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Dr. 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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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.
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Thank you.
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No, thank you.
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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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What is sleep?
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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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and system.
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That said though,
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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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of your own body.
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Amazing.
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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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You're done.
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You're done.
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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,
link |
00:14:28.960
that you'll go through periods
link |
00:14:30.320
where your heart rate decelerates and drops
link |
00:14:33.240
and your blood pressure goes down,
link |
00:14:35.120
and then utterly randomly,
link |
00:14:37.040
your heart rate accelerates dramatically
link |
00:14:39.700
and what we call the fight or flight branch
link |
00:14:41.760
of the autonomic nervous system
link |
00:14:43.020
or the sympathetic nervous system,
link |
00:14:44.880
a badly named because it's anything but sympathetic,
link |
00:14:47.140
it's very aggravating,
link |
00:14:49.360
that all of a sudden fires up and then it shuts down again.
link |
00:14:53.080
And it's not in any regular way.
link |
00:14:55.320
And it's when you get those autonomic storms,
link |
00:14:57.520
you get very activated from a physiological perspective,
link |
00:15:01.020
that you can have these erections
link |
00:15:02.640
and you have vaginal discharge, et cetera.
link |
00:15:04.600
But you're totally paralyzed.
link |
00:15:05.920
But you are still paralyzed.
link |
00:15:07.740
There are only two voluntary muscle groups
link |
00:15:14.840
that are spurred from the paralysis, bizarre.
link |
00:15:18.280
One, your extra ocular muscles,
link |
00:15:20.620
because if they were paralyzed,
link |
00:15:22.780
you wouldn't be able to have rapid eye movements.
link |
00:15:25.720
And the other that we later discovered
link |
00:15:27.700
was the inner ear muscle.
link |
00:15:30.120
And we've got no good understanding
link |
00:15:33.200
as to why those two muscle groups
link |
00:15:35.400
are spurred from the paralysis.
link |
00:15:37.160
It may have something to do with cranial nerve,
link |
00:15:39.760
but I don't think it's that.
link |
00:15:42.040
I think it's perhaps something more sensory related.
link |
00:15:45.200
Some people have argued that the reason the eyeballs
link |
00:15:47.640
are spurred from the paralysis
link |
00:15:49.480
is because if your eyeballs are left
link |
00:15:51.200
for long periods of time inactive,
link |
00:15:53.540
you may get things such as oxygen sort of issues
link |
00:15:56.840
in the aqueous or vitreous humor.
link |
00:16:00.000
And so the eyeballs have to keep moving in some way.
link |
00:16:02.440
The drainage systems of the anterior eye
link |
00:16:04.680
are made to require movement.
link |
00:16:06.520
People with glaucoma have deficits in drainage
link |
00:16:10.040
through the anterior chamber, but there I'm speculating.
link |
00:16:12.560
I'm also speculating when I asked this.
link |
00:16:16.920
I would imagine that there are states in waking
link |
00:16:20.520
that also resemble slow wave sleep,
link |
00:16:22.480
or rather that there are states that slow wave sleep
link |
00:16:25.100
also resembles waking states.
link |
00:16:27.020
You've beautifully illustrated how REM sleep
link |
00:16:30.080
can mimic some of the more active brain states
link |
00:16:32.240
that we achieve in waking.
link |
00:16:34.200
What sort of waking state that I might've experienced
link |
00:16:36.960
or experienced on a daily basis might look similar
link |
00:16:40.520
to slow wave sleep, non-REM sleep, if any?
link |
00:16:43.640
It's a genius way of thinking about it.
link |
00:16:45.720
Turns the tables, I love it.
link |
00:16:47.960
We almost never see anything like the true ultra slow waves
link |
00:16:53.960
of deep non-REM sleep.
link |
00:16:55.520
So we spoke about these two stages, non-REM and REM.
link |
00:16:59.200
Non-REM is further subdivided into four separate stages,
link |
00:17:03.000
stages one through four, increasing in the depth of sleep.
link |
00:17:06.580
So stages three and four,
link |
00:17:07.960
that's what we typically call deep non-REM sleep,
link |
00:17:10.420
stages one and two.
link |
00:17:11.520
So maybe take me through the arc of a night,
link |
00:17:13.160
just so that, so I put my head down.
link |
00:17:16.560
Well, for you, what time do you normally go to sleep?
link |
00:17:18.680
So I'm usually sort of around about a 10.30 PM guy,
link |
00:17:23.520
and usually I'll naturally wake up
link |
00:17:26.040
sort of a little bit before seven,
link |
00:17:27.840
sometimes before 6.45 or seven.
link |
00:17:30.000
I have an alarm set for 7.04 AM.
link |
00:17:34.040
You heard it here, folks.
link |
00:17:35.040
Matt Walker does use an alarm clock.
link |
00:17:37.520
I really, really, I'm usually-
link |
00:17:39.240
He doesn't recommend it, but he does use it.
link |
00:17:40.960
Yeah, I usually-
link |
00:17:41.800
You're human after all.
link |
00:17:42.840
Oh, I am so human.
link |
00:17:44.960
And I've had my sleep issues
link |
00:17:46.620
and I'd love to speak about that too,
link |
00:17:47.960
but it's only just in the event that,
link |
00:17:53.080
cause I like to keep regularity too,
link |
00:17:54.780
you've got to keep those two things in balance.
link |
00:17:56.920
And 7.04, just because, you know, why not be idiosyncratic?
link |
00:18:01.240
I don't know why we always set things on these hard numbers.
link |
00:18:05.000
So, yep, so when-
link |
00:18:06.840
So you go to sleep around 10.30,
link |
00:18:08.760
so using you as an example,
link |
00:18:11.120
because I imagine a number of people go to sleep
link |
00:18:12.640
at different times, but 10.30 is about
link |
00:18:13.960
when I go sleep, 11 is for me,
link |
00:18:15.540
but so you go to sleep at 10.30.
link |
00:18:17.840
So for that first, let's say three hours of sleep,
link |
00:18:22.000
what is the architecture of that sleep look like
link |
00:18:24.400
as compared to the last three hours of your sleep
link |
00:18:27.320
before morning?
link |
00:18:28.160
Yeah, so I should note that that sort of,
link |
00:18:30.480
you know, 10.30 to seven,
link |
00:18:32.320
that's just based on my chronotype and my preferential.
link |
00:18:36.100
It's different for different people.
link |
00:18:37.480
I'm not suggesting that that's the perfect sweet spot
link |
00:18:40.040
for humanity's sleep.
link |
00:18:41.560
It's just my-
link |
00:18:42.400
But I imagine most people probably go to sleep
link |
00:18:45.440
somewhere between 10 and PM and midnight.
link |
00:18:50.000
And most probably wake up between 5 AM and 7 AM
link |
00:18:53.320
or 5.30 and 7.30.
link |
00:18:55.180
Yeah, yeah, at least in,
link |
00:18:57.520
if you look at sort of first world nations,
link |
00:18:59.340
that's a typical sleep profile.
link |
00:19:02.640
So when I first fall asleep,
link |
00:19:05.120
I'll go into the light stages of non-REM sleep,
link |
00:19:07.920
stages one and two of non-REM,
link |
00:19:10.240
and then I'll start to descend down
link |
00:19:12.100
into the deeper stages of non-REM sleep.
link |
00:19:14.600
So after about maybe 20 minutes,
link |
00:19:16.400
I'm starting to head down into stage three non-REM
link |
00:19:19.600
and then into stage four non-REM sleep.
link |
00:19:22.820
And as I'm starting to fall asleep,
link |
00:19:24.800
as I've cast off from the usually with me
link |
00:19:28.080
murky waters of wakefulness,
link |
00:19:30.000
and I'm in the shallows of sleep stages one and two,
link |
00:19:33.080
my heart rate starts to drop a little bit,
link |
00:19:35.780
and then my brainwave pattern activity starts to slow down.
link |
00:19:39.960
Normally when I'm awake,
link |
00:19:41.280
it's going up and down maybe 20, 30, 40,
link |
00:19:44.440
50 times a second.
link |
00:19:47.200
As I'm going into light non-REM sleep,
link |
00:19:49.920
it will slow down to maybe 15, 20,
link |
00:19:53.140
and then really starts to slow down,
link |
00:19:54.820
down to about sort of 10 or eight cycles per second,
link |
00:19:58.200
eight cycle waves per second.
link |
00:20:01.480
Then as I'm starting to move into
link |
00:20:04.340
stages three and four non-REM sleep,
link |
00:20:06.680
several remarkable things happen.
link |
00:20:08.780
All of a sudden, my heart rate really does start to drop.
link |
00:20:13.560
Oh, and I'll come back to temperature.
link |
00:20:15.280
I'm going to write temperature down
link |
00:20:16.560
because I always forget these things.
link |
00:20:18.780
Now I'm solidly in the foothills of middle age.
link |
00:20:21.800
So as I'm starting to go into those deeper stages
link |
00:20:24.800
of non-REM sleep, all of a sudden,
link |
00:20:27.120
hundreds of thousands of cells in my cortex
link |
00:20:30.560
all decide to fire together,
link |
00:20:33.840
and then they all go silent together.
link |
00:20:36.080
And it's this remarkable physiological coordination
link |
00:20:40.360
of the likes that we just don't see
link |
00:20:43.240
during any other brain state.
link |
00:20:45.200
That's really interesting.
link |
00:20:46.020
Having recorded from the brains of animals
link |
00:20:48.160
and a little bit from humans,
link |
00:20:49.440
I don't think I've ever seen the entire cortex
link |
00:20:51.400
or even entire regions of cortex light up like that.
link |
00:20:54.240
Yeah, it's stunning.
link |
00:20:56.160
It's almost like this beautiful sort of mantra chant,
link |
00:21:00.440
or this sort of, you know, it's a slow inhale,
link |
00:21:03.460
and then a meditative exhale, inhale, exhale.
link |
00:21:07.000
And these waves are just enormous in their size.
link |
00:21:10.240
And the body is capable of movement at this time.
link |
00:21:12.360
There is no paralysis.
link |
00:21:14.240
There is no paralysis, but for the most part,
link |
00:21:16.560
muscle tone has also dropped significantly
link |
00:21:19.720
at that point.
link |
00:21:21.180
And then you will, or I will then stay there
link |
00:21:23.760
for about another 20 or 30 minutes.
link |
00:21:26.160
So now I'm maybe 60 or 70 minutes into my first sleep cycle.
link |
00:21:31.520
And then I'll start to rise back up,
link |
00:21:33.440
back up into stage two non-REM sleep.
link |
00:21:36.080
And then after about 80 or so minutes,
link |
00:21:38.520
I'll pop up and I'll have a short REM sleep period.
link |
00:21:41.640
And then back down I go again,
link |
00:21:43.540
down into non-REM, up into REM.
link |
00:21:46.160
And you do that reliably, repeatedly,
link |
00:21:49.080
and I will be doing that, and I do do that,
link |
00:21:51.480
every 90 minutes.
link |
00:21:53.160
At least that's the average for most adults.
link |
00:21:56.880
It's different in different species.
link |
00:21:59.160
What changes to your question is the ratio
link |
00:22:02.320
of non-REM to REM within that 90 minute cycle
link |
00:22:05.460
as you move across the night.
link |
00:22:07.540
And what I mean by this is in the first half of the night,
link |
00:22:10.540
the majority of those 90 minute cycles
link |
00:22:13.180
are comprised of lots of deep non-REM sleep.
link |
00:22:15.840
That's when I get my stage three and four
link |
00:22:18.200
of deep non-REM sleep.
link |
00:22:19.960
Once I push through to the second half of the night,
link |
00:22:22.860
now that seesaw balance changes,
link |
00:22:25.500
and instead the majority of those 90 minute cycles
link |
00:22:28.680
are comprised either of this lighter form
link |
00:22:31.160
of non-REM sleep, stage two non-REM sleep,
link |
00:22:33.720
and much more, and increasingly more,
link |
00:22:36.440
rapid eye movement sleep.
link |
00:22:38.880
And the implication that I was sort of speaking about
link |
00:22:41.200
pragmatically is let's say that
link |
00:22:45.280
I have to and I usually never do
link |
00:22:47.480
early morning flights or red eyes
link |
00:22:49.600
just because I'm a mess if that happens.
link |
00:22:51.760
I'm not suggesting that other people shouldn't.
link |
00:22:53.520
I'm suggesting people not do that.
link |
00:22:55.160
Every time I've taken a red eye or I've done that,
link |
00:22:57.420
two or three days later,
link |
00:22:58.480
I get some sort of general feeling of malaise.
link |
00:23:01.200
My brain doesn't work as well.
link |
00:23:02.800
I think red eyes should be abolished.
link |
00:23:05.520
For the pilots too, I mean, and for the-
link |
00:23:07.280
Oh, and we can speak about those.
link |
00:23:08.840
And for the emergency room, I mean,
link |
00:23:10.520
long shifts have been shown to lead to
link |
00:23:12.880
physician-induced errors that lead to a lot of fatalities.
link |
00:23:17.120
I mean, there are a lot of reasons why
link |
00:23:18.660
staying up too long or being up at the wrong times
link |
00:23:20.780
if you're not adapted to it is just terrible.
link |
00:23:23.320
The data in all of those cases,
link |
00:23:25.320
and particularly physicians too,
link |
00:23:26.780
there was some recent data looking at suicidality.
link |
00:23:29.880
And the rates of suicide in training physicians
link |
00:23:32.640
are far, far above the norm.
link |
00:23:35.440
And I don't suspect that their schedules are helping them.
link |
00:23:40.160
I suspect that sleep is a missing part
link |
00:23:43.480
of that explanatory equation, but-
link |
00:23:45.640
I teach medical students and they're phenomenal,
link |
00:23:48.600
but yeah, they're under extremely challenged conditions.
link |
00:23:51.720
It's-
link |
00:23:52.560
We shouldn't put them under those conditions.
link |
00:23:53.400
No, it's not optimizing performance.
link |
00:23:56.040
I have one-
link |
00:23:56.880
But sorry, I was-
link |
00:23:57.720
No, no, no, this is important.
link |
00:23:59.520
It's an important digression.
link |
00:24:00.840
I have one question,
link |
00:24:02.100
which is you're saying that as across the night,
link |
00:24:04.660
a greater percentage of these 90-minute cycles
link |
00:24:06.700
are going to be occupied by REM sleep
link |
00:24:08.560
as you progress through the night.
link |
00:24:13.080
I'm aware that based on work that you've done
link |
00:24:15.760
and from your public education efforts and others,
link |
00:24:20.200
that we have so-called circadian forces
link |
00:24:25.040
and we have other forces that are driving when we sleep
link |
00:24:28.240
and when we want to sleep, et cetera,
link |
00:24:29.440
without going into the details of those.
link |
00:24:31.200
I have a simple question.
link |
00:24:32.140
The experiment is the following.
link |
00:24:33.520
Let's say, God forbid,
link |
00:24:35.480
you are prevented from going to sleep at your normal time
link |
00:24:38.920
and you stay up for the four hours or five hours
link |
00:24:42.920
that normally you would be
link |
00:24:44.060
in predominantly slow-wave sleep.
link |
00:24:45.840
Yep.
link |
00:24:46.680
If, let's say, you finally get to lie down at 3 a.m.,
link |
00:24:51.200
a time when normally your sleep would be occupied
link |
00:24:53.800
mostly by rapid eye movement sleep,
link |
00:24:57.440
will you experience a greater percentage
link |
00:25:00.500
of rapid eye movement sleep
link |
00:25:01.800
because of these so-called circadian forces,
link |
00:25:04.600
meaning that's what's appropriate for that time,
link |
00:25:06.760
or will your system need to start
link |
00:25:09.040
at the beginning of the race that we're,
link |
00:25:11.600
as I'm referring to it, that we're calling sleep?
link |
00:25:14.400
Yep.
link |
00:25:15.240
If that's not clear to anybody,
link |
00:25:16.200
basically what I'm asking is if you are forced
link |
00:25:18.240
to skip the slow-wave sleep part of the night,
link |
00:25:20.600
will your system leap into rapid eye movement sleep
link |
00:25:24.720
or does it have to start at the beginning
link |
00:25:26.400
and get slow-wave sleep first?
link |
00:25:27.820
In other words, does one sleep state
link |
00:25:29.840
drive the entry to the next sleep state?
link |
00:25:32.440
Great question.
link |
00:25:33.360
So there is some degree of reciprocity
link |
00:25:35.600
between the sleep states, I should note,
link |
00:25:37.740
that when we drive one of those up,
link |
00:25:40.420
we often, but not always, see a change in the other.
link |
00:25:44.880
There are some pharmacologies
link |
00:25:46.580
that have shown an independence to that,
link |
00:25:49.280
and we've also played around with things like temperature,
link |
00:25:51.600
and sometimes you can nudge one
link |
00:25:55.020
and not seem to upset or perturb the other.
link |
00:25:58.680
But to your, I think, lovely point,
link |
00:26:02.480
the answer is it's a mix, but it's mostly the latter,
link |
00:26:06.560
meaning you will mostly go into your REM sleep phases
link |
00:26:11.660
and be significantly deficient in your deep sleep.
link |
00:26:15.920
So just because I start my sleep cycle at 3 a.m.
link |
00:26:19.640
rather than at 10.30 p.m.,
link |
00:26:22.800
it doesn't mean that my brain just says,
link |
00:26:24.380
well, I've got a program
link |
00:26:25.720
and I'm just going to run the program,
link |
00:26:27.140
and the way the program runs is that we always start
link |
00:26:29.680
with a first couple of hours of deep sleep.
link |
00:26:32.800
So we're just gonna begin act number one, scene one.
link |
00:26:36.640
It doesn't do that.
link |
00:26:37.880
Now, I will get some deep sleep to begin with,
link |
00:26:41.640
and part of that is just because of how sleep works
link |
00:26:45.120
based on how long I've been awake.
link |
00:26:47.440
Longer I'm awake,
link |
00:26:48.520
there is a significantly greater pressure for deep sleep.
link |
00:26:51.880
But we actually use exactly what you just described
link |
00:26:55.960
as an experimental technique
link |
00:26:57.680
to selectively deprive people
link |
00:26:59.980
of one of those stages of sleep or the other.
link |
00:27:02.520
So we will do first half of the night deprivation
link |
00:27:06.040
and then let you sleep the second half.
link |
00:27:08.200
So that means that you will be mostly deep sleep deprived
link |
00:27:12.120
and you will still get mostly all of your REM sleep.
link |
00:27:15.760
And then we switch it so you only get your first four hours,
link |
00:27:19.600
which means you will mostly get deep non-REM sleep,
link |
00:27:22.280
but you will get almost no REM sleep.
link |
00:27:24.540
So in both of those groups,
link |
00:27:26.100
they've both had four hours of sleep.
link |
00:27:28.100
So the difference between them
link |
00:27:29.400
in terms of an experimental outcome is not the sleep time
link |
00:27:33.240
because they've both slept for the same amount.
link |
00:27:35.740
It's the contribution of those different stages.
link |
00:27:38.340
Now, we actually have more elegant methods
link |
00:27:40.780
for sort of selectively going in there
link |
00:27:42.780
and scooping out different stages of sleep.
link |
00:27:45.440
But that's the way we used to do it old school
link |
00:27:47.460
was just using this timing difference.
link |
00:27:49.720
And who suffers more, those that lack the early phase
link |
00:27:52.980
and were those that lack the later phase of the night sleep?
link |
00:27:55.960
In other words, if I have to sleep only four hours
link |
00:27:59.800
for whatever reason, am I better off
link |
00:28:01.280
getting the early part of the night sleep
link |
00:28:03.000
or the second half of the night sleep?
link |
00:28:05.440
Depends on what the outcome measure is.
link |
00:28:08.120
So that gets right to the differences
link |
00:28:09.800
between slow wave sleep and REM.
link |
00:28:12.120
I was probably misinformed, but my understanding,
link |
00:28:15.840
a very crude understanding, I should say before-
link |
00:28:18.600
I very much doubt it, au contraire with someone like you.
link |
00:28:21.480
Which is very nice of you.
link |
00:28:22.740
But the first part of the night,
link |
00:28:24.600
this slow wave sleep is restorative to the musculature,
link |
00:28:27.400
to motor learning, and that the dream content
link |
00:28:29.920
tends to be less emotional.
link |
00:28:31.440
The second half of the night being more emotional dreams
link |
00:28:33.960
and sort of the unpairing of the emotional load
link |
00:28:36.840
of our previous day and other experiences.
link |
00:28:39.960
So in other words, if I were to deprive myself of REM,
link |
00:28:43.760
I would be hyper emotional, maybe not as settled
link |
00:28:46.800
with the kind of experiences of my life.
link |
00:28:49.040
Whereas if I had to deprive myself of slow wave sleep,
link |
00:28:51.760
I would feel a more physical malaise.
link |
00:28:54.280
Is that correct or is that far too simple?
link |
00:28:56.320
And if it is too simple, please tell me where I'm wrong.
