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it's going up and down maybe 20, 30, 40,
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50 times a second.
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As I'm going into light non-REM sleep,
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it will slow down to maybe 15, 20,
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and then really starts to slow down,
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down to about sort of 10 or eight cycles per second,
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eight cycle waves per second.
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Then as I'm starting to move into
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stages three and four non-REM sleep,
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several remarkable things happen.
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All of a sudden, my heart rate really does start to drop.
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Oh, and I'll come back to temperature.
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I'm going to write temperature down
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because I always forget these things.
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Now I'm solidly in the foothills of middle age.
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So as I'm starting to go into those deeper stages
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of non-REM sleep, all of a sudden,
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hundreds of thousands of cells in my cortex
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all decide to fire together,
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and then they all go silent together.
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And it's this remarkable physiological coordination
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of the likes that we just don't see
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during any other brain state.
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That's really interesting.
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Having recorded from the brains of animals
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and a little bit from humans,
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I don't think I've ever seen the entire cortex
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or even entire regions of cortex light up like that.
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Yeah, it's stunning.
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It's almost like this beautiful sort of mantra chant,
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or this sort of, you know, it's a slow inhale,
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and then a meditative exhale, inhale, exhale.
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And these waves are just enormous in their size.
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And the body is capable of movement at this time.
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There is no paralysis.
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There is no paralysis, but for the most part,
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muscle tone has also dropped significantly
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And then you will, or I will then stay there
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for about another 20 or 30 minutes.
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So now I'm maybe 60 or 70 minutes into my first sleep cycle.
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And then I'll start to rise back up,
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back up into stage two non-REM sleep.
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And then after about 80 or so minutes,
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I'll pop up and I'll have a short REM sleep period.
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And then back down I go again,
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down into non-REM, up into REM.
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And you do that reliably, repeatedly,
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and I will be doing that, and I do do that,
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At least that's the average for most adults.
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It's different in different species.
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What changes to your question is the ratio
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of non-REM to REM within that 90 minute cycle
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as you move across the night.
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And what I mean by this is in the first half of the night,
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the majority of those 90 minute cycles
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are comprised of lots of deep non-REM sleep.
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That's when I get my stage three and four
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of deep non-REM sleep.
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Once I push through to the second half of the night,
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now that seesaw balance changes,
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and instead the majority of those 90 minute cycles
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are comprised either of this lighter form
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of non-REM sleep, stage two non-REM sleep,
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and much more, and increasingly more,
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rapid eye movement sleep.
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And the implication that I was sort of speaking about
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pragmatically is let's say that
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I have to and I usually never do
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early morning flights or red eyes
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just because I'm a mess if that happens.
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I'm not suggesting that other people shouldn't.
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I'm suggesting people not do that.
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Every time I've taken a red eye or I've done that,
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two or three days later,
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I get some sort of general feeling of malaise.
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My brain doesn't work as well.
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I think red eyes should be abolished.
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For the pilots too, I mean, and for the-
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Oh, and we can speak about those.
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And for the emergency room, I mean,
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long shifts have been shown to lead to
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physician-induced errors that lead to a lot of fatalities.
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I mean, there are a lot of reasons why
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staying up too long or being up at the wrong times
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if you're not adapted to it is just terrible.
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The data in all of those cases,
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and particularly physicians too,
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there was some recent data looking at suicidality.
link |
And the rates of suicide in training physicians
link |
are far, far above the norm.
link |
And I don't suspect that their schedules are helping them.
link |
I suspect that sleep is a missing part
link |
of that explanatory equation, but-
link |
I teach medical students and they're phenomenal,
link |
but yeah, they're under extremely challenged conditions.
link |
We shouldn't put them under those conditions.
link |
No, it's not optimizing performance.
link |
No, no, no, this is important.
link |
It's an important digression.
link |
I have one question,
link |
which is you're saying that as across the night,
link |
a greater percentage of these 90-minute cycles
link |
are going to be occupied by REM sleep
link |
as you progress through the night.
link |
I'm aware that based on work that you've done
link |
and from your public education efforts and others,
link |
that we have so-called circadian forces
link |
and we have other forces that are driving when we sleep
link |
and when we want to sleep, et cetera,
link |
without going into the details of those.
link |
I have a simple question.
link |
The experiment is the following.
link |
Let's say, God forbid,
link |
you are prevented from going to sleep at your normal time
link |
and you stay up for the four hours or five hours
link |
that normally you would be
link |
in predominantly slow-wave sleep.
link |
If, let's say, you finally get to lie down at 3 a.m.,
link |
a time when normally your sleep would be occupied
link |
mostly by rapid eye movement sleep,
link |
will you experience a greater percentage
link |
of rapid eye movement sleep
link |
because of these so-called circadian forces,
link |
meaning that's what's appropriate for that time,
link |
or will your system need to start
link |
at the beginning of the race that we're,
link |
as I'm referring to it, that we're calling sleep?
link |
If that's not clear to anybody,
link |
basically what I'm asking is if you are forced
link |
to skip the slow-wave sleep part of the night,
link |
will your system leap into rapid eye movement sleep
link |
or does it have to start at the beginning
link |
and get slow-wave sleep first?
link |
In other words, does one sleep state
link |
drive the entry to the next sleep state?
link |
So there is some degree of reciprocity
link |
between the sleep states, I should note,
link |
that when we drive one of those up,
link |
we often, but not always, see a change in the other.
link |
There are some pharmacologies
link |
that have shown an independence to that,
link |
and we've also played around with things like temperature,
link |
and sometimes you can nudge one
link |
and not seem to upset or perturb the other.
link |
But to your, I think, lovely point,
link |
the answer is it's a mix, but it's mostly the latter,
link |
meaning you will mostly go into your REM sleep phases
link |
and be significantly deficient in your deep sleep.
link |
So just because I start my sleep cycle at 3 a.m.
link |
rather than at 10.30 p.m.,
link |
it doesn't mean that my brain just says,
link |
well, I've got a program
link |
and I'm just going to run the program,
link |
and the way the program runs is that we always start
link |
with a first couple of hours of deep sleep.
link |
So we're just gonna begin act number one, scene one.
link |
It doesn't do that.
link |
Now, I will get some deep sleep to begin with,
link |
and part of that is just because of how sleep works
link |
based on how long I've been awake.
link |
there is a significantly greater pressure for deep sleep.
link |
But we actually use exactly what you just described
link |
as an experimental technique
link |
to selectively deprive people
link |
of one of those stages of sleep or the other.
link |
So we will do first half of the night deprivation
link |
and then let you sleep the second half.
link |
So that means that you will be mostly deep sleep deprived
link |
and you will still get mostly all of your REM sleep.
link |
And then we switch it so you only get your first four hours,
link |
which means you will mostly get deep non-REM sleep,
link |
but you will get almost no REM sleep.
link |
So in both of those groups,
link |
they've both had four hours of sleep.
link |
So the difference between them
link |
in terms of an experimental outcome is not the sleep time
link |
because they've both slept for the same amount.
link |
It's the contribution of those different stages.
link |
Now, we actually have more elegant methods
link |
for sort of selectively going in there
link |
and scooping out different stages of sleep.
link |
But that's the way we used to do it old school
link |
was just using this timing difference.
link |
And who suffers more, those that lack the early phase
link |
and were those that lack the later phase of the night sleep?
link |
In other words, if I have to sleep only four hours
link |
for whatever reason, am I better off
link |
getting the early part of the night sleep
link |
or the second half of the night sleep?
link |
Depends on what the outcome measure is.
link |
So that gets right to the differences
link |
between slow wave sleep and REM.
link |
I was probably misinformed, but my understanding,
link |
a very crude understanding, I should say before-
link |
I very much doubt it, au contraire with someone like you.
link |
Which is very nice of you.
link |
But the first part of the night,
link |
this slow wave sleep is restorative to the musculature,
link |
to motor learning, and that the dream content
link |
tends to be less emotional.
link |
The second half of the night being more emotional dreams
link |
and sort of the unpairing of the emotional load
link |
of our previous day and other experiences.
link |
So in other words, if I were to deprive myself of REM,
link |
I would be hyper emotional, maybe not as settled
link |
with the kind of experiences of my life.
link |
Whereas if I had to deprive myself of slow wave sleep,
link |
I would feel a more physical malaise.
link |
Is that correct or is that far too simple?
link |
And if it is too simple, please tell me where I'm wrong.
link |
No, I think much of that is correct.
link |
And it's sort of that plus.
link |
So for example, during deep non-REM sleep,
link |
that's where we get this, it's almost a form
link |
of natural blood pressure medication.
link |
And so when I take that away from you, the next day,
link |
we're usually going to see autonomic dysfunction.
link |
We're usually going to see abnormalities in heart rate,
link |
We also know that during deep non-REM sleep
link |
that there is a certain control of specific hormones.
link |
For example, we know that the insulin regulation
link |
of sort of metabolism, meaning how will you look
link |
from a regulated blood sugar perspective
link |
versus dysregulated pre-diabetic look of profile,
link |
that's where deep sleep seems to matter.
link |
If we selectively deprive you of that, we can see them.
link |
Growth hormone is different actually.
link |
So that's a beautiful demonstration
link |
where growth hormone seems to be more REM sleep dependent.
link |
And that's why we can come on to the effects of alcohol.
link |
And there was some really impressive frightening data
link |
on alcohol and its disruption of sleep.
link |
But then we also know testosterone.
link |
Peak levels of testosterone happen during REM sleep.
link |
So the second half of the night.
link |
Which is the second half of the night.
link |
So it really just means that your profile
link |
of mental and physical dysfunction will be different
link |
under both of those conditions.
link |
Which one would you prefer?
link |
I would prefer neither of them.
link |
And it really depends on what you're trying to optimize for.
link |
So it's just so complete.
link |
Sleep is just so plory potent.
link |
It's so physiologically systemic
link |
that it's almost impossible not to undergo
link |
one of those two things, just deep sleep deprivation
link |
or just REM sleep deprivation and not show a profile
link |
that you would really prefer to avoid.
link |
And that's the reason from an evolutionary standpoint
link |
that we have preserved those stages of sleep.
link |
I mean sleep is just so idiotic
link |
from an evolutionary perspective.
link |
Or maybe waking is idiotic.
link |
Or waking is, you know, well yeah.
link |
Based on your previous idea.
link |
Who have you been talking to?
link |
I think that comment is very specific to me.
link |
Yeah, I am normally always an idiot when waking.
link |
But I think this idea that sleep, you know,
link |
is so profoundly detrimental to us.
link |
If you were to take it at face value, you know,
link |
you're not finding a mate, you're not reproducing,
link |
you're not foraging for food,
link |
you're not caring for your young.
link |
And worst of all, you're vulnerable to predation.
link |
On any one of those grounds,
link |
sleep probably should have been selected against.
link |
Sleep has fought its way through heroically.
link |
You know, every step along the evolutionary path.
link |
And therefore every sleep stage
link |
has also survived as best we can tell.
link |
What that means is that those are non-negotiable.
link |
If mother nature had found a way
link |
to even just sort of, you know,
link |
thin slice some of that sleep from us,
link |
there would have been vast, I'm sure, evolutionary benefits.
link |
But it looks as though she hasn't.
link |
And I'm usually in favor of her wisdom
link |
after 3.6 million years, so.
link |
Yeah, it's incredible.
link |
I want to introduce another Gedanken experiment,
link |
another thought experiment.
link |
So in this arc of the night,
link |
slow-wave sleep predominates early in the night,
link |
and then REM sleep.
link |
There's a scenario that many people,
link |
including myself, experience on a regular basis,
link |
which is they go to sleep, sleeping just fine,
link |
three, four hours into it, they wake up.
link |
They wake up for whatever reason.
link |
Maybe there was a noise, maybe the temperature isn't right.
link |
We will certainly talk about sleep hygiene, et cetera.
link |
They get up, they go to the restroom.
link |
They might flip on the lights, they might not.
link |
They'll get back in bed.
link |
Hopefully they're not picking up their phone
link |
and starting to browse and wake up the brain
link |
through various mechanisms,
link |
light and cognitive stimulation, et cetera.
link |
They go back to sleep.
link |
Let's say after about 10, 15 minutes,
link |
they're able to fall back asleep.
link |
And then they sleep till their more typical wake time.
link |
How detrimental is that wake up episode or event
link |
in terms of longevity, learning, et cetera?
link |
I would love to sleep the entire night through every night,
link |
but most nights I don't.
link |
And yet I feel pretty good throughout the day.
link |
Some days better than others.
link |
So if you were to kind of evaluate that waking episode
link |
and compare it to sleeping the whole night through,
link |
what are your thoughts on that?
link |
So I think if you're waking up sort of frequently
link |
as you're describing,
link |
I would probably get your estate in order
link |
because my guess is within the next year,
link |
you're going to be done for, no, I'm kidding you.
link |
Absolutely kidding you.
link |
It is perfectly natural and normal,
link |
particularly as we progress with age.
link |
Children tend to have typically more continuous sleep.
link |
Now it's not that they aren't waking up
link |
for brief periods of time, they are.
link |
And in fact, we all do.
link |
When we come out the other end of our sleep cycle,
link |
at the end of our REM sleep period of the 90 minute cycle,
link |
almost everybody wakes up and we make a postural movement.
link |
We turn over because we've been paralyzed for so long
link |
and the body will also like to shift.
link |
Do we ever look around?
link |
Do we ever open our eyes and look around?
link |
You sometimes people will open their eyes,
link |
but usually it's only for a brief period of time
link |
and they usually never commit those awakenings to memory.
link |
Your situation and it's my situation as well.
link |
I usually now at this stage of life,
link |
I don't sleep through the night.
link |
I'll usually have a bathroom break and then I'll come back.
link |
That's perfectly normal.
link |
We tend to forget that in sleep science,
link |
we think of sleep efficiency.
link |
So of the total amount of time that you're in bed,
link |
how much of that percent time is spent asleep?
link |
And we usually look to numbers that are above 85% or more
link |
as a healthy sleep efficiency.
link |
So if you were to think about me going to bed and I spend,
link |
you know, let's say eight and a quarter,
link |
eight and a half hours of time in bed
link |
with a normal healthy sleep efficiency,
link |
I still may be only sleeping a total of seven and a half
link |
hours or seven and three quarter hours,
link |
meaning that I'm going to be awake in total,
link |
not in one long bout,
link |
but I'm going to be awake for upwards of 30 minutes,
link |
Sometimes that can be after a 10 minute, you know,
link |
dalliance after having gone to the bathroom
link |
and I'm just gradually drifting back off again.
link |
Other times it will just be for a couple of minutes.
link |
And most of those you don't commit.
link |
So I think we need to stop.
link |
We don't need to get too worried about, you know,
link |
periods of time awake,
link |
just because we're not sleeping throughout the night.
link |
I would love to do that too.
link |
And I remember when I, that used to happen
link |
and it still happens occasionally.
link |
It feels great when it does happen.
link |
It's a lovely thing.
link |
It's a surprise, right?
link |
It is not now a surprise.
link |
Yeah, it is a surprise.
link |
But for the most part,
link |
I think we can be more relaxed about that.
link |
Where we have to be a bit more attentive though,
link |
is if you are spending long periods of time,
link |
not being able to get back to sleep.
link |
And usually we define that by saying,
link |
if it's been 20, 25 minutes,
link |
normally that's a time when we would really say,
link |
okay, let's explore this, what's going on.
link |
Let's see what's happening.
link |
The other thing is if it's happening very frequently.
link |
So even if you're, you know,
link |
not awake for 25 minute stretches,
link |
but you're finding yourself waking up
link |
and being consciously aware that you've woken up
link |
for maybe six, seven or eight times throughout the night.
link |
And your sleep is very, what we call fragmented.
link |
The great science of sleep in the past five or 10 years
link |
has been, yes, quantity is important,
link |
but quality is just as important.
link |
And you can't have one without the other
link |
in terms of a good beneficial next day outcome.
link |
You can't just get four hours of sleep,
link |
but brilliant quality of sleep and be unimpaired.
link |
Nor can you get eight hours of sleep,
link |
but have very poor quality of sleep
link |
and be unimpaired the next day.
link |
So that's why I just sort of want to asterisk this idea of,
link |
let's not get too worried about waking up
link |
and having some time awake.
link |
That's perfectly normal and natural.
link |
But if it's happening very frequently throughout the night
link |
or those periods of time or long stretches of time,
link |
upwards of 25 minutes, then let's look into it.
link |
Well, I can assure you just helped a lot of people
link |
feel better about this waking up episode
link |
that I and many other people experience.
link |
I hope so because I think it's really important that we,
link |
you know, I think I've been desperately guilty
link |
of perhaps, you know, early on being too puritanical
link |
about, you know, sleep and I've, I've retrospected
link |
and I've tried to explore why this was the case.
link |
You know, it was almost sleep or else dot, dot, dot,
link |
you know, and at the time when I was starting
link |
to write the book, which was back in 2016,
link |
you know, sleep was still a neglected step sister
link |
in the health conversation of today.
link |
And I could see all of the, and it's changing, you know,
link |
and not because of my efforts,
link |
but because of all of my colleagues.
link |
I would say, well, it's great that you give attribution
link |
to your other people involved in it.
link |
Of course, it's a big field,
link |
but I think you've done a great service by queuing people
link |
to the importance of this state,
link |
not just for avoiding troublesome outcomes,
link |
but also for optimizing their waking state.
link |
It's really, you know, I view sleep as this period
link |
that feels good, but we're not aware of how it feels
link |
when we're in it necessarily.
link |
It has tremendous benefits when you're doing it well,
link |
so to speak, and it has tremendous deficits when we're not.
link |
And I think it was an important thing for you to do
link |
to cue people to this issue.
link |
And I would say mission accomplished,
link |
that people are aware of the need for sleep.
link |
I think that knowing that waking up
link |
in the middle of the night is normal,
link |
provided it's not too frequent, is great
link |
and will also help people
link |
who may have been overly concerned about that.
link |
I do want to use this as an opportunity to raise something
link |
about the so-called Uberman schedule,
link |
not to be confused with the Huberman schedule.
link |
Fortunately, no one has confused those yet.
link |
Some years ago, there was a discussion
link |
about the so-called Uberman schedule,
link |
meaning the Superman schedule.
link |
So that's Huberman without an H,
link |
which I have nothing to do with.
link |
If you read your Nietzsche, this will have a subtext.
link |
But regardless, the Uberman schedule,
link |
as I understand, is one in which the person
link |
elects to sleep in 90-minute bouts
link |
spread throughout the day and night
link |
in an attempt to get more productivity
link |
and or reduce their overall sleep need.
link |
There was a paper published recently
link |
that explored whether or not this is good or bad for us.
link |
Maybe you just give us the take-home message on that.
link |
Yeah, so these Uberman-like schedules,
link |
and there's lots of different forms of that,
link |
they tried to essentially pie chart the 24-hour period
link |
into short bouts of sleep with some shorter,
link |
well, slightly longer periods of wakefulness,
link |
then short bouts of sleep, then wakefulness.
link |
I sort of made it, I think, a quip.
link |
It's almost like you're sleeping like a baby,
link |
because that's the way that babies will sleep.