link |
00:28:59.680
No, I think much of that is correct.
link |
00:29:02.020
And it's sort of that plus.
link |
00:29:04.660
So for example, during deep non-REM sleep,
link |
00:29:07.880
that's where we get this, it's almost a form
link |
00:29:09.800
of natural blood pressure medication.
link |
00:29:12.140
And so when I take that away from you, the next day,
link |
00:29:15.080
we're usually going to see autonomic dysfunction.
link |
00:29:17.680
We're usually going to see abnormalities in heart rate,
link |
00:29:20.440
blood pressure.
link |
00:29:21.640
We also know that during deep non-REM sleep
link |
00:29:24.020
that there is a certain control of specific hormones.
link |
00:29:26.960
For example, we know that the insulin regulation
link |
00:29:29.800
of sort of metabolism, meaning how will you look
link |
00:29:34.140
from a regulated blood sugar perspective
link |
00:29:37.200
versus dysregulated pre-diabetic look of profile,
link |
00:29:42.420
that's where deep sleep seems to matter.
link |
00:29:44.440
If we selectively deprive you of that, we can see them.
link |
00:29:47.920
Growth hormone is different actually.
link |
00:29:49.600
So that's a beautiful demonstration
link |
00:29:51.480
where growth hormone seems to be more REM sleep dependent.
link |
00:29:55.120
And that's why we can come on to the effects of alcohol.
link |
00:29:58.120
And there was some really impressive frightening data
link |
00:30:00.880
on alcohol and its disruption of sleep.
link |
00:30:04.780
But then we also know testosterone.
link |
00:30:07.680
Peak levels of testosterone happen during REM sleep.
link |
00:30:11.180
So the second half of the night.
link |
00:30:12.720
Which is the second half of the night.
link |
00:30:14.440
So it really just means that your profile
link |
00:30:18.680
of mental and physical dysfunction will be different
link |
00:30:23.200
under both of those conditions.
link |
00:30:25.480
Which one would you prefer?
link |
00:30:27.900
I would prefer neither of them.
link |
00:30:29.440
And it really depends on what you're trying to optimize for.
link |
00:30:33.200
So it's just so complete.
link |
00:30:35.080
Sleep is just so plory potent.
link |
00:30:39.320
It's so physiologically systemic
link |
00:30:42.980
that it's almost impossible not to undergo
link |
00:30:46.840
one of those two things, just deep sleep deprivation
link |
00:30:49.360
or just REM sleep deprivation and not show a profile
link |
00:30:52.680
that you would really prefer to avoid.
link |
00:30:55.560
And that's the reason from an evolutionary standpoint
link |
00:30:59.580
that we have preserved those stages of sleep.
link |
00:31:02.040
I mean sleep is just so idiotic
link |
00:31:05.200
from an evolutionary perspective.
link |
00:31:07.000
Or maybe waking is idiotic.
link |
00:31:08.560
Or waking is, you know, well yeah.
link |
00:31:11.120
Based on your previous idea.
link |
00:31:12.960
Who have you been talking to?
link |
00:31:13.800
I think that comment is very specific to me.
link |
00:31:16.340
Yeah, I am normally always an idiot when waking.
link |
00:31:19.720
But I think this idea that sleep, you know,
link |
00:31:25.280
is so profoundly detrimental to us.
link |
00:31:28.540
If you were to take it at face value, you know,
link |
00:31:30.720
you're not finding a mate, you're not reproducing,
link |
00:31:33.220
you're not foraging for food,
link |
00:31:34.560
you're not caring for your young.
link |
00:31:36.160
And worst of all, you're vulnerable to predation.
link |
00:31:39.280
On any one of those grounds,
link |
00:31:41.080
sleep probably should have been selected against.
link |
00:31:44.000
But it wasn't.
link |
00:31:44.840
Sleep has fought its way through heroically.
link |
00:31:47.840
You know, every step along the evolutionary path.
link |
00:31:51.040
And therefore every sleep stage
link |
00:31:54.800
has also survived as best we can tell.
link |
00:31:58.220
What that means is that those are non-negotiable.
link |
00:32:01.240
If mother nature had found a way
link |
00:32:03.920
to even just sort of, you know,
link |
00:32:06.160
thin slice some of that sleep from us,
link |
00:32:09.240
there would have been vast, I'm sure, evolutionary benefits.
link |
00:32:12.880
But it looks as though she hasn't.
link |
00:32:14.920
And I'm usually in favor of her wisdom
link |
00:32:17.860
after 3.6 million years, so.
link |
00:32:20.360
Yeah, it's incredible.
link |
00:32:22.480
I want to introduce another Gedanken experiment,
link |
00:32:25.760
another thought experiment.
link |
00:32:26.940
So in this arc of the night,
link |
00:32:28.640
slow-wave sleep predominates early in the night,
link |
00:32:31.700
and then REM sleep.
link |
00:32:33.460
There's a scenario that many people,
link |
00:32:34.960
including myself, experience on a regular basis,
link |
00:32:37.680
which is they go to sleep, sleeping just fine,
link |
00:32:41.400
three, four hours into it, they wake up.
link |
00:32:43.720
They wake up for whatever reason.
link |
00:32:45.400
Maybe there was a noise, maybe the temperature isn't right.
link |
00:32:47.400
We will certainly talk about sleep hygiene, et cetera.
link |
00:32:51.360
They get up, they go to the restroom.
link |
00:32:53.460
They might flip on the lights, they might not.
link |
00:32:56.200
They'll get back in bed.
link |
00:32:57.640
Hopefully they're not picking up their phone
link |
00:32:59.520
and starting to browse and wake up the brain
link |
00:33:01.800
through various mechanisms,
link |
00:33:02.920
light and cognitive stimulation, et cetera.
link |
00:33:05.400
They go back to sleep.
link |
00:33:06.960
Let's say after about 10, 15 minutes,
link |
00:33:08.680
they're able to fall back asleep.
link |
00:33:10.480
And then they sleep till their more typical wake time.
link |
00:33:12.920
How detrimental is that wake up episode or event
link |
00:33:20.000
in terms of longevity, learning, et cetera?
link |
00:33:25.040
I would love to sleep the entire night through every night,
link |
00:33:27.800
but most nights I don't.
link |
00:33:29.760
And yet I feel pretty good throughout the day.
link |
00:33:32.000
Some days better than others.
link |
00:33:33.640
So if you were to kind of evaluate that waking episode
link |
00:33:37.800
and compare it to sleeping the whole night through,
link |
00:33:42.420
what are your thoughts on that?
link |
00:33:44.520
So I think if you're waking up sort of frequently
link |
00:33:47.540
as you're describing,
link |
00:33:49.180
I would probably get your estate in order
link |
00:33:51.320
because my guess is within the next year,
link |
00:33:53.820
you're going to be done for, no, I'm kidding you.
link |
00:33:57.500
Absolutely kidding you.
link |
00:33:58.820
It is perfectly natural and normal,
link |
00:34:01.700
particularly as we progress with age.
link |
00:34:04.560
Children tend to have typically more continuous sleep.
link |
00:34:08.240
Now it's not that they aren't waking up
link |
00:34:10.360
for brief periods of time, they are.
link |
00:34:12.020
And in fact, we all do.
link |
00:34:13.800
When we come out the other end of our sleep cycle,
link |
00:34:16.560
at the end of our REM sleep period of the 90 minute cycle,
link |
00:34:21.140
almost everybody wakes up and we make a postural movement.
link |
00:34:25.620
We turn over because we've been paralyzed for so long
link |
00:34:28.760
and the body will also like to shift.
link |
00:34:30.860
Do we ever look around?
link |
00:34:31.900
Do we ever open our eyes and look around?
link |
00:34:33.940
You sometimes people will open their eyes,
link |
00:34:36.560
but usually it's only for a brief period of time
link |
00:34:39.180
and they usually never commit those awakenings to memory.
link |
00:34:42.940
Right.
link |
00:34:44.180
Your situation and it's my situation as well.
link |
00:34:47.060
I usually now at this stage of life,
link |
00:34:48.660
I don't sleep through the night.
link |
00:34:50.000
I'll usually have a bathroom break and then I'll come back.
link |
00:34:54.820
That's perfectly normal.
link |
00:34:57.660
We tend to forget that in sleep science,
link |
00:35:00.600
we think of sleep efficiency.
link |
00:35:02.780
So of the total amount of time that you're in bed,
link |
00:35:06.540
how much of that percent time is spent asleep?
link |
00:35:11.320
And we usually look to numbers that are above 85% or more
link |
00:35:16.180
as a healthy sleep efficiency.
link |
00:35:19.180
So if you were to think about me going to bed and I spend,
link |
00:35:22.980
you know, let's say eight and a quarter,
link |
00:35:25.540
eight and a half hours of time in bed
link |
00:35:28.080
with a normal healthy sleep efficiency,
link |
00:35:31.460
I still may be only sleeping a total of seven and a half
link |
00:35:35.860
hours or seven and three quarter hours,
link |
00:35:38.640
meaning that I'm going to be awake in total,
link |
00:35:43.180
not in one long bout,
link |
00:35:45.700
but I'm going to be awake for upwards of 30 minutes,
link |
00:35:48.980
net some time.
link |
00:35:51.460
Sometimes that can be after a 10 minute, you know,
link |
00:35:54.960
dalliance after having gone to the bathroom
link |
00:35:56.920
and I'm just gradually drifting back off again.
link |
00:35:59.980
Other times it will just be for a couple of minutes.
link |
00:36:02.460
And most of those you don't commit.
link |
00:36:04.680
So I think we need to stop.
link |
00:36:06.500
We don't need to get too worried about, you know,
link |
00:36:10.380
periods of time awake,
link |
00:36:11.940
just because we're not sleeping throughout the night.
link |
00:36:13.620
I would love to do that too.
link |
00:36:14.460
And I remember when I, that used to happen
link |
00:36:16.500
and it still happens occasionally.
link |
00:36:18.540
It feels great when it does happen.
link |
00:36:20.060
It's a lovely thing.
link |
00:36:21.100
It's a surprise, right?
link |
00:36:22.420
It is not now a surprise.
link |
00:36:24.260
Yeah, it is a surprise.
link |
00:36:25.820
But for the most part,
link |
00:36:27.660
I think we can be more relaxed about that.
link |
00:36:30.060
Where we have to be a bit more attentive though,
link |
00:36:33.020
is if you are spending long periods of time,
link |
00:36:36.220
not being able to get back to sleep.
link |
00:36:37.940
And usually we define that by saying,
link |
00:36:40.300
if it's been 20, 25 minutes,
link |
00:36:42.900
normally that's a time when we would really say,
link |
00:36:45.760
okay, let's explore this, what's going on.
link |
00:36:48.060
Let's see what's happening.
link |
00:36:49.920
The other thing is if it's happening very frequently.
link |
00:36:52.700
So even if you're, you know,
link |
00:36:55.620
not awake for 25 minute stretches,
link |
00:36:58.620
but you're finding yourself waking up
link |
00:37:00.620
and being consciously aware that you've woken up
link |
00:37:03.700
for maybe six, seven or eight times throughout the night.
link |
00:37:07.140
And your sleep is very, what we call fragmented.
link |
00:37:10.940
The great science of sleep in the past five or 10 years
link |
00:37:13.780
has been, yes, quantity is important,
link |
00:37:17.780
but quality is just as important.
link |
00:37:21.100
And you can't have one without the other
link |
00:37:23.740
in terms of a good beneficial next day outcome.
link |
00:37:27.640
You can't just get four hours of sleep,
link |
00:37:30.220
but brilliant quality of sleep and be unimpaired.
link |
00:37:33.660
Nor can you get eight hours of sleep,
link |
00:37:36.340
but have very poor quality of sleep
link |
00:37:38.780
and be unimpaired the next day.
link |
00:37:41.620
So that's why I just sort of want to asterisk this idea of,
link |
00:37:45.900
let's not get too worried about waking up
link |
00:37:48.020
and having some time awake.
link |
00:37:49.320
That's perfectly normal and natural.
link |
00:37:51.960
But if it's happening very frequently throughout the night
link |
00:37:54.860
or those periods of time or long stretches of time,
link |
00:37:58.020
upwards of 25 minutes, then let's look into it.
link |
00:38:01.100
Well, I can assure you just helped a lot of people
link |
00:38:04.380
feel better about this waking up episode
link |
00:38:07.580
that I and many other people experience.
link |
00:38:09.800
I hope so because I think it's really important that we,
link |
00:38:13.780
you know, I think I've been desperately guilty
link |
00:38:17.220
of perhaps, you know, early on being too puritanical
link |
00:38:21.100
about, you know, sleep and I've, I've retrospected
link |
00:38:26.100
and I've tried to explore why this was the case.
link |
00:38:28.180
You know, it was almost sleep or else dot, dot, dot,
link |
00:38:32.220
you know, and at the time when I was starting
link |
00:38:35.940
to write the book, which was back in 2016,
link |
00:38:39.340
you know, sleep was still a neglected step sister
link |
00:38:42.120
in the health conversation of today.
link |
00:38:44.240
And I could see all of the, and it's changing, you know,
link |
00:38:47.900
and not because of my efforts,
link |
00:38:49.140
but because of all of my colleagues.
link |
00:38:50.420
I would say, well, it's great that you give attribution
link |
00:38:54.900
to your other people involved in it.
link |
00:38:56.780
Of course, it's a big field,
link |
00:38:58.060
but I think you've done a great service by queuing people
link |
00:39:01.380
to the importance of this state,
link |
00:39:03.380
not just for avoiding troublesome outcomes,
link |
00:39:06.740
but also for optimizing their waking state.
link |
00:39:09.200
It's really, you know, I view sleep as this period
link |
00:39:12.420
that feels good, but we're not aware of how it feels
link |
00:39:14.500
when we're in it necessarily.
link |
00:39:15.940
It has tremendous benefits when you're doing it well,
link |
00:39:19.140
so to speak, and it has tremendous deficits when we're not.
link |
00:39:24.100
And I think it was an important thing for you to do
link |
00:39:28.460
to cue people to this issue.
link |
00:39:29.860
And I would say mission accomplished,
link |
00:39:32.780
that people are aware of the need for sleep.
link |
00:39:35.780
I think that knowing that waking up
link |
00:39:37.520
in the middle of the night is normal,
link |
00:39:39.660
provided it's not too frequent, is great
link |
00:39:42.260
and will also help people
link |
00:39:43.820
who may have been overly concerned about that.
link |
00:39:46.260
I do want to use this as an opportunity to raise something
link |
00:39:49.840
about the so-called Uberman schedule,
link |
00:39:52.420
not to be confused with the Huberman schedule.
link |
00:39:56.980
Fortunately, no one has confused those yet.
link |
00:40:00.660
Some years ago, there was a discussion
link |
00:40:02.700
about the so-called Uberman schedule,
link |
00:40:04.960
meaning the Superman schedule.
link |
00:40:06.580
So that's Huberman without an H,
link |
00:40:08.340
which I have nothing to do with.
link |
00:40:11.020
If you read your Nietzsche, this will have a subtext.
link |
00:40:13.620
But regardless, the Uberman schedule,
link |
00:40:16.100
as I understand, is one in which the person
link |
00:40:20.220
elects to sleep in 90-minute bouts
link |
00:40:22.860
spread throughout the day and night
link |
00:40:25.440
in an attempt to get more productivity
link |
00:40:28.420
and or reduce their overall sleep need.
link |
00:40:30.740
There was a paper published recently
link |
00:40:32.480
that explored whether or not this is good or bad for us.
link |
00:40:36.020
Maybe you just give us the take-home message on that.
link |
00:40:38.540
Yeah, so these Uberman-like schedules,
link |
00:40:41.660
and there's lots of different forms of that,
link |
00:40:44.220
they tried to essentially pie chart the 24-hour period
link |
00:40:49.220
into short bouts of sleep with some shorter,
link |
00:40:53.700
well, slightly longer periods of wakefulness,
link |
00:40:55.700
then short bouts of sleep, then wakefulness.
link |
00:40:59.820
I sort of made it, I think, a quip.
link |
00:41:01.820
It's almost like you're sleeping like a baby,
link |
00:41:04.140
because that's the way that babies will sleep.
link |
00:41:06.820
That they will have these brief naps,
link |
00:41:08.740
then they're awake, then they're asleep, then they're awake.
link |
00:41:10.280
And to the chagrin of parents, across the night,
link |
00:41:13.120
it's basically the same.
link |
00:41:14.640
They're awake, they're asleep, they're awake, they're asleep.
link |
00:41:16.780
And that's more the schedule
link |
00:41:18.940
that these types of protocols have suggested.
link |
00:41:23.640
And there was a really great comprehensive review
link |
00:41:26.760
that found not only that they weren't necessarily helpful,
link |
00:41:30.620
but they were actually really quite detrimental.
link |
00:41:33.280
And on almost every performance metric,
link |
00:41:35.880
whether it be task performance,
link |
00:41:37.600
whether it be physiological outcome measures,
link |
00:41:40.340
whether it even be the quality of the sleep
link |
00:41:43.020
that they were having when they were trying to get it,
link |
00:41:45.820
all of those were in a downward direction.
link |
00:41:48.860
And it's not surprising.
link |
00:41:50.140
If you look at the way that your physiology is programmed,
link |
00:41:53.300
if you look at the way your circadian rhythm is programmed,
link |
00:41:56.420
none of that screams to us
link |
00:41:58.360
that we should be sleeping in that way.
link |
00:42:02.160
Well, I'm chuckling because we always hear sleep like a baby.
link |
00:42:04.900
This is how babies sleep.
link |
00:42:06.460
And I would say, don't sleep like a baby,
link |
00:42:08.620
sleep like an adult, be an adult.
link |
00:42:10.680
Get your solid eight hours.
link |
00:42:11.940
Billy Crystal's line, he was a long-standing,
link |
00:42:14.820
suffering insomniac.
link |
00:42:16.260
He says, I sleep like a baby, I'm awake every 20 minutes.
link |
00:42:19.580
And I think this is another one of those demonstrations
link |
00:42:23.520
that when you fight biology, you normally lose.
link |
00:42:28.260
And the way you know you've lost
link |
00:42:29.860
is disease, sickness, and impairment.
link |
00:42:32.580
And I think if you sleep in accordance
link |
00:42:35.940
with the natural biological edict
link |
00:42:38.580
that we've all been given,
link |
00:42:40.260
life tends to be both of a higher quality
link |
00:42:43.180
and a longer duration.
link |
00:42:44.780
Yeah, I agree.
link |
00:42:45.680
Along those lines, as a vision scientist,
link |
00:42:48.940
I've been very excited by the work
link |
00:42:50.380
on these non-image-forming cells in the eye,
link |
00:42:52.500
the so-called melanopsin cells that inform the brain
link |
00:42:54.620
about circadian time of day.
link |
00:42:56.420
And I'm a big proponent of people getting some sunlight,
link |
00:43:01.100
ideally sunlight, but other forms of bright light
link |
00:43:03.420
into their eyes early in the day
link |
00:43:04.880
and when they want to be awake.
link |
00:43:06.780
Essentially during the phase of their 24-hour
link |
00:43:09.020
circadian cycle when temperature is rising
link |
00:43:12.420
and then starting to get less light in their eyes
link |
00:43:15.620
as our temperature is going down
link |
00:43:17.680
later in the day and in the evening.
link |
00:43:19.540
Are there any adjustments to that general theme
link |
00:43:22.360
that you'd like to add or is, in any way?
link |
00:43:25.900
No, I think that's exactly what we recommend right now,
link |
00:43:29.340
which is try to get at least 30 to 40 minutes of exposure
link |
00:43:33.900
to some kind of natural daylight.
link |
00:43:35.620
Now, there may be parts of the world where, you know,
link |
00:43:38.700
it's-
link |
00:43:39.540
You're from a rather cloudy part of the world.
link |
00:43:41.380
I am from, yeah, Liverpool, England
link |
00:43:44.700
and the northwest of England is not known
link |
00:43:47.820
for its beach resorts and fine weather.
link |
00:43:51.620
I remember I sort of, I went back home for a trip
link |
00:43:55.700
when I'd first been out in California
link |
00:43:58.380
and I thought, why is the sky so low?
link |
00:44:01.300
You know, it's just, you know, constantly out.
link |
00:44:03.900
We joke that in the UK,
link |
00:44:06.940
we usually have nine months of bad weather
link |
00:44:09.660
and then three months of winter.
link |
00:44:11.480
And then that's your entire year in terms of a climate.
link |
00:44:15.420
But to come to your point, you're exactly right.
link |
00:44:17.780
Try to get that daylight.
link |
00:44:19.000
Now it can be, you know, working next to a window
link |
00:44:22.480
and you're getting that natural sunlight.
link |
00:44:24.520
But that natural sunlight is,
link |
00:44:26.860
even on a cloudy day in England,
link |
00:44:28.880
is usually far more potent than anything that you'll get
link |
00:44:31.880
from indoor lighting.