link |
That they will have these brief naps,
link |
then they're awake, then they're asleep, then they're awake.
link |
And to the chagrin of parents, across the night,
link |
it's basically the same.
link |
They're awake, they're asleep, they're awake, they're asleep.
link |
And that's more the schedule
link |
that these types of protocols have suggested.
link |
And there was a really great comprehensive review
link |
that found not only that they weren't necessarily helpful,
link |
but they were actually really quite detrimental.
link |
And on almost every performance metric,
link |
whether it be task performance,
link |
whether it be physiological outcome measures,
link |
whether it even be the quality of the sleep
link |
that they were having when they were trying to get it,
link |
all of those were in a downward direction.
link |
And it's not surprising.
link |
If you look at the way that your physiology is programmed,
link |
if you look at the way your circadian rhythm is programmed,
link |
none of that screams to us
link |
that we should be sleeping in that way.
link |
Well, I'm chuckling because we always hear sleep like a baby.
link |
This is how babies sleep.
link |
And I would say, don't sleep like a baby,
link |
sleep like an adult, be an adult.
link |
Get your solid eight hours.
link |
Billy Crystal's line, he was a long-standing,
link |
suffering insomniac.
link |
He says, I sleep like a baby, I'm awake every 20 minutes.
link |
And I think this is another one of those demonstrations
link |
that when you fight biology, you normally lose.
link |
And the way you know you've lost
link |
is disease, sickness, and impairment.
link |
And I think if you sleep in accordance
link |
with the natural biological edict
link |
that we've all been given,
link |
life tends to be both of a higher quality
link |
and a longer duration.
link |
Along those lines, as a vision scientist,
link |
I've been very excited by the work
link |
on these non-image-forming cells in the eye,
link |
the so-called melanopsin cells that inform the brain
link |
about circadian time of day.
link |
And I'm a big proponent of people getting some sunlight,
link |
ideally sunlight, but other forms of bright light
link |
into their eyes early in the day
link |
and when they want to be awake.
link |
Essentially during the phase of their 24-hour
link |
circadian cycle when temperature is rising
link |
and then starting to get less light in their eyes
link |
as our temperature is going down
link |
later in the day and in the evening.
link |
Are there any adjustments to that general theme
link |
that you'd like to add or is, in any way?
link |
No, I think that's exactly what we recommend right now,
link |
which is try to get at least 30 to 40 minutes of exposure
link |
to some kind of natural daylight.
link |
Now, there may be parts of the world where, you know,
link |
You're from a rather cloudy part of the world.
link |
I am from, yeah, Liverpool, England
link |
and the northwest of England is not known
link |
for its beach resorts and fine weather.
link |
I remember I sort of, I went back home for a trip
link |
when I'd first been out in California
link |
and I thought, why is the sky so low?
link |
You know, it's just, you know, constantly out.
link |
We joke that in the UK,
link |
we usually have nine months of bad weather
link |
and then three months of winter.
link |
And then that's your entire year in terms of a climate.
link |
But to come to your point, you're exactly right.
link |
Try to get that daylight.
link |
Now it can be, you know, working next to a window
link |
and you're getting that natural sunlight.
link |
But that natural sunlight is,
link |
even on a cloudy day in England,
link |
is usually far more potent than anything that you'll get
link |
from indoor lighting.
link |
Despite you thinking sort of from a perception-wise,
link |
maybe they're much closer than I would think.
link |
Yeah, I've been, sorry to interrupt,
link |
I've been a big proponent of,
link |
there's an app called Light Meter, which will,
link |
it's a free app, I have nothing to do with it,
link |
that will allow you to get a pretty decent measurement
link |
of the amount of light energy coming toward you.
link |
And if you hold it up to a cloudy morning
link |
where you don't think it's very bright out,
link |
kind of a dismal day,
link |
you'll notice that there'll be a thousand, 2,000,
link |
even, you know, 5,000 lux, lux just being a measure
link |
of brightness, of course.
link |
And then you can point the same light meter
link |
toward an indoor light that seems very bright
link |
and very intense, and it'll say 500 lux.
link |
And you realize that the intensity
link |
as we gauge it perceptually is not really
link |
what the system is receiving.
link |
So outdoor light is key.
link |
How do you, how do you get this natural stimulation
link |
or I should just say light stimulation early in the day?
link |
What is your typical, what does Matt Walker do
link |
to get this light stimulation?
link |
I am no poster child, but usually I will,
link |
if I'm working out, I usually work out most days.
link |
And I shopped around and I found a gym
link |
that has huge amounts of window exposure facing to the east.
link |
This is gonna sound so ridiculous.
link |
You know, Matt Walker chooses a gym
link |
on the basis of the solar input.
link |
So he can, you know, correct a circadian.
link |
There are a lot of criteria for selecting gyms.
link |
This one is actually grounded in physiology and biology.
link |
And selfishness about my own sleep.
link |
So you get your exercise and your light stimulation
link |
simultaneously. That's right.
link |
And so you're stacking cues for wakefulness
link |
So both exercise and daylight are wonderful cues
link |
for circadian rhythm alignment
link |
and also circadian rhythm reset each day.
link |
And so I will use both exercise.
link |
I mean, I am, I'm neither a strong morning type
link |
or a strong evening type.
link |
And my preference to exercise is probably some time
link |
in the middle of the day.
link |
Probably somewhere around 1 p.m., sorry, not 1 a.m.
link |
But I'm usually working out probably around
link |
the sort of seven, sort of 45, 8 a.m. time.
link |
That's usually when I'll start my workout.
link |
And there I'll start with cardio, spin bike,
link |
And luckily for the most part here in California,
link |
there's usually sunlight coming through.
link |
But it doesn't matter to me because just as you said,
link |
even when it's a cloudy day,
link |
that lux coming through of light,
link |
the intensity is splendid.
link |
So I would prefer to favor my exercise
link |
just because for efficiency too,
link |
I wanna get also working on the day.
link |
I'll try to match my exercise
link |
more with my circadian light exposure
link |
than I would probably if I'm going to,
link |
do I really wanna crush your workout
link |
or do I want to just make sure it's a good workout?
link |
I would prefer to work out at a different time.
link |
But I like that because of the daylight.
link |
And we can speak about exercise timing at some point
link |
because there's a lot of discussion around that,
link |
when is the right time to exercise during sleep?
link |
And we can sort of bust some myths there too.
link |
So I think you're spot on with the suggestion,
link |
get some morning daylight, try to get that exposure,
link |
usually at least 30 to 40 minutes.
link |
There was some great work recently coming out
link |
in the occupational health domain,
link |
where they moved workers from offices
link |
that were just facing walls
link |
and didn't have any exposure to natural daylight.
link |
And then they did a time period during that study
link |
where they actually were in front of a window and working.
link |
And they measured their sleep.
link |
And their sleep time and their sleep efficiency
link |
increased quite dramatically.
link |
I'm forgetting the numbers now,
link |
but I think the increase in total sleep time
link |
was well over 30 minutes.
link |
And the improvement in sleep efficiency was five to 10%.
link |
And if you're batting an 80% sleep efficiency average,
link |
we're a bit concerned about that.
link |
But add 10% to that,
link |
now you're in a great echelon of healthy sleepers.
link |
And all you did was just spend some time
link |
working in front of windows.
link |
And probably folks might want to consider
link |
spending a little less time with sunglasses
link |
provided they can do that safely, driving, et cetera.
link |
You're not alone with your exercise behavior
link |
So the one and only Tim Ferriss told me recently
link |
that his morning routine nowadays
link |
consists of jumping rope while facing east
link |
to get the sunlight stimulation of the eyes.
link |
And as Matt and I both know, it has to be of the eyes, right?
link |
These portals are the only way to convey
link |
to the rest of the brain and body
link |
about the time of day and wakefulness.
link |
Along the lines of wakefulness,
link |
I have a number of questions about caffeine.
link |
The dreaded and beloved caffeine.
link |
I love caffeine, but I like it in relatively
link |
restricted periods of time.
link |
So I'm a big fan of waking up
link |
and even though I wake up very groggy,
link |
allowing my natural wakefulness signals to take hold.
link |
Meaning I wake up very slowly,
link |
but I don't drink caffeine right away.
link |
I sort of delay caffeine by a little while,
link |
usually 90 minutes to two hours.
link |
And that idea came to me on the basis of my understanding
link |
of how caffeine and the adenosine receptor interact.
link |
I have a feeling you're going to pronounce
link |
adenosine differently than I do.
link |
No, no, no, I will go with adenosine.
link |
I'll try to go with your skeletal
link |
instead of skeletal and synapse and synapse.
link |
Schedule and schedule.
link |
But to make it really simple for folks,
link |
how does caffeine work to make us feel more alert?
link |
And does the timing in which we ingest caffeine
link |
play an important role in whether or not
link |
it works for us or against us?
link |
So maybe we just start with how does caffeine work?
link |
Why is it that when I drink mate or coffee,
link |
which are my preferred sources of caffeine,
link |
do I feel a mental and physical lift?
link |
Yeah, so I'm going to suggest counter
link |
to what most people would think, drink coffee.
link |
Or mate, is mate okay also?
link |
Or whatever form you enjoy.
link |
Well, we'll come on to sort of why I suggest that,
link |
but when it comes to coffee,
link |
I would say the dose and the timing makes the poison.
link |
So let's start with how caffeine works.
link |
Caffeine is in a class of drugs
link |
that we call the psychoactive stimulants.
link |
So it works through a variety of mechanisms.
link |
One is a dopamine mechanism.
link |
Dopamine we often think of as a reward chemical,
link |
but dopamine is also very much
link |
an alerting neurochemical as well.
link |
And caffeine has some role it seems to play
link |
in increasing dopamine,
link |
but it's principle mode of action we believe
link |
in terms of making me more alert
link |
and keeping me awake throughout the day
link |
is on the effects of adenosine.
link |
And to explain what adenosine is,
link |
from the moment that you and I woke up this morning,
link |
this chemical adenosine has been building up in our brain.
link |
And the longer that we're awake,
link |
the more of that adenosine accumulates.
link |
Is it, may I ask, is it accumulating in neurons,
link |
in glia or in the blood vessels?
link |
Where, and is it also accumulating in my body?
link |
Where is this adenosine coming from
link |
and where is it accumulating?
link |
Yeah, so the adenosine here that we're talking about
link |
that is creating the sleep pressure
link |
is a central brain phenomenon.
link |
And it comes from the neurons themselves combusting energy.
link |
And as they're combusting energy,
link |
one of the offshoots of that is this chemical adenosine.
link |
And so as we're awake throughout the day
link |
and our brain is metabolically very active,
link |
it's accumulating and building up this adenosine.
link |
Now, the more adenosine that we have,
link |
the sleepier that we will feel.
link |
So it really is like a sleep pressure is what we call it.
link |
Now, it's not a mechanical pressure.
link |
Don't worry, your head's not going to explode.
link |
It's a chemical pressure.
link |
And it's this weight of sleepiness
link |
that we feel gradually growing as we get into the evening.
link |
May I just interrupt you again to just ask,
link |
do we know what the circuit mechanism is for that?
link |
I mean, not to go too far down the rabbit hole,
link |
but for the aficionados and for myself,
link |
we have brain mechanisms like locus coeruleus
link |
that release things that our brain areas,
link |
locus coeruleus just being a brain area, of course,
link |
that release things that proactively create wakefulness.
link |
So are those neurons shutting down
link |
as a consequence of having too much adenosine
link |
or are there areas of the brain that promote sleepiness
link |
that are becoming activated?
link |
Because you can imagine both things working in parallel.
link |
One or the other would accomplish the same end point.
link |
Yeah, and it's both.
link |
And so there are two main receptors for adenosine,
link |
the A1 receptor and the A2 receptor,
link |
and they have different modes of activating brain cells
link |
or inactivating or decreasing the likelihood of firing.
link |
And adenosine works in this beautiful, elegant way
link |
where it will inhibit and shut down
link |
the wake promoting areas of the brain
link |
whilst also increasing and dialing up the volume
link |
on sleep activating, sleep promoting.
link |
Biology is so beautiful.
link |
Oh, it's always a push-pull.
link |
I mean, and we could have a larger discussion
link |
at some point about that everything,
link |
seeing dark edges, seeing light edges,
link |
our ability to smell or to sense pressure on this,
link |
everything's a push-pull in biology.
link |
Oh, that's great, yeah, yep.
link |
So this is another example where as I am awake longer,
link |
adenosine is released in the brain
link |
and my wakefulness areas are being actively shut down
link |
by that adenosine and my sleepiness brain areas,
link |
so to speak, are being promoted to be more active.
link |
That's right, and it's a very progressive process.
link |
It's not like a step function where,
link |
and sometimes that happens occasionally,
link |
but it's usually because you've been sort of driving through
link |
and as we'll come on to have caffeine in the system.
link |
And then all of a sudden you just hit a wall
link |
and it just engulfs you and you go from a zero
link |
to the one of sleepiness within a short period of time.
link |
What explains the fatigue after a hard conversation?
link |
The desire to go to sleep
link |
or the desire to go to sleep during a hard conversation.
link |
That's an interesting one.
link |
I think it's usually just based
link |
on personality type interactions and for the most part-
link |
Not that I've ever experienced that before.
link |
No, people with you don't, but with me, they always-
link |
Oh, no, no, no, I mean, I've experienced the desire
link |
to take some conversations, I'm halfway through them
link |
and I feel like I want to take a nap, right?
link |
And I would love to look at people's sleep history.
link |
We've sort of seen that time and time again,
link |
but, and then it could be with folks like me,
link |
people just lose the will to live
link |
within about five minutes of speaking with me.
link |
So that's- Not true.
link |
They hear that sleep is important.
link |
And unrelated and that's flattery, that's great.
link |
But so the way that then caffeine comes into this equation,
link |
as I was saying, it's usually a kind of a linear process
link |
or maybe it's probably closer to an exponential
link |
in terms of your subjective feeling of sleepiness.
link |
And we haven't really been able to measure that in humans
link |
because normally it's hard to actually
link |
stick something into the brain and be sucking,
link |
siphoning off stuff every couple of minutes
link |
as you could do in animal studies
link |
and keep asking people every couple of minutes,
link |
how sleepy do you feel, how sleepy?
link |
And track to see if there's a linear rise in adenosine,
link |
which then creates an exponential rise
link |
in subjective sleepiness or what the dynamics are.
link |
But I'm kind of nerding out.
link |
So caffeine comes into play here
link |
because caffeine comes into your system
link |
and it latches onto those welcome sites of adenosine,
link |
the adenosine receptors.
link |
But what it doesn't do is latch onto them
link |
and activate them because if it was doing that,
link |
then it would, in lots of ways,
link |
it would dial up more sort of sleepiness.
link |
It does the opposite.
link |
The way that caffeine works is that it comes in,
link |
competes with quite sharp elbows with adenosine,
link |
competitively forces them out of the way,
link |
hijacks that receptor by latching onto it,
link |
but then just essentially blocks it.
link |
It doesn't inactivate the receptor.
link |
It doesn't activate the receptor.
link |
It functionally inactivates it in the sense
link |
that it takes it out of the game for adenosine.
link |
So it's like someone coming into a room
link |
and you're just about to sit down on the chair
link |
and caffeine comes in and just pulls out the chair
link |
and you're like, well, now I've got nowhere to sit.
link |
And caffeine just keeps pulling out the chairs
link |
from adenosine and adenosine,
link |
even though it's at the same concentration in your brain,
link |
your brain doesn't know that you've been awake
link |
for 10 hours, 16 hours at that point
link |
when you've downed a cup of coffee
link |
because all of that adenosine that's still there
link |
can't communicate to the brain
link |
that you've been awake for 16 hours because-
link |
But the adenosine is still in brain-
link |
So the real question is what happens
link |
when caffeine is dislodged from the adenosine receptor?
link |
Unfortunate things happen.
link |
And that's what we call the caffeine crash,
link |
which is caffeine has a half-life and it's metabolized.
link |
Do you recall what the half-life is?
link |
Yeah, the half-life is somewhere between five to six hours
link |
and the quarter-life therefore is somewhere
link |
between 10 to 12 hours.
link |
Different people have different durations of its action,
link |
but for the average adult, five to six hours.
link |
That variation, we understand it's down to a liver enzyme
link |
or a set of liver enzymes of the class
link |
that we call the cytochrome P450 enzymes.
link |
And there are, I think last I delved into the data,
link |
which is pretty recently, there are two gene variants
link |
that will dictate the enzymatic speed
link |
with which the liver breaks down caffeine.
link |
And that's why you can have some people
link |
who are very sensitive to caffeine
link |
and other people who say,
link |
I'm just doesn't affect me really that much at all.
link |
These are the people that have a double espresso
link |
after a 9 p.m. dinner and can sleep just fine.
link |
Well, and we'll come on to-
link |
Or at least subjectively they think they're sleeping.
link |
Yeah, and we should speak about that,
link |
that assumptive danger too.
link |
So then the caffeine is in the system
link |
and after some time period,
link |
it will be inactive in the system.
link |
So let's say that I've been awake for 12 hours now
link |
and it's 8 p.m. and I'm feeling a bit tired,
link |
but I want to push through
link |
and I want to keep working for another couple of hours.
link |
So I have a cup of coffee.
link |
All of a sudden I was feeling tired,
link |
but I don't feel like I've been awake for 12 hours anymore
link |
because with the caffeine in the system,
link |
maybe only half of that adenosine
link |
is being communicated through the receptor to my brain.
link |
100% of the adenosine is still there.
link |
Only half of it is allowed to communicate to my brain.
link |
well, I haven't been awake for 12 hours,
link |
I've just been awake for six hours, I feel great.
link |
Then after a few hours
link |
and the caffeine is starting to come out of my system,
link |
not only am I hit with the same levels of adenosine
link |
that I had before I'd had the cup of coffee
link |
several hours ago,
link |
it's that plus all of the adenosine
link |
that's been building up
link |
during the time that the caffeine has been in my system.
link |
So sort of an avalanche of adenosine.
link |
It is a tsunami wave.
link |
And that's the caffeine crash.
link |
And it's interesting because the caffeine crash
link |
at two o'clock in the afternoon
link |
when you have work to do is a terrible thing.
link |
But what about the person,
link |
maybe this person is me in my 20s,
link |
who says, I'm going to drink caffeine all day long
link |
and then I want the crash because at nine or 10 PM,
link |
if I stopped drinking caffeine at say six PM and I crash,
link |
then I crash into a slumber, a deep night of sleep.
link |
Is that sleep really as deep as I think it is?
link |
Because given the half-life of caffeine
link |
that you mentioned a few moments ago,
link |
I have to imagine that having some of that caffeine
link |
circulating in my system might disrupt the depth of sleep
link |
or somehow the architecture of sleep in a way
link |
that even if I get eight or who knows even 10 hours of sleep
link |
it might not be as restorative as I would like it to be.
link |
Yeah, and that is the danger.
link |
Just sort of those people that you described who say,
link |
and a lot of them will speak with me too,
link |
say, look, I can have two espressos with dinner
link |
and I fall asleep fine and I stay asleep
link |
because usually those are the two phenotypes
link |
that we typically see with too much caffeine.