link |
00:44:34.300
Despite you thinking sort of from a perception-wise,
link |
00:44:37.260
maybe they're much closer than I would think.
link |
00:44:40.640
Yeah, I've been, sorry to interrupt,
link |
00:44:42.300
I've been a big proponent of,
link |
00:44:43.780
there's an app called Light Meter, which will,
link |
00:44:46.420
it's a free app, I have nothing to do with it,
link |
00:44:48.340
that will allow you to get a pretty decent measurement
link |
00:44:51.080
of the amount of light energy coming toward you.
link |
00:44:53.260
And if you hold it up to a cloudy morning
link |
00:44:56.940
where you don't think it's very bright out,
link |
00:44:58.280
kind of a dismal day,
link |
00:44:59.340
you'll notice that there'll be a thousand, 2,000,
link |
00:45:01.860
even, you know, 5,000 lux, lux just being a measure
link |
00:45:04.460
of brightness, of course.
link |
00:45:05.420
And then you can point the same light meter
link |
00:45:07.960
toward an indoor light that seems very bright
link |
00:45:10.100
and very intense, and it'll say 500 lux.
link |
00:45:13.260
And you realize that the intensity
link |
00:45:15.160
as we gauge it perceptually is not really
link |
00:45:18.340
what the system is receiving.
link |
00:45:19.540
So outdoor light is key.
link |
00:45:20.860
How do you, how do you get this natural stimulation
link |
00:45:24.120
or I should just say light stimulation early in the day?
link |
00:45:27.020
What is your typical, what does Matt Walker do
link |
00:45:29.660
to get this light stimulation?
link |
00:45:31.120
I am no poster child, but usually I will,
link |
00:45:35.520
if I'm working out, I usually work out most days.
link |
00:45:38.500
And I shopped around and I found a gym
link |
00:45:41.240
that has huge amounts of window exposure facing to the east.
link |
00:45:45.580
This is gonna sound so ridiculous.
link |
00:45:48.700
You know, Matt Walker chooses a gym
link |
00:45:50.420
on the basis of the solar input.
link |
00:45:52.940
So he can, you know, correct a circadian.
link |
00:45:54.020
There are a lot of criteria for selecting gyms.
link |
00:45:55.980
This one is actually grounded in physiology and biology.
link |
00:45:59.720
And selfishness about my own sleep.
link |
00:46:02.020
No, that's great.
link |
00:46:02.860
So you get your exercise and your light stimulation
link |
00:46:05.140
simultaneously. That's right.
link |
00:46:05.980
Yep, yep.
link |
00:46:06.800
And so you're stacking cues for wakefulness
link |
00:46:08.900
early in the day.
link |
00:46:09.720
Exactly.
link |
00:46:10.560
So both exercise and daylight are wonderful cues
link |
00:46:14.180
for circadian rhythm alignment
link |
00:46:16.420
and also circadian rhythm reset each day.
link |
00:46:19.260
And so I will use both exercise.
link |
00:46:22.020
I mean, I am, I'm neither a strong morning type
link |
00:46:24.640
or a strong evening type.
link |
00:46:25.980
And my preference to exercise is probably some time
link |
00:46:29.260
in the middle of the day.
link |
00:46:32.100
Probably somewhere around 1 p.m., sorry, not 1 a.m.
link |
00:46:35.980
But I'm usually working out probably around
link |
00:46:39.500
the sort of seven, sort of 45, 8 a.m. time.
link |
00:46:44.900
That's usually when I'll start my workout.
link |
00:46:46.740
And there I'll start with cardio, spin bike,
link |
00:46:49.140
facing a window.
link |
00:46:50.340
And luckily for the most part here in California,
link |
00:46:53.180
there's usually sunlight coming through.
link |
00:46:55.640
But it doesn't matter to me because just as you said,
link |
00:46:58.720
even when it's a cloudy day,
link |
00:47:01.060
that lux coming through of light,
link |
00:47:04.260
the intensity is splendid.
link |
00:47:07.020
So I would prefer to favor my exercise
link |
00:47:10.840
just because for efficiency too,
link |
00:47:12.320
I wanna get also working on the day.
link |
00:47:15.880
I'll try to match my exercise
link |
00:47:19.140
more with my circadian light exposure
link |
00:47:22.080
than I would probably if I'm going to,
link |
00:47:24.340
do I really wanna crush your workout
link |
00:47:26.060
or do I want to just make sure it's a good workout?
link |
00:47:30.120
I would prefer to work out at a different time.
link |
00:47:32.940
But I like that because of the daylight.
link |
00:47:34.780
And we can speak about exercise timing at some point
link |
00:47:37.200
because there's a lot of discussion around that,
link |
00:47:38.820
when is the right time to exercise during sleep?
link |
00:47:41.660
And we can sort of bust some myths there too.
link |
00:47:45.460
So I think you're spot on with the suggestion,
link |
00:47:49.040
get some morning daylight, try to get that exposure,
link |
00:47:52.260
usually at least 30 to 40 minutes.
link |
00:47:54.740
There was some great work recently coming out
link |
00:47:56.860
in the occupational health domain,
link |
00:47:59.040
where they moved workers from offices
link |
00:48:01.580
that were just facing walls
link |
00:48:03.220
and didn't have any exposure to natural daylight.
link |
00:48:06.700
And then they did a time period during that study
link |
00:48:09.620
where they actually were in front of a window and working.
link |
00:48:12.940
And they measured their sleep.
link |
00:48:14.760
And their sleep time and their sleep efficiency
link |
00:48:17.820
increased quite dramatically.
link |
00:48:19.500
I'm forgetting the numbers now,
link |
00:48:20.700
but I think the increase in total sleep time
link |
00:48:23.140
was well over 30 minutes.
link |
00:48:24.780
And the improvement in sleep efficiency was five to 10%.
link |
00:48:28.740
And if you're batting an 80% sleep efficiency average,
link |
00:48:33.100
we're a bit concerned about that.
link |
00:48:35.500
But add 10% to that,
link |
00:48:37.060
now you're in a great echelon of healthy sleepers.
link |
00:48:40.660
And all you did was just spend some time
link |
00:48:43.140
working in front of windows.
link |
00:48:44.400
That's great.
link |
00:48:45.240
And probably folks might want to consider
link |
00:48:47.220
spending a little less time with sunglasses
link |
00:48:48.820
provided they can do that safely, driving, et cetera.
link |
00:48:51.800
You're not alone with your exercise behavior
link |
00:48:53.620
in facing east.
link |
00:48:54.460
So the one and only Tim Ferriss told me recently
link |
00:48:57.760
that his morning routine nowadays
link |
00:49:00.220
consists of jumping rope while facing east
link |
00:49:03.240
to get the sunlight stimulation of the eyes.
link |
00:49:05.780
And as Matt and I both know, it has to be of the eyes, right?
link |
00:49:11.220
These portals are the only way to convey
link |
00:49:14.180
to the rest of the brain and body
link |
00:49:15.680
about the time of day and wakefulness.
link |
00:49:18.000
Along the lines of wakefulness,
link |
00:49:22.040
I have a number of questions about caffeine.
link |
00:49:24.480
The dreaded and beloved caffeine.
link |
00:49:26.720
I love caffeine, but I like it in relatively
link |
00:49:33.020
restricted periods of time.
link |
00:49:35.540
So I'm a big fan of waking up
link |
00:49:38.800
and even though I wake up very groggy,
link |
00:49:40.440
allowing my natural wakefulness signals to take hold.
link |
00:49:43.920
Meaning I wake up very slowly,
link |
00:49:45.640
but I don't drink caffeine right away.
link |
00:49:47.760
I sort of delay caffeine by a little while,
link |
00:49:51.200
usually 90 minutes to two hours.
link |
00:49:53.520
And that idea came to me on the basis of my understanding
link |
00:49:58.040
of how caffeine and the adenosine receptor interact.
link |
00:50:01.640
I have a feeling you're going to pronounce
link |
00:50:02.760
adenosine differently than I do.
link |
00:50:04.000
No, no, no, I will go with adenosine.
link |
00:50:06.320
I'll try to go with your skeletal
link |
00:50:08.200
instead of skeletal and synapse and synapse.
link |
00:50:11.440
Schedule and schedule.
link |
00:50:12.520
There we go.
link |
00:50:13.340
But to make it really simple for folks,
link |
00:50:17.560
how does caffeine work to make us feel more alert?
link |
00:50:21.720
And does the timing in which we ingest caffeine
link |
00:50:25.560
play an important role in whether or not
link |
00:50:27.800
it works for us or against us?
link |
00:50:30.080
So maybe we just start with how does caffeine work?
link |
00:50:32.960
Why is it that when I drink mate or coffee,
link |
00:50:35.560
which are my preferred sources of caffeine,
link |
00:50:37.620
do I feel a mental and physical lift?
link |
00:50:40.380
Yeah, so I'm going to suggest counter
link |
00:50:43.160
to what most people would think, drink coffee.
link |
00:50:47.640
Or mate, is mate okay also?
link |
00:50:50.200
Yeah, yeah, yeah.
link |
00:50:51.040
Or whatever form you enjoy.
link |
00:50:51.880
Well, we'll come on to sort of why I suggest that,
link |
00:50:55.120
but when it comes to coffee,
link |
00:50:58.060
I would say the dose and the timing makes the poison.
link |
00:51:02.920
So let's start with how caffeine works.
link |
00:51:06.720
Caffeine is in a class of drugs
link |
00:51:08.460
that we call the psychoactive stimulants.
link |
00:51:11.100
So it works through a variety of mechanisms.
link |
00:51:15.540
One is a dopamine mechanism.
link |
00:51:18.380
Dopamine we often think of as a reward chemical,
link |
00:51:21.860
but dopamine is also very much
link |
00:51:24.900
an alerting neurochemical as well.
link |
00:51:27.740
And caffeine has some role it seems to play
link |
00:51:30.460
in increasing dopamine,
link |
00:51:32.200
but it's principle mode of action we believe
link |
00:51:34.980
in terms of making me more alert
link |
00:51:36.960
and keeping me awake throughout the day
link |
00:51:39.720
is on the effects of adenosine.
link |
00:51:42.260
And to explain what adenosine is,
link |
00:51:43.920
from the moment that you and I woke up this morning,
link |
00:51:46.900
this chemical adenosine has been building up in our brain.
link |
00:51:51.060
And the longer that we're awake,
link |
00:51:52.820
the more of that adenosine accumulates.
link |
00:51:55.300
Is it, may I ask, is it accumulating in neurons,
link |
00:51:59.380
in glia or in the blood vessels?
link |
00:52:02.140
Where, and is it also accumulating in my body?
link |
00:52:05.340
Where is this adenosine coming from
link |
00:52:07.140
and where is it accumulating?
link |
00:52:08.260
Yeah, so the adenosine here that we're talking about
link |
00:52:10.940
that is creating the sleep pressure
link |
00:52:12.620
is a central brain phenomenon.
link |
00:52:14.980
And it comes from the neurons themselves combusting energy.
link |
00:52:19.260
And as they're combusting energy,
link |
00:52:20.980
one of the offshoots of that is this chemical adenosine.
link |
00:52:26.140
And so as we're awake throughout the day
link |
00:52:28.260
and our brain is metabolically very active,
link |
00:52:31.360
it's accumulating and building up this adenosine.
link |
00:52:35.820
Now, the more adenosine that we have,
link |
00:52:38.980
the sleepier that we will feel.
link |
00:52:41.180
So it really is like a sleep pressure is what we call it.
link |
00:52:45.680
Now, it's not a mechanical pressure.
link |
00:52:47.500
Don't worry, your head's not going to explode.
link |
00:52:49.000
It's a chemical pressure.
link |
00:52:51.460
And it's this weight of sleepiness
link |
00:52:53.780
that we feel gradually growing as we get into the evening.
link |
00:52:57.580
May I just interrupt you again to just ask,
link |
00:53:00.220
do we know what the circuit mechanism is for that?
link |
00:53:03.020
I mean, not to go too far down the rabbit hole,
link |
00:53:05.660
but for the aficionados and for myself,
link |
00:53:08.680
we have brain mechanisms like locus coeruleus
link |
00:53:11.300
that release things that our brain areas,
link |
00:53:14.100
locus coeruleus just being a brain area, of course,
link |
00:53:15.620
that release things that proactively create wakefulness.
link |
00:53:20.220
So are those neurons shutting down
link |
00:53:21.940
as a consequence of having too much adenosine
link |
00:53:24.980
or are there areas of the brain that promote sleepiness
link |
00:53:29.600
that are becoming activated?
link |
00:53:31.180
Because you can imagine both things working in parallel.
link |
00:53:33.740
One or the other would accomplish the same end point.
link |
00:53:36.140
Yeah, and it's both.
link |
00:53:38.300
And so there are two main receptors for adenosine,
link |
00:53:41.300
the A1 receptor and the A2 receptor,
link |
00:53:44.780
and they have different modes of activating brain cells
link |
00:53:48.240
or inactivating or decreasing the likelihood of firing.
link |
00:53:52.780
And adenosine works in this beautiful, elegant way
link |
00:53:56.660
where it will inhibit and shut down
link |
00:53:59.660
the wake promoting areas of the brain
link |
00:54:02.500
whilst also increasing and dialing up the volume
link |
00:54:06.540
on sleep activating, sleep promoting.
link |
00:54:08.580
Biology is so beautiful.
link |
00:54:10.020
Oh, it's always a push-pull.
link |
00:54:11.620
Yeah.
link |
00:54:12.460
I mean, and we could have a larger discussion
link |
00:54:13.500
at some point about that everything,
link |
00:54:16.340
seeing dark edges, seeing light edges,
link |
00:54:18.660
our ability to smell or to sense pressure on this,
link |
00:54:21.820
everything's a push-pull in biology.
link |
00:54:22.660
Oh, that's great, yeah, yep.
link |
00:54:23.760
So this is another example where as I am awake longer,
link |
00:54:28.240
adenosine is released in the brain
link |
00:54:30.760
and my wakefulness areas are being actively shut down
link |
00:54:34.300
by that adenosine and my sleepiness brain areas,
link |
00:54:37.820
so to speak, are being promoted to be more active.
link |
00:54:41.100
Is that correct?
link |
00:54:41.940
That's right, and it's a very progressive process.
link |
00:54:44.060
It's not like a step function where,
link |
00:54:46.500
and sometimes that happens occasionally,
link |
00:54:49.020
but it's usually because you've been sort of driving through
link |
00:54:51.660
and as we'll come on to have caffeine in the system.
link |
00:54:54.500
And then all of a sudden you just hit a wall
link |
00:54:56.400
and it just engulfs you and you go from a zero
link |
00:55:00.220
to the one of sleepiness within a short period of time.
link |
00:55:03.160
What explains the fatigue after a hard conversation?
link |
00:55:06.580
The desire to go to sleep
link |
00:55:07.820
or the desire to go to sleep during a hard conversation.
link |
00:55:11.620
That's an interesting one.
link |
00:55:12.540
I think it's usually just based
link |
00:55:13.980
on personality type interactions and for the most part-
link |
00:55:16.940
Not that I've ever experienced that before.
link |
00:55:18.380
No, people with you don't, but with me, they always-
link |
00:55:20.740
Oh, no, no, no, I mean, I've experienced the desire
link |
00:55:22.800
to take some conversations, I'm halfway through them
link |
00:55:26.500
and I feel like I want to take a nap, right?
link |
00:55:30.100
And I would love to look at people's sleep history.
link |
00:55:32.620
We've sort of seen that time and time again,
link |
00:55:34.820
but, and then it could be with folks like me,
link |
00:55:38.040
people just lose the will to live
link |
00:55:39.580
within about five minutes of speaking with me.
link |
00:55:41.420
So that's- Not true.
link |
00:55:42.620
They hear that sleep is important.
link |
00:55:43.940
And unrelated and that's flattery, that's great.
link |
00:55:46.180
But so the way that then caffeine comes into this equation,
link |
00:55:50.580
as I was saying, it's usually a kind of a linear process
link |
00:55:53.060
or maybe it's probably closer to an exponential
link |
00:55:55.620
in terms of your subjective feeling of sleepiness.
link |
00:55:59.340
And we haven't really been able to measure that in humans
link |
00:56:02.600
because normally it's hard to actually
link |
00:56:05.620
stick something into the brain and be sucking,
link |
00:56:08.340
siphoning off stuff every couple of minutes
link |
00:56:10.420
as you could do in animal studies
link |
00:56:12.020
and keep asking people every couple of minutes,
link |
00:56:13.780
how sleepy do you feel, how sleepy?
link |
00:56:15.440
And track to see if there's a linear rise in adenosine,
link |
00:56:20.540
which then creates an exponential rise
link |
00:56:23.140
in subjective sleepiness or what the dynamics are.
link |
00:56:26.060
But I'm kind of nerding out.
link |
00:56:27.580
So caffeine comes into play here
link |
00:56:30.540
because caffeine comes into your system
link |
00:56:34.060
and it latches onto those welcome sites of adenosine,
link |
00:56:37.340
the adenosine receptors.
link |
00:56:39.740
But what it doesn't do is latch onto them
link |
00:56:42.860
and activate them because if it was doing that,
link |
00:56:46.580
then it would, in lots of ways,
link |
00:56:48.840
it would dial up more sort of sleepiness.
link |
00:56:51.640
It does the opposite.
link |
00:56:53.220
The way that caffeine works is that it comes in,
link |
00:56:56.540
competes with quite sharp elbows with adenosine,
link |
00:57:00.660
competitively forces them out of the way,
link |
00:57:03.580
hijacks that receptor by latching onto it,
link |
00:57:07.100
but then just essentially blocks it.
link |
00:57:09.860
It doesn't inactivate the receptor.
link |
00:57:12.740
It doesn't activate the receptor.
link |
00:57:15.260
It functionally inactivates it in the sense
link |
00:57:18.960
that it takes it out of the game for adenosine.
link |
00:57:21.900
So it's like someone coming into a room
link |
00:57:25.380
and you're just about to sit down on the chair
link |
00:57:27.460
and caffeine comes in and just pulls out the chair
link |
00:57:29.300
and you're like, well, now I've got nowhere to sit.
link |
00:57:32.060
And caffeine just keeps pulling out the chairs
link |
00:57:34.220
from adenosine and adenosine,
link |
00:57:36.460
even though it's at the same concentration in your brain,
link |
00:57:40.500
your brain doesn't know that you've been awake
link |
00:57:43.620
for 10 hours, 16 hours at that point
link |
00:57:47.660
when you've downed a cup of coffee
link |
00:57:50.040
because all of that adenosine that's still there
link |
00:57:54.060
can't communicate to the brain
link |
00:57:57.140
that you've been awake for 16 hours because-
link |
00:57:59.580
But the adenosine is still in brain-
link |
00:58:01.120
Correct.
link |
00:58:02.580
So the real question is what happens
link |
00:58:03.940
when caffeine is dislodged from the adenosine receptor?
link |
00:58:07.260
Unfortunate things happen.
link |
00:58:08.620
And that's what we call the caffeine crash,
link |
00:58:10.700
which is caffeine has a half-life and it's metabolized.
link |
00:58:15.380
Do you recall what the half-life is?
link |
00:58:16.740
Yeah, the half-life is somewhere between five to six hours
link |
00:58:20.400
and the quarter-life therefore is somewhere
link |
00:58:22.140
between 10 to 12 hours.
link |
00:58:24.180
It's variable.
link |
00:58:25.260
Different people have different durations of its action,
link |
00:58:29.820
but for the average adult, five to six hours.
link |
00:58:32.320
That variation, we understand it's down to a liver enzyme
link |
00:58:35.780
or a set of liver enzymes of the class
link |
00:58:38.200
that we call the cytochrome P450 enzymes.
link |
00:58:41.300
And there are, I think last I delved into the data,
link |
00:58:45.100
which is pretty recently, there are two gene variants
link |
00:58:48.820
that will dictate the enzymatic speed
link |
00:58:52.300
with which the liver breaks down caffeine.
link |
00:58:54.980
And that's why you can have some people
link |
00:58:56.440
who are very sensitive to caffeine
link |
00:58:58.820
and other people who say,
link |
00:59:00.420
I'm just doesn't affect me really that much at all.
link |
00:59:02.980
These are the people that have a double espresso
link |
00:59:04.500
after a 9 p.m. dinner and can sleep just fine.
link |
00:59:07.160
Well, and we'll come on to-
link |
00:59:08.000
Or at least subjectively they think they're sleeping.
link |
00:59:10.380
Yeah, and we should speak about that,
link |
00:59:12.220
that assumptive danger too.
link |
00:59:14.820
So then the caffeine is in the system
link |
00:59:18.300
and after some time period,
link |
00:59:20.120
it will be inactive in the system.
link |
00:59:23.420
So let's say that I've been awake for 12 hours now
link |
00:59:27.200
and it's 8 p.m. and I'm feeling a bit tired,
link |
00:59:31.140
but I want to push through
link |
00:59:32.340
and I want to keep working for another couple of hours.