link |
I just can't fall asleep as easily as I want to,
link |
or I fall asleep but I just can't stay asleep
link |
and caffeine can do both of those things quite potently.
link |
How late in the day do you think is,
link |
assuming somebody, translate this folks,
link |
if you go to bed earlier or later
link |
you have to shift the hours accordingly,
link |
but given somebody who typically gets into bed
link |
around 10, 10, 30 and falls asleep around 11, 11, 30,
link |
when would you recommend they halt caffeine intake?
link |
And these are not strict prescriptives
link |
but I think people do benefit
link |
from having some fairly clear guidelines
link |
of what might work for them.
link |
Would you say cut off caffeine by what time of the day?
link |
I would usually say take your typical bedtime
link |
and count back sort of somewhere between 10 to eight hours
link |
is probably getting a little bit close,
link |
but take back sort of 10 hours or eight hours of time.
link |
That's the time when you should really stop using caffeine
link |
is the suggestion.
link |
And the reason is because for those people
link |
who even just keep drinking up until into the evening,
link |
you're right that they can fall asleep fine,
link |
maybe they stay asleep,
link |
but the depth of their deep sleep is not as deep anymore.
link |
And so there are two consequences.
link |
The first is that for me, and it can be up to by 30%,
link |
and for me to drop your deep sleep by 30%,
link |
I'd have to age you by between 10 to 12 years,
link |
or you can just do it every night to yourself
link |
with a couple of espressos.
link |
The second is that you then wake up the next morning
link |
and you think, well, I didn't have problems falling asleep
link |
and I didn't have problems staying asleep,
link |
but I don't feel particularly restored by my sleep.
link |
So now I'm reaching for three or four cups of coffee
link |
rather than just two or three cups of coffee.
link |
And so goes this dependency cycle
link |
that you then need your uppers to wake you up in the morning
link |
and then sometimes people will use alcohol in the evening
link |
to bring them down because they're overly caffeinated
link |
and alcohol, and we can speak about that too,
link |
also has very deleterious impacts on your sleep as well.
link |
So you're right that it's not just the quantity
link |
of your sleep or even difficulties falling
link |
or staying asleep, it can also be deep sleep.
link |
But here again, I think,
link |
I don't want to be frightening people.
link |
And I mentioned this before,
link |
I think one of the real problems that I,
link |
or mistakes that I made,
link |
I'd never had much public exposure before the book.
link |
And I was so saddened by, you know,
link |
the disease and the suffering that I was seeing
link |
as a consequence of a lack of sleep in our society.
link |
And the fact that it wasn't really being discussed
link |
very much, I sort of came out, you know,
link |
a little bit headstrong, more than a little bit headstrong.
link |
And I think I was, you know,
link |
perhaps too much gas pedal and too little,
link |
you know, brake as it were.
link |
And I don't think that's the right way
link |
to approach health message within the public sphere.
link |
And I've become much softer
link |
in how I think about these things.
link |
I have ideas about what the ideal world looks like
link |
for sleep, but I also realized that none of us live
link |
in this thing called the ideal world.
link |
We certainly don't.
link |
So, you know, I want to be really mindful of that.
link |
And I think I've done a really bad job
link |
of being sort of too forthright,
link |
particularly for people who struggle with sleep.
link |
You know, early on when I would offer these sort
link |
of messages about sleep, I want to be, you know,
link |
I want to be veritical when it comes to the science.
link |
I want to be faithful to the science,
link |
but I also don't want to go out
link |
and scare the living daylight set of people,
link |
particularly people who are struggling with their sleep,
link |
because it's probably only gonna make matters worse.
link |
So I've been beautifully schooled by learning
link |
how to be a slightly better public communicator.
link |
I'm nowhere near of the standing that you are.
link |
You're very elegant and it's very intuitive to you.
link |
I'm still with training wheels,
link |
but I'm getting a little bit better,
link |
but I just want to say that when I'm speaking about caffeine
link |
because it sounds as though I'm very sort of overt about it,
link |
but I will come back to why I say drink coffee,
link |
but I just want to make that point.
link |
Yeah, well, I appreciate you making that point
link |
and I'm sure our listeners will too.
link |
I still will stand behind my statement,
link |
which is that what you've done for the notion
link |
that sleep is vital for all aspects of health
link |
and for performance, mental, and physical, and wakefulness,
link |
the message and the packaging it was contained in
link |
and has been clearly, clearly net positive.
link |
People needed to be cued to this.
link |
The I'll sleep when I'm dead mentality is one that I had.
link |
It's one that other people have.
link |
People in a huge number of vital communities,
link |
not just your students, but also people.
link |
This, the messaging that you provided
link |
and continue to provide has positively impacted
link |
the first responder community, the medical community.
link |
There's still steps that need to be taken,
link |
the military community, and of course the civilian community.
link |
And so I think these adjustments about, yeah,
link |
caffeine's okay, just restrict it
link |
to the early part of the day if you can most days.
link |
I mean, I think the law of averages,
link |
it's like the light viewing behavior.
link |
I think it is critical to view sunlight or natural,
link |
some other form of bright light early in the day.
link |
But if you miss a day, it's not that your whole system
link |
is going to dissolve into a puddle of tears.
link |
That'll happen on the second or the third day.
link |
You got a couple of days.
link |
Biology works in averages except
link |
with respect to accident or injury.
link |
A car accident is a car accident, right?
link |
You don't get to have three of those
link |
before the brain damage occurs
link |
if the accident is severe enough.
link |
But with sleep behavior,
link |
these homeostatic type behaviors or with food,
link |
one chocolate sundae, is it going to kill you?
link |
Every night, yeah, it's going to make you demented
link |
and kill you early.
link |
And so I think the middle ground
link |
is often a hard place to achieve.
link |
So I think you've done a phenomenal job,
link |
but I appreciate you raising these points.
link |
And I think it's clear that we all need to,
link |
that we all can and should do certain things better,
link |
including being gentle with ourselves from time to time
link |
when we deviate from these ideal circumstances.
link |
Along these lines, I do want to talk about alcohol
link |
because I think caffeine and alcohol represent
link |
the kind of two opposite ends of the spectrum.
link |
Clearly, there are other stimulants.
link |
There are your Adderalls
link |
and your high-energy drinks that people use.
link |
But alcohol and caffeine are the most commonly consumed,
link |
stimulants and sedatives,
link |
depressants as they're sometimes called.
link |
So what happens when somebody has a glass,
link |
we always hear a glass or two of wine in the evening
link |
or a cocktail after dinner or before dinner,
link |
how does that impact their sleep?
link |
And then we'll be sure to circle back
link |
in terms of what is reasonable ranges of behavior
link |
when it comes to avoiding alcohol
link |
or if it's age appropriate, et cetera, enjoying alcohol.
link |
So alcohol, if we're thinking about classes of drugs,
link |
they're in a class of drugs that we call the sedatives.
link |
And I think one of the first problems
link |
that people often mistake,
link |
alcohol is often used as a sleep aid
link |
for people who are struggling with sleep
link |
when things like over-the-counter remedies, et cetera,
link |
or herbal remedies have just not worked out for them.
link |
And alcohol unfortunately is anything but a sleep aid.
link |
The first reason that most people use it
link |
is to try and help them fall asleep.
link |
And this process of this event that we call falling asleep,
link |
I have to imagine is a process.
link |
Like everything in biology.
link |
And that that process involves in some way,
link |
as we talked about push pull before,
link |
turning off thinking, planning, et cetera,
link |
and turning on some sort of relaxation mechanism.
link |
I have to imagine that these two things are knobs
link |
turning in opposite directions.
link |
That gives us this outcome we call falling asleep.
link |
Alcohol, it seems is helpful for some people
link |
to turn off their thoughts or their planning.
link |
And so I think if we look at the pattern of brain activity,
link |
if I were to place you inside an MRI scanner,
link |
where we're looking at the activity of your brain
link |
and watch you drifting off,
link |
some parts of your brain will become less active.
link |
Other parts will become more active.
link |
And this is the push pull model.
link |
It's inhibition excitation.
link |
But alcohol is quite different in that regard.
link |
Alcohol is because it's a sedative.
link |
What it's really doing is trying to essentially
link |
knock out your cortex.
link |
It's sedating your cortex.
link |
And sedation is not sleep.
link |
But when we have a couple of drinks in the evening,
link |
when we have a couple of night caps,
link |
we mistake sedation for sleep saying,
link |
well, I always when I have a couple of whiskeys
link |
or a couple of cocktails,
link |
it always helps me fall asleep faster.
link |
In truth, what's happening is that
link |
you're losing consciousness quicker,
link |
but you're not necessarily falling
link |
naturalistically asleep any quicker.
link |
So that's one of the first sort of things
link |
just to keep in mind.
link |
The second thing with alcohol
link |
is that it fragments your sleep.
link |
And we spoke about the quality of your sleep
link |
being just as important as the quantity.
link |
And alcohol through a variety of mechanisms,
link |
some of which are activation
link |
of that autonomic nervous system,
link |
that fight or flight branch of the nervous system.
link |
Alcohol will actually have you waking up
link |
many more times throughout the night.
link |
So your sleep is far less continuous.
link |
Now, some of those awakenings
link |
will be of conscious recollection the next day.
link |
You'll just remember waking up.
link |
Many of them won't be.
link |
And so, but yet your sleep will be littered
link |
with these sort of punctured awakenings
link |
throughout the night.
link |
And again, when you wake up the next morning,
link |
you don't feel restored by your sleep.
link |
You know, fragmented sleep or non continuous sleep
link |
in this alcohol induced way
link |
is usually not good quality sleep
link |
that you feel great on the next day.
link |
The third part of alcohol in terms of an equation
link |
is that it's quite potent at blocking your REM sleep,
link |
your rapid eye movement sleep.
link |
And REM sleep is critical
link |
for a variety of cognitive functions.
link |
Some aspects of learning and memory
link |
seems to be critical for aspects
link |
of emotional and mental health.
link |
You've described it before
link |
as a sort of self-generated therapy
link |
that occurs while we sleep.
link |
Yeah, it's overnight therapy.
link |
You know, it's emotional first aid.
link |
Certainly people that don't get enough sleep
link |
are very easy to derail emotionally.
link |
Not that one would want to do that to people,
link |
but we all sort of fall apart emotionally.
link |
I always think about it as almost like
link |
our skin sensitivity can be heightened
link |
when we are sleep deprived.
link |
Our emotional sensitivity is such that
link |
when we're sleep deprived,
link |
such that it takes a much finer grain of sandpaper
link |
to create that kind of friction.
link |
Threshold to trigger. Even online comments
link |
bother us when we're sleep deprived.
link |
And never when we're well rested.
link |
I would love to say that I never look at them,
link |
except I look at maybe every one of them.
link |
Here I will editorialize
link |
because the notion of not looking at comments
link |
is unreasonable to ask of any academic.
link |
Because academics, we are all trained
link |
to look at our teaching evaluations.
link |
And just like with online comments,
link |
to ignore 20% of them.
link |
We look at them all.
link |
In any event, so in terms of translating this to behavior,
link |
I'm not, I don't particularly enjoy alcohol.
link |
I guess I might be fortunate in that sense,
link |
but I also have never really experienced
link |
the pleasure of drinking alcohol.
link |
I sometimes like the taste of a drink,
link |
but I never liked the sensation.
link |
So that's, I don't have a lot of familiarity with this,
link |
but many people do, and I understand that.
link |
So let's say somebody enjoys a glass of wine or two
link |
with dinner and they eat dinner at 7 p.m.
link |
Is that likely to disrupt their sleep at all?
link |
Let's just sort of, let's make this a series of gradations.
link |
Yeah, and the answer is yes.
link |
I think one study just looked at a single glass of wine
link |
in the evening with dinner.
link |
And I would be untruthful if I didn't just simply say
link |
it has an effect and we can measure that
link |
in terms of the actual- Less REM sleep.
link |
And one of the fascinating studies,
link |
I can't remember what dose,
link |
I think they got them close to a standard
link |
illegal blood alcohol level.
link |
So maybe they were a little bit tipsy.
link |
And yes, you see all of the changes that we just described.
link |
They sort of lose consciousness more quickly.
link |
They have fragmented sleep
link |
and they have a significant reduction in REM sleep.
link |
But what was also interesting,
link |
because REM sleep, as we spoke about before,
link |
is a time when some hormonal systems
link |
are essentially recharged and refreshed,
link |
growth hormone being one of them,
link |
there was well over a 50%, 5-0 drop in their growth hormone
link |
release during alcohol-laced sleep at night.
link |
And growth hormone is so vital for metabolism
link |
and repair of tissues and-
link |
Yeah, it's not just for kids.
link |
Keeping body fat low.
link |
This is essentially adults, yeah.
link |
Along those lines, I just want to highlight the fact
link |
that this information that you're sharing,
link |
that growth hormone is released as strongly tethered
link |
to the presence of healthy amounts of REM sleep,
link |
is interesting to me because I always thought
link |
that growth hormone was released
link |
in the early part of the night.
link |
Well, it is released across both of those,
link |
but across the different stages.
link |
But what we also know is that when you disrupt REM sleep,
link |
there are those growth hormone consequences.
link |
So it's not an exclusive system.
link |
Just like with testosterone,
link |
we can see changes throughout non-REM sleep.
link |
But if you ask when are the peak release rates
link |
of testosterone, it's right before we go into REM sleep
link |
and then during REM sleep.
link |
And of course, testosterone being important
link |
both for males and for females, right?
link |
For libido and tissue repair and wellbeing.
link |
Nobody, regardless of chromosomal, hormonal,
link |
or any other background,
link |
wants to have their normal levels
link |
of testosterone reduced acutely.
link |
That's just a bad, it equates to a terrible set
link |
of psychological and physical symptoms.
link |
Yeah, and the mortality risk that's associated
link |
with low testosterone is non-trivial.
link |
So coming back to just the point on REM sleep
link |
that you mentioned regarding emotional instability,
link |
and we see that, that's one of the things,
link |
one of the most reliable signatures
link |
of just insufficient sleep.
link |
It doesn't have to be sleep deprivation.
link |
What we've discovered over the past 20 years
link |
here at the Sleep Center is that
link |
there is no major psychiatric disorder that we can find
link |
in which sleep is normal.
link |
And so I think that firstly told us
link |
there is a very intimate association
link |
between your emotional mental health and your sleep health.
link |
But when it also comes to REM sleep,
link |
I think what's fascinating is that it's not just
link |
about your emotional health.
link |
It's not just about your hormonal health.
link |
We've also been seeing other aspects of cognition,
link |
but then there was a report,
link |
I think it could have been about two years ago,
link |
out of Harvard, I think it was Beth Clearman's group.
link |
They found that, and they replicated it
link |
in two different large populations.
link |
If you look at the contribution of different sleep stages
link |
to your lifespan, REM sleep was the strongest predictor
link |
of your longevity.
link |
And it was a linear relationship.
link |
It wasn't sort of one of these U-shape or J-shaped curves
link |
that we often see with total sleep and mortality risk.
link |
It really was linear.
link |
That the less and less REM sleep that you were getting,
link |
the higher and higher your probability of death.
link |
And then they did-
link |
Was that death due to natural causes or accident?
link |
Because I could imagine if you're not getting enough REM
link |
sleep, you're more likely to drive off the freeway,
link |
Yeah, I think it was all cause and-
link |
Or just make bad decisions about anything
link |
and love relationships, which can also be life threatening.
link |
Yeah, I've tried to lean into that and claim that
link |
with those bad relationship situations that,
link |
oh, I just didn't have enough REM sleep last night,
link |
The REM sleep defense.
link |
And, but she's far wiser than I thought.
link |
But so they did this great machine learning analysis
link |
and I may get these numbers backwards,
link |
but I think for every 5% reduction in REM sleep,
link |
there was a 13% associated increased risk of mortality.
link |
And I could have, I'll have to go back and check.
link |
But to me, in the machine learning algorithm,
link |
what they ultimately spat out was that
link |
of all of the sleep stages,
link |
REM sleep is the most predictive of your longevity,
link |
So we often, I hear people saying,
link |
how can I get more deep sleep?
link |
Or they sometimes say, how can I get more dream sleep?
link |
And my answer is a question.
link |
Why do you want to get more of that?
link |
And they'll say, well, isn't that the good stuff?
link |
And I'll say, well, actually all stages of sleep are, yeah.
link |
Well, it's like the exercise question.
link |
And it took decades for people to understand
link |
that moving around at, for about 150,
link |
probably 180 minutes a week at doing endurance type work,
link |
zone two cardio type work,
link |
it is correlated with living longer,
link |
feeling better, less diabetes, et cetera.
link |
There's really no way around it.
link |
I mean, you can ingest metformin until the cows come home.
link |
all of which I think have their place in certain contexts.
link |
I'm a big fan of the work surrounding all those protocols,
link |
but without getting proper amounts of movement,
link |
meaning sufficient numbers.
link |
It doesn't matter how many 12 minute exercise regimes
link |
you follow per week, you need that threshold level.
link |
And it sounds like the same is true of REM sleep
link |
and total amount of sleep.
link |
There's just, you pay the piper somehow.
link |
Yeah, the return on investment, I mean, to flip the coin,
link |
the return on investment is astronomical.
link |
I think of sleep, it is the tide that moves,
link |
that raises all of those health boats.
link |
And the most fundamental layer of mental
link |
and physical health.
link |
Whenever people ask me, even though I'm not a physician,
link |
they'll ask me, what should I take or what should I do?
link |
The first question is always, how's your sleep?
link |
Meaning, how well do you sleep every night
link |
and how long you sleep?
link |
I always recommend your book.
link |
I always recommend the podcast you've been a guest on,
link |
Who knows, maybe you'll even release your own podcast
link |
at some point soon and keep,
link |
because I do think people need to hear from you more often.
link |
One thing I don't want to return to the notion
link |
of public health discourse too much, but I do want to say,
link |
one issue with books in general is that they can be revised,
link |
but it's more or less a one and done kind of thing
link |
until the next book comes out.
link |
One thing that I like about the podcast format
link |
is that updates can be provided regularly,
link |
corrections and updates as new data come out.
link |
And so that's a wonderful aspect to this format
link |
and hopefully the format that you'll be embracing.
link |
I think the world needs to hear more from you more often
link |
about sleep and its various contours, not less.
link |
And so I do have a question about drinking alcohol,
link |
not that we want to promote day drinking,
link |
but let's say that the one or two glasses of wine
link |
or a cocktail is consumed with lunch,
link |
something that isn't traditionally done nowadays,
link |
or in a late afternoon happy hour cocktail,
link |
and then one is going to sleep seven or eight hours later.
link |
Do you think that that will improve
link |
or somehow mitigate the effects of alcohol?
link |
Or if you have a drink,
link |
are you basically screwed for the next 24 hours?
link |
No, I think there's going to be a time window dependency.