link |
00:59:34.980
So I have a cup of coffee.
link |
00:59:36.580
All of a sudden I was feeling tired,
link |
00:59:38.660
but I don't feel like I've been awake for 12 hours anymore
link |
00:59:41.780
because with the caffeine in the system,
link |
00:59:43.900
maybe only half of that adenosine
link |
00:59:46.480
is being communicated through the receptor to my brain.
link |
00:59:50.460
100% of the adenosine is still there.
link |
00:59:53.080
Only half of it is allowed to communicate to my brain.
link |
00:59:55.380
So now I think,
link |
00:59:56.380
well, I haven't been awake for 12 hours,
link |
00:59:57.700
I've just been awake for six hours, I feel great.
link |
01:00:00.340
Then after a few hours
link |
01:00:01.980
and the caffeine is starting to come out of my system,
link |
01:00:05.080
not only am I hit with the same levels of adenosine
link |
01:00:09.220
that I had before I'd had the cup of coffee
link |
01:00:11.940
several hours ago,
link |
01:00:13.300
it's that plus all of the adenosine
link |
01:00:16.180
that's been building up
link |
01:00:17.380
during the time that the caffeine has been in my system.
link |
01:00:20.700
So sort of an avalanche of adenosine.
link |
01:00:22.620
It is a tsunami wave.
link |
01:00:24.620
And that's the caffeine crash.
link |
01:00:25.940
And it's interesting because the caffeine crash
link |
01:00:28.340
at two o'clock in the afternoon
link |
01:00:29.900
when you have work to do is a terrible thing.
link |
01:00:32.320
But what about the person,
link |
01:00:34.920
maybe this person is me in my 20s,
link |
01:00:37.180
who says, I'm going to drink caffeine all day long
link |
01:00:40.880
and then I want the crash because at nine or 10 PM,
link |
01:00:44.500
if I stopped drinking caffeine at say six PM and I crash,
link |
01:00:48.780
then I crash into a slumber, a deep night of sleep.
link |
01:00:53.260
Is that sleep really as deep as I think it is?
link |
01:00:55.660
Because given the half-life of caffeine
link |
01:00:57.700
that you mentioned a few moments ago,
link |
01:01:00.440
I have to imagine that having some of that caffeine
link |
01:01:02.980
circulating in my system might disrupt the depth of sleep
link |
01:01:06.560
or somehow the architecture of sleep in a way
link |
01:01:09.220
that even if I get eight or who knows even 10 hours of sleep
link |
01:01:13.460
it might not be as restorative as I would like it to be.
link |
01:01:16.940
Yeah, and that is the danger.
link |
01:01:19.060
Just sort of those people that you described who say,
link |
01:01:22.220
and a lot of them will speak with me too,
link |
01:01:24.780
say, look, I can have two espressos with dinner
link |
01:01:27.460
and I fall asleep fine and I stay asleep
link |
01:01:29.860
because usually those are the two phenotypes
link |
01:01:32.220
that we typically see with too much caffeine.
link |
01:01:34.460
I just can't fall asleep as easily as I want to,
link |
01:01:37.100
or I fall asleep but I just can't stay asleep
link |
01:01:39.540
and caffeine can do both of those things quite potently.
link |
01:01:42.180
How late in the day do you think is,
link |
01:01:44.540
assuming somebody, translate this folks,
link |
01:01:46.660
if you go to bed earlier or later
link |
01:01:48.060
you have to shift the hours accordingly,
link |
01:01:49.700
but given somebody who typically gets into bed
link |
01:01:52.960
around 10, 10, 30 and falls asleep around 11, 11, 30,
link |
01:01:58.360
when would you recommend they halt caffeine intake?
link |
01:02:02.660
And these are not strict prescriptives
link |
01:02:04.620
but I think people do benefit
link |
01:02:05.860
from having some fairly clear guidelines
link |
01:02:08.460
of what might work for them.
link |
01:02:10.980
Would you say cut off caffeine by what time of the day?
link |
01:02:15.020
I would usually say take your typical bedtime
link |
01:02:17.820
and count back sort of somewhere between 10 to eight hours
link |
01:02:21.720
is probably getting a little bit close,
link |
01:02:23.360
but take back sort of 10 hours or eight hours of time.
link |
01:02:27.220
That's the time when you should really stop using caffeine
link |
01:02:31.500
is the suggestion.
link |
01:02:33.100
And the reason is because for those people
link |
01:02:34.780
who even just keep drinking up until into the evening,
link |
01:02:39.460
you're right that they can fall asleep fine,
link |
01:02:41.520
maybe they stay asleep,
link |
01:02:42.560
but the depth of their deep sleep is not as deep anymore.
link |
01:02:46.640
And so there are two consequences.
link |
01:02:49.000
The first is that for me, and it can be up to by 30%,
link |
01:02:53.180
and for me to drop your deep sleep by 30%,
link |
01:02:55.700
I'd have to age you by between 10 to 12 years,
link |
01:02:59.440
or you can just do it every night to yourself
link |
01:03:01.380
with a couple of espressos.
link |
01:03:03.560
The second is that you then wake up the next morning
link |
01:03:07.480
and you think, well, I didn't have problems falling asleep
link |
01:03:10.740
and I didn't have problems staying asleep,
link |
01:03:13.380
but I don't feel particularly restored by my sleep.
link |
01:03:15.860
So now I'm reaching for three or four cups of coffee
link |
01:03:18.700
the next morning,
link |
01:03:19.520
rather than just two or three cups of coffee.
link |
01:03:21.660
And so goes this dependency cycle
link |
01:03:24.300
that you then need your uppers to wake you up in the morning
link |
01:03:28.000
and then sometimes people will use alcohol in the evening
link |
01:03:31.060
to bring them down because they're overly caffeinated
link |
01:03:34.300
and alcohol, and we can speak about that too,
link |
01:03:36.180
also has very deleterious impacts on your sleep as well.
link |
01:03:39.740
So you're right that it's not just the quantity
link |
01:03:44.000
of your sleep or even difficulties falling
link |
01:03:46.340
or staying asleep, it can also be deep sleep.
link |
01:03:49.340
But here again, I think,
link |
01:03:51.060
I don't want to be frightening people.
link |
01:03:53.180
And I mentioned this before,
link |
01:03:54.140
I think one of the real problems that I,
link |
01:03:56.300
or mistakes that I made,
link |
01:03:58.000
because I didn't,
link |
01:03:59.180
I'd never had much public exposure before the book.
link |
01:04:01.960
And I was so saddened by, you know,
link |
01:04:06.440
the disease and the suffering that I was seeing
link |
01:04:08.980
as a consequence of a lack of sleep in our society.
link |
01:04:12.640
And the fact that it wasn't really being discussed
link |
01:04:14.800
very much, I sort of came out, you know,
link |
01:04:17.840
a little bit headstrong, more than a little bit headstrong.
link |
01:04:20.920
And I think I was, you know,
link |
01:04:22.400
perhaps too much gas pedal and too little,
link |
01:04:28.040
you know, brake as it were.
link |
01:04:30.280
And I don't think that's the right way
link |
01:04:33.240
to approach health message within the public sphere.
link |
01:04:38.120
And I've become much softer
link |
01:04:40.760
in how I think about these things.
link |
01:04:43.380
I have ideas about what the ideal world looks like
link |
01:04:46.600
for sleep, but I also realized that none of us live
link |
01:04:49.480
in this thing called the ideal world.
link |
01:04:51.680
We certainly don't.
link |
01:04:52.520
So, you know, I want to be really mindful of that.
link |
01:04:55.240
And I think I've done a really bad job
link |
01:04:57.000
of being sort of too forthright,
link |
01:04:58.840
particularly for people who struggle with sleep.
link |
01:05:01.100
You know, early on when I would offer these sort
link |
01:05:03.880
of messages about sleep, I want to be, you know,
link |
01:05:08.640
I want to be veritical when it comes to the science.
link |
01:05:10.860
I want to be faithful to the science,
link |
01:05:13.080
but I also don't want to go out
link |
01:05:14.560
and scare the living daylight set of people,
link |
01:05:16.420
particularly people who are struggling with their sleep,
link |
01:05:19.040
because it's probably only gonna make matters worse.
link |
01:05:21.560
So I've been beautifully schooled by learning
link |
01:05:25.920
how to be a slightly better public communicator.
link |
01:05:27.960
I'm nowhere near of the standing that you are.
link |
01:05:30.360
You're very elegant and it's very intuitive to you.
link |
01:05:32.960
I'm still with training wheels,
link |
01:05:34.800
but I'm getting a little bit better,
link |
01:05:36.360
but I just want to say that when I'm speaking about caffeine
link |
01:05:39.160
because it sounds as though I'm very sort of overt about it,
link |
01:05:42.940
but I will come back to why I say drink coffee,
link |
01:05:46.580
but I just want to make that point.
link |
01:05:48.000
Yeah, well, I appreciate you making that point
link |
01:05:49.520
and I'm sure our listeners will too.
link |
01:05:52.040
I still will stand behind my statement,
link |
01:05:56.580
which is that what you've done for the notion
link |
01:05:59.440
that sleep is vital for all aspects of health
link |
01:06:02.880
and for performance, mental, and physical, and wakefulness,
link |
01:06:06.160
the message and the packaging it was contained in
link |
01:06:09.120
and has been clearly, clearly net positive.
link |
01:06:13.320
People needed to be cued to this.
link |
01:06:15.600
The I'll sleep when I'm dead mentality is one that I had.
link |
01:06:18.320
It's one that other people have.
link |
01:06:20.140
People in a huge number of vital communities,
link |
01:06:22.320
not just your students, but also people.
link |
01:06:25.860
This, the messaging that you provided
link |
01:06:28.440
and continue to provide has positively impacted
link |
01:06:31.380
the first responder community, the medical community.
link |
01:06:34.520
There's still steps that need to be taken,
link |
01:06:36.040
the military community, and of course the civilian community.
link |
01:06:40.200
And so I think these adjustments about, yeah,
link |
01:06:42.560
caffeine's okay, just restrict it
link |
01:06:44.480
to the early part of the day if you can most days.
link |
01:06:47.080
I mean, I think the law of averages,
link |
01:06:48.600
it's like the light viewing behavior.
link |
01:06:50.360
I think it is critical to view sunlight or natural,
link |
01:06:53.940
some other form of bright light early in the day.
link |
01:06:56.060
But if you miss a day, it's not that your whole system
link |
01:06:58.400
is going to dissolve into a puddle of tears.
link |
01:07:00.600
That'll happen on the second or the third day.
link |
01:07:02.760
No, I'm kidding.
link |
01:07:03.600
You got a couple of days.
link |
01:07:04.440
Biology works in averages except
link |
01:07:07.200
with respect to accident or injury.
link |
01:07:09.640
A car accident is a car accident, right?
link |
01:07:11.480
You don't get to have three of those
link |
01:07:13.200
before the brain damage occurs
link |
01:07:14.960
if the accident is severe enough.
link |
01:07:16.920
But with sleep behavior,
link |
01:07:18.080
these homeostatic type behaviors or with food,
link |
01:07:21.360
one chocolate sundae, is it going to kill you?
link |
01:07:23.440
No.
link |
01:07:24.280
Every night, yeah, it's going to make you demented
link |
01:07:26.720
and kill you early.
link |
01:07:27.640
We know this.
link |
01:07:28.480
And so I think the middle ground
link |
01:07:30.680
is often a hard place to achieve.
link |
01:07:33.200
So I think you've done a phenomenal job,
link |
01:07:34.760
but I appreciate you raising these points.
link |
01:07:36.880
And I think it's clear that we all need to,
link |
01:07:42.160
that we all can and should do certain things better,
link |
01:07:45.000
including being gentle with ourselves from time to time
link |
01:07:48.280
when we deviate from these ideal circumstances.
link |
01:07:52.640
Along these lines, I do want to talk about alcohol
link |
01:07:55.520
because I think caffeine and alcohol represent
link |
01:07:57.600
the kind of two opposite ends of the spectrum.
link |
01:08:00.080
Clearly, there are other stimulants.
link |
01:08:02.240
There are your Adderalls
link |
01:08:03.320
and your high-energy drinks that people use.
link |
01:08:06.400
But alcohol and caffeine are the most commonly consumed,
link |
01:08:10.200
stimulants and sedatives,
link |
01:08:11.760
depressants as they're sometimes called.
link |
01:08:13.960
So what happens when somebody has a glass,
link |
01:08:19.600
we always hear a glass or two of wine in the evening
link |
01:08:22.600
or a cocktail after dinner or before dinner,
link |
01:08:28.140
how does that impact their sleep?
link |
01:08:29.840
And then we'll be sure to circle back
link |
01:08:32.920
in terms of what is reasonable ranges of behavior
link |
01:08:35.960
when it comes to avoiding alcohol
link |
01:08:38.960
or if it's age appropriate, et cetera, enjoying alcohol.
link |
01:08:42.920
Yeah.
link |
01:08:43.760
So alcohol, if we're thinking about classes of drugs,
link |
01:08:47.000
they're in a class of drugs that we call the sedatives.
link |
01:08:50.180
And I think one of the first problems
link |
01:08:51.860
that people often mistake,
link |
01:08:53.620
alcohol is often used as a sleep aid
link |
01:08:57.760
for people who are struggling with sleep
link |
01:08:59.560
when things like over-the-counter remedies, et cetera,
link |
01:09:02.920
or herbal remedies have just not worked out for them.
link |
01:09:05.880
And alcohol unfortunately is anything but a sleep aid.
link |
01:09:09.540
The first reason that most people use it
link |
01:09:11.520
is to try and help them fall asleep.
link |
01:09:14.260
And this process of this event that we call falling asleep,
link |
01:09:18.020
I have to imagine is a process.
link |
01:09:19.680
It is a process.
link |
01:09:20.520
Like everything in biology.
link |
01:09:21.480
And that that process involves in some way,
link |
01:09:24.820
as we talked about push pull before,
link |
01:09:26.160
turning off thinking, planning, et cetera,
link |
01:09:29.560
and turning on some sort of relaxation mechanism.
link |
01:09:32.800
I have to imagine that these two things are knobs
link |
01:09:34.680
turning in opposite directions.
link |
01:09:36.000
That gives us this outcome we call falling asleep.
link |
01:09:39.160
Alcohol, it seems is helpful for some people
link |
01:09:41.940
to turn off their thoughts or their planning.
link |
01:09:45.280
Is that right?
link |
01:09:46.600
Yes, it is.
link |
01:09:47.520
And so I think if we look at the pattern of brain activity,
link |
01:09:50.920
if I were to place you inside an MRI scanner,
link |
01:09:53.300
where we're looking at the activity of your brain
link |
01:09:55.560
and watch you drifting off,
link |
01:09:57.140
some parts of your brain will become less active.
link |
01:10:00.160
Other parts will become more active.
link |
01:10:02.000
And this is the push pull model.
link |
01:10:03.920
It's inhibition excitation.
link |
01:10:06.960
But alcohol is quite different in that regard.
link |
01:10:09.760
Alcohol is because it's a sedative.
link |
01:10:12.420
What it's really doing is trying to essentially
link |
01:10:15.100
knock out your cortex.
link |
01:10:16.760
It's sedating your cortex.
link |
01:10:20.040
And sedation is not sleep.
link |
01:10:22.160
But when we have a couple of drinks in the evening,
link |
01:10:24.100
when we have a couple of night caps,
link |
01:10:25.740
we mistake sedation for sleep saying,
link |
01:10:28.240
well, I always when I have a couple of whiskeys
link |
01:10:31.100
or a couple of cocktails,
link |
01:10:32.440
it always helps me fall asleep faster.
link |
01:10:35.220
In truth, what's happening is that
link |
01:10:36.640
you're losing consciousness quicker,
link |
01:10:38.900
but you're not necessarily falling
link |
01:10:41.360
naturalistically asleep any quicker.
link |
01:10:44.060
So that's one of the first sort of things
link |
01:10:46.320
just to keep in mind.
link |
01:10:47.740
The second thing with alcohol
link |
01:10:49.240
is that it fragments your sleep.
link |
01:10:51.160
And we spoke about the quality of your sleep
link |
01:10:53.160
being just as important as the quantity.
link |
01:10:56.360
And alcohol through a variety of mechanisms,
link |
01:10:59.080
some of which are activation
link |
01:11:01.320
of that autonomic nervous system,
link |
01:11:03.160
that fight or flight branch of the nervous system.
link |
01:11:06.520
Alcohol will actually have you waking up
link |
01:11:09.140
many more times throughout the night.
link |
01:11:11.220
So your sleep is far less continuous.
link |
01:11:14.360
Now, some of those awakenings
link |
01:11:16.000
will be of conscious recollection the next day.
link |
01:11:19.020
You'll just remember waking up.
link |
01:11:20.680
Many of them won't be.
link |
01:11:22.640
And so, but yet your sleep will be littered
link |
01:11:25.780
with these sort of punctured awakenings
link |
01:11:28.720
throughout the night.
link |
01:11:29.560
And again, when you wake up the next morning,
link |
01:11:31.920
you don't feel restored by your sleep.
link |
01:11:34.960
You know, fragmented sleep or non continuous sleep
link |
01:11:38.080
in this alcohol induced way
link |
01:11:40.480
is usually not good quality sleep
link |
01:11:42.500
that you feel great on the next day.
link |
01:11:45.120
The third part of alcohol in terms of an equation
link |
01:11:48.960
is that it's quite potent at blocking your REM sleep,
link |
01:11:52.040
your rapid eye movement sleep.
link |
01:11:53.960
And REM sleep is critical
link |
01:11:55.520
for a variety of cognitive functions.
link |
01:11:57.920
Some aspects of learning and memory
link |
01:11:59.800
seems to be critical for aspects
link |
01:12:01.360
of emotional and mental health.
link |
01:12:03.200
You've described it before
link |
01:12:04.240
as a sort of self-generated therapy
link |
01:12:06.840
that occurs while we sleep.
link |
01:12:08.260
Yeah, it's overnight therapy.
link |
01:12:09.880
You know, it's emotional first aid.
link |
01:12:12.600
Certainly people that don't get enough sleep
link |
01:12:14.800
are very easy to derail emotionally.
link |
01:12:17.480
Not that one would want to do that to people,
link |
01:12:19.080
but we all sort of fall apart emotionally.
link |
01:12:23.200
I always think about it as almost like
link |
01:12:24.800
our skin sensitivity can be heightened
link |
01:12:27.400
when we are sleep deprived.
link |
01:12:30.000
Our emotional sensitivity is such that
link |
01:12:33.520
when we're sleep deprived,
link |
01:12:34.880
such that it takes a much finer grain of sandpaper
link |
01:12:39.280
to create that kind of friction.
link |
01:12:41.320
Things bother us.
link |
01:12:42.760
Threshold to trigger. Even online comments
link |
01:12:45.280
bother us when we're sleep deprived.
link |
01:12:47.280
And never when we're well rested.
link |
01:12:49.120
I would love to say that I never look at them,
link |
01:12:51.120
except I look at maybe every one of them.
link |
01:12:54.640
Here I will editorialize
link |
01:12:56.000
because the notion of not looking at comments
link |
01:12:58.320
is unreasonable to ask of any academic.
link |
01:13:02.800
Because academics, we are all trained
link |
01:13:05.480
to look at our teaching evaluations.
link |
01:13:07.760
And just like with online comments,
link |
01:13:09.520
to ignore 20% of them.
link |
01:13:11.400
No, I'm kidding.
link |
01:13:12.240
We look at them all.
link |
01:13:14.240
In any event, so in terms of translating this to behavior,
link |
01:13:17.220
I'm not, I don't particularly enjoy alcohol.
link |
01:13:19.360
I guess I might be fortunate in that sense,
link |
01:13:21.420
but I also have never really experienced
link |
01:13:23.440
the pleasure of drinking alcohol.
link |
01:13:25.920
I sometimes like the taste of a drink,
link |
01:13:27.920
but I never liked the sensation.
link |
01:13:29.440
So that's, I don't have a lot of familiarity with this,
link |
01:13:32.360
but many people do, and I understand that.
link |
01:13:34.600
So let's say somebody enjoys a glass of wine or two
link |
01:13:39.740
with dinner and they eat dinner at 7 p.m.
link |
01:13:43.280
Is that likely to disrupt their sleep at all?
link |
01:13:46.800
Let's just sort of, let's make this a series of gradations.
link |
01:13:49.600
Yeah, and the answer is yes.
link |
01:13:52.640
I think one study just looked at a single glass of wine
link |
01:13:56.320
in the evening with dinner.
link |
01:13:57.920
And I would be untruthful if I didn't just simply say
link |
01:14:02.640
it has an effect and we can measure that
link |
01:14:06.360
in terms of the actual- Less REM sleep.
link |
01:14:07.740
Less REM sleep.
link |
01:14:08.940
And one of the fascinating studies,
link |
01:14:10.680
I can't remember what dose,
link |
01:14:12.040
I think they got them close to a standard
link |
01:14:15.280
illegal blood alcohol level.
link |
01:14:17.600
So maybe they were a little bit tipsy.
link |
01:14:20.040
And yes, you see all of the changes that we just described.
link |
01:14:24.060
They sort of lose consciousness more quickly.
link |
01:14:26.200
They have fragmented sleep
link |
01:14:27.560
and they have a significant reduction in REM sleep.
link |
01:14:30.000
But what was also interesting,
link |
01:14:31.160
because REM sleep, as we spoke about before,
link |
01:14:33.360
is a time when some hormonal systems
link |
01:14:36.280
are essentially recharged and refreshed,
link |
01:14:38.760
growth hormone being one of them,
link |
01:14:40.600
there was well over a 50%, 5-0 drop in their growth hormone
link |
01:14:45.780
release during alcohol-laced sleep at night.
link |
01:14:49.760
Wow.
link |
01:14:50.600
And growth hormone is so vital for metabolism
link |
01:14:53.000
and repair of tissues and-
link |
01:14:54.480
Yeah, it's not just for kids.
link |
01:14:55.800
Keeping body fat low.
link |
01:14:56.640
This is essentially adults, yeah.
link |
01:14:58.560
Essential.
link |
01:14:59.960
Along those lines, I just want to highlight the fact
link |
01:15:02.440
that this information that you're sharing,
link |
01:15:06.040
that growth hormone is released as strongly tethered
link |
01:15:09.640
to the presence of healthy amounts of REM sleep,
link |
01:15:13.360
is interesting to me because I always thought
link |
01:15:15.660
that growth hormone was released
link |
01:15:17.000
in the early part of the night.
link |
01:15:18.440
Well, it is released across both of those,
link |
01:15:21.440
but across the different stages.
link |
01:15:23.720
But what we also know is that when you disrupt REM sleep,
link |
01:15:26.440
there are those growth hormone consequences.
link |
01:15:29.320
So it's not an exclusive system.
link |
01:15:32.080
Just like with testosterone,
link |
01:15:33.820
we can see changes throughout non-REM sleep.
link |
01:15:36.480
But if you ask when are the peak release rates
link |
01:15:39.560
of testosterone, it's right before we go into REM sleep
link |
01:15:42.720
and then during REM sleep.
link |
01:15:44.360
And of course, testosterone being important
link |
01:15:46.520
both for males and for females, right?
link |
01:15:48.840
For libido and tissue repair and wellbeing.
link |
01:15:51.480
Nobody, regardless of chromosomal, hormonal,
link |
01:15:54.880
or any other background,
link |
01:15:56.360
wants to have their normal levels
link |
01:15:58.560
of testosterone reduced acutely.
link |
01:16:00.880
That's just a bad, it equates to a terrible set
link |
01:16:03.960
of psychological and physical symptoms.
link |
01:16:05.720
Yeah, and the mortality risk that's associated
link |
01:16:08.000
with low testosterone is non-trivial.
link |
01:16:09.800
Prostate cancer.
link |
01:16:10.640
Right, exactly.
link |
01:16:12.000
So coming back to just the point on REM sleep
link |
01:16:16.780
that you mentioned regarding emotional instability,
link |
01:16:19.760
and we see that, that's one of the things,
link |
01:16:21.520
one of the most reliable signatures
link |
01:16:23.120
of just insufficient sleep.
link |
01:16:24.560
It doesn't have to be sleep deprivation.
link |
01:16:26.740
What we've discovered over the past 20 years
link |
01:16:29.680
here at the Sleep Center is that
link |
01:16:31.760
there is no major psychiatric disorder that we can find
link |
01:16:36.240
in which sleep is normal.
link |
01:16:38.400
And so I think that firstly told us
link |
01:16:40.240
there is a very intimate association
link |
01:16:42.140
between your emotional mental health and your sleep health.
link |
01:16:46.680
But when it also comes to REM sleep,
link |
01:16:49.960
I think what's fascinating is that it's not just
link |
01:16:53.480
about your emotional health.
link |
01:16:54.560
It's not just about your hormonal health.
link |
01:16:57.560
We've also been seeing other aspects of cognition,
link |
01:17:01.760
but then there was a report,
link |
01:17:03.940
I think it could have been about two years ago,
link |
01:17:06.820
out of Harvard, I think it was Beth Clearman's group.
link |
01:17:11.720
They found that, and they replicated it
link |
01:17:14.280
in two different large populations.
link |
01:17:16.640
If you look at the contribution of different sleep stages
link |
01:17:20.240
to your lifespan, REM sleep was the strongest predictor
link |
01:17:25.680
of your longevity.
link |
01:17:27.840
And it was a linear relationship.
link |
01:17:29.520
It wasn't sort of one of these U-shape or J-shaped curves
link |
01:17:32.800
that we often see with total sleep and mortality risk.
link |
01:17:36.480
It really was linear.
link |
01:17:38.000
That the less and less REM sleep that you were getting,
link |
01:17:40.420
the higher and higher your probability of death.
link |
01:17:44.120
And then they did-
link |
01:17:44.960
Was that death due to natural causes or accident?
link |
01:17:47.920
Because I could imagine if you're not getting enough REM
link |
01:17:49.680
sleep, you're more likely to drive off the freeway,
link |
01:17:51.800
step off a cliff.
link |
01:17:52.640
Yeah, I think it was all cause and-
link |
01:17:53.480
Or just make bad decisions about anything
link |
01:17:55.360
and love relationships, which can also be life threatening.
link |
01:17:58.560
Yeah, I've tried to lean into that and claim that
link |
01:18:01.240
with those bad relationship situations that,
link |
01:18:03.000
oh, I just didn't have enough REM sleep last night,
link |
01:18:05.240
my darling.
link |
01:18:06.080
The REM sleep defense.
link |
01:18:07.240
And, but she's far wiser than I thought.
link |
01:18:10.720
But so they did this great machine learning analysis
link |
01:18:15.760
and I may get these numbers backwards,
link |
01:18:18.600
but I think for every 5% reduction in REM sleep,
link |
01:18:23.720
there was a 13% associated increased risk of mortality.
link |
01:18:28.960
And I could have, I'll have to go back and check.
link |
01:18:31.980
But to me, in the machine learning algorithm,
link |
01:18:36.120
what they ultimately spat out was that
link |
01:18:38.600
of all of the sleep stages,
link |
01:18:40.120
REM sleep is the most predictive of your longevity,
link |
01:18:43.360
of your lifespan.
link |
01:18:44.820
So we often, I hear people saying,
link |
01:18:46.840
how can I get more deep sleep?
link |
01:18:49.520
Or they sometimes say, how can I get more dream sleep?
link |
01:18:51.840
And my answer is a question.
link |
01:18:54.880
Why do you want to get more of that?
link |
01:18:56.680
And they'll say, well, isn't that the good stuff?
link |
01:18:58.940
And I'll say, well, actually all stages of sleep are, yeah.
link |
01:19:02.640
Well, it's like the exercise question.
link |
01:19:04.200
And it took decades for people to understand
link |
01:19:07.500
that moving around at, for about 150,
link |
01:19:12.240
probably 180 minutes a week at doing endurance type work,
link |
01:19:15.920
zone two cardio type work,
link |
01:19:18.060
it is correlated with living longer,
link |
01:19:20.560
feeling better, less diabetes, et cetera.
link |
01:19:22.360
There's really no way around it.
link |
01:19:24.200
I mean, you can ingest metformin until the cows come home.
link |
01:19:29.440
You can take NMN,
link |
01:19:31.140
all of which I think have their place in certain contexts.
link |
01:19:34.440
I'm a big fan of the work surrounding all those protocols,
link |
01:19:37.480
but without getting proper amounts of movement,
link |
01:19:41.480
meaning sufficient numbers.
link |
01:19:43.200
It doesn't matter how many 12 minute exercise regimes
link |
01:19:46.140
you follow per week, you need that threshold level.
link |
01:19:49.960
And it sounds like the same is true of REM sleep
link |
01:19:53.000
and total amount of sleep.
link |
01:19:54.440
There's just, you pay the piper somehow.
link |
01:19:58.160
Yeah, the return on investment, I mean, to flip the coin,
link |
01:20:01.040
the return on investment is astronomical.
link |
01:20:04.440
I think of sleep, it is the tide that moves,
link |
01:20:08.440
that raises all of those health boats.
link |
01:20:10.920
And the most fundamental layer of mental
link |
01:20:12.880
and physical health.
link |
01:20:14.000
Whenever people ask me, even though I'm not a physician,
link |
01:20:16.480
they'll ask me, what should I take or what should I do?
link |
01:20:19.640
The first question is always, how's your sleep?
link |
01:20:22.000
Meaning, how well do you sleep every night
link |
01:20:23.720
and how long you sleep?
link |
01:20:25.220
I always recommend your book.
link |
01:20:26.820
I always recommend the podcast you've been a guest on,
link |
01:20:31.600
et cetera.
link |
01:20:34.320
Who knows, maybe you'll even release your own podcast
link |
01:20:36.560
at some point soon and keep,
link |
01:20:37.920
because I do think people need to hear from you more often.
link |
01:20:40.520
One thing I don't want to return to the notion
link |
01:20:43.600
of public health discourse too much, but I do want to say,
link |
01:20:46.920
one issue with books in general is that they can be revised,
link |
01:20:51.800
but it's more or less a one and done kind of thing
link |
01:20:54.200
until the next book comes out.
link |
01:20:55.720
One thing that I like about the podcast format
link |
01:20:58.240
is that updates can be provided regularly,
link |
01:21:00.360
corrections and updates as new data come out.
link |
01:21:03.400
And so that's a wonderful aspect to this format
link |
01:21:06.680
and hopefully the format that you'll be embracing.
link |
01:21:09.800
I think the world needs to hear more from you more often
link |
01:21:13.360
about sleep and its various contours, not less.
link |
01:21:17.480
And so I do have a question about drinking alcohol,
link |
01:21:22.440
not that we want to promote day drinking,
link |
01:21:24.640
but let's say that the one or two glasses of wine
link |
01:21:29.020
or a cocktail is consumed with lunch,
link |
01:21:31.360
something that isn't traditionally done nowadays,
link |
01:21:33.760
or in a late afternoon happy hour cocktail,
link |
01:21:37.600
and then one is going to sleep seven or eight hours later.
link |
01:21:40.460
Do you think that that will improve
link |
01:21:43.720
or somehow mitigate the effects of alcohol?
link |
01:21:46.120
Or if you have a drink,
link |
01:21:48.320
are you basically screwed for the next 24 hours?
link |
01:21:51.080
No, I think there's going to be a time window dependency.
link |
01:21:56.160
Now, I don't know of anyone who's essentially done
link |
01:21:59.220
what you and I would like,
link |
01:22:00.400
which is the time separation dose dependent curve
link |
01:22:04.720
where, okay, you drink at 10 a.m. then,
link |
01:22:07.520
or 11, 12, one, two, three, four, five,
link |
01:22:10.000
all the way up to 10 p.m.,
link |
01:22:12.460
and estimate what is the blast radius
link |
01:22:15.600
and is it linear or is it non-linear?
link |
01:22:18.280
Is it such that only when you drink in the last four hours,
link |
01:22:22.200
do you just hit this exponential and it's bad, bad, bad,
link |
01:22:25.600
or is there some other curve that we could imagine
link |
01:22:28.840
that would be many possibilities?
link |
01:22:31.360
But certainly what we know is that the less alcohol
link |
01:22:34.600
and the less, and more specifically,
link |
01:22:36.280
the metabolic byproducts, aldehydes and ketones,
link |
01:22:39.280
they're the sort of the nefarious players here.
link |
01:22:41.680
And not the ketones that people are all excited about,
link |
01:22:44.480
the other ketones, the chemists know
link |
01:22:47.200
what we're referring to.
link |
01:22:48.040
But this is not about ketogenesis.
link |
01:22:48.880
This is not about ketogenesis.
link |
01:22:50.320
There are ketone bodies that are released
link |
01:22:53.960
after ingesting alcohol that are not of the positive sort
link |
01:22:58.000
that a ketogenic diet might promote.
link |
01:23:00.160
Right.
link |
01:23:01.000
So I think in terms of that alcohol profile,
link |
01:23:05.860
we certainly know that as you're heading
link |
01:23:08.140
into the evening hours,
link |
01:23:10.200
once again, timing and dose make the poison,
link |
01:23:14.280
but I think it's also important once again,
link |
01:23:16.960
from that public message standpoint, and thank you.
link |
01:23:19.260
I think I am leaning into the sort of the podcast
link |
01:23:23.040
consideration arena at some point,
link |
01:23:25.040
but I don't want to be puritanical here.
link |
01:23:28.720
I'm just a scientist and I'm not here to tell anyone
link |
01:23:32.200
how to live.
link |
01:23:33.080
All I'm trying to do is empower people
link |
01:23:35.840
with some of the scientific literature regarding sleep.
link |
01:23:39.640
And then you can make whatever informed choices
link |
01:23:42.500
that you want.
link |
01:23:43.340
You know, unlike you, it turns out I'm not a big drinker.
link |
01:23:46.360
It's just because I've never liked the taste.
link |
01:23:48.720
And I'm surprised that they haven't taken away
link |
01:23:50.980
my British passport because I don't like lager or beer.
link |
01:23:55.040
But I also want to say that life is to be lived
link |
01:23:59.080
to a certain degree.
link |
01:24:00.480
It's all about checks and balances.
link |
01:24:02.600
So, you know, if I go out and you know,
link |
01:24:05.380
I have an ice cream sundae, I'm not big on those either,
link |
01:24:08.200
but you know, sure I know that my, you know,
link |
01:24:11.100
blood glucose is not gonna be ideal
link |
01:24:13.340
for another 12 hours maybe.
link |
01:24:16.160
That's just the price you pay for having
link |
01:24:18.440
some kind of relaxed, fun life.
link |
01:24:20.800
I don't want to look back on life and think,
link |
01:24:23.960
gosh, you know, I lived until I was, you know, 111
link |
01:24:28.240
and it was utterly miserable, you know?
link |
01:24:31.480
Right, so, but it's all about some kind of a balance.
link |
01:24:34.760
And my job is not to tell people a prescription for life,
link |
01:24:39.820
it's just to offer some scientific information.
link |
01:24:42.240
I think you're doing a terrific job of that.
link |
01:24:44.440
People are, I always say we have all these neural circuits
link |
01:24:47.100
and if it's working properly, we all have a circuit
link |
01:24:50.320
that allows us to skip over information or as we wish, right?
link |
01:24:53.960
If the circuits between your brain and your thumbs
link |
01:24:56.540
are working, you can slide right along,
link |
01:24:58.880
you can drop to the next content, however you like.
link |
01:25:01.820
I would like to ask about marijuana and CBD.
link |
01:25:06.640
This is a discussion that I think five years ago
link |
01:25:08.580
would have ventured into the realm of illegal,
link |
01:25:10.520
but now in many places, not all,
link |
01:25:13.840
medical marijuana is approved or is legal
link |
01:25:16.340
and certainly it's in widespread use.
link |
01:25:20.560
Certainly not recommending people do it.
link |
01:25:22.160
I have my own thoughts about marijuana, CBD.
link |
01:25:24.400
I've been fortunate, I suppose,
link |
01:25:26.480
that I don't particularly like marijuana or CBD.
link |
01:25:29.400
I don't even know if I've ever tried CBD.
link |
01:25:32.700
First of all, does marijuana disrupt the depth of sleep,
link |
01:25:37.920
the architecture of sleep?
link |
01:25:40.140
And if so, as with alcohol and caffeine,
link |
01:25:44.040
does when you ingest it or when it's in your bloodstream,
link |
01:25:48.600
does relative to when you go to sleep,
link |
01:25:50.740
does that play an important role?
link |
01:25:52.260
So does marijuana disrupt sleep?
link |
01:25:55.240
Yeah, it does, and there's a pretty good amount of data on,
link |
01:26:00.360
so we can break sort of cannabis down
link |
01:26:03.000
into two of its key ingredients.
link |
01:26:05.640
We've got THC, tetrahydrocannabinol, and we've got CBD.
link |
01:26:10.480
And CBD is sort of the less,
link |
01:26:14.600
what we think of as the non-psychoactive component.
link |
01:26:17.640
In other words, when you take CBD, you don't get high.
link |
01:26:21.120
If you take THC, you can get high.
link |
01:26:24.040
That's the psychoactive part of the equation.
link |
01:26:27.020
Are both considered sedatives in the technical sense?
link |
01:26:30.360
No, they're not.
link |
01:26:32.680
Neither of them have that class right now.
link |
01:26:36.900
THC can, seems to speed up the time
link |
01:26:42.300
with which you fall asleep.
link |
01:26:44.280
But again, if you look at the electrical brainwave signature
link |
01:26:48.160
of your falling asleep with and without that THC,
link |
01:26:51.560
it's not going to be an ideal fit.
link |
01:26:54.000
So you could argue it's non-natural,
link |
01:26:56.460
but many people use THC for that fact
link |
01:26:58.920
because they find it difficult to fall asleep.
link |
01:27:01.600
And it can speed the onset of at least non-consciousness,
link |
01:27:05.440
I guess is the best way of describing it.
link |
01:27:07.520
But there are problems with THC and there are twofold.
link |
01:27:11.880
The first is that it too, but through different mechanisms
link |
01:27:15.080
seems to block REM sleep.
link |
01:27:16.920
And that's why a lot of people when they're using
link |
01:27:18.900
will tell me, look, I definitely, I was dreaming.
link |
01:27:22.400
I don't remember many of my dreams.
link |
01:27:24.680
And then when they stop using THC,
link |
01:27:28.080
they'll say, I was having just crazy, crazy dreams.
link |
01:27:31.860
And the reason is because there is a rebound mechanism.
link |
01:27:35.340
REM sleep is very clever and alcohol is the same way
link |
01:27:38.460
in this sense, it's the same homeostatic mechanism.
link |
01:27:40.980
Some people will tell me, look,
link |
01:27:42.600
if I have a bit of a wild Friday night with some alcohol,
link |
01:27:46.440
maybe I'll sleep late into the next morning.
link |
01:27:48.780
And I'll just have these really intense dreams.
link |
01:27:52.120
So, and I thought I wasn't having any REM sleep.
link |
01:27:54.800
Well, the way it works is that it's during
link |
01:27:56.720
in the middle of the night, really,
link |
01:27:59.040
when alcohol blocks your REM sleep.
link |
01:28:02.240
And your brain is smart.
link |
01:28:03.920
It understands how much REM sleep you should have had,
link |
01:28:06.880
how much REM sleep you have not
link |
01:28:08.640
because the alcohol has been in the system.
link |
01:28:10.680
And finally, in those early morning hours
link |
01:28:12.760
when you're getting through to sort of,
link |
01:28:14.120
you know, six, seven, eight AM,
link |
01:28:16.200
all of a sudden your brain not only goes back
link |
01:28:18.440
to having the same amount of REM it would have had,
link |
01:28:21.240
it does that, plus it tries to get back all
link |
01:28:24.160
of the REM sleep that it's lost.
link |
01:28:25.760
Does it get back all of the REM sleep?
link |
01:28:27.560
No, it doesn't.
link |
01:28:28.520
It never gets back all of the REM sleep, but it tries.
link |
01:28:31.720
And so you have these really intense periods of REM sleep.
link |
01:28:34.760
Hence, you have really intense, bizarre dreams.
link |
01:28:38.080
And that's what happens also with THC.
link |
01:28:40.540
You build up this pressure for REM sleep,
link |
01:28:44.020
this debt for REM sleep.
link |
01:28:45.920
Will you ever pay it back?
link |
01:28:48.160
Doesn't seem as though you get back everything
link |
01:28:50.100
that you lost, but will you get back some of it?
link |
01:28:52.800
Yes, the brain will start to devour more
link |
01:28:55.240
because it's been starved of REM sleep for so long.
link |
01:28:59.480
But one of the bigger problems with THC
link |
01:29:02.200
that we worry about is withdrawal dependency.
link |
01:29:05.820
So as you start to use THC for sleep,
link |
01:29:09.160
there can be a dependency tolerance.
link |
01:29:12.880
So you start to need more to get the same sleep benefit.
link |
01:29:16.780
And when you stop using,
link |
01:29:18.280
you usually get a very severe rebound insomnia.
link |
01:29:21.720
And in fact, it's so potent that it's typically part
link |
01:29:24.500
of the clinical withdrawal profile from THC, from cannabis.
link |
01:29:30.640
And there's anxiety withdrawal.
link |
01:29:35.200
I don't ask anybody to change their behavior.
link |
01:29:38.360
We just, as you said,
link |
01:29:39.560
we try and inform people about what the science says
link |
01:29:41.600
and let them make choices for themselves.
link |
01:29:43.600
People who are regular pot smokers,
link |
01:29:45.680
that many will insist they're not addicted.