link |
Now, I don't know of anyone who's essentially done
link |
what you and I would like,
link |
which is the time separation dose dependent curve
link |
where, okay, you drink at 10 a.m. then,
link |
or 11, 12, one, two, three, four, five,
link |
all the way up to 10 p.m.,
link |
and estimate what is the blast radius
link |
and is it linear or is it non-linear?
link |
Is it such that only when you drink in the last four hours,
link |
do you just hit this exponential and it's bad, bad, bad,
link |
or is there some other curve that we could imagine
link |
that would be many possibilities?
link |
But certainly what we know is that the less alcohol
link |
and the less, and more specifically,
link |
the metabolic byproducts, aldehydes and ketones,
link |
they're the sort of the nefarious players here.
link |
And not the ketones that people are all excited about,
link |
the other ketones, the chemists know
link |
what we're referring to.
link |
But this is not about ketogenesis.
link |
This is not about ketogenesis.
link |
There are ketone bodies that are released
link |
after ingesting alcohol that are not of the positive sort
link |
that a ketogenic diet might promote.
link |
So I think in terms of that alcohol profile,
link |
we certainly know that as you're heading
link |
into the evening hours,
link |
once again, timing and dose make the poison,
link |
but I think it's also important once again,
link |
from that public message standpoint, and thank you.
link |
I think I am leaning into the sort of the podcast
link |
consideration arena at some point,
link |
but I don't want to be puritanical here.
link |
I'm just a scientist and I'm not here to tell anyone
link |
All I'm trying to do is empower people
link |
with some of the scientific literature regarding sleep.
link |
And then you can make whatever informed choices
link |
You know, unlike you, it turns out I'm not a big drinker.
link |
It's just because I've never liked the taste.
link |
And I'm surprised that they haven't taken away
link |
my British passport because I don't like lager or beer.
link |
But I also want to say that life is to be lived
link |
to a certain degree.
link |
It's all about checks and balances.
link |
So, you know, if I go out and you know,
link |
I have an ice cream sundae, I'm not big on those either,
link |
but you know, sure I know that my, you know,
link |
blood glucose is not gonna be ideal
link |
for another 12 hours maybe.
link |
That's just the price you pay for having
link |
some kind of relaxed, fun life.
link |
I don't want to look back on life and think,
link |
gosh, you know, I lived until I was, you know, 111
link |
and it was utterly miserable, you know?
link |
Right, so, but it's all about some kind of a balance.
link |
And my job is not to tell people a prescription for life,
link |
it's just to offer some scientific information.
link |
I think you're doing a terrific job of that.
link |
People are, I always say we have all these neural circuits
link |
and if it's working properly, we all have a circuit
link |
that allows us to skip over information or as we wish, right?
link |
If the circuits between your brain and your thumbs
link |
are working, you can slide right along,
link |
you can drop to the next content, however you like.
link |
I would like to ask about marijuana and CBD.
link |
This is a discussion that I think five years ago
link |
would have ventured into the realm of illegal,
link |
but now in many places, not all,
link |
medical marijuana is approved or is legal
link |
and certainly it's in widespread use.
link |
Certainly not recommending people do it.
link |
I have my own thoughts about marijuana, CBD.
link |
I've been fortunate, I suppose,
link |
that I don't particularly like marijuana or CBD.
link |
I don't even know if I've ever tried CBD.
link |
First of all, does marijuana disrupt the depth of sleep,
link |
the architecture of sleep?
link |
And if so, as with alcohol and caffeine,
link |
does when you ingest it or when it's in your bloodstream,
link |
does relative to when you go to sleep,
link |
does that play an important role?
link |
So does marijuana disrupt sleep?
link |
Yeah, it does, and there's a pretty good amount of data on,
link |
so we can break sort of cannabis down
link |
into two of its key ingredients.
link |
We've got THC, tetrahydrocannabinol, and we've got CBD.
link |
And CBD is sort of the less,
link |
what we think of as the non-psychoactive component.
link |
In other words, when you take CBD, you don't get high.
link |
If you take THC, you can get high.
link |
That's the psychoactive part of the equation.
link |
Are both considered sedatives in the technical sense?
link |
Neither of them have that class right now.
link |
THC can, seems to speed up the time
link |
with which you fall asleep.
link |
But again, if you look at the electrical brainwave signature
link |
of your falling asleep with and without that THC,
link |
it's not going to be an ideal fit.
link |
So you could argue it's non-natural,
link |
but many people use THC for that fact
link |
because they find it difficult to fall asleep.
link |
And it can speed the onset of at least non-consciousness,
link |
I guess is the best way of describing it.
link |
But there are problems with THC and there are twofold.
link |
The first is that it too, but through different mechanisms
link |
seems to block REM sleep.
link |
And that's why a lot of people when they're using
link |
will tell me, look, I definitely, I was dreaming.
link |
I don't remember many of my dreams.
link |
And then when they stop using THC,
link |
they'll say, I was having just crazy, crazy dreams.
link |
And the reason is because there is a rebound mechanism.
link |
REM sleep is very clever and alcohol is the same way
link |
in this sense, it's the same homeostatic mechanism.
link |
Some people will tell me, look,
link |
if I have a bit of a wild Friday night with some alcohol,
link |
maybe I'll sleep late into the next morning.
link |
And I'll just have these really intense dreams.
link |
So, and I thought I wasn't having any REM sleep.
link |
Well, the way it works is that it's during
link |
in the middle of the night, really,
link |
when alcohol blocks your REM sleep.
link |
And your brain is smart.
link |
It understands how much REM sleep you should have had,
link |
how much REM sleep you have not
link |
because the alcohol has been in the system.
link |
And finally, in those early morning hours
link |
when you're getting through to sort of,
link |
you know, six, seven, eight AM,
link |
all of a sudden your brain not only goes back
link |
to having the same amount of REM it would have had,
link |
it does that, plus it tries to get back all
link |
of the REM sleep that it's lost.
link |
Does it get back all of the REM sleep?
link |
It never gets back all of the REM sleep, but it tries.
link |
And so you have these really intense periods of REM sleep.
link |
Hence, you have really intense, bizarre dreams.
link |
And that's what happens also with THC.
link |
You build up this pressure for REM sleep,
link |
this debt for REM sleep.
link |
Will you ever pay it back?
link |
Doesn't seem as though you get back everything
link |
that you lost, but will you get back some of it?
link |
Yes, the brain will start to devour more
link |
because it's been starved of REM sleep for so long.
link |
But one of the bigger problems with THC
link |
that we worry about is withdrawal dependency.
link |
So as you start to use THC for sleep,
link |
there can be a dependency tolerance.
link |
So you start to need more to get the same sleep benefit.
link |
And when you stop using,
link |
you usually get a very severe rebound insomnia.
link |
And in fact, it's so potent that it's typically part
link |
of the clinical withdrawal profile from THC, from cannabis.
link |
And there's anxiety withdrawal.
link |
I don't ask anybody to change their behavior.
link |
We just, as you said,
link |
we try and inform people about what the science says
link |
and let them make choices for themselves.
link |
People who are regular pot smokers,
link |
that many will insist they're not addicted.
link |
And maybe indeed they don't actually follow the profile
link |
of classical addiction.
link |
I'm guessing some do, some don't.
link |
But if you ask them, well,
link |
what if I took away all marijuana consumption
link |
for, I don't know, two weeks?
link |
That thought scares many of them.
link |
And many of them will experience intense anxiety
link |
without marijuana, which speaks to perhaps not addiction,
link |
but a certain kind of dependency.
link |
And again, I know many pot smokers,
link |
some of whom have jobs that are quite high performing
link |
Here in Berkeley, I don't know any of those.
link |
Yeah, I know none of those, right.
link |
I mean, we hear so much about CBD.
link |
I've been a little concerned about the fact
link |
that the analysis of a lot of CBD supplements out there
link |
has confirmed that much like with melatonin,
link |
the levels that are reported on the labels
link |
in no way, shape, or form match the levels
link |
that are actually contained in the various supplements.
link |
Sometimes the levels are much higher
link |
than they're reported on the labels.
link |
Other times it's much lower.
link |
What does ingesting CBD do to the architecture
link |
and quality of sleep?
link |
Right now, I don't think we have enough data
link |
to make some kind of meaningful sense out of it.
link |
I think the picture that is emerging, however,
link |
is probably the following.
link |
Firstly, CBD does not seem to be detrimental
link |
in the same ways that THC is.
link |
So we can start by saying,
link |
does it create potential problems?
link |
Not of the nature necessarily that we see with THC,
link |
but the devil is a little bit in the details
link |
from the data that we do have
link |
and it comes onto your valid point of purity.
link |
At low dose, CBD can seem to be wake promoting.
link |
So in lower doses, let's say sort of five or 10 milligrams,
link |
I'm trying to remember some of the studies
link |
off the top of my head,
link |
there it actually may enhance wakefulness
link |
and cause problems with sleep.
link |
It's only once you get into the higher dose range
link |
that there seem to have been some increases in sleepiness
link |
or sort of sedation like increases.
link |
And that's usually, I think above about 25 milligrams
link |
as best I can recall from the data.
link |
And then when we look in animal models,
link |
you typically see the same type of profile too.
link |
So then the question becomes,
link |
and now again, you just don't know about purity,
link |
it's very difficult.
link |
Although I think, and again, I'm not a user,
link |
not necessarily because I have anything against it,
link |
it's just that's not necessarily my cup of tea.
link |
There are some firms that are now doing
link |
third party independent laboratory tests.
link |
I don't know how gamed that is,
link |
so I've got no sense of it.
link |
No, I think some supplement companies
link |
are quite honest and accurate
link |
about the amounts of various substances
link |
that are in other products and some are not.
link |
And I think there's just a huge range.
link |
I think the FDA is starting to explore CBD.
link |
There are, certainly I saw some grant announcements
link |
to explore the function of CBD.
link |
Most of the work on CBD is being done
link |
by the general public, ingesting it and seeing how they feel.
link |
I gave it to my dog who had some
link |
dementia-related sleep disturbances
link |
and it actually created a heightened wakefulness.
link |
It completely screwed up his sleep.
link |
He's a bulldog, so if he's going to get access to sleep,
link |
he's going to take it.
link |
Really messed him up, took it away, he did better.
link |
But that's a canine, so.
link |
Right, and it could have been, you know,
link |
sort of dose-related too, but-
link |
Or binders or other things that are in there.
link |
Correct, yeah, and we, but right now,
link |
if we were to, and I'm not making this statement,
link |
I don't think anyone can make the statement now,
link |
but if it ends up being that CBD
link |
is potentially beneficial for sleep,
link |
how can we reconcile that mechanistically?
link |
And I think there are, to me at least,
link |
there are at least three candidate mechanisms
link |
that I've been exploring and thinking about.
link |
The first is that it's thermoregulatory,
link |
and what we found in some animal models
link |
is that CBD will create a profile of hypothermia.
link |
In other words, it cools the body,
link |
the core body temperature down,
link |
and that's something that we know is good for sleep.
link |
The second is that it's an anxiolytic,
link |
that it can reduce anxiety,
link |
and that data is actually quite strong,
link |
even with some functional imaging work
link |
that's been coming out recently,
link |
showing that one epicenter of emotion
link |
called the amygdala deep within the brain
link |
is quietened down with CBD.
link |
So I think that's at least a second
link |
non-mutually exclusive possibility.
link |
I think the third is some recent data that's come out
link |
that was suggesting that CBD
link |
can alter the signaling of adenosine.
link |
So it doesn't necessarily mean
link |
that you produce more adenosine,
link |
but what it can do is perhaps modulate
link |
the sensitivity perhaps of the brain
link |
so that the weight of that same adenosine
link |
is weightier in its brain signal,
link |
and therefore it creates this stronger pressure for sleep.
link |
So I think these are all tentative mechanisms.
link |
I think any one of them is viable.
link |
I think all three are viable together,
link |
but right now I think,
link |
does that sort of help think through
link |
the tapestry of THC and CBD?
link |
Yeah, very much so,
link |
and actually it's a perfect segue from,
link |
we've talked about caffeine, alcohol, THC,
link |
and CBD as sort of,
link |
we framed them anyway,
link |
as things that done in moderation at the appropriate times
link |
are probably okay for most people,
link |
certainly not for everybody,
link |
there will be differences in sensitivity,
link |
but that done at the incorrect times
link |
and certainly in the incorrect amounts
link |
will greatly disrupt this vital stage of life we call sleep.
link |
CBD it seems represents a kind of bridge
link |
to the topic I'd like to talk about next,
link |
which is things that promote more healthy sleep,
link |
or somehow contribute to enhancing the architecture
link |
and quality of sleep.
link |
So I'd love to chat for a moment about the kind of grant,
link |
the original, I should say that not the granddaddy,
link |
but the OG of sleep supplementation, which is melatonin,
link |
the so-called hormone of darkness
link |
that's inhibited by light, et cetera,
link |
frame for us melatonin
link |
in the context of its naturally occurring form.
link |
And then I'd like to talk about melatonin, the supplement,
link |
because as in my experience,
link |
anytime I say the word melatonin,
link |
people think about the supplement melatonin,
link |
which in itself is an interesting phenomenon
link |
that people are so cued to its role as something you take,
link |
we often forget that this is something
link |
that we make endogenously.
link |
I'd love for you to comment in particular on,
link |
without necessarily getting into precise nanograms
link |
per deciliter values,
link |
what are the typical amounts of melatonin
link |
that we release each night?
link |
And then I'd like to compare that to what is contained
link |
in say a three milligram or six milligram tablet
link |
that one might buy at the pharmacy.
link |
So I go to sleep at night,
link |
has melatonin already kicked in
link |
before I shut my eyes and lay down my head?
link |
If your system is working in the correct way,
link |
as dusk is starting to happen,
link |
so let's say that you look at hunter gatherer tribes
link |
who aren't touched by electricity.
link |
And so that's sort of the puritanical state,
link |
par excellence when it comes to electric light influence.
link |
And usually it's as dusk is approaching,
link |
that's when melatonin will start to rise.
link |
And so when you lose the brake pedal of light
link |
coming through the eyes,
link |
not normally acts like a hard brake pedal that stamps down
link |
and prevents the release and production of melatonin.
link |
As that light brake pedal starts to fade with dusk,
link |
then we ease off the brake pedal and melatonin,
link |
the spigot of melatonin is opened up
link |
and melatonin starts getting released.
link |
And usually we'll see this rising peak of melatonin
link |
sometime usually an hour, two hours later or around
link |
and it varies from different people
link |
around the time of sleep itself.
link |
But it's already been on the march for some hours
link |
before you actually hit sleep itself.
link |
Interesting, and I was always taught
link |
and I'm assuming it's still true
link |
that the only source of melatonin in the brain and body
link |
is the pineal gland, is that still true?
link |
Yeah, it seems to be from best that we can tell
link |
and the pineal gland sort of meaning P like sort of shape.
link |
It's actually, I think usually people say
link |
it's P like, I think if you look at the Latin derivative,
link |
it's more, I think it's derived from pine cone, not P.
link |
Because in fact, if you look at the pineal,
link |
it is more pine cone shaped and so it's aptly named.
link |
Any human brain I've ever dissected,
link |
I confess I've dissected a lot
link |
because I teach neuroanatomy and have for years.
link |
I love looking at the pineal.
link |
It's the one structure in the brain that's not on both sides.
link |
It's usually pretty easy to find and it's pretty good size.
link |
It looks like a P and it's sitting right there
link |
and it's remarkable that it releases this hormone,
link |
probably our entire lifespan and is inhibited by light.
link |
So our pineal starts to release this
link |
into the general circulation.
link |
I have to imagine we have melatonin receptors
link |
in the brain and body.
link |
So yeah, essentially your brain
link |
has a central master 24 hour clock
link |
called the suprachiasmatic nucleus that keeps internal time.
link |
Now it's not a precise clock if left to its own devices,
link |
nothing that a Swiss clockmaker would be proud of.
link |
It runs a little bit long and laggy.
link |
It's like an American clock.
link |
So there are a couple of good American watches by the way.
link |
Hamiltons are very nice, but we're not famous
link |
for our timekeeping or our punctuality for them,
link |
but the Swiss are.
link |
It's very, it's not quite Swiss-like,
link |
it's more Berkeley-like, which is very relaxed.
link |
Oh, you know, whatever.
link |
So in most adults, the average adult, I should say,
link |
your biological clock normally runs a little bit long.
link |
It's about 24 hours and 13 minutes,
link |
I think was the last calculation.
link |
But the reason that we don't keep drifting forward in time
link |
and kind of running consistently, you know,
link |
more and later and later,
link |
30 minutes by 30 minutes by 30 minutes each day
link |
is because your central brain clock
link |
is regulated by external things such as daylight
link |
and temperature, as well as food and activity.
link |
All of these are essentially different fingers
link |
that come along and on the wristwatch of the 24 hour clock
link |
will pull the dial out and reset it each day
link |
to precisely 24 hours.
link |
And I make that point because it knows 24 hour time,
link |
but it needs to tell the rest of the brain and the body
link |
the 24 hour time as well.
link |
And one of the ways that it does this
link |
is by communicating a chemical signal of 24 hour nurse
link |
of light and day using this hormone melatonin.
link |
And when it is at low levels or it's non-existent,
link |
it's communicating the message, it's daytime.
link |
And for us, diurnal species, it says,
link |
it's time to be awake.
link |
Yet at nighttime when dusk approaches
link |
and the brake comes off melatonin
link |
and we start to release it,
link |
then it signals to the rest of the brain and the body,
link |
look, it's dusk and it's nighttime.
link |
And for us, diurnal species, it's time to think about sleep.
link |
So melatonin essentially tells the brain and the body
link |
when it's day and when it's night.
link |
And with that, when it's time to sleep,
link |
when it's time to wake.
link |
And therefore that's why melatonin helps
link |
with the timing of the onset of sleep,
link |
but it doesn't really help
link |
with the generation of sleep itself.
link |
And this is why we'll come on to what those studies
link |
of supplementation have taught us.
link |
So it tells the rest of my brain and body,
link |
it's time to go to sleep.
link |
Perhaps even aids with the transition to sleep,
link |
but it's not going to, for instance,
link |
ensure the overall structure of sleep
link |
or it's not the conductor that's guiding the sleep orchestra
link |
so to speak throughout the entire night.
link |
It's more like the people that essentially take you
link |
to your seat and sit you down and give you your program.
link |
Yeah, so the far less sophisticated analogy I have is,
link |
you know, melatonin is like the starting official
link |
at the 100 meter race in the Olympics.
link |
That's a better analogy.
link |
It calls all of the sleep races to the line
link |
and it begins the great sleep race.
link |
Yeah, better analogy by the way,
link |
coming from the sleep researcher of all people.
link |
But it doesn't participate in the race itself.
link |
That's a whole different set of brain chemicals
link |
and brain regions.
link |
Which then brings us on to perhaps the question
link |
of supplementation, which is,
link |
is it helpful for my sleep?
link |
Will I sleep longer?
link |
Will I sleep better?
link |
And if I am, what doses should I be taking?
link |
Sadly, the evidence in healthy adults who are not older age
link |
suggests that melatonin is not really particularly helpful
link |
I think there was a recent meta analysis
link |
that demonstrated when it looked
link |
at all of the different sleep parameters.
link |
Melatonin and a meta analysis
link |
for those not knowing what that is,
link |
it's a scientific sort of method that we use
link |
where we gather all the individual studies
link |
and we put them in a big bucket
link |
and we kind of do this kind of statistical fancy sleight
link |
of hand and we try to come up with a big picture
link |
of what all of those individual studies tell us.
link |
And what that meta analysis told us is that melatonin
link |
will only increase total amount of sleep by 3.9 minutes
link |
And it will only increase your sleep efficiency by 2.2%.
link |
This is as they say in certain parts of California,
link |
that's weak sauce.
link |
That's a weak sauce effect.
link |
The sauce is not strong.
link |
The force is not strong in this one.
link |
When it comes to a tool that in healthy people
link |
who are not of older age,
link |
it doesn't seem to be especially beneficial.
link |
Now, you know, results can vary.
link |
Everyone is different, of course.
link |
So we're talking about the average,
link |
the so-called average human adult here.
link |
Well, melatonin in defense of what you're saying,
link |
and also I should mention,
link |
I have a colleague at Stanford, Jamie Zeitzer,
link |
who we know comes from Chuck Zeitzer's lab at Harvard Med
link |
where he also trained a terrific sleep researcher.
link |
And I asked him about melatonin
link |
and he essentially said the same thing that you just said,
link |
which is very little, if any, evidence
link |
that it can improve sleep.
link |
And yet it's probably the most commonly consumed
link |
so-called sleep aid.
link |
Hundreds of million dollars industry.
link |
Yeah, so either massive placebo effect
link |
or it's operating through some other mechanism
link |
related to quelling anxiety, perhaps.
link |
Yeah, that is actually interesting.
link |
You know, there are some studies
link |
where you do see some, you know, effects.
link |
Now, again, when you do the grand average of all studies,
link |
it just doesn't seem to have an effect.
link |
But let's assume that for some people
link |
it does have an effect.
link |
Let's not, again, be sort of completely dismissive of that.
link |
How could it have that effect?
link |
One of the reasons that I've become
link |
a little bit more bullish on melatonin
link |
from a sleep perspective,
link |
and then melatonin more generally for a,
link |
maybe we can speak about this too,
link |
as a counter measure
link |
when you're undergoing insufficient sleep,
link |
there are two different routes there.
link |
The first reason that I think it could have a sleep benefit
link |
for some people is not because it helps
link |
in the generation of sleep.
link |
We know that it doesn't.
link |
It's because it too seems to drop core body temperature.
link |
There it is temperature again.
link |
I'm fascinated these days more and more by temperature
link |
as maybe not just a reflection of brain state
link |
and wakefulness and in sleep,
link |
but actually a lever that is quite powerful.
link |
And with all the interest in ice baths and hot showers
link |
and saunas and stuff, something that we will definitely
link |
touch on, temperature variation is so key.
link |
So if melatonin is dropping body temperature
link |
by a degree or so, something that you've said before
link |
can help induce a sleepy state,
link |
maybe that's what's allowing people to get in to sleep.
link |
I think that's one possibility.
link |
I don't think melatonin by itself will drop it
link |
by sort of a degree, certainly not a degree Celsius.
link |
And for ordinary in us to fall asleep
link |
and then stay asleep across the night,
link |
we do need to drop our core body temperature
link |
by about one degree Celsius
link |
or about two to three degrees Fahrenheit.
link |
And that's why it's always easier to fall asleep
link |
in a room that's too cold than too hot.
link |
I think that that's one potential avenue
link |
that we are considering thinking more deeply about
link |
when it comes to melatonin.
link |
And then the other is melatonin as an antioxidant,
link |
but let me table that for now
link |
because I'll just get us sidetracked.
link |
That's what we know so far about melatonin
link |
in terms of its supplementation benefit or lack thereof.
link |
Two final points that I shouldn't forget.
link |
One is the only population where we typically see
link |
some benefit and it often is prescribed is in older adults.
link |
Older meaning 60 and older?
link |
Yeah, 60, 65 and older.
link |
Because as we get older,
link |
you can typically have what's called calcification
link |
of the pineal gland, which means that that gland
link |
that's releasing melatonin doesn't work as well anymore.
link |
As a consequence, they tend to have a flatter overall curve
link |
of melatonin released throughout the night.
link |
It's not this beautiful, lovely peak
link |
and this bullhorn message of it's darkness,
link |
please get to sleep.
link |
That's why older adults can have problems falling asleep
link |
or staying asleep.
link |
It's not the only reason by any stretch of the imagination,
link |
but it's one of the reasons
link |
and it's why melatonin supplementation in those cohorts,
link |
older adults, especially older adults with insomnia,
link |
people have thought about that
link |
as maybe an appropriate use case.
link |
Well, on those lines, if we were to compare dosages,
link |
do we know how much melatonin is typically released
link |
into the bloodstream per night?
link |
And can we use that as a kind of a rule of thumb
link |
by which to compare the typical amount
link |
that someone would supplement?
link |
I mean, typically the supplements for melatonin that I see
link |
in the pharmacy and elsewhere and online
link |
range anywhere from one milligram to 12
link |
or even 20 milligrams.
link |
My guess is that a normal night's release of melatonin,
link |
typical for somebody in their 20s, 30s, 40s,
link |
would be far lower than that, am I correct or wrong?
link |
Yeah, it's many magnitudes lower
link |
and this is one of the problems is that I see that too.
link |
I see typical doses are five milligrams or 10 milligrams
link |
and of course, if you're a supplement company,
link |
putting 10 milligrams versus five milligrams
link |
if that's what you're actually doing,
link |
which we'll speak about purity as well,
link |
it's kind of like the super gulp size.
link |
Nobody wants to lower price.
link |
They just want you to,
link |
we'll just give you more for the same price
link |
and that's how we'll compete.
link |
So it's been this escalating arms race
link |
of melatonin concentration
link |
and it really does not look meaningful
link |
for sleep in any way.
link |
What we've actually found is that the optimal doses
link |
for where you do get sleep benefits
link |
in the populations that we've looked at
link |
are somewhere between 0.1 and 0.3 milligrams of melatonin.
link |
In other words, the typical doses are usually 10 times,
link |
20 times, maybe more than what your body
link |
would naturally expect
link |
and this is what we call a supra physiological dose.
link |
In other words, it's far above
link |
what is physiologically normal.
link |
And to put that in context,
link |
imagine I said to you,
link |
I want you to eat 20 times as much food today.
link |
I thought you're going to use testosterone as example.
link |
You're going to take 300 times
link |
the normal amount of testosterone.
link |
We know that would have tons of deleterious effects.
link |
It'd be terrible and yet you can do this.
link |
One thing that I'm concerned about
link |
about these supra physiological levels of melatonin
link |
is that many years ago,
link |
actually here at Berkeley when I was a graduate student,
link |
we would inject animals
link |
which were seasonally breeding animals with melatonin.
link |
And the consequence of that was that their gonads,
link |
either their testes or ovaries
link |
would shrink many hundred fold or more.
link |
In other words, they would go
link |
from having nice healthy sized hamster testicles,
link |
what a hamster would consider healthy size for a hamster,
link |
and they would shrink to the size of a grain of rice.
link |
So from like an almonds to a grain size of a grain of rice.
link |
I had to see that only once for me to be very concerned
link |
about super physiological levels of melatonin.
link |
And I realized that melatonin does different things
link |
in different species.
link |
We are not hamsters, we are not seasonal breeders,
link |
seasonally restricted breeders.
link |
There might be more breeding during certain seasons.
link |
I don't know those data,
link |
but nonetheless, hormones are powerful.
link |
And sure, there is an optimal,
link |
and sometimes we see that going slightly above
link |
endogenous levels for certain hormones,
link |
not always can have beneficial effects.
link |
And sometimes it can have detrimental effects.
link |
I'm just concerned about taking high levels of a hormone
link |
that has effects on the reproductive axis.
link |
And that's one of the reasons why I get very concerned
link |
when I see people really getting aggressive
link |
about melatonin supplementation,
link |
taking 110, 500, sometimes even 10,000 times
link |
the amount that we would normally release.
link |
That's my concern,
link |
although it's not nested in any one specific human study.
link |
I just don't like to see,
link |
I certainly don't want to see other people
link |
and I don't want to personally take a hormone
link |
that's known to be androgen suppressive at high levels.
link |
Why would I take that?
link |
That's the question I asked myself.
link |
I think it's a very good point.
link |
And if you look at some of the evidence
link |
around melatonin's lethality,
link |
if you want to go to that extreme,
link |
for the most part, it's pretty safe.
link |
You mean you can take a lot of it before you die.
link |
Yeah, but that should not be your yardstick
link |
because you really need to think about your health,
link |
not just whether this thing is going to kill you or not
link |
as the decision matrix through which you pop a pill.
link |
And it comes on to this concern around melatonin
link |
because there was a study,
link |
I think it's one that you mentioned too,
link |
where they looked at over,
link |
I think it was at least over 20 different brands
link |
of melatonin supplements.
link |
And what they found is that based on what it said
link |
on the bottle versus what was in the capsules themselves,
link |
it ranged from, I think it was 83% less
link |
than what it said on the bottle to 478% more
link |
than what it said on the bottle.
link |
Now, if that's a 10 milligram pill
link |
and it's 478% more than 10 milligrams
link |
and we're already at 10 milligrams
link |
at many tens of times more than is a physiological
link |
rather than a supra physiological dose,
link |
we do need to be a bit thoughtful.
link |
Yeah, remember those hamsters folks.
link |
Well, and I do appreciate the deep dive on melatonin
link |
because I think people need to understand
link |
that it's nuanced, it's a matter of dosages
link |
and timing, et cetera.
link |
And then it may have its place,
link |
as you mentioned in older individuals.
link |
And I should mention that I'm an avid consumer
link |
of supplements that I believe in for me.
link |
And I have been for a very long time.
link |
So I'm by no means anti supplement.
link |
Some supplements I refuse to take or avoid taking,
link |
others I am quite avidly take.
link |
And along those lines, I personally,
link |
and I don't know what your thoughts on this are,
link |
but there are a few things
link |
that I've personally found beneficial.
link |
I'd love your thoughts on them.
link |
And I would love it if you would tell me
link |
that everything I'm about to refer to as placebo,
link |
that would be fine.
link |
So that's what we do.
link |
We're scientists, we argue,
link |
and then we remain friends as it goes.
link |
There are many forms of magnesium.
link |
Magnesium citrate is, as we know, is a terrific laxative.
link |
Magnesium malate seems, at least from a few studies,
link |
seems to relieve some of delayed onset muscle soreness,
link |
doesn't seem to create a kind of sedation.
link |
Two forms of magnesium that I'm aware of,
link |
magnesium biglycinate and magnesium threonate.
link |
We believe, based on the data,
link |
can more actively cross the blood-brain barrier.
link |
So you put it in your gut,
link |
but some of that needs to get into your brain
link |
in order to have the sedative effect.
link |
What are your thoughts on magnesium supplementation?
link |
Do you supplement with magnesium?
link |
And what studies would you like to see done
link |
if they haven't been done already?
link |
So I don't supplement with magnesium,
link |
but I do think threonate is interesting
link |
because of that higher capacity
link |
to cross the blood-brain barrier
link |
and actually have a central nervous system effect.
link |
And the reason that that interests me
link |
is because the sleep is by the brain, of the brain,
link |
and also for the brain, as well as for the body.
link |
We just don't have a particularly good set of studies
link |
that have targeted exclusively threonate.
link |
We do have lots of studies that have just looked
link |
at magnesium in general for sleep.
link |
And overall, the data is uncompelling.
link |
And for a while, I was confused as to why.
link |
Where did this come from?
link |
This kind of myth of magnesium.
link |
So I started looking back into the literature
link |
and I've best traced it, at least as far as I can tell,
link |
to early studies showing that those who were deficient
link |
in magnesium also had sleep problems.
link |
They had other problems too, of course,
link |
but sleep problems were one of that set of sequelae
link |
that came from having lower magnesium.
link |
And when they supplemented with magnesium
link |
and tried to restore those levels,
link |
some of those sleep problems dissipated.
link |
And then that seems to have gotten lost in sort of
link |
some game of sort of like whispers around the room.
link |
And it's become translated into people
link |
who don't have sleep problems,
link |
who are healthy sleepers and who are healthy in general,
link |
and who have healthy normal levels of magnesium.
link |
If they take more magnesium, they will sleep better.
link |
And the data really there is not good.
link |
Once again, the only study that I've seen
link |
where magnesium did have some efficacy
link |
was in a study with older adults.
link |
I think they were 60 to 80 years old.
link |
It may have been exclusively women now I think about it.
link |
And they also had insomnia.
link |
And in that population, you did see some benefits.
link |
And my guess is that because it's an older community
link |
as well, they were probably deficient in magnesium.
link |
So they fit the former category of simply
link |
when you're deficient and you restore,
link |
you can help sleep sort of return to normal.
link |
But if you are not deficient and you're healthy
link |
and you're not old and you don't have insomnia,
link |
and you're supplementing thinking that it provides sleep,
link |
right now, the data isn't supportive of that.
link |
But I just don't think we have enough threonate data
link |
to actually speak about that
link |
because it could just be a blood brain barrier issue so far
link |
with the other forms.
link |
So maybe some additional studies looking specifically
link |
at threonate or biglycinate would be useful.
link |
Magnesium is involved in so many cellular processes.
link |
You can imagine that this effect, if it truly exists,
link |
is, as we say in science, in the noise,
link |
meaning it's in the jitter of the data.
link |
But to isolate the real effect,
link |
one needs to do some more refined studies.
link |
What are some things that are of interest to you,
link |
if not things that you happen to take?
link |
These are not things that I personally take,
link |
mostly because I just haven't experimented with them.
link |
Valerian root is one.
link |
Tart cherry and kiwi fruit.
link |
Tell me about Valerian root, tart cherry, and kiwi fruit.
link |
This is new to me.
link |
I mean, I've certainly heard of them,
link |
and tart cherry and kiwi sounds delicious.
link |
But what's happening with Valerian root,
link |
tart cherry, and kiwi,
link |
and are we talking about eating tart cherries and kiwis
link |
and Valerian roots?
link |
Or are we talking about taking them in pill form?
link |
Usually it's supplements,
link |
but it's also both for tart cherries and for kiwis.
link |
It's the actual fruit themselves.
link |
Valerian often touted as a beneficial sleep aid,
link |
and lots of people swear by it too.
link |
But the evidence is actually quite against that.
link |
Not that it makes your sleep worse,
link |
but of at least the seven good studies
link |
that I've been able to find.
link |
And typically these are of the nature
link |
of what we call a randomized placebo crossover design.
link |
And I won't bore people with what that means.
link |
It's sort of one of the-
link |
Good studies, solid studies.
link |
Yeah, it's one of the sort of gold standard methods
link |
that we have when we're looking at intervention studies,
link |
such as drug studies.
link |
Five of the seven found no benefit
link |
of Valerian root on sleep.
link |
Then two out of the seven,
link |
the data was just insufficient.
link |
I think it was a power issue
link |
where they just couldn't make any strong conclusions.
link |
And then I think there was the most recent study,
link |
I think looked at two different doses of Valerian.
link |
I could have this wrong,
link |
and they just failed to find any effects once again.
link |
But the stunning part of that paper,
link |
as I recall, they had this big table
link |
with all of the different sleep metrics that they looked at.
link |
And there were well over 25 different things
link |
that they tried to see if Valerian impacted.
link |
And none of them were significant,
link |
which stuns me because from statistical probabilities,
link |
we know if you just randomly perform 25 statistical tests,
link |
chances are probabilistically,
link |
you'll just get one significant result by random chance.
link |
And even with random chance on their side,
link |
they still couldn't find a benefit of Valerian.
link |
So Valerian root might be worse than nothing at all
link |
if there is, so to speak.
link |
I mean, again, placebo effect,
link |
we can think about that too.
link |
And I would say that if you feel
link |
as though it's having a benefit for you,
link |
and with all of the caveats that we have with supplements,
link |
things like melatonin, purity, concentration, et cetera,
link |
maybe it's no harm, no foul,
link |
but I'm not a medical doctor,
link |
and I don't tell anyone about,
link |
we have all of these disclaimers about not recommending.
link |
Sure, and we'll include these.
link |
I mean, I always say, we're not physicians,
link |
we don't prescribe anything.
link |
We're scientists and professors, so we profess things.
link |
And it's up to people to be responsible for their own health,
link |
not just to protect us, but to protect themselves.
link |
I do want to hear about tart cherry and kiwi fruit.
link |
What's the story there?
link |
Strange, isn't it?
link |
I was, you know, I'm kind of a hard-nosed scientist.
link |
And when people, you know, some years ago started saying,
link |
oh, tart cherries, it's the thing, or kiwi fruits,
link |
I was thinking, oh my goodness, this sounds a bit-
link |
You've been in California a little too long.
link |
Yeah, I know, yeah, the sun has softened me.
link |
But I thought, look, one of the things
link |
that we have to do as scientists
link |
is be as open-minded as possible,
link |
and I should not be so quick to dismiss.
link |
So I went to the literature,
link |
just started reading as much as I could about it.
link |
And there were three really good randomized
link |
placebo crossover trials with tart cherries.
link |
And what they found was that in one study,
link |
it reduced the amount of time that you spent awake at night
link |
And then the other two studies,
link |
one of them found that it increased the amount of sleep
link |
that you got by 34 minutes.
link |
The other, it increased the amount of sleep
link |
that you got by 84 minutes.
link |
Which, you know, these are,
link |
and what's striking is that they were independent studies,
link |
I think, meaning that they were from independent groups.
link |
And these were, you know, some of these guys,
link |
you know, girls, I know pretty well.
link |
And they're really-
link |
You know and trust their work.
link |
Right, I really trust their work too.
link |
Were they ingesting actual tart cherries
link |
or they're drinking the juice or in capsule?
link |
So they, in all three studies, it was juice.
link |
Although you can, I think as a supplement,
link |
you can buy it in a capsule and we've got no idea
link |
whether that changes the benefit or not.
link |
What was also interesting in,
link |
I think it was that last study
link |
where they got an increase in sleep by 84 minutes.
link |
It also decreased daytime napping significantly.
link |
Oh, that's one that I could certainly make use of.
link |
I love my daytime naps, but I'd love to skip them too.
link |
Right, and we can speak about naps
link |
and sort of the upside and downside of that.
link |
Which then made me think, well, if that's the case,
link |
maybe the net benefit on sleep overall is no different.
link |
It's just that it decreases the amount of time
link |
that some people were taking to sleep during the day
link |
and giving it back to the night.
link |
But that wasn't the case
link |
because if you added the total amount of sleep
link |
that they were getting without tart cherries,
link |
both naps and nightly sleep combined,
link |
still when you took tart cherries,
link |
you still got a net sum benefit of total amount of sleep.
link |
So, you know, so far when it comes to supplements
link |
and those types of studies, they're good studies
link |
and the data looks interesting.