link |
01:29:48.900
And maybe indeed they don't actually follow the profile
link |
01:29:52.660
of classical addiction.
link |
01:29:53.820
I don't know.
link |
01:29:54.660
I'm guessing some do, some don't.
link |
01:29:56.200
But if you ask them, well,
link |
01:29:58.460
what if I took away all marijuana consumption
link |
01:30:01.700
for, I don't know, two weeks?
link |
01:30:04.480
That thought scares many of them.
link |
01:30:07.000
And many of them will experience intense anxiety
link |
01:30:10.240
without marijuana, which speaks to perhaps not addiction,
link |
01:30:13.120
but a certain kind of dependency.
link |
01:30:15.360
And again, I know many pot smokers,
link |
01:30:18.000
some of whom have jobs that are quite high performing
link |
01:30:21.360
and they manage.
link |
01:30:22.840
Here in Berkeley, I don't know any of those.
link |
01:30:24.440
Yeah, I know none of those, right.
link |
01:30:27.280
What about CBD?
link |
01:30:28.500
I mean, we hear so much about CBD.
link |
01:30:30.000
I've been a little concerned about the fact
link |
01:30:31.560
that the analysis of a lot of CBD supplements out there
link |
01:30:34.800
has confirmed that much like with melatonin,
link |
01:30:37.400
the levels that are reported on the labels
link |
01:30:41.040
in no way, shape, or form match the levels
link |
01:30:43.460
that are actually contained in the various supplements.
link |
01:30:45.560
Sometimes the levels are much higher
link |
01:30:47.640
than they're reported on the labels.
link |
01:30:49.600
Other times it's much lower.
link |
01:30:52.480
What does ingesting CBD do to the architecture
link |
01:30:56.200
and quality of sleep?
link |
01:30:58.280
Right now, I don't think we have enough data
link |
01:31:00.960
to make some kind of meaningful sense out of it.
link |
01:31:05.220
I think the picture that is emerging, however,
link |
01:31:07.760
is probably the following.
link |
01:31:09.720
Firstly, CBD does not seem to be detrimental
link |
01:31:13.840
in the same ways that THC is.
link |
01:31:16.240
So we can start by saying,
link |
01:31:18.340
does it create potential problems?
link |
01:31:22.340
Not of the nature necessarily that we see with THC,
link |
01:31:26.920
but the devil is a little bit in the details
link |
01:31:29.840
from the data that we do have
link |
01:31:31.260
and it comes onto your valid point of purity.
link |
01:31:33.820
At low dose, CBD can seem to be wake promoting.
link |
01:31:40.140
So in lower doses, let's say sort of five or 10 milligrams,
link |
01:31:43.460
I'm trying to remember some of the studies
link |
01:31:44.880
off the top of my head,
link |
01:31:46.640
there it actually may enhance wakefulness
link |
01:31:49.560
and cause problems with sleep.
link |
01:31:51.960
It's only once you get into the higher dose range
link |
01:31:54.620
that there seem to have been some increases in sleepiness
link |
01:31:59.620
or sort of sedation like increases.
link |
01:32:03.820
And that's usually, I think above about 25 milligrams
link |
01:32:08.160
as best I can recall from the data.
link |
01:32:10.560
And then when we look in animal models,
link |
01:32:13.840
you typically see the same type of profile too.
link |
01:32:17.900
So then the question becomes,
link |
01:32:20.180
and now again, you just don't know about purity,
link |
01:32:23.860
it's very difficult.
link |
01:32:25.440
Although I think, and again, I'm not a user,
link |
01:32:28.540
not necessarily because I have anything against it,
link |
01:32:31.540
it's just that's not necessarily my cup of tea.
link |
01:32:35.500
There are some firms that are now doing
link |
01:32:38.060
third party independent laboratory tests.
link |
01:32:41.140
I don't know how gamed that is,
link |
01:32:43.100
so I've got no sense of it.
link |
01:32:43.940
No, I think some supplement companies
link |
01:32:45.620
are quite honest and accurate
link |
01:32:47.660
about the amounts of various substances
link |
01:32:49.740
that are in other products and some are not.
link |
01:32:53.460
And I think there's just a huge range.
link |
01:32:55.540
I think the FDA is starting to explore CBD.
link |
01:32:58.340
There are, certainly I saw some grant announcements
link |
01:33:01.300
to explore the function of CBD.
link |
01:33:03.260
Most of the work on CBD is being done
link |
01:33:05.060
by the general public, ingesting it and seeing how they feel.
link |
01:33:07.660
I gave it to my dog who had some
link |
01:33:10.180
dementia-related sleep disturbances
link |
01:33:11.980
and it actually created a heightened wakefulness.
link |
01:33:14.740
It completely screwed up his sleep.
link |
01:33:16.220
He's a bulldog, so if he's going to get access to sleep,
link |
01:33:19.220
he's going to take it.
link |
01:33:21.140
Really messed him up, took it away, he did better.
link |
01:33:25.660
But that's a canine, so.
link |
01:33:27.660
Right, and it could have been, you know,
link |
01:33:29.260
sort of dose-related too, but-
link |
01:33:30.900
Or binders or other things that are in there.
link |
01:33:32.700
Correct, yeah, and we, but right now,
link |
01:33:35.260
if we were to, and I'm not making this statement,
link |
01:33:38.300
I don't think anyone can make the statement now,
link |
01:33:39.980
but if it ends up being that CBD
link |
01:33:42.940
is potentially beneficial for sleep,
link |
01:33:46.060
how can we reconcile that mechanistically?
link |
01:33:49.300
And I think there are, to me at least,
link |
01:33:51.960
there are at least three candidate mechanisms
link |
01:33:54.040
that I've been exploring and thinking about.
link |
01:33:57.400
The first is that it's thermoregulatory,
link |
01:34:00.440
and what we found in some animal models
link |
01:34:02.520
is that CBD will create a profile of hypothermia.
link |
01:34:07.420
In other words, it cools the body,
link |
01:34:09.040
the core body temperature down,
link |
01:34:10.620
and that's something that we know is good for sleep.
link |
01:34:12.940
The second is that it's an anxiolytic,
link |
01:34:15.080
that it can reduce anxiety,
link |
01:34:16.840
and that data is actually quite strong,
link |
01:34:19.400
even with some functional imaging work
link |
01:34:21.260
that's been coming out recently,
link |
01:34:22.600
showing that one epicenter of emotion
link |
01:34:24.700
called the amygdala deep within the brain
link |
01:34:26.880
is quietened down with CBD.
link |
01:34:30.240
So I think that's at least a second
link |
01:34:31.660
non-mutually exclusive possibility.
link |
01:34:35.520
I think the third is some recent data that's come out
link |
01:34:38.920
that was suggesting that CBD
link |
01:34:41.060
can alter the signaling of adenosine.
link |
01:34:43.960
So it doesn't necessarily mean
link |
01:34:45.360
that you produce more adenosine,
link |
01:34:48.320
but what it can do is perhaps modulate
link |
01:34:50.800
the sensitivity perhaps of the brain
link |
01:34:53.600
so that the weight of that same adenosine
link |
01:34:57.260
is weightier in its brain signal,
link |
01:35:02.160
and therefore it creates this stronger pressure for sleep.
link |
01:35:06.220
So I think these are all tentative mechanisms.
link |
01:35:09.040
I think any one of them is viable.
link |
01:35:10.700
I think all three are viable together,
link |
01:35:13.320
but right now I think,
link |
01:35:14.600
does that sort of help think through
link |
01:35:16.040
the tapestry of THC and CBD?
link |
01:35:18.560
Yeah, very much so,
link |
01:35:19.540
and actually it's a perfect segue from,
link |
01:35:22.140
we've talked about caffeine, alcohol, THC,
link |
01:35:27.280
and CBD as sort of,
link |
01:35:29.700
we framed them anyway,
link |
01:35:30.920
as things that done in moderation at the appropriate times
link |
01:35:33.600
are probably okay for most people,
link |
01:35:36.120
certainly not for everybody,
link |
01:35:37.140
there will be differences in sensitivity,
link |
01:35:39.000
but that done at the incorrect times
link |
01:35:42.120
and certainly in the incorrect amounts
link |
01:35:44.520
will greatly disrupt this vital stage of life we call sleep.
link |
01:35:48.120
CBD it seems represents a kind of bridge
link |
01:35:50.520
to the topic I'd like to talk about next,
link |
01:35:52.560
which is things that promote more healthy sleep,
link |
01:35:56.940
or somehow contribute to enhancing the architecture
link |
01:36:00.680
and quality of sleep.
link |
01:36:02.220
So I'd love to chat for a moment about the kind of grant,
link |
01:36:06.700
the original, I should say that not the granddaddy,
link |
01:36:09.280
but the OG of sleep supplementation, which is melatonin,
link |
01:36:13.600
the so-called hormone of darkness
link |
01:36:15.960
that's inhibited by light, et cetera,
link |
01:36:18.480
frame for us melatonin
link |
01:36:20.680
in the context of its naturally occurring form.
link |
01:36:23.560
And then I'd like to talk about melatonin, the supplement,
link |
01:36:25.840
because as in my experience,
link |
01:36:27.360
anytime I say the word melatonin,
link |
01:36:28.760
people think about the supplement melatonin,
link |
01:36:32.120
which in itself is an interesting phenomenon
link |
01:36:35.780
that people are so cued to its role as something you take,
link |
01:36:39.280
we often forget that this is something
link |
01:36:40.760
that we make endogenously.
link |
01:36:42.200
I'd love for you to comment in particular on,
link |
01:36:45.440
even though we,
link |
01:36:46.280
without necessarily getting into precise nanograms
link |
01:36:48.760
per deciliter values,
link |
01:36:50.140
what are the typical amounts of melatonin
link |
01:36:52.640
that we release each night?
link |
01:36:53.760
And then I'd like to compare that to what is contained
link |
01:36:56.640
in say a three milligram or six milligram tablet
link |
01:36:59.440
that one might buy at the pharmacy.
link |
01:37:01.560
So I go to sleep at night,
link |
01:37:04.040
has melatonin already kicked in
link |
01:37:05.680
before I shut my eyes and lay down my head?
link |
01:37:07.760
Usually, yes.
link |
01:37:08.920
If your system is working in the correct way,
link |
01:37:12.080
as dusk is starting to happen,
link |
01:37:14.400
so let's say that you look at hunter gatherer tribes
link |
01:37:17.280
who aren't touched by electricity.
link |
01:37:19.620
And so that's sort of the puritanical state,
link |
01:37:22.640
par excellence when it comes to electric light influence.
link |
01:37:27.820
And usually it's as dusk is approaching,
link |
01:37:30.580
that's when melatonin will start to rise.
link |
01:37:33.720
And so when you lose the brake pedal of light
link |
01:37:38.120
coming through the eyes,
link |
01:37:39.920
not normally acts like a hard brake pedal that stamps down
link |
01:37:44.280
and prevents the release and production of melatonin.
link |
01:37:47.720
As that light brake pedal starts to fade with dusk,
link |
01:37:52.400
then we ease off the brake pedal and melatonin,
link |
01:37:55.360
the spigot of melatonin is opened up
link |
01:37:58.320
and melatonin starts getting released.
link |
01:38:00.840
And usually we'll see this rising peak of melatonin
link |
01:38:05.760
sometime usually an hour, two hours later or around
link |
01:38:09.920
and it varies from different people
link |
01:38:11.800
around the time of sleep itself.
link |
01:38:14.880
But it's already been on the march for some hours
link |
01:38:18.400
before you actually hit sleep itself.
link |
01:38:22.640
Interesting, and I was always taught
link |
01:38:25.040
and I'm assuming it's still true
link |
01:38:26.380
that the only source of melatonin in the brain and body
link |
01:38:28.940
is the pineal gland, is that still true?
link |
01:38:31.520
Yeah, it seems to be from best that we can tell
link |
01:38:34.160
and the pineal gland sort of meaning P like sort of shape.
link |
01:38:39.840
It's actually, I think usually people say
link |
01:38:41.740
it's P like, I think if you look at the Latin derivative,
link |
01:38:44.660
it's more, I think it's derived from pine cone, not P.
link |
01:38:49.240
Because in fact, if you look at the pineal,
link |
01:38:50.840
it is more pine cone shaped and so it's aptly named.
link |
01:38:54.480
Any human brain I've ever dissected,
link |
01:38:56.280
I confess I've dissected a lot
link |
01:38:57.440
because I teach neuroanatomy and have for years.
link |
01:39:00.600
I love looking at the pineal.
link |
01:39:02.240
It's the one structure in the brain that's not on both sides.
link |
01:39:05.320
It's usually pretty easy to find and it's pretty good size.
link |
01:39:08.080
It looks like a P and it's sitting right there
link |
01:39:11.360
and it's remarkable that it releases this hormone,
link |
01:39:15.200
probably our entire lifespan and is inhibited by light.
link |
01:39:20.040
So our pineal starts to release this
link |
01:39:22.340
into the general circulation.
link |
01:39:23.480
I have to imagine we have melatonin receptors
link |
01:39:25.080
in the brain and body.
link |
01:39:26.280
It's correct.
link |
01:39:27.120
So yeah, essentially your brain
link |
01:39:29.520
has a central master 24 hour clock
link |
01:39:32.320
called the suprachiasmatic nucleus that keeps internal time.
link |
01:39:37.320
Now it's not a precise clock if left to its own devices,
link |
01:39:41.840
nothing that a Swiss clockmaker would be proud of.
link |
01:39:44.480
It runs a little bit long and laggy.
link |
01:39:47.120
It's like an American clock.
link |
01:39:48.160
So there are a couple of good American watches by the way.
link |
01:39:51.060
Hamiltons are very nice, but we're not famous
link |
01:39:53.740
for our timekeeping or our punctuality for them,
link |
01:39:56.040
but the Swiss are.
link |
01:39:57.560
It's very, it's not quite Swiss-like,
link |
01:39:59.880
it's more Berkeley-like, which is very relaxed.
link |
01:40:02.120
Oh, you know, whatever.
link |
01:40:03.600
So in most adults, the average adult, I should say,
link |
01:40:07.440
your biological clock normally runs a little bit long.
link |
01:40:10.280
It's about 24 hours and 13 minutes,
link |
01:40:15.080
I think was the last calculation.
link |
01:40:17.200
But the reason that we don't keep drifting forward in time
link |
01:40:20.720
and kind of running consistently, you know,
link |
01:40:23.000
more and later and later,
link |
01:40:24.640
30 minutes by 30 minutes by 30 minutes each day
link |
01:40:27.560
is because your central brain clock
link |
01:40:30.000
is regulated by external things such as daylight
link |
01:40:33.360
and temperature, as well as food and activity.
link |
01:40:36.440
All of these are essentially different fingers
link |
01:40:39.820
that come along and on the wristwatch of the 24 hour clock
link |
01:40:43.680
will pull the dial out and reset it each day
link |
01:40:46.660
to precisely 24 hours.
link |
01:40:48.440
And I make that point because it knows 24 hour time,
link |
01:40:53.720
but it needs to tell the rest of the brain and the body
link |
01:40:57.680
the 24 hour time as well.
link |
01:41:00.520
And one of the ways that it does this
link |
01:41:02.520
is by communicating a chemical signal of 24 hour nurse
link |
01:41:08.640
of light and day using this hormone melatonin.
link |
01:41:13.000
And when it is at low levels or it's non-existent,
link |
01:41:16.400
it's communicating the message, it's daytime.
link |
01:41:19.080
And for us, diurnal species, it says,
link |
01:41:21.560
it's time to be awake.
link |
01:41:23.320
Yet at nighttime when dusk approaches
link |
01:41:25.880
and the brake comes off melatonin
link |
01:41:27.560
and we start to release it,
link |
01:41:28.960
then it signals to the rest of the brain and the body,
link |
01:41:31.900
look, it's dusk and it's nighttime.
link |
01:41:34.040
And for us, diurnal species, it's time to think about sleep.
link |
01:41:38.220
So melatonin essentially tells the brain and the body
link |
01:41:42.840
when it's day and when it's night.
link |
01:41:44.320
And with that, when it's time to sleep,
link |
01:41:46.280
when it's time to wake.
link |
01:41:47.720
And therefore that's why melatonin helps
link |
01:41:50.120
with the timing of the onset of sleep,
link |
01:41:53.760
but it doesn't really help
link |
01:41:55.160
with the generation of sleep itself.
link |
01:41:56.880
And this is why we'll come on to what those studies
link |
01:41:58.680
of supplementation have taught us.
link |
01:42:01.360
So it tells the rest of my brain and body,
link |
01:42:03.660
it's time to go to sleep.
link |
01:42:05.280
Perhaps even aids with the transition to sleep,
link |
01:42:07.880
but it's not going to, for instance,
link |
01:42:09.840
ensure the overall structure of sleep
link |
01:42:12.200
or it's not the conductor that's guiding the sleep orchestra
link |
01:42:16.440
so to speak throughout the entire night.
link |
01:42:18.180
Yeah, it's-
link |
01:42:19.020
It's more like the people that essentially take you
link |
01:42:22.740
to your seat and sit you down and give you your program.
link |
01:42:25.040
Right, exactly.
link |
01:42:25.880
Yeah, so the far less sophisticated analogy I have is,
link |
01:42:30.880
you know, melatonin is like the starting official
link |
01:42:33.380
at the 100 meter race in the Olympics.
link |
01:42:35.680
That's a better analogy.
link |
01:42:36.520
It calls all of the sleep races to the line
link |
01:42:40.200
and it begins the great sleep race.
link |
01:42:42.240
Yeah, better analogy by the way,
link |
01:42:43.720
coming from the sleep researcher of all people.
link |
01:42:46.520
But it doesn't participate in the race itself.
link |
01:42:48.920
That's a whole different set of brain chemicals
link |
01:42:51.440
and brain regions.
link |
01:42:54.080
Which then brings us on to perhaps the question
link |
01:42:57.800
of supplementation, which is,
link |
01:43:02.440
is it helpful for my sleep?
link |
01:43:04.200
Will I sleep longer?
link |
01:43:05.240
Will I sleep better?
link |
01:43:07.400
And if I am, what doses should I be taking?
link |
01:43:12.360
Sadly, the evidence in healthy adults who are not older age
link |
01:43:17.520
suggests that melatonin is not really particularly helpful
link |
01:43:20.960
as a sleep aid.
link |
01:43:22.040
I think there was a recent meta analysis
link |
01:43:24.440
that demonstrated when it looked
link |
01:43:28.080
at all of the different sleep parameters.
link |
01:43:30.040
Melatonin and a meta analysis
link |
01:43:32.560
for those not knowing what that is,
link |
01:43:34.320
it's a scientific sort of method that we use
link |
01:43:36.160
where we gather all the individual studies
link |
01:43:38.960
and we put them in a big bucket
link |
01:43:40.400
and we kind of do this kind of statistical fancy sleight
link |
01:43:43.040
of hand and we try to come up with a big picture
link |
01:43:45.280
of what all of those individual studies tell us.
link |
01:43:47.480
And what that meta analysis told us is that melatonin
link |
01:43:50.480
will only increase total amount of sleep by 3.9 minutes
link |
01:43:55.620
on average.
link |
01:43:56.460
Minutes?
link |
01:43:57.280
Minutes.
link |
01:43:58.120
Not even percent.
link |
01:43:58.960
And it will only increase your sleep efficiency by 2.2%.
link |
01:44:04.040
So it really-
link |
01:44:05.520
This is as they say in certain parts of California,
link |
01:44:10.000
that's weak sauce.
link |
01:44:11.680
That's a weak sauce effect.
link |
01:44:13.480
The sauce is not strong.
link |
01:44:14.760
The force is not strong in this one.
link |
01:44:16.900
When it comes to a tool that in healthy people
link |
01:44:21.160
who are not of older age,
link |
01:44:24.200
it doesn't seem to be especially beneficial.
link |
01:44:26.440
Now, you know, results can vary.
link |
01:44:28.600
Everyone is different, of course.
link |
01:44:29.920
So we're talking about the average,
link |
01:44:31.480
the so-called average human adult here.
link |
01:44:33.360
Well, melatonin in defense of what you're saying,
link |
01:44:36.400
and also I should mention,
link |
01:44:37.280
I have a colleague at Stanford, Jamie Zeitzer,
link |
01:44:39.760
who we know comes from Chuck Zeitzer's lab at Harvard Med
link |
01:44:42.240
where he also trained a terrific sleep researcher.
link |
01:44:44.500
And I asked him about melatonin
link |
01:44:45.840
and he essentially said the same thing that you just said,
link |
01:44:48.200
which is very little, if any, evidence
link |
01:44:50.320
that it can improve sleep.
link |
01:44:51.560
And yet it's probably the most commonly consumed
link |
01:44:55.000
so-called sleep aid.
link |
01:44:56.480
Hundreds of million dollars industry.