link |
But as a drug itself, you know, if this was clinical drug,
link |
you know, three studies that are somewhat small in nature
link |
and have some positive benefit,
link |
that's what we would call preliminary data
link |
of maybe a chin scratching kind.
link |
So keep this in context.
link |
Yeah, and depending on the margins for safety,
link |
one might think, well, given that it's a tart cherry
link |
as opposed to some pharmaceutical you need a prescription for
link |
then, you know, some people their threshold
link |
to experiment with supplements is quite low,
link |
some people their threshold is quite high.
link |
I feel like, you know, there are two categories
link |
or at least two categories of folks out there.
link |
People who hear, oh, tart cherry can improve sleep
link |
and will run out and try it.
link |
And people who hear, well, that sounds crazy,
link |
why would I do that?
link |
But of course we have to remind people
link |
that tart cherry isn't really what we're talking about,
link |
presumably, if this is a real effect
link |
and it sounds like it might be,
link |
that there's a compound in tart cherry
link |
that if we were to call it whatever, whatever,
link |
five, alpha, six, you know, some molecule,
link |
if we refer to it by its technical name,
link |
then people would say, oh, that sounds like
link |
a very interesting technical way to approach sleep,
link |
but doesn't sound very natural.
link |
So both groups are a little bit misguided
link |
in the sense that people who think that everything
link |
that comes from naturally occurring foods, plants, et cetera,
link |
things that grow out of the ground,
link |
that that's all safe, that's not true.
link |
And people that think that pharmaceuticals are the only,
link |
if it's not evidence with the purified molecule,
link |
then something's not of utility.
link |
Well, that's certainly not true.
link |
Somewhere in the middle, I think lies the answer,
link |
which is, it sounds to me like tart cherry
link |
is at least an intriguing potential sleep aid,
link |
intriguing potential sleep aid,
link |
and I'm underscoring potential.
link |
I'm certainly intrigued by it to the point
link |
where I might experiment a bit,
link |
but I'm an experimenter for myself.
link |
Before I ask you about kiwi,
link |
I've had quite good results
link |
from taking something called apigenin,
link |
which is a derivative of chamomile,
link |
but in supplement form, I think I take 50 milligrams
link |
about 30 minutes before sleep,
link |
and I subjectively experience a better night's sleep,
link |
I don't measure, I confess I don't measure my sleep.
link |
I'm not a sleep tracker guy.
link |
But there are a few papers out there.
link |
They're not what we would call
link |
published in blue ribbon journals,
link |
but they have control groups
link |
and it looks somewhat interesting.
link |
And there, when I say apigenin,
link |
people get somewhat intrigued,
link |
oh, this molecule, chamomile, has long been thought
link |
to be a sedative, a mild sedative, but a sedative.
link |
Do you drink chamomile tea?
link |
Do you take apigenin?
link |
What are your thoughts on apigenin?
link |
Yeah, I don't, and I have looked into some of the data
link |
regarding sleep as well.
link |
Right now, from best I can tell,
link |
it's mostly subjective data
link |
rather than objective, hard sort of sleep measures.
link |
And that's why right now, it's sort of unclear,
link |
not no comment, but just unclear,
link |
not dismissing it because I think you and I
link |
both ascribe to the idea of absence of evidence
link |
is not evidence of absence.
link |
So keep your mind open, at least I tell that to myself.
link |
I think if you're finding a benefit
link |
and you can do what I would think of
link |
if I was personally experimenting,
link |
which is both the positive and negative
link |
parts of the experiment, what I mean by that is,
link |
let's say that I now want to think about
link |
some kind of a sleep supplement.
link |
I will take some kind of baseline set of recordings
link |
for a month and I will just gauge where I'm at,
link |
sort of supplement free.
link |
Then I'll go on for a month
link |
to whatever I'm thinking of taking.
link |
And I don't supplement, but let's say that I want to
link |
and I experiment with that.
link |
And I feel as though based on my metrics,
link |
be them objective from my aura ring
link |
or be them subjective from whatever I'm writing down
link |
in the morning and both are important and valid,
link |
subjective and objective.
link |
We like both in the sleep world.
link |
And I think, okay, look, it's clearly that
link |
it seems to have some kind of an effect.
link |
The key thing, however, is then do the negative experiment,
link |
which is now come off it for another month
link |
and see do things get worse?
link |
And if I can see that by directionality,
link |
then I'm starting to think maybe I'm believing this
link |
a little bit more.
link |
So that's the way I would sort of typically approach
link |
a supplementation regimen if I were to do it.
link |
And that's just me, that's just the way my mind works, but.
link |
I think it's very scientific and organized
link |
in a way that allows you and would allow other people
link |
to make very informed decisions for themselves.
link |
I like to think in terms of manipulating
link |
any aspect of our biology,
link |
that behavioral tools always are the first line of entry.
link |
Then nutrition, everyone has to eat sooner or later,
link |
even if you're fasting.
link |
Then perhaps supplementation, then prescription drugs,
link |
and then perhaps brain machine interface,
link |
devices that you use to induce something.
link |
And those could be done in combination.
link |
But what concerns me is when I hear people say,
link |
well, what should I take without thinking
link |
about their behavior, their light viewing behavior, et cetera.
link |
But of course these things work in combination.
link |
I think it's, you're right that there's many,
link |
when it comes to sleep, there are many low hanging fruits
link |
that don't necessarily require you to, you know,
link |
put sort of exogenous molecules, in other words,
link |
things like supplements into your body,
link |
or, you know, use different types of drugs
link |
to help you get there.
link |
Now, when it comes to prescription sleep aids,
link |
I think I've been, again, a little bit too forthright.
link |
We know in clinical practice that there may be a time
link |
and a place for things like sleeping pills.
link |
They are a short term solution to certain forms of insomnia,
link |
but they are not recommended for the longterm.
link |
And we also know that there are lots of other ways
link |
that you can get a sleep help,
link |
or you can get a sleep curative profile
link |
from things like cognitive behavioral therapy for insomnia,
link |
which is a non-drug approach, psychological one.
link |
And quite effective from what I understand, good data.
link |
Just as effective as sleeping pills, great data,
link |
more effective in the longterm.
link |
There was a recent study published that
link |
after working with that therapist,
link |
some of the benefits lasted almost a decade, you know.
link |
Now, if you stop sleeping pills,
link |
usually you have rebound insomnia where your sleep goes back
link |
to being just as bad, if not worse.
link |
And I think the same is true
link |
when we think about supplementation.
link |
There are so many things that are easy to implement
link |
when it comes to sleep that don't require venturing out
link |
into those waters.
link |
And again, we're not here to tell anyone
link |
about whether they should venture or not.
link |
That's completely your choice.
link |
All I'm saying is that if you want to think
link |
about optimizing your sleep,
link |
there are a number of ways that you can do it
link |
that don't necessarily require you to swallow anything
link |
or inject anything, or smoke anything, or free base.
link |
And for which the margins of safety are quite wide.
link |
That's the other one.
link |
Yeah, sorry, thank you for that.
link |
So speaking of low hanging fruit,
link |
I don't know how low it hangs in reality,
link |
but what about kiwi?
link |
They're delicious to me anyway.
link |
Yeah, the humble kiwi fruit.
link |
Named not, shouldn't be mistaken
link |
for the flightless bird of New Zealand,
link |
which is the native bird there.
link |
We're talking about the kiwi, the fruit here,
link |
which those trees and shrubs are mostly Southeast Asia.
link |
Kiwi fruits have been previously touted
link |
as potentially having a sleep benefit,
link |
which again got me curious,
link |
and I at first threw it out.
link |
To my knowledge, there's really only one
link |
published human study that's of any value.
link |
But what they did find was that it decreased
link |
the speed of time with which it took you to fall asleep.
link |
These are people ingesting the whole kiwi?
link |
So it's ingesting the whole kiwi.
link |
With the skin, I eat the skin,
link |
people cringe when they see me do it.
link |
Well, I think, no, no, no,
link |
I think the idea is some of the good stuff,
link |
and I'll come on to this,
link |
may actually be in the skin itself.
link |
Thank you, you just helped me win a bet.
link |
I'll give you your-
link |
Okay, okay, yeah, you can pay me later.
link |
By the way, this skin is used, no, no, no,
link |
he just told me to say that, so he went, no, he did not.
link |
So the skin seems to be part
link |
of this potential sleep equation.
link |
And that's the, yeah, you fell asleep faster,
link |
and you stayed asleep for longer,
link |
and you spent less time awake throughout the night.
link |
And I just thought, well, that's one study,
link |
what can you really do with that?
link |
There was another study, however, in an animal model,
link |
which is a little bit more interesting.
link |
And once again, they found a very similar phenotype
link |
that the rats, oh, sorry, they were mice.
link |
The mice fell asleep faster,
link |
and they also spent longer time in sleep.
link |
The sleep duration also increased.
link |
What was also interesting mechanistically,
link |
and this is not the mechanism that I think ties together
link |
tart cherries, kiwi fruit, and things like melatonin,
link |
because I think there could be one common binding mechanism.
link |
What they found in the animal study
link |
is that they could block those kiwi fruit sleep benefits
link |
using a GABA blocking agent.
link |
Now, GABA, which stands for gamma-aminobutyric acid,
link |
is one of the major inhibitory neurotransmitters
link |
It's kind of like the red-
link |
It's kind of like the red light on the traffic light signal.
link |
Others are green light, GABA is red light.
link |
So by playing around with some sort of clever drugs
link |
to manipulate the system,
link |
they could prevent the benefit of the kiwi fruit
link |
by sort of buggering around with the GABA receptor,
link |
meaning that perhaps part of the kiwi fruit benefit on sleep
link |
was mediated by the brain's natural inhibitory
link |
neurotransmitter system called the GABA system.
link |
And I thought that convinced me a little bit more
link |
that maybe there's something here to read into.
link |
So to be determined, again, here is the banner,
link |
but tart cherries and kiwi fruits, the data surprised me,
link |
because in part, I was so preoccupied with being,
link |
I don't know, a bit purish about it and a bit snobby,
link |
thinking, oh, come on,
link |
that's definitely not going to work well.
link |
The data's so far.
link |
I look forward to a day when supplements
link |
are no longer called supplements,
link |
because at the end of the day,
link |
whether or not something has an effect,
link |
whether or not it's a whole kiwi fruit
link |
or a derivative kiwi fruit,
link |
will depend on the molecular compound.
link |
And as you mentioned,
link |
this potential mechanism via the GABA system,
link |
that's, we both as scientists get excited about mechanism,
link |
because when you can trace a mechanism and a pathway,
link |
it provides a rationale,
link |
a grounding for why kiwi of all things
link |
or tart cherry of all things
link |
might help increase total sleep time.
link |
I'd be remiss if I didn't mention
link |
or ask about tryptophan and serotonin.
link |
I can anecdotally say when I've taken tryptophan,
link |
the precursor to serotonin or serotonin itself,
link |
I have a horrendous night's sleep.
link |
I fall asleep very easily
link |
and I experience ridiculously vivid dreams,
link |
neither pleasant nor unpleasant, it's kind of a mishmash.
link |
And then I wake up
link |
and I experienced several days of insomnia that,
link |
and I've done the positive control and the negative control
link |
and all the variations thereof,
link |
to confirm that at least for me,
link |
supplementing with serotonergic agents
link |
is a bad idea for me.
link |
And tryptophan is a common sleep supplement
link |
and sleep aid that's discussed.
link |
The normal architecture of sleep
link |
involves the release of serotonin,
link |
but in a very timed and regulated way.
link |
What are your thoughts about serotonin in sleep,
link |
if you had to kind of put that into a nutshell,
link |
and then why supplementing with serotonin
link |
and or its precursor, tryptophan,
link |
might be a good or a bad idea for somebody?
link |
Well, I think one of the potential dangers
link |
is that based on what's going on in your body,
link |
that can change the absorption
link |
of natural sort of tryptophan and serotonin uptake
link |
within the brain itself.
link |
So I'm always thoughtful when you're playing around
link |
with that mother nature dynamic, as it were.
link |
The data, as you described,
link |
is a little bit all over the map.
link |
Some people say that it knocks them out.
link |
Other people say, just like you do,
link |
it has a terrible impact on my sleep.
link |
And when I stop, it's pretty bad for a couple of days.
link |
It seems to have this lingering after effect.
link |
I think what could be happening here is
link |
we need serotonin to, just as you described,
link |
be modulated in very specific ways
link |
during the different stages of sleep.
link |
If you look at the firing of the brain epicenters
link |
where serotonin is released,
link |
and there's a bunch of them in the brainstem,
link |
what you find on the release of serotonin too,
link |
when we're awake, it's usually in high concentrations.
link |
As we start to drift off to sleep,
link |
it lowers some, but not necessarily dramatically
link |
as we're going into non-REM sleep.
link |
But then when we go into REM sleep, serotonin is shut off.
link |
One of the other neuromodulators, noradrenaline,
link |
REM sleep is the only time during the 24-hour period
link |
where we see noradrenaline and serotonin,
link |
or norepinephrine, completely shut down.
link |
When I say serotonin, we're also talking 5-HTP,
link |
sorry, 5-HT, that's just its chemical name here.
link |
So whether it, speaking about serotonin or 5-HT,
link |
it's the same thing, norepinephrine, noradrenaline,
link |
both of those need to be shut down
link |
for you to produce REM sleep.
link |
The other, one of the other neuromodulators
link |
that then ramps up to produce REM sleep is acetylcholine.
link |
So these three neuromodulators
link |
have this incredible reciprocal dance that they have
link |
for you to generate what is called a natural architecture
link |
of sleep throughout the night.
link |
It's the push-pull again.
link |
It's a push-pull again.
link |
It's chest and back, it's whatever you want to think of.
link |
That's why I think if you're trying to increase,
link |
dramatically drive up your serotonin levels at night,
link |
and that sustains throughout the night,
link |
when you're trying to get into REM sleep,
link |
you could be artificially fragmenting REM sleep.
link |
Now, I don't know the data.
link |
I don't think anyone's really got good data,
link |
but that's why I would be,
link |
you know, if you were to say, Matt, two years time,
link |
that's the data, help me understand the potential mechanism,
link |
or let's design some experiments, where would you go first?
link |
I would say, let's look at the disruption of REM sleep,
link |
non-REM sleep reciprocal regulation,
link |
because, you know, you need serotonin to be, you know,
link |
up at one time, down at another, so.
link |
I agree with everything you said,
link |
and I'm personally never taking tryptophan or serotonin
link |
again, unless there's some clinical reason for that,
link |
that I would need to do that.
link |
I want to ask about some other pro-sleep behaviors,
link |
but before I do that, let's talk about naps.
link |
I come from a long history of nappers.
link |
My dad always took a nap in the afternoon.
link |
I take a 20 or 30 minute nap, or I do a practice,
link |
which I took the liberty of coining NSDR,
link |
non-sleep deep breaths,
link |
some sort of just passive laying out there,
link |
feet up, elevated, sometimes people do you,
link |
or I'll do yoga nidra,
link |
I'll do hypnosis or something of that sort,
link |
but 20 or 30 minutes of that has been very beneficial
link |
for me to get up from that nap
link |
or period of minimal wakefulness, we'll call it,
link |
and go about my day quite well,
link |
and also fall asleep just fine.
link |
What are the data on naps?
link |
Do you nap, and what are your thoughts
link |
about keeping naps short, meaning 20 to 30 minutes,
link |
versus getting out past 90 minutes, two hours?
link |
So for you personally, naps, yay, nay, or meh?
link |
I don't nap, and I've just never been a habitual napper.
link |
Is that because you don't feel sleepy in the afternoon,
link |
or because- I typically don't feel sleepy.
link |
So you're just hardier than I am.
link |
I wouldn't say hardier.
link |
I may be less capable of falling asleep.
link |
My sleep drive- But you're not
link |
dragging through the afternoon.
link |
No, no, I don't drag through everything.
link |
So you don't nap because you don't feel a need to nap.
link |
That's right, yep.
link |
Now, it's not that I am immune
link |
to what we call a postprandial dip in alertness.
link |
I definitely feel as though there can be
link |
this kind of afternoon lull,
link |
where I'm not quite as on as I was
link |
at 11 o'clock in the morning.
link |
And we know the physiology to that,
link |
which brings us back to whether we were designed to nap.
link |
So for naps, we've done lots of different studies,
link |
and other colleagues have done these studies too.
link |
Naps can have some really great benefits.
link |
We found benefits for cardiovascular health,
link |
blood pressure, for example.
link |
We found benefits for levels of cortisol.
link |
We found benefits for learning and memory,
link |
and also emotional regulation.
link |
How long are the naps typically in those studies?
link |
Anywhere between 20 minutes to 90 minutes.
link |
Sometimes we like to use a 90 minute window
link |
so that the participant can have a full cycle of sleep.
link |
And therefore they get both non-REM and REM sleep
link |
within that time period.
link |
Then when we wake them up,
link |
we usually wait a period of time
link |
to get them past what we call sleep inertia,
link |
which is that kind of window of grogginess
link |
where you say to your better half,
link |
look, you know, darling,
link |
please don't speak to me for the first hour.
link |
Don't anything right now.
link |
After the first hour of waking up,
link |
you know, I'm just not the best version of myself.
link |
So we wait for that time period,
link |
and then we do some testing.
link |
And we've done some testing before and after,
link |
and we look at the change.
link |
And that's how we measure what was the benefit of naps.
link |
And the reason why we sometimes do 90 minutes
link |
so that they get all of those stages of sleep.
link |
And then we correlate how much benefit did you get
link |
from the nap and how much of that benefit
link |
was explained by what REM sleep you got,
link |
what deep sleep you got, what light sleep you got.
link |
So that's the only reason that we use that
link |
as an experimental tool.
link |
What we've also found is that naps
link |
of as little as 17 minutes
link |
can have some quite potent effects on,
link |
for example, learning.
link |
None of this is novel.
link |
NASA pioneered this back in the 1990s.
link |
And during the missions,
link |
they were experimenting with naps for their astronauts.
link |
And what they found was that naps of little as 26 minutes
link |
improved mission performance by 34%
link |
and improved daytime alertness by 50%.
link |
And it birthed what was then called the NASA nap culture
link |
throughout all terrestrial NASA staff
link |
during that time period.
link |
So it's long been known that naps can have a benefit.
link |
Naps, however, can have a double-edged sword.
link |
There is a dark side to naps.
link |
And it comes back to our story
link |
of adenosine and sleep pressure.
link |
The longer we're awake,
link |
the more of that sleep pressure adenosine that we build up.
link |
But what I didn't tell you is that when we sleep,
link |
the brain gets the chance
link |
to essentially clear out that adenosine.
link |
And after about 16 hours of wakefulness,
link |
and then after about eight hours of sleep,
link |
eight hours of sleep seems to be able
link |
to allow the brain to decrease its adenosine levels
link |
And so naturally we should start to wake up,
link |
which also aligns with your circadian rhythm.
link |
And those are two separate processes.
link |
But with about eight hours of good quality sleep,
link |
seven to nine hours for the average adult,
link |
we are free of all of that adenosine.
link |
We've evacuated it essentially out of the brain
link |
and we wake up naturally feeling refreshed.
link |
The reason that naps can be potentially dangerous
link |
is that when you nap,
link |
you are essentially opening the valve
link |
on the pressure cooker of sleep pressure.
link |
And some of that sleepiness is lost by way of the nap.
link |
So for some people and not all people,
link |
and you're a great example of this,
link |
some people, however,
link |
if they are struggling with sleep at night
link |
and they nap during the day,
link |
it makes their sleep problems even worse.
link |
So for people with insomnia,
link |
we typically advise against napping.
link |
And the advice is if you can nap regularly
link |
and you don't struggle with sleep at night,
link |
then naps are just fine.
link |
But if you do struggle with sleep, stay away from naps.
link |
If you are going to nap, try to limit your naps,
link |
try to cut them off a bit like sort of caffeine,
link |
maybe eight to sort of 12 hours,
link |
maybe not that far off,
link |
maybe sort of seven to six hours is a good rule of thumb.
link |
Try not to nap essentially late in the afternoon.
link |
And if you do take a nap and you want to maintain your,
link |
you don't want to have that grogginess hangover
link |
that can happen after a full night of sleep
link |
for the first hour,
link |
try to limit it to about 20, 25 minutes.
link |
And that way you don't go down
link |
into the very deepest stages of sleep,
link |
which if I wrench you out of with an alarm,
link |
then you just kind of feel,
link |
you almost feel worse for the first hour after the nap.
link |
I've definitely experienced that if I oversleep.
link |
Certainly if the sun goes down during my nap
link |
and I wake up and overall lighting conditions have changed,
link |
I find it very hard to jolt myself back into the evening
link |
and it can screw me up.
link |
So I try and keep those naps pretty brief.
link |
I'm very happy to hear you mention individual differences
link |
and why some people might want to nap
link |
and other people might not want to nap.
link |
I have a colleague Leach and Lowe,
link |
he'll be familiar to many neurobiologists,
link |
who's a absolutely spectacular scientist,
link |
member of the National Academy,
link |
Howard Hughes Investigator, just a phenom
link |
and has a ton of energy.
link |
I learned that he always takes a nap in the afternoon,
link |
so much so that when he travels to give seminars
link |
at other universities,
link |
he will tell his post lunch,
link |
post, whoever it is that he's supposed to meet with,
link |
may I have your office for 30 minutes
link |
of our sometimes 30 minute discussion
link |
or 60 minute discussion,
link |
because I like to take a nap and he does that
link |
and then gives his talks are typically in the afternoon
link |
in academic culture.
link |
And he describes the effect of the nap for him,
link |
these short naps in the afternoon
link |
being so profound for his productivity.
link |
That's actually what inspired me to start feeling okay
link |
about my desire to nap.
link |
And so I think for me,
link |
that was great vindication for those that might feel guilty
link |
about wanting a nap.
link |
But I take to heart your note about avoiding naps
link |
if you have trouble falling and staying asleep,
link |
because I think that I have family members
link |
who also if they nap, they're a wreck, they can't sleep.
link |
Yeah, I think it's just,
link |
we've often been very pro sleep,
link |
we as the sort of the sleep community.
link |
So I think it's good to always point out
link |
these potential dark sides of any aspect.
link |
But you're absolutely right,
link |
no one should feel guilty
link |
about getting the sleep that they need.
link |
And I think that's been one of the big problems in society.
link |
Society has stigmatized sleep
link |
with these labels of being slothful or lazy.
link |
And we're almost embarrassed,
link |
to tell colleagues that we take a nap.
link |
I think sleep is a right of human beings.
link |
And I therefore think that sleep is a civil right
link |
of all human beings.
link |
And no one should make you feel un-proud
link |
of getting the sleep that you need.
link |
I love that and it's an important point.
link |
I also feel that one of the best ways
link |
to beat your competition in any endeavor is to outlive them.
link |
So now that we know that sleep can enhance longevity
link |
and lack of sleep can shorten one's life.
link |
That's all the justification I need anyway.
link |
Can somebody sleep too much?
link |
Is it possible to get too much sleep?
link |
It's a very good question.
link |
And there are probably two things to say about it.
link |
There is a condition that we call hypersomnia.
link |
But that's a mixture of things.
link |
It's where people have either a very high sleep need,
link |
or they are very sleepy during the day
link |
and they're typically falling asleep.
link |
And these can happen in a variety
link |
of different clinical contexts.
link |
One of the places where we've often seen hypersomnia
link |
believed to manifest is in depression.
link |
But if you look at some of those studies,
link |
it turns out it looks more as though those people
link |
are simply reporting being in bed longer,
link |
but not necessarily sleeping longer.
link |
And that fits very well with one of the profiles
link |
that we know of depression, which is anhedonia.
link |
You don't get pleasure from normally pleasurable things.
link |
So you just don't want to go out into the world.
link |
You don't want to interact because you're depressed.
link |
So what do you do?
link |
You just stay in bed.
link |
Blinds, clothes, watching TV.
link |
Right, and that just looks as though,
link |
when people say, what time did you go to bed
link |
and what time did you get out of bed?
link |
The mistake made in that question is,
link |
okay, that's how much time they're sleeping.
link |
When you should have said, what time did you fall asleep
link |
and what time did you wake up?
link |
And the answer could be very different.
link |
So that's hypersomnia from a clinical context.
link |
Can you sleep too much though?
link |
One of the data points that argue is yes, that's possible
link |
is when we look at all cause mortality.
link |
Certainly what you find is that
link |
using the sweet spot of seven to nine hours,
link |
when you start to drop below seven hours,
link |
there is a relationship which suggests
link |
that the shorter your sleep, the shorter your life.
link |
Short sleep in that regard predicts all cause mortality.
link |
But it's again, not a linear relationship
link |
like the one that we've seen with REM sleep.
link |
Once you get past nine hours,
link |
the mortality curve stops going down.
link |
And then once you get further 10 or 11 hours,
link |
it hooks back up again.
link |
It's almost like a J shape tilted over a little bit
link |
So there's this strange hook.
link |
What's going on here?
link |
Right now, sleep science has at least
link |
two non-mutually exclusive explanations for this.
link |
The first is that if you look at some of those populations,
link |
the idea is that whatever was causing them illness
link |
and took their lives was just too much
link |
for sleep to deal with.
link |
However, we know that when we get sick,
link |
one of the things that we do immediately
link |
in this whole mechanism,
link |
an inflammatory mechanism, cytokine mediated,
link |
when we get sick, we want to sleep more.
link |
We just want to curl up in bed and sleep it off.
link |
So the argument there is that it's not that sleep
link |
was killing people prematurely.
link |
It was that these people were calling on the help of sleep.
link |
They were calling on this thing called
link |
the Swiss army knife of health that is sleep.
link |
But whatever it is that they were facing
link |
was just too powerful for sleep to overcome.
link |
So it artificially looks as though more sleep leads
link |
to a higher risk of death when sleep was actually responding
link |
to the mortality risk and it lost the battle.
link |
That's one argument.
link |
The second is that we know that sleep quality
link |
and poor sleep efficiency is a very strong predictor
link |
of all cause mortality.
link |
And when you look at people who often report
link |
sleeping long amounts, 10 or 11 hours,
link |
they typically report having very poor quality sleep.
link |
So because their quality of sleep is poor,
link |
they just try to sleep longer to try
link |
and get some of that back.
link |
So again, here now it's poor quality sleep
link |
masking as too much sleep leading to this artificial hook,
link |
which looks like mortality.
link |
That's a second explanation.
link |
A third, which is more of a Goduncan,
link |
which is just the kind of like a thought experiment.
link |
And I'm of this mentality.
link |
I don't know how many other people share this.
link |
I actually think that could be a thing as too much sleep.
link |
Physiologically, I think it's possible.
link |
But the reason I think that is because it's no different
link |
than food, water, or oxygen.
link |
Or light, light in the early part of the day,
link |
throughout the day, wonderful.
link |
Light late in the day and at night, detrimental.
link |
Bi-directional, you know, for water,
link |
can you over hydrate, hyponutremia, it can lead,
link |
you know, it happened in the 1990s and 2000
link |
with the ecstasy craze, where governments were saying,
link |
you're dehydrating, you're dancing all night,
link |
please drink water.
link |
And they drank too much water.
link |
The blood electrolytes went, you know, all over the place
link |
and they were having cardiac arrests or stroke.
link |
Yeah, people were dying.
link |
And they were dying because of excessive hydration.
link |
Can you get too much oxygen, hyperoxemia,
link |
and it can cause free radical damage,
link |
which can be profoundly harmful and kill brain cells.
link |
Can you sleep too much, you know,
link |
which is the fifth element of the life equation,
link |
you know, alongside, you know, food, water, oxygen,
link |
you know, so forth, I should say, I can't even count.
link |
Clearly I'm sleeping well.
link |
Yes, I think there could be that possibility.
link |
Are most people in danger of getting too much sleep?
link |
Au contraire, if you look at the data.
link |
So, but I don't dismiss that idea.
link |
I think it's possible.
link |
All right, that's a very thorough and very nuanced
link |
and yet very clear answer.
link |
So I, it's so interesting to think that a lot of the data
link |
that out there that talking about being in bed too long,
link |
that it's just trying to compensate
link |
for the actual fragmentation of sleep.
link |
So what I'm coming away with is that there are many paths
link |
to this and both positive and things to avoid.
link |
But the idea is to get most nights, a similar amount,
link |
probably seven to nine hours, somewhere in there,
link |
of high quality sleep.
link |
That this notion of sleep quality is going to become,
link |
I would hope, a phrase that more people think about
link |
and learn about and cultivate as a practice.
link |
Want to ask about a set of behaviors that I'm at least,
link |
I'm aware of at least one company is starting to track
link |
in their sleep monitoring device, and that's orgasm.
link |
And sex, orgasm, and masturbation,
link |
topics that are somewhat sensitive,
link |
but from the perspective of biology,
link |
none of us would be here were it not for a sperm meets egg
link |
in some fashion, either in a dish or in vivo.
link |
But what are the data as you know them to be,
link |
or maybe your lab is even doing this kind of work
link |
and exploration, about the role that sex, orgasm,
link |
masturbation play in getting to sleep and staying asleep
link |
and sleep quality?
link |
Certainly those behaviors and those physiological events
link |
have been part of our evolutionary history.
link |
What's the story there?
link |
What can we say about this in terms of science
link |
and dare I say, practice?
link |
Yeah, I mean, it's almost that caricature of,
link |
in the movies where a couple makes love
link |
and then all of a sudden you just sort of hear snoring
link |
or it happens with the idea that it's somewhat somnogenic
link |
that it's sleep promoting.
link |
Well, the post orgasmic increase in prolactin
link |
Well, that's very interesting.
link |
Is thought to be a naturally occurring sedative
link |
that presumably has a function in-
link |
An oxytocin has that also that benefit
link |
where you see a dissipation of the fight or flight branch
link |
of the nervous system,
link |
which has to happen for you to fall asleep.
link |
That's why we often see, here at the sleep center,
link |
we'll see a phenomenon called wired and tired,
link |
where people say, look, I am so desperately tired.
link |
I just, I'm so, so tired, but I can't fall asleep
link |
because I'm too wired.
link |
So your sleep drive, you're desperately tired, it's there.
link |
But because you're wired,
link |
because you've got too much sympathetic activation,
link |
too much cortisol as well, you can't fall asleep.
link |
It's an impressive roadblock to anything like good sleep.
link |
And it's one of the principle mechanisms
link |
that we now believe stress and physiological activation
link |
that is the underlying cause of many forms of insomnia.
link |
But coming back to sex,
link |
the data is actually quite compelling
link |
that both either subjectively assessed sleep quality
link |
or objective amount of sleep.
link |
Sex that has resulted in orgasm,
link |
and I think it's that latter part
link |
that typically needs to happen.
link |
I would imagine so.
link |
That, you know, so between two mutually exclusive individuals
link |
where both are, you know,
link |
beneficial in terms of receiving an orgasm.
link |
Yeah, I would say any discussion about sex,
link |
we were referring to consensual, age appropriate,
link |
species appropriate, context appropriate.
link |
Wow, I would never have even gone to the species appropriate.
link |
I put species in there because it's the internet
link |
and people will come up with all sorts of ideas.
link |
So I think that age appropriate,
link |
I think age appropriate, consensual, context appropriate,
link |
and species appropriate covers all the bases.
link |
But if I missed any, put them in the comment section
link |
and then we'll be sure to take note.
link |
Yeah, no, I think that's really well said
link |
and important to say.
link |
So the data is the,
link |
when you look at couples who have orgasm,
link |
we've also however found benefits of masturbation.
link |
And it's not frequently spoken about,
link |
but if you do some surveys,
link |
it turns out that people will often use masturbation
link |
as a sleep tool if they're struggling with sleep.
link |
And I know this sort of sounds almost
link |
like a strange conversation or it's a taboo conversation,
link |
but I think we just need to be very open about all of this.
link |
When I started off in science,
link |
one of the things I worked on early in my career,
link |
not the very first topic,
link |
was the topic of early influences of hormones,
link |
estrogen and testosterone on sexual development
link |
of the brain and body.
link |
And when you are weaned in a laboratory like that,
link |
regardless of what era,
link |
you look at sex and its behaviors and its hormones
link |
and its physiologies as a scientist.
link |
And so I think that's, to be clear what we're doing here,
link |
we're exploring these behaviors from that perspective.
link |
I mean, one thing is for certain,
link |
everyone is here because a sperm met an egg,
link |
either in a dish or in vivo, as we said before.
link |
And at least in 2021, there's no way around that fact.
link |
And what preceded that is typically this act we call sex.
link |
And sometimes, hopefully I like to think,
link |
orgasm is associated with that sexual activity.
link |
Masturbation as one dimension of that
link |
is something that I think can and should be discussed
link |
if in fact there are data that relate it to sleep.
link |
Yeah, and both of those routes
link |
seem to lead to a sleep benefit.
link |
Now, I'm not saying that it's all about the orgasm.
link |
I think as we spoke about with oxytocin,
link |
there is some degree of per bonding
link |
that if you have a partner and you experience
link |
an intimate loving relationship that involves that,
link |
then you can have hormonal benefits that are sleep promoting
link |
that may not necessarily be seen if you're just engaging
link |
in the solo singular act of masturbation.
link |
So what we certainly know now,
link |
and I am not someone to take any advice on
link |
when it comes to anything relationship wise or sex wise.
link |
That's a different episode of the podcast.
link |
Certainly, and that's not a podcast series
link |
that I'm going to be releasing anytime soon.
link |
It's going to be mostly about sleep,
link |
although I will touch on,
link |
I'll release a podcast on sleep and sex,
link |
but that's the data that we have so far.
link |
We also know that it works both ways though,
link |
and it's commonly the same way with sleep,
link |
sleep and exercise, sleep and diet.
link |
How you eat can affect how you sleep,
link |
how you sleep can affect how you eat,
link |
same with exercise.
link |
And it turns out it's the same way
link |
with sexual behavior too.
link |
So here we're talking about whether sex can help with sleep.
link |
Can sleep help with your relationship and sex?
link |
And the answer is yes, it can.
link |
Firstly, we know, and we've spoken a little bit about this,
link |
that the reproductive hormones
link |
are under profound sleep regulation.
link |
Both estrogen and testosterone as I understand.
link |
Testosterone, FSH as well.
link |
But women who, or I should say anyone who's interested
link |
in having higher levels of estrogen
link |
or normal healthy levels of estrogen,
link |
I presume the data show for estrogen,
link |
what the data also show similarly for testosterone,
link |
which is if you get too little or poor quality of sleep,
link |
both sex steroid hormones as they're referred to,
link |
testosterone, crammed estrogen,
link |
which are present in both males and females
link |
and every variation thereof are going to be diminished
link |
below normal healthy levels, correct?
link |
Yep, estrogen, testosterone, FSH in women,
link |
a key hormone in the regulation for,
link |
key for conception, of course.
link |
All of these sex hormones
link |
seem to become significantly disrupted
link |
when sleep becomes of short quantity or poor quality.
link |
We also know that in women,
link |
sleep disruption can usually lead
link |
to menstrual cycle disruption.
link |
We know this particularly from evidence
link |
in shift working women,
link |
where they are nighttime shift workers,
link |
they struggle with sleep during the day,
link |
often menstruation is disrupted or even becomes impaired.
link |
But we also know it works this way,
link |
not just for sex hormones, but for sex itself.
link |
For example, we found that for every one hour of sleep,
link |
extra sleep that a woman gets,
link |
her interest in becoming sexually intimate with her partner
link |
increases by 14%, which is a non-trivial amount.
link |
And then the final part of, I think this equation
link |
when it comes to sleep and sex is your relationship itself.
link |
And there was some great work here from UC Berkeley
link |
by Professor Serena Chen.
link |
And what she found was that restless nights
link |
mean for far more brutal fights in your relationship.
link |
And they did this in a number of different
link |
elegant ways and vice versa as well.
link |
I mean, not that I've ever had conflict in relationships.
link |
Me like, you know, this is just data I've read,
link |
I've never experienced that at all.
link |
So they found reliably that sleep would predict
link |
higher likelihood of relationship conflict.
link |
Secondly, if you got into that conflict,
link |
the chances of you resolving it were significantly lower
link |
when the parties had not been sleeping well.
link |
Part of the reason is because when you are not well slept,
link |
your empathy goes down.
link |
So you're not, you're taking more of an abrasive stance
link |
with your partner rather than a more agreeable stance
link |
with your partner.
link |
So at almost every dimension of a human loving relationship,
link |
sleep can have a dramatic impact.
link |
I think these are really important things to underscore.
link |
One of the most common questions I get
link |
because there seems to be a community of people
link |
on the internet that are obsessed with this.
link |
I don't know who they are because it's all,
link |
all this internet stuff is shouting into a tunnel
link |
and getting comments back in written form.
link |
It's a very bizarre conversation, so to speak,
link |
is whether or not sexual behavior itself
link |
lowers or increases testosterone.
link |
And I went into the data, which spans many decades actually,
link |
both animal studies and human studies.
link |
And it seems just to underscore this,
link |
as long as we're talking about the subject,
link |
that it does seem that sexual activity,
link |
sex between two people,
link |
does seem to increase testosterone in both.
link |
There is this question about orgasm or no orgasm,
link |
ejaculation, no ejaculation.
link |
And indeed there do seem to be some effects
link |
of restricting ejaculation in males
link |
as a form of further increasing testosterone.
link |
So sex without ejaculation, further increasing testosterone.
link |
But the data are not clean,
link |
presumably because organizing these sorts of studies
link |
and getting truth in self-reporting
link |
is probably hard to get from subjects.
link |
But everything sort of points in the direction
link |
that provided that the relationship is a healthy one,
link |
it's consensual, it's age appropriate,
link |
context appropriate, species appropriate,
link |
that sex between two individuals does seem to increase
link |
the sex steroid hormones, testosterone and estrogen,
link |
toward healthy ranges.
link |
And what I'm hearing now,
link |
the sort of gestalt of the discussion we just had,
link |
is that that too can promote sleepiness,
link |
restful states, and quality sleep.