link |
01:44:58.120
Yeah, so either massive placebo effect
link |
01:45:00.960
or it's operating through some other mechanism
link |
01:45:03.200
related to quelling anxiety, perhaps.
link |
01:45:05.560
Yeah, that is actually interesting.
link |
01:45:07.400
You know, there are some studies
link |
01:45:08.700
where you do see some, you know, effects.
link |
01:45:10.960
Now, again, when you do the grand average of all studies,
link |
01:45:13.180
it just doesn't seem to have an effect.
link |
01:45:14.840
But let's assume that for some people
link |
01:45:16.620
it does have an effect.
link |
01:45:17.560
Let's not, again, be sort of completely dismissive of that.
link |
01:45:20.440
How could it have that effect?
link |
01:45:22.000
One of the reasons that I've become
link |
01:45:23.480
a little bit more bullish on melatonin
link |
01:45:26.040
from a sleep perspective,
link |
01:45:27.960
and then melatonin more generally for a,
link |
01:45:31.420
maybe we can speak about this too,
link |
01:45:32.900
as a counter measure
link |
01:45:37.440
when you're undergoing insufficient sleep,
link |
01:45:40.920
there are two different routes there.
link |
01:45:43.080
The first reason that I think it could have a sleep benefit
link |
01:45:45.640
for some people is not because it helps
link |
01:45:47.760
in the generation of sleep.
link |
01:45:48.800
We know that it doesn't.
link |
01:45:50.160
It's because it too seems to drop core body temperature.
link |
01:45:54.400
There it is temperature again.
link |
01:45:55.520
I'm fascinated these days more and more by temperature
link |
01:45:59.000
as maybe not just a reflection of brain state
link |
01:46:03.620
and wakefulness and in sleep,
link |
01:46:05.460
but actually a lever that is quite powerful.
link |
01:46:08.720
And with all the interest in ice baths and hot showers
link |
01:46:11.560
and saunas and stuff, something that we will definitely
link |
01:46:13.600
touch on, temperature variation is so key.
link |
01:46:17.320
So if melatonin is dropping body temperature
link |
01:46:20.200
by a degree or so, something that you've said before
link |
01:46:22.600
can help induce a sleepy state,
link |
01:46:25.400
maybe that's what's allowing people to get in to sleep.
link |
01:46:27.360
I think that's one possibility.
link |
01:46:28.400
I don't think melatonin by itself will drop it
link |
01:46:31.080
by sort of a degree, certainly not a degree Celsius.
link |
01:46:34.720
And for ordinary in us to fall asleep
link |
01:46:37.240
and then stay asleep across the night,
link |
01:46:38.900
we do need to drop our core body temperature
link |
01:46:41.040
by about one degree Celsius
link |
01:46:42.820
or about two to three degrees Fahrenheit.
link |
01:46:45.940
And that's why it's always easier to fall asleep
link |
01:46:48.120
in a room that's too cold than too hot.
link |
01:46:51.380
I think that that's one potential avenue
link |
01:46:54.440
that we are considering thinking more deeply about
link |
01:46:58.080
when it comes to melatonin.
link |
01:47:00.160
And then the other is melatonin as an antioxidant,
link |
01:47:03.540
but let me table that for now
link |
01:47:05.840
because I'll just get us sidetracked.
link |
01:47:07.800
That's what we know so far about melatonin
link |
01:47:11.520
in terms of its supplementation benefit or lack thereof.
link |
01:47:15.440
Two final points that I shouldn't forget.
link |
01:47:17.680
One is the only population where we typically see
link |
01:47:21.000
some benefit and it often is prescribed is in older adults.
link |
01:47:25.240
Because as we-
link |
01:47:26.080
Older meaning 60 and older?
link |
01:47:27.840
Yeah, 60, 65 and older.
link |
01:47:29.680
Because as we get older,
link |
01:47:31.120
you can typically have what's called calcification
link |
01:47:33.860
of the pineal gland, which means that that gland
link |
01:47:36.300
that's releasing melatonin doesn't work as well anymore.
link |
01:47:40.080
As a consequence, they tend to have a flatter overall curve
link |
01:47:44.720
of melatonin released throughout the night.
link |
01:47:47.020
It's not this beautiful, lovely peak
link |
01:47:49.280
and this bullhorn message of it's darkness,
link |
01:47:52.000
please get to sleep.
link |
01:47:53.360
That's why older adults can have problems falling asleep
link |
01:47:55.920
or staying asleep.
link |
01:47:56.960
It's not the only reason by any stretch of the imagination,
link |
01:48:00.360
but it's one of the reasons
link |
01:48:01.540
and it's why melatonin supplementation in those cohorts,
link |
01:48:04.640
older adults, especially older adults with insomnia,
link |
01:48:07.840
people have thought about that
link |
01:48:09.680
as maybe an appropriate use case.
link |
01:48:12.520
Well, on those lines, if we were to compare dosages,
link |
01:48:17.880
do we know how much melatonin is typically released
link |
01:48:20.240
into the bloodstream per night?
link |
01:48:23.160
And can we use that as a kind of a rule of thumb
link |
01:48:26.440
by which to compare the typical amount
link |
01:48:28.060
that someone would supplement?
link |
01:48:29.320
I mean, typically the supplements for melatonin that I see
link |
01:48:32.920
in the pharmacy and elsewhere and online
link |
01:48:35.100
range anywhere from one milligram to 12
link |
01:48:38.200
or even 20 milligrams.
link |
01:48:40.360
My guess is that a normal night's release of melatonin,
link |
01:48:45.000
typical for somebody in their 20s, 30s, 40s,
link |
01:48:47.840
would be far lower than that, am I correct or wrong?
link |
01:48:51.520
Yeah, it's many magnitudes lower
link |
01:48:54.080
and this is one of the problems is that I see that too.
link |
01:48:56.480
I see typical doses are five milligrams or 10 milligrams
link |
01:49:01.420
and of course, if you're a supplement company,
link |
01:49:04.600
putting 10 milligrams versus five milligrams
link |
01:49:06.720
if that's what you're actually doing,
link |
01:49:07.960
which we'll speak about purity as well,
link |
01:49:11.480
it's kind of like the super gulp size.
link |
01:49:14.800
Nobody wants to lower price.
link |
01:49:17.000
They just want you to,
link |
01:49:19.120
we'll just give you more for the same price
link |
01:49:20.960
and that's how we'll compete.
link |
01:49:22.000
So it's been this escalating arms race
link |
01:49:25.080
of melatonin concentration
link |
01:49:26.980
and it really does not look meaningful
link |
01:49:29.760
for sleep in any way.
link |
01:49:32.980
What we've actually found is that the optimal doses
link |
01:49:36.600
for where you do get sleep benefits
link |
01:49:38.720
in the populations that we've looked at
link |
01:49:41.200
are somewhere between 0.1 and 0.3 milligrams of melatonin.
link |
01:49:47.320
In other words, the typical doses are usually 10 times,
link |
01:49:51.320
20 times, maybe more than what your body
link |
01:49:55.520
would naturally expect
link |
01:49:56.500
and this is what we call a supra physiological dose.
link |
01:50:00.480
In other words, it's far above
link |
01:50:02.320
what is physiologically normal.
link |
01:50:04.840
And to put that in context,
link |
01:50:06.200
imagine I said to you,
link |
01:50:07.480
I want you to eat 20 times as much food today.
link |
01:50:11.200
I thought you're going to use testosterone as example.
link |
01:50:13.960
You're going to take 300 times
link |
01:50:15.520
the normal amount of testosterone.
link |
01:50:16.720
We know that would have tons of deleterious effects.
link |
01:50:20.440
It'd be terrible and yet you can do this.
link |
01:50:22.680
One thing that I'm concerned about
link |
01:50:24.240
about these supra physiological levels of melatonin
link |
01:50:27.240
is that many years ago,
link |
01:50:28.640
actually here at Berkeley when I was a graduate student,
link |
01:50:30.440
we would inject animals
link |
01:50:33.360
which were seasonally breeding animals with melatonin.
link |
01:50:36.760
And the consequence of that was that their gonads,
link |
01:50:41.280
either their testes or ovaries
link |
01:50:42.600
would shrink many hundred fold or more.
link |
01:50:46.680
In other words, they would go
link |
01:50:47.680
from having nice healthy sized hamster testicles,
link |
01:50:51.400
what a hamster would consider healthy size for a hamster,
link |
01:50:54.280
and they would shrink to the size of a grain of rice.
link |
01:50:56.440
So from like an almonds to a grain size of a grain of rice.
link |
01:50:59.320
I had to see that only once for me to be very concerned
link |
01:51:01.880
about super physiological levels of melatonin.
link |
01:51:04.420
And I realized that melatonin does different things
link |
01:51:06.760
in different species.
link |
01:51:07.580
We are not hamsters, we are not seasonal breeders,
link |
01:51:10.920
seasonally restricted breeders.
link |
01:51:12.440
There might be more breeding during certain seasons.
link |
01:51:14.140
I don't know those data,
link |
01:51:15.260
but nonetheless, hormones are powerful.
link |
01:51:18.520
And sure, there is an optimal,
link |
01:51:21.960
and sometimes we see that going slightly above
link |
01:51:26.420
endogenous levels for certain hormones,
link |
01:51:28.300
not always can have beneficial effects.
link |
01:51:30.460
And sometimes it can have detrimental effects.
link |
01:51:33.000
I'm just concerned about taking high levels of a hormone
link |
01:51:37.040
that has effects on the reproductive axis.
link |
01:51:40.060
And that's one of the reasons why I get very concerned
link |
01:51:42.820
when I see people really getting aggressive
link |
01:51:46.040
about melatonin supplementation,
link |
01:51:49.160
taking 110, 500, sometimes even 10,000 times
link |
01:51:53.280
the amount that we would normally release.
link |
01:51:54.560
That's my concern,
link |
01:51:55.840
although it's not nested in any one specific human study.
link |
01:51:58.800
I just don't like to see,
link |
01:52:01.220
I certainly don't want to see other people
link |
01:52:02.920
and I don't want to personally take a hormone
link |
01:52:06.180
that's known to be androgen suppressive at high levels.
link |
01:52:10.640
Why would I take that?
link |
01:52:12.600
That's the question I asked myself.
link |
01:52:14.320
I think it's a very good point.
link |
01:52:16.320
And if you look at some of the evidence
link |
01:52:19.720
around melatonin's lethality,
link |
01:52:23.160
if you want to go to that extreme,
link |
01:52:24.800
for the most part, it's pretty safe.
link |
01:52:27.520
You mean you can take a lot of it before you die.
link |
01:52:29.640
Right, exactly.
link |
01:52:30.640
Yeah, but that should not be your yardstick
link |
01:52:34.080
because you really need to think about your health,
link |
01:52:37.600
not just whether this thing is going to kill you or not
link |
01:52:40.280
as the decision matrix through which you pop a pill.
link |
01:52:45.480
And it comes on to this concern around melatonin
link |
01:52:49.060
because there was a study,
link |
01:52:50.560
I think it's one that you mentioned too,
link |
01:52:53.280
where they looked at over,
link |
01:52:54.840
I think it was at least over 20 different brands
link |
01:52:57.480
of melatonin supplements.
link |
01:52:59.640
And what they found is that based on what it said
link |
01:53:01.920
on the bottle versus what was in the capsules themselves,
link |
01:53:04.960
it ranged from, I think it was 83% less
link |
01:53:08.440
than what it said on the bottle to 478% more
link |
01:53:12.760
than what it said on the bottle.
link |
01:53:14.260
Now, if that's a 10 milligram pill
link |
01:53:18.840
and it's 478% more than 10 milligrams
link |
01:53:23.920
and we're already at 10 milligrams
link |
01:53:26.280
at many tens of times more than is a physiological
link |
01:53:30.720
rather than a supra physiological dose,
link |
01:53:34.080
we do need to be a bit thoughtful.
link |
01:53:35.960
Yeah, remember those hamsters folks.
link |
01:53:38.560
Well, and I do appreciate the deep dive on melatonin
link |
01:53:43.200
because I think people need to understand
link |
01:53:46.280
that it's nuanced, it's a matter of dosages
link |
01:53:48.560
and timing, et cetera.
link |
01:53:50.020
And then it may have its place,
link |
01:53:51.200
as you mentioned in older individuals.
link |
01:53:53.760
And I should mention that I'm an avid consumer
link |
01:53:56.720
of supplements that I believe in for me.
link |
01:53:59.560
And I have been for a very long time.
link |
01:54:00.900
So I'm by no means anti supplement.
link |
01:54:04.340
Some supplements I refuse to take or avoid taking,
link |
01:54:07.200
others I am quite avidly take.
link |
01:54:09.860
And along those lines, I personally,
link |
01:54:14.800
and I don't know what your thoughts on this are,
link |
01:54:17.600
but there are a few things
link |
01:54:19.120
that I've personally found beneficial.
link |
01:54:20.520
I'd love your thoughts on them.
link |
01:54:21.600
And I would love it if you would tell me
link |
01:54:23.680
that everything I'm about to refer to as placebo,
link |
01:54:26.560
that would be fine.
link |
01:54:27.400
So that's what we do.
link |
01:54:28.680
We're scientists, we argue,
link |
01:54:29.840
and then we remain friends as it goes.
link |
01:54:33.920
So magnesium.
link |
01:54:37.000
There are many forms of magnesium.
link |
01:54:38.320
Magnesium citrate is, as we know, is a terrific laxative.
link |
01:54:41.840
Magnesium malate seems, at least from a few studies,
link |
01:54:45.600
seems to relieve some of delayed onset muscle soreness,
link |
01:54:48.160
doesn't seem to create a kind of sedation.
link |
01:54:49.960
Two forms of magnesium that I'm aware of,
link |
01:54:51.720
magnesium biglycinate and magnesium threonate.
link |
01:54:55.160
Yeah.
link |
01:54:56.620
We believe, based on the data,
link |
01:54:58.620
can more actively cross the blood-brain barrier.
link |
01:55:01.560
So you put it in your gut,
link |
01:55:02.480
but some of that needs to get into your brain
link |
01:55:03.840
in order to have the sedative effect.
link |
01:55:05.600
What are your thoughts on magnesium supplementation?
link |
01:55:08.140
Do you supplement with magnesium?
link |
01:55:10.560
And what studies would you like to see done
link |
01:55:14.540
if they haven't been done already?
link |
01:55:16.160
So I don't supplement with magnesium,
link |
01:55:19.240
but I do think threonate is interesting
link |
01:55:21.800
because of that higher capacity
link |
01:55:24.480
to cross the blood-brain barrier
link |
01:55:26.080
and actually have a central nervous system effect.
link |
01:55:28.520
And the reason that that interests me
link |
01:55:30.160
is because the sleep is by the brain, of the brain,
link |
01:55:33.880
and also for the brain, as well as for the body.
link |
01:55:37.840
We just don't have a particularly good set of studies
link |
01:55:40.840
that have targeted exclusively threonate.
link |
01:55:43.800
We do have lots of studies that have just looked
link |
01:55:45.840
at magnesium in general for sleep.
link |
01:55:48.240
And overall, the data is uncompelling.
link |
01:55:51.880
Interesting.
link |
01:55:52.720
And for a while, I was confused as to why.
link |
01:55:57.440
Where did this come from?
link |
01:55:59.080
This kind of myth of magnesium.
link |
01:56:01.900
So I started looking back into the literature
link |
01:56:04.320
and I've best traced it, at least as far as I can tell,
link |
01:56:08.880
to early studies showing that those who were deficient
link |
01:56:12.440
in magnesium also had sleep problems.
link |
01:56:15.800
They had other problems too, of course,
link |
01:56:17.920
but sleep problems were one of that set of sequelae
link |
01:56:21.200
that came from having lower magnesium.
link |
01:56:24.260
And when they supplemented with magnesium
link |
01:56:28.120
and tried to restore those levels,
link |
01:56:29.780
some of those sleep problems dissipated.
link |
01:56:32.320
And then that seems to have gotten lost in sort of
link |
01:56:35.640
some game of sort of like whispers around the room.
link |
01:56:38.480
And it's become translated into people
link |
01:56:40.920
who don't have sleep problems,
link |
01:56:42.720
who are healthy sleepers and who are healthy in general,
link |
01:56:45.360
and who have healthy normal levels of magnesium.
link |
01:56:47.920
If they take more magnesium, they will sleep better.
link |
01:56:51.600
And the data really there is not good.
link |
01:56:53.740
Once again, the only study that I've seen
link |
01:56:56.980
where magnesium did have some efficacy
link |
01:56:59.240
was in a study with older adults.
link |
01:57:00.880
I think they were 60 to 80 years old.
link |
01:57:03.000
It may have been exclusively women now I think about it.
link |
01:57:06.480
And they also had insomnia.
link |
01:57:08.400
And in that population, you did see some benefits.
link |
01:57:11.680
And my guess is that because it's an older community
link |
01:57:15.360
as well, they were probably deficient in magnesium.
link |
01:57:18.440
So they fit the former category of simply
link |
01:57:21.660
when you're deficient and you restore,
link |
01:57:23.840
you can help sleep sort of return to normal.
link |
01:57:27.460
But if you are not deficient and you're healthy
link |
01:57:29.640
and you're not old and you don't have insomnia,
link |
01:57:31.480
and you're supplementing thinking that it provides sleep,
link |
01:57:34.920
right now, the data isn't supportive of that.
link |
01:57:37.600
But I just don't think we have enough threonate data
link |
01:57:39.960
to actually speak about that
link |
01:57:41.140
because it could just be a blood brain barrier issue so far
link |
01:57:44.200
with the other forms.
link |
01:57:45.500
So maybe some additional studies looking specifically
link |
01:57:47.960
at threonate or biglycinate would be useful.
link |
01:57:51.040
Magnesium is involved in so many cellular processes.
link |
01:57:54.000
You can imagine that this effect, if it truly exists,
link |
01:57:57.080
is, as we say in science, in the noise,
link |
01:57:59.160
meaning it's in the jitter of the data.
link |
01:58:02.360
But to isolate the real effect,
link |
01:58:03.920
one needs to do some more refined studies.
link |
01:58:07.700
What are some things that are of interest to you,
link |
01:58:11.160
if not things that you happen to take?
link |
01:58:15.020
These are not things that I personally take,
link |
01:58:16.620
mostly because I just haven't experimented with them.
link |
01:58:19.880
Valerian root is one.
link |
01:58:23.960
Tart cherry and kiwi fruit.
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01:58:27.100
Tell me about Valerian root, tart cherry, and kiwi fruit.
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01:58:30.960
This is new to me.
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01:58:32.560
I mean, I've certainly heard of them,
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01:58:34.300
and tart cherry and kiwi sounds delicious.
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01:58:38.020
But what's happening with Valerian root,
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01:58:41.320
tart cherry, and kiwi,
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01:58:42.920
and are we talking about eating tart cherries and kiwis
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01:58:45.840
and Valerian roots?
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01:58:47.480
Or are we talking about taking them in pill form?
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01:58:49.140
Usually it's supplements,
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01:58:50.500
but it's also both for tart cherries and for kiwis.
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01:58:54.880
It's the actual fruit themselves.
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01:58:58.120
Valerian often touted as a beneficial sleep aid,
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01:59:02.380
and lots of people swear by it too.
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01:59:04.940
But the evidence is actually quite against that.
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01:59:08.120
Not that it makes your sleep worse,
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01:59:09.920
but of at least the seven good studies
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01:59:13.360
that I've been able to find.
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01:59:14.560
And typically these are of the nature
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01:59:17.000
of what we call a randomized placebo crossover design.
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01:59:21.260
And I won't bore people with what that means.
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01:59:23.620
It's sort of one of the-
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01:59:24.460
Good studies, solid studies.
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01:59:25.360
Yeah, it's one of the sort of gold standard methods
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01:59:27.680
that we have when we're looking at intervention studies,
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01:59:29.540
such as drug studies.
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01:59:30.880
Five of the seven found no benefit
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01:59:33.860
of Valerian root on sleep.
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01:59:36.140
Then two out of the seven,
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01:59:37.960
the data was just insufficient.
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01:59:40.680
I think it was a power issue
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01:59:42.080
where they just couldn't make any strong conclusions.
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01:59:45.280
And then I think there was the most recent study,
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01:59:51.320
I think looked at two different doses of Valerian.
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01:59:56.880
I could have this wrong,
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01:59:58.420
and they just failed to find any effects once again.
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02:00:01.680
But the stunning part of that paper,
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02:00:03.800
as I recall, they had this big table
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02:00:05.800
with all of the different sleep metrics that they looked at.
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02:00:08.400
And there were well over 25 different things
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02:00:10.800
that they tried to see if Valerian impacted.
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02:00:14.240
And none of them were significant,
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02:00:16.300
which stuns me because from statistical probabilities,
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02:00:19.280
we know if you just randomly perform 25 statistical tests,
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02:00:23.520
chances are probabilistically,
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02:00:25.220
you'll just get one significant result by random chance.