link |
And I think this is an important conversation
link |
that just hasn't been held enough.
link |
I mean, sooner or later, both in the US and elsewhere,
link |
we're going to have to acknowledge
link |
that we are biological organisms of some sort
link |
and that we have choice in life about all these things
link |
from supplementation to sex or no sex, et cetera,
link |
but that they have profound effects on our core biology.
link |
I mean, it's fascinating to me
link |
that the areas of the hypothalamus,
link |
the preoptic area, the superoptic areas,
link |
those areas, which the names might not mean anything
link |
to anybody besides Matt and I sitting here,
link |
but those areas sit cheek to jowl with each other
link |
in the hypothalamus and control sleep and sex.
link |
The trigger of orgasm, the appetite for food,
link |
the appetite for water, for electrolytes.
link |
I mean, the hypothalamus is kind of a festival of neurons
link |
with different booths for different primitive behaviors.
link |
It's such a small, small structure in the brain,
link |
but it's the orchestrator of a fast number of our behaviors,
link |
disproportionate in terms of its size versus effect.
link |
Yeah, I don't think you can go to this hypothalamic festival
link |
without at least seeing all the booths,
link |
whether or not you decide to visit them or not.
link |
So I'm glad that we've broached that conversation,
link |
and I hope people will think that we've approached it
link |
with the appropriate level of sensitivity.
link |
It's an important one that we're going to hear more about
link |
one way or the other.
link |
People are certainly thinking about this,
link |
if not engaging in these sorts of behaviors
link |
So the more we can understand about the biology, the better.
link |
And so thank you for bringing that topic up
link |
because for the record, Matt tabled it for discussion.
link |
I said, we were just like chatting outside.
link |
And I think we'd said something about, yeah,
link |
sort of sex and I said, yeah, we can go there.
link |
That's actually interesting data.
link |
I want to touch on just two remaining topics.
link |
One is, are there any unconventional sleep tips
link |
or things about sleep that we've overlooked?
link |
If we've covered everything, great,
link |
but you know, we're here to keep the room cool.
link |
We here, because of this temperature phenomenon,
link |
the light aspects, the considerations about alcohol, CBD,
link |
marijuana, cognitive behavioral,
link |
tart cherry fruit, kiwis, perhaps.
link |
Please don't put me on the hook for tart cherries and kiwi.
link |
I was just offering what I know about the data.
link |
And these are considerations
link |
and whether or not people batch these things.
link |
I won't even list them off now
link |
because there are too many jokes that one could make.
link |
And I have no affiliation with any of these products
link |
or companies or whatever.
link |
I'm going to take out stock in a kiwi company.
link |
No, I'm just kidding.
link |
But the question I have is about any unconventional
link |
or lesser known things, or maybe you do things
link |
or you think about things just in a purely exploratory way
link |
as a scientist, you know, the what if kind of things
link |
that, yeah, what if it turns out that,
link |
and I hear I've got a blank there for you to fill in.
link |
I think, you know, beyond the standard, you know,
link |
fair that I've dished out plenty of times of sleep hygiene
link |
of, you know, regularity, temperature, darkness,
link |
alcohol, caffeine, and we've spoken about all of those.
link |
What are some more unconventional tips, I guess?
link |
The first one, which is unconventional
link |
along the lines of naps,
link |
if you've had a bad night of sleep,
link |
let's say that you're starting to emerge with insomnia
link |
and you've had a bad night of sleep,
link |
the advice and I learned this
link |
from my wonderful colleague, Michael Perlis, do nothing.
link |
What I mean by that is, don't wake up any later,
link |
don't sleep in the following day to try and make up for it.
link |
Don't nap during the day.
link |
Don't consume extra caffeine to wake you up
link |
to try to get you through the day.
link |
And don't go to bed any earlier
link |
to think that you're going to compensate.
link |
And I can explain all of those things,
link |
but if you wake up later,
link |
you're not going to be sleepy until later the evening.
link |
So you're gonna go to bed at your normal time
link |
and you won't be sleeping.
link |
You'll think, well, I just came off a bad night of sleep
link |
and now I still, I can't even get to sleep
link |
and it's my normal time.
link |
It's because you slept in later than you would otherwise
link |
and you reduce the window of adenosine accumulation
link |
before your normal bedtime.
link |
So don't go, don't wake up any later.
link |
Don't use more caffeine for the reasons that are obvious
link |
because that's only gonna crank you
link |
and keep you awake the following night
link |
or decrease the probability of a good following night
link |
of recovery sleep.
link |
Third, I mentioned don't take naps
link |
because once again, that will just take,
link |
naps particularly later in the afternoon,
link |
I almost liken them to snacking before a main meal.
link |
It just takes your appetite off the edge
link |
of that main meal of sleep, so don't do it.
link |
And then finally, don't go to bed any earlier.
link |
Resist and resist and go to bed at your normal time.
link |
What I want to try and do is prevent you from thinking,
link |
well, I had such a bad night last night
link |
and I normally go to bed at 10.30,
link |
I'm just gonna get into bed at nine o'clock
link |
because last night was just so bad.
link |
But that's not your natural bedtime
link |
and it's not aligned with your natural chronotype
link |
because presumably you kind of know something about that
link |
or a morning type, evening type
link |
and you're trying to sleep in harmony,
link |
which is usually how you get best quality sleep.
link |
But you go to bed at nine and my body is not ready
link |
to sleep at nine o'clock.
link |
But I'm worried because I had a bad night of sleep
link |
last night, so I get into bed and now I'm tossing
link |
and turning for the first hour and a half
link |
because it's not my natural sleep window,
link |
but I just thought it was a good idea.
link |
And if I didn't know anything about sleep,
link |
I would think all of these same things too,
link |
so I'm not finger wagging.
link |
But if I have a bad night of sleep and I am not immune,
link |
just because I know a little bit about sleep
link |
doesn't mean I don't have my bad nights, I do.
link |
Doesn't mean I haven't had bouts of insomnia in my life,
link |
But after a bad night of sleep, I do nothing.
link |
I don't do any of those four things.
link |
I think the second tip I would offer
link |
in terms of unconventional is have a wind down routine.
link |
Many of us think of sleep as if it's like a light switch,
link |
that we just jump into bed and when we turn the light out,
link |
sleep should arrive in that same way.
link |
Just the binary, you know, it's on or it's off.
link |
Sleep is a physiological process.
link |
It's much more like landing a plane.
link |
It takes time to gradually descend down
link |
onto the terra firma of what we call
link |
good solid sleep at night.
link |
Find out whatever works for you
link |
and it could be light stretching.
link |
I usually meditate for about 10 or 15 minutes before bed.
link |
Some people like reading.
link |
Try not to watch television in bed,
link |
that's usually advised against.
link |
Something that doesn't emit too much light to your eyes.
link |
Too much light, too activating.
link |
You know, you can listen to a relaxing podcast,
link |
although we can speak about technology in the bedroom too,
link |
but have some kind of a wind down routine.
link |
It's, you know, it's almost like, you know,
link |
you wouldn't race into your garage
link |
and come to a screeching halt from 60 miles an hour.
link |
You typically downshift your gears
link |
and you slow down as you come into the garage.
link |
That's the same thing with sleep too.
link |
So that's the second thing.
link |
Have some kind of a wind down routine.
link |
Find what works for you.
link |
Maybe it's taking a hot bath or a warm shower
link |
and then stick to it.
link |
Just, we do this with kids all the time.
link |
We find out what their bedroom,
link |
sorry, their bedtime regiment is
link |
and then we just stick to it faithfully
link |
because we humans are the same way too.
link |
The third thing is a myth.
link |
Don't count sheep.
link |
There was a study done here at UC Berkeley.
link |
I didn't do this today, I wish I did.
link |
It was by my colleague, Professor Alison Harvey.
link |
And they found that counting sheep
link |
actually made it harder to fall asleep.
link |
It made matters worse.
link |
As a counter, sorry, counter measure to that,
link |
what they did find was that taking yourself
link |
on some kind of a mental walk.
link |
So think about a nice walk that you take in nature
link |
or a walk on the beach
link |
or even a walk around an urban environment
link |
and visualizing that, that seemed to be beneficial.
link |
The other thing about sort of that idea
link |
of shifting focus away from your mind itself,
link |
get your mind off itself is a good piece of advice.
link |
Catharsis, you can try to write down
link |
all of the concerns that you have
link |
and do this not right before bed,
link |
but usually an hour or two before bed.
link |
Some people call it a worry journal.
link |
And to me, it's a little bit like closing down
link |
all of the emotional tabs on my browser.
link |
Because if I shut the computer down
link |
and all of those tabs are still open,
link |
I'm going to come back in the morning
link |
and the computer's red hot, the fan's going
link |
because it didn't go to sleep.
link |
Because it couldn't,
link |
because there were too many tabs active and open.
link |
I think it's the same way with sleep as well.
link |
So try to think about doing that.
link |
So just vomit out all of your concerns on the page.
link |
My 3 a.m. waking is often associated
link |
with me writing down the list of things
link |
that I forgot to do that I need to do.
link |
And once I eventually wake up
link |
from the later night, second half of the night's sleep,
link |
that stuff seems much more tractable and reasonable,
link |
but it sure would be great to get that stuff
link |
out of the way before sleep.
link |
Well, there's also something
link |
that I don't think people have spoken about a lot
link |
and I'd like to research it, which is
link |
difficulty and anxiety at night in the dark
link |
is not the same difficulty and anxiety in the light of day.
link |
And when we have those thoughts at night,
link |
it comes with a magnitude of rumination
link |
and catastrophization that is disproportionate
link |
to that which you would describe when you are awake.
link |
And I don't know what's going on about the brain
link |
and thought and emotion at the time.
link |
I've got a bunch of theories as to why.
link |
And that's why I like the idea of closing up,
link |
zipping up all of those different components,
link |
just get them out on the page and it feel,
link |
and I at first thought, this just sounds like Huey.
link |
It sounds very Berkeley.
link |
It's kind of come by our, we all hold hands
link |
and walk home at the end of the day.
link |
But then the data started coming out,
link |
really good studies from good people.
link |
And they found that keeping one of those journals
link |
decreased the time it takes you to fall asleep by 50%, 5-0.
link |
Well on par with any pharmaceutical agent.
link |
I'm convinced that, well,
link |
I've long thought that the worries and concerns
link |
and ideas I have at three, 4 a.m.,
link |
I've learned to not place any stock in them.
link |
Because something, I'm glad that you might decide
link |
to eventually look at this in your laboratory,
link |
because I feel like something is melted away or altered.
link |
I suspect it's in the regulation
link |
of the autonomic nervous system,
link |
that it makes sense why a concern at three, 4 a.m.
link |
ought to evoke more of a panic sense than a concern sense.
link |
And certainly that's my experience,
link |
although I'm fortunate to not suffer
link |
from full-blown panic attacks,
link |
but everything seems worse at three, 4 a.m.,
link |
provided you're awake.
link |
And we need to sort of look into that,
link |
because if you look at suicide rates
link |
around the 24-hour clock face,
link |
disproportionately higher rates
link |
in those middle sort of night hours.
link |
So now I don't know if that's causative or not,
link |
but something, it could just be that
link |
that's the time when we're mostly lonely
link |
and we're by ourselves, and that's the reason.
link |
So it's got nothing to do with sleep or the nighttime.
link |
So that's the third thing.
link |
I think the fourth sort of little tip I would give
link |
that's unconventional is remove all clock faces
link |
from your bedroom.
link |
Including your phone.
link |
Including your phone, and resist checking it.
link |
Now I know, and I can speak about the phone too,
link |
that genie of technology is out the bottle,
link |
and it's not going back in anytime soon.
link |
So we've got to think as scientists and sleep scientists
link |
as to what we do with phones in the bedroom.
link |
Years ago, I was a counselor at a summer camp.
link |
I worked with at-risk kids,
link |
and there was a phrase that comes to mind here.
link |
It's be a channel, not a dam.
link |
Because when you try and dam certain kinds of behavior,
link |
physically dam certain kinds of behavior, not morally dam,
link |
that too, it just creeps over the edge,
link |
and you get a waterfall.
link |
So it has to be channeled.
link |
The phone and devices have to be worked with
link |
and negotiated, not eliminated.
link |
That's right, and think about those mindfully too.
link |
But clock faces, remove all of those.
link |
Because if you are having a tough night,
link |
knowing that it's 3.22 in the morning,
link |
or it's 4.48 in the morning,
link |
does not help you in the slightest.
link |
And it's only going to make matters worse than better.
link |
So try to remove all clock faces.
link |
And I think that's one of those other tips
link |
that some people have found helpful.
link |
But those would be sort of some slightly unconventional,
link |
I guess, more than your stock fare of,
link |
here are the five tips for sleep hygiene tonight.
link |
Those are terrific sleep tips, and several of which,
link |
if not all of which, I'm going to incorporate.
link |
Matt, this has been an amazing deep dive on sleep,
link |
and it's positive and negative regulators.
link |
I hope it hasn't been too long.
link |
No, this has been great.
link |
Please cut it down, shorten it to the five minutes
link |
of meaningful stuff that I offer.
link |
Absolutely not, absolutely not.
link |
It is chock-a-block full of valuable takeaways.
link |
It's been tremendously fun for me
link |
to dissect out this incredible aspect of our lives
link |
that we call sleep with a fellow scientist
link |
and a fellow public educator.
link |
I want to say several things.
link |
First of all, we should say where people can find you,
link |
although it shouldn't be that difficult these days.
link |
You're a very present on the internet.
link |
For better or for worse.
link |
I think it's wonderful that you're out there.
link |
Look, it's a public health service that you're doing.
link |
No one requires you or any other scientist to get out
link |
and share this information.
link |
My sense of you knowing you a bit
link |
and from following your work very closely,
link |
both your scientific work in detail
link |
and your public facing educational work
link |
is that you very much want the best for people.
link |
And it's an interesting thing as a scientist or a clinician
link |
to know that certain answers exist,
link |
that we don't have all the answers,
link |
but that there is a better path.
link |
There are better ways
link |
and people can benefit in a myriad of ways.
link |
So for that, because I know that to be very genuine in you,
link |
you want the best for people
link |
and you're offering tremendous advice and considerations
link |
and people can take it or leave it.
link |
That's the way I view it.
link |
I also want to thank you for taking the time out of your day
link |
to sit with me here and have this discussion.
link |
You know, you and I, I think we're like kind
link |
And I take you as a shining example
link |
of how you can effectively connect with the public.
link |
And I know that we've had our conversations
link |
before we ever sat down sort of together about, you know,
link |
how to think about communicating with the public
link |
and the pros and cons of that.
link |
And I've just loved your opinions.
link |
I've been drinking it all in.
link |
And then I think the third thing I'd like to say is,
link |
thank you for being such an incredible sleep ambassador.
link |
The series that you've released on sleep,
link |
the way that you speak about sleep,
link |
the way that you moderate and have championed sleep,
link |
So thank you for just being a brother in arms in that way.
link |
Well, we are, and thanks for those words.
link |
99% of what I discussed there was the work of you
link |
and your colleagues in the sleep field.
link |
So proper acknowledgement, but thank you.
link |
Where can people learn more
link |
about what you're doing currently and what's coming next?
link |
You're on Twitter.
link |
I typically tweet.
link |
As the sleep diplomat.
link |
So it's, no, it's just sleep diplomat.
link |
Sleep diplomat on Twitter, sleepdiplomat.com website.
link |
If you want to learn more about the science that we do here,
link |
it's humansleepscience.com.
link |
It's the Center for Human Sleep Science.
link |
You can pick up a copy of the book if you want.
link |
It's called Why We Sleep.
link |
If you're curious about sleep, that's one path to take.
link |
Is there another book someday in the future?
link |
I think there may be.
link |
Yeah, I think there are.
link |
Many, many millions of people
link |
will be very happy to hear that.
link |
I think it's starting to take hold.
link |
And then as we discussed,
link |
I am more than kicking around the idea
link |
of a short form podcast rather than a long form.
link |
Not long form because I don't have the mental capacity
link |
or the interviewing just capability
link |
that someone like you has.
link |
So it will probably just be monologue short form.
link |
So if there is some interest, I'll probably do that as well.
link |
So those are the ways that people can find me.
link |
But overall, if you're interested in sleep,
link |
just listen to Andrew.
link |
That's the best thing I can tell people.
link |
All right, well now we're batting back and forth
link |
the vector of action, so to speak.
link |
But I do hope you'll start a podcast,
link |
however brief or lengthy these episodes turn out to be,
link |
because I do believe that's a great venue
link |
to get information out into the world.
link |
And we don't just want to hear more from Matt Walker.
link |
I speak for many people.
link |
The work you're doing is both influential,
link |
but more importantly, it is important work.
link |
It has the impact that's needed,
link |
especially in this day and age where science and medicine,
link |
public health, and the issues of the world, et cetera,
link |
are really converging.
link |
So I know I speak on behalf of a tremendous number of people
link |
and I just say thank you for doing the work you do
link |
and for being you.
link |
And thanks for being a good friend.
link |
And by the way, I just going to note that
link |
it was nice that the two of us both got the Johnny Cash memo
link |
about how to dress today.
link |
It seems as though we're both kind of,
link |
we got that same memo,
link |
which will mean nothing to people who are listening.
link |
But if you're watching the video,
link |
you'll probably see what I mean.
link |
Andrew, thank you for taking this time.
link |
Thank you so much.
link |
Thanks so much, Matt.
link |
Thank you for joining me for my discussion
link |
with Dr. Matt Walker.
link |
Please also check out his podcast, the Matt Walker Podcast.
link |
A link to that podcast can be found in the show notes.
link |
If you're enjoying this podcast,
link |
please subscribe to us on YouTube.
link |
On YouTube, you can also leave us comments and suggestions
link |
for future episodes and guests in the comment section.
link |
As well, please subscribe to us on Apple and on Spotify.
link |
And at Apple, you can leave us up to a five-star review.
link |
You can also support us by checking out our Patreon account.
link |
That's patreon.com slash Andrew Huberman.
link |
And there you can support us at any level that you like.
link |
Please also check out our sponsors mentioned
link |
at the beginning of this episode.
link |
Links to those sponsors can be found in the show notes.
link |
During this episode and in many previous episodes,
link |
we discussed supplements.
link |
One issue in the supplement industry
link |
is that many supplements don't contain
link |
what's listed on the bottle.
link |
We therefore have partnered with Thorne,
link |
that's T-H-O-R-N-E, Thorne supplements,
link |
because Thorne supplements have the highest levels
link |
of stringency in terms of the purity of the ingredients
link |
and precision with respect to what's listed on the bottle
link |
is actually what's contained in those supplement bottles.
link |
If you'd like to see the supplements that I take
link |
for sleep and for other things,
link |
you can go to thorne.com slash the letter U slash Huberman.
link |
And there you'll see all the supplements that I take
link |
and can get 20% off any of those supplements
link |
as well as any other supplements
link |
that Thorne happens to make.
link |
That's Thorne, T-H-O-R-N-E,.com slash the letter U
link |
And last, but certainly not least,
link |
thank you for your interest in science.
link |
And I'll see you in the next one.