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02:00:28.960
And even with random chance on their side,
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02:00:32.360
they still couldn't find a benefit of Valerian.
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02:00:36.160
So Valerian root might be worse than nothing at all
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02:00:38.880
if there is, so to speak.
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02:00:41.080
I mean, again, placebo effect,
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02:00:43.040
we can think about that too.
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02:00:44.600
And I would say that if you feel
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02:00:45.960
as though it's having a benefit for you,
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02:00:48.180
and with all of the caveats that we have with supplements,
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02:00:51.360
things like melatonin, purity, concentration, et cetera,
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02:00:54.920
maybe it's no harm, no foul,
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02:00:56.640
but I'm not a medical doctor,
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02:00:59.000
and I don't tell anyone about,
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02:01:01.100
we have all of these disclaimers about not recommending.
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02:01:03.160
Sure, and we'll include these.
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02:01:04.480
I mean, I always say, we're not physicians,
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02:01:06.400
we don't prescribe anything.
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02:01:07.360
We're scientists and professors, so we profess things.
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02:01:10.000
And it's up to people to be responsible for their own health,
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02:01:13.620
not just to protect us, but to protect themselves.
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02:01:17.840
I do want to hear about tart cherry and kiwi fruit.
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02:01:23.000
What's the story there?
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02:01:24.360
Strange, isn't it?
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02:01:25.200
I was, you know, I'm kind of a hard-nosed scientist.
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02:01:30.140
And when people, you know, some years ago started saying,
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02:01:32.820
oh, tart cherries, it's the thing, or kiwi fruits,
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02:01:35.560
I was thinking, oh my goodness, this sounds a bit-
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02:01:38.120
You've been in California a little too long.
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02:01:39.200
Yeah, I know, yeah, the sun has softened me.
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02:01:42.200
But I thought, look, one of the things
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02:01:44.440
that we have to do as scientists
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02:01:46.440
is be as open-minded as possible,
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02:01:49.080
and I should not be so quick to dismiss.
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02:01:51.320
So I went to the literature,
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02:01:53.120
just started reading as much as I could about it.
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02:01:56.100
And there were three really good randomized
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02:01:59.440
placebo crossover trials with tart cherries.
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02:02:03.000
And what they found was that in one study,
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02:02:06.040
it reduced the amount of time that you spent awake at night
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02:02:10.760
by over an hour.
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02:02:12.840
And then the other two studies,
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02:02:14.520
one of them found that it increased the amount of sleep
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02:02:17.680
that you got by 34 minutes.
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02:02:19.840
The other, it increased the amount of sleep
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02:02:21.820
that you got by 84 minutes.
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02:02:24.880
Which, you know, these are,
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02:02:26.600
and what's striking is that they were independent studies,
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02:02:30.160
I think, meaning that they were from independent groups.
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02:02:33.000
And these were, you know, some of these guys,
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02:02:35.440
you know, girls, I know pretty well.
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02:02:38.760
And they're really-
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02:02:39.600
You know and trust their work.
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02:02:40.440
Right, I really trust their work too.
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02:02:41.960
Were they ingesting actual tart cherries
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02:02:43.620
or they're drinking the juice or in capsule?
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02:02:45.320
It was juice.
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02:02:46.240
So they, in all three studies, it was juice.
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02:02:49.360
Although you can, I think as a supplement,
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02:02:51.260
you can buy it in a capsule and we've got no idea
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02:02:53.440
whether that changes the benefit or not.
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02:02:56.360
What was also interesting in,
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02:02:57.700
I think it was that last study
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02:02:58.880
where they got an increase in sleep by 84 minutes.
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02:03:02.340
It also decreased daytime napping significantly.
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02:03:06.360
Oh, that's one that I could certainly make use of.
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02:03:08.800
I love my daytime naps, but I'd love to skip them too.
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02:03:11.480
Right, and we can speak about naps
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02:03:13.360
and sort of the upside and downside of that.
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02:03:15.980
Which then made me think, well, if that's the case,
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02:03:18.640
maybe the net benefit on sleep overall is no different.
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02:03:23.360
It's just that it decreases the amount of time
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02:03:25.360
that some people were taking to sleep during the day
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02:03:27.980
and giving it back to the night.
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02:03:29.600
But that wasn't the case
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02:03:30.440
because if you added the total amount of sleep
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02:03:32.880
that they were getting without tart cherries,
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02:03:34.600
both naps and nightly sleep combined,
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02:03:37.200
still when you took tart cherries,
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02:03:39.360
you still got a net sum benefit of total amount of sleep.
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02:03:42.900
So, you know, so far when it comes to supplements
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02:03:48.400
and those types of studies, they're good studies
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02:03:51.860
and the data looks interesting.
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02:03:53.400
But as a drug itself, you know, if this was clinical drug,
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02:03:57.320
you know, three studies that are somewhat small in nature
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02:04:00.480
and have some positive benefit,
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02:04:02.000
that's what we would call preliminary data
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02:04:04.480
of maybe a chin scratching kind.
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02:04:07.560
So keep this in context.
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02:04:08.400
Yeah, and depending on the margins for safety,
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02:04:10.100
one might think, well, given that it's a tart cherry
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02:04:13.260
as opposed to some pharmaceutical you need a prescription for
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02:04:16.160
then, you know, some people their threshold
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02:04:18.860
to experiment with supplements is quite low,
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02:04:21.080
some people their threshold is quite high.
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02:04:23.100
I feel like, you know, there are two categories
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02:04:25.880
or at least two categories of folks out there.
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02:04:27.960
People who hear, oh, tart cherry can improve sleep
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02:04:31.120
and will run out and try it.
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02:04:32.680
And people who hear, well, that sounds crazy,
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02:04:35.160
why would I do that?
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02:04:37.460
But of course we have to remind people
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02:04:39.000
that tart cherry isn't really what we're talking about,
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02:04:41.840
presumably, if this is a real effect
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02:04:43.640
and it sounds like it might be,
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02:04:45.320
that there's a compound in tart cherry
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02:04:47.680
that if we were to call it whatever, whatever,
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02:04:50.160
five, alpha, six, you know, some molecule,
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02:04:53.380
if we refer to it by its technical name,
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02:04:55.580
then people would say, oh, that sounds like
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02:04:57.640
a very interesting technical way to approach sleep,
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02:05:00.080
but doesn't sound very natural.
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02:05:01.240
So both groups are a little bit misguided
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02:05:04.440
in the sense that people who think that everything
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02:05:06.240
that comes from naturally occurring foods, plants, et cetera,
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02:05:08.680
things that grow out of the ground,
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02:05:09.820
that that's all safe, that's not true.
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02:05:12.200
And people that think that pharmaceuticals are the only,
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02:05:15.640
if it's not evidence with the purified molecule,
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02:05:18.780
then something's not of utility.
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02:05:20.680
Well, that's certainly not true.
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02:05:21.720
Somewhere in the middle, I think lies the answer,
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02:05:23.600
which is, it sounds to me like tart cherry
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02:05:25.840
is at least an intriguing potential sleep aid,
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02:05:29.700
intriguing potential sleep aid,
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02:05:31.640
and I'm underscoring potential.
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02:05:34.200
I'm certainly intrigued by it to the point
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02:05:35.880
where I might experiment a bit,
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02:05:37.280
but I'm an experimenter for myself.
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02:05:39.780
Before I ask you about kiwi,
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02:05:43.400
I've had quite good results
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02:05:44.840
from taking something called apigenin,
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02:05:46.560
which is a derivative of chamomile,
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02:05:48.520
but in supplement form, I think I take 50 milligrams
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02:05:51.520
about 30 minutes before sleep,
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02:05:53.600
and I subjectively experience a better night's sleep,
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02:05:59.140
so to speak.
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02:05:59.980
I don't measure, I confess I don't measure my sleep.
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02:06:02.040
I'm not a sleep tracker guy.
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02:06:05.160
But there are a few papers out there.
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02:06:08.100
They're not what we would call
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02:06:09.800
published in blue ribbon journals,
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02:06:11.400
but they have control groups
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02:06:13.920
and it looks somewhat interesting.
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02:06:15.400
And there, when I say apigenin,
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02:06:18.080
people get somewhat intrigued,
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02:06:19.320
oh, this molecule, chamomile, has long been thought
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02:06:22.780
to be a sedative, a mild sedative, but a sedative.
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02:06:26.260
Do you drink chamomile tea?
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02:06:27.440
Do you take apigenin?
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02:06:28.800
What are your thoughts on apigenin?
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02:06:29.960
Yeah, I don't, and I have looked into some of the data
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02:06:33.520
regarding sleep as well.
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02:06:35.360
Right now, from best I can tell,
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02:06:37.000
it's mostly subjective data
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02:06:39.120
rather than objective, hard sort of sleep measures.
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02:06:42.280
And that's why right now, it's sort of unclear,
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02:06:46.520
not no comment, but just unclear,
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02:06:49.600
not dismissing it because I think you and I
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02:06:52.320
both ascribe to the idea of absence of evidence
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02:06:55.240
is not evidence of absence.
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02:06:57.000
So keep your mind open, at least I tell that to myself.
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02:07:02.280
I think if you're finding a benefit
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02:07:04.320
and you can do what I would think of
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02:07:06.700
if I was personally experimenting,
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02:07:08.500
which is both the positive and negative
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02:07:11.280
parts of the experiment, what I mean by that is,
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02:07:13.660
let's say that I now want to think about
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02:07:16.440
some kind of a sleep supplement.
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02:07:18.680
I will take some kind of baseline set of recordings
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02:07:21.880
for a month and I will just gauge where I'm at,
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02:07:26.520
sort of supplement free.
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02:07:28.240
Then I'll go on for a month
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02:07:30.360
to whatever I'm thinking of taking.
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02:07:32.440
And I don't supplement, but let's say that I want to
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02:07:35.660
and I experiment with that.
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02:07:37.480
And I feel as though based on my metrics,
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02:07:39.940
be them objective from my aura ring
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02:07:41.840
or be them subjective from whatever I'm writing down
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02:07:45.160
in the morning and both are important and valid,
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02:07:47.460
subjective and objective.
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02:07:49.160
We like both in the sleep world.
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02:07:51.880
And I think, okay, look, it's clearly that
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02:07:54.280
it seems to have some kind of an effect.
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02:07:56.980
The key thing, however, is then do the negative experiment,
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02:08:00.320
which is now come off it for another month
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02:08:04.000
and see do things get worse?
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02:08:06.280
And if I can see that by directionality,
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02:08:09.260
then I'm starting to think maybe I'm believing this
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02:08:13.000
a little bit more.
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02:08:14.100
So that's the way I would sort of typically approach
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02:08:17.400
a supplementation regimen if I were to do it.
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02:08:20.240
And that's just me, that's just the way my mind works, but.
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02:08:23.020
No, that's great.
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02:08:23.860
I think it's very scientific and organized
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02:08:26.240
in a way that allows you and would allow other people
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02:08:29.600
to make very informed decisions for themselves.
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02:08:32.940
I like that.
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02:08:34.840
I like to think in terms of manipulating
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02:08:37.740
any aspect of our biology,
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02:08:39.680
that behavioral tools always are the first line of entry.
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02:08:43.920
Then nutrition, everyone has to eat sooner or later,
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02:08:46.680
even if you're fasting.
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02:08:48.300
Then perhaps supplementation, then prescription drugs,
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02:08:52.280
and then perhaps brain machine interface,
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02:08:54.320
devices that you use to induce something.
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02:08:56.560
And those could be done in combination.
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02:08:57.960
But what concerns me is when I hear people say,
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02:09:01.280
well, what should I take without thinking
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02:09:03.720
about their behavior, their light viewing behavior, et cetera.
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02:09:06.140
But of course these things work in combination.
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02:09:08.840
I think it's, you're right that there's many,
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02:09:11.300
when it comes to sleep, there are many low hanging fruits
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02:09:14.840
that don't necessarily require you to, you know,
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02:09:18.720
put sort of exogenous molecules, in other words,
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02:09:21.600
things like supplements into your body,
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02:09:23.620
or, you know, use different types of drugs
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02:09:26.480
to help you get there.
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02:09:28.080
Now, when it comes to prescription sleep aids,
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02:09:31.360
I think I've been, again, a little bit too forthright.
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02:09:34.860
We know in clinical practice that there may be a time
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02:09:38.340
and a place for things like sleeping pills.
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02:09:40.600
They are a short term solution to certain forms of insomnia,
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02:09:46.240
but they are not recommended for the longterm.
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02:09:49.680
And we also know that there are lots of other ways
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02:09:51.440
that you can get a sleep help,
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02:09:55.340
or you can get a sleep curative profile
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02:09:58.040
from things like cognitive behavioral therapy for insomnia,
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02:10:00.760
which is a non-drug approach, psychological one.
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02:10:02.640
And quite effective from what I understand, good data.
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02:10:05.120
Just as effective as sleeping pills, great data,
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02:10:07.140
more effective in the longterm.
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02:10:08.700
There was a recent study published that
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02:10:10.520
after working with that therapist,
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02:10:11.880
some of the benefits lasted almost a decade, you know.
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02:10:15.480
Now, if you stop sleeping pills,
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02:10:17.400
usually you have rebound insomnia where your sleep goes back
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02:10:20.600
to being just as bad, if not worse.
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02:10:23.200
And I think the same is true
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02:10:24.400
when we think about supplementation.
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02:10:25.800
There are so many things that are easy to implement
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02:10:29.560
when it comes to sleep that don't require venturing out
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02:10:33.540
into those waters.
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02:10:34.380
And again, we're not here to tell anyone
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02:10:36.860
about whether they should venture or not.
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02:10:38.440
That's completely your choice.
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02:10:40.040
All I'm saying is that if you want to think
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02:10:41.880
about optimizing your sleep,
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02:10:43.660
there are a number of ways that you can do it
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02:10:45.840
that don't necessarily require you to swallow anything
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02:10:49.360
or inject anything, or smoke anything, or free base.
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02:10:52.760
And for which the margins of safety are quite wide.
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02:10:55.960
That's the other one.
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02:10:56.960
Yeah, sorry, thank you for that.
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02:10:57.800
So speaking of low hanging fruit,
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02:10:59.040
I don't know how low it hangs in reality,
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02:11:01.080
but what about kiwi?
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02:11:02.620
They're delicious to me anyway.
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02:11:04.260
Yeah, the humble kiwi fruit.
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02:11:07.200
Named not, shouldn't be mistaken
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02:11:09.400
for the flightless bird of New Zealand,
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02:11:13.400
which is the native bird there.
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02:11:14.800
We're talking about the kiwi, the fruit here,
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02:11:16.700
which those trees and shrubs are mostly Southeast Asia.
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02:11:24.000
Kiwi fruits have been previously touted
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02:11:26.520
as potentially having a sleep benefit,
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02:11:28.880
which again got me curious,
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02:11:30.120
and I at first threw it out.
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02:11:32.800
To my knowledge, there's really only one
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02:11:35.220
published human study that's of any value.
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02:11:38.280
But what they did find was that it decreased
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02:11:41.400
the speed of time with which it took you to fall asleep.
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02:11:43.760
These are people ingesting the whole kiwi?
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02:11:45.480
So it's ingesting the whole kiwi.
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02:11:46.840
With the skin, I eat the skin,
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02:11:48.440
people cringe when they see me do it.
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02:11:49.600
Well, I think, no, no, no,
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02:11:51.360
I think the idea is some of the good stuff,
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02:11:53.720
and I'll come on to this,
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02:11:54.680
may actually be in the skin itself.
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02:11:57.080
Thank you, you just helped me win a bet.
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02:12:00.000
I'll give you your-
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02:12:00.840
Okay, okay, yeah, you can pay me later.
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02:12:02.400
By the way, this skin is used, no, no, no,
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02:12:04.120
he just told me to say that, so he went, no, he did not.
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02:12:07.760
So the skin seems to be part
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02:12:09.520
of this potential sleep equation.
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02:12:12.160
And that's the, yeah, you fell asleep faster,
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02:12:16.460
and you stayed asleep for longer,
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02:12:19.000
and you spent less time awake throughout the night.
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02:12:22.100
And I just thought, well, that's one study,
link |
02:12:24.320
what can you really do with that?
link |
02:12:26.340
There was another study, however, in an animal model,
link |
02:12:29.940
which is a little bit more interesting.
link |
02:12:33.400
And once again, they found a very similar phenotype
link |
02:12:36.600
that the rats, oh, sorry, they were mice.
link |
02:12:39.140
The mice fell asleep faster,
link |
02:12:41.480
and they also spent longer time in sleep.
link |
02:12:44.880
The sleep duration also increased.
link |
02:12:47.120
What was also interesting mechanistically,
link |
02:12:49.280
and this is not the mechanism that I think ties together
link |
02:12:52.760
tart cherries, kiwi fruit, and things like melatonin,
link |
02:12:58.760
because I think there could be one common binding mechanism.
link |
02:13:02.240
What they found in the animal study
link |
02:13:03.800
is that they could block those kiwi fruit sleep benefits
link |
02:13:08.360
using a GABA blocking agent.
link |
02:13:11.360
Now, GABA, which stands for gamma-aminobutyric acid,
link |
02:13:16.800
is one of the major inhibitory neurotransmitters
link |
02:13:19.720
of the brain.
link |
02:13:20.560
It's kind of like the red-
link |
02:13:21.400
It's kind of like the red light on the traffic light signal.
link |
02:13:27.360
Others are green light, GABA is red light.
link |
02:13:32.040
So by playing around with some sort of clever drugs
link |
02:13:35.800
to manipulate the system,
link |
02:13:37.320
they could prevent the benefit of the kiwi fruit
link |
02:13:40.200
by sort of buggering around with the GABA receptor,
link |
02:13:43.360
meaning that perhaps part of the kiwi fruit benefit on sleep
link |
02:13:48.200
was mediated by the brain's natural inhibitory
link |
02:13:52.640
neurotransmitter system called the GABA system.
link |
02:13:55.400
And I thought that convinced me a little bit more
link |
02:13:58.520
that maybe there's something here to read into.
link |
02:14:01.240
So to be determined, again, here is the banner,
link |
02:14:06.140
but tart cherries and kiwi fruits, the data surprised me,
link |
02:14:10.440
because in part, I was so preoccupied with being,
link |
02:14:15.440
I don't know, a bit purish about it and a bit snobby,
link |
02:14:20.380
thinking, oh, come on,
link |
02:14:21.800
that's definitely not going to work well.
link |
02:14:24.120
The data's so far.
link |
02:14:25.320
I look forward to a day when supplements
link |
02:14:26.980
are no longer called supplements,
link |
02:14:28.300
because at the end of the day,
link |
02:14:29.220
whether or not something has an effect,
link |
02:14:30.940
whether or not it's a whole kiwi fruit
link |
02:14:32.280
or a derivative kiwi fruit,
link |
02:14:33.840
will depend on the molecular compound.
link |
02:14:35.500
And as you mentioned,
link |
02:14:36.480
this potential mechanism via the GABA system,
link |
02:14:41.180
that's, we both as scientists get excited about mechanism,
link |
02:14:44.400
because when you can trace a mechanism and a pathway,
link |
02:14:46.520
it provides a rationale,
link |
02:14:47.680
a grounding for why kiwi of all things
link |
02:14:50.400
or tart cherry of all things
link |
02:14:51.920
might help increase total sleep time.
link |
02:14:56.440
I'd be remiss if I didn't mention
link |
02:14:58.360
or ask about tryptophan and serotonin.
link |
02:15:01.680
I can anecdotally say when I've taken tryptophan,
link |
02:15:05.920
the precursor to serotonin or serotonin itself,
link |
02:15:10.320
I have a horrendous night's sleep.
link |
02:15:12.640
I fall asleep very easily
link |
02:15:14.680
and I experience ridiculously vivid dreams,
link |
02:15:19.520
neither pleasant nor unpleasant, it's kind of a mishmash.
link |
02:15:22.240
And then I wake up
link |
02:15:23.440
and I experienced several days of insomnia that,
link |
02:15:27.400
and I've done the positive control and the negative control
link |
02:15:30.420
and all the variations thereof,
link |
02:15:32.340
to confirm that at least for me,
link |
02:15:34.640
supplementing with serotonergic agents
link |
02:15:38.080
is a bad idea for me.
link |
02:15:40.560
And tryptophan is a common sleep supplement
link |
02:15:44.680
and sleep aid that's discussed.
link |
02:15:48.340
The normal architecture of sleep
link |
02:15:50.160
involves the release of serotonin,
link |
02:15:52.080
but in a very timed and regulated way.
link |
02:15:54.040
What are your thoughts about serotonin in sleep,
link |
02:15:56.560
if you had to kind of put that into a nutshell,
link |
02:15:59.120
and then why supplementing with serotonin
link |
02:16:03.520
and or its precursor, tryptophan,
link |
02:16:05.980
might be a good or a bad idea for somebody?
link |
02:16:08.640
Well, I think one of the potential dangers
link |
02:16:13.640
is that based on what's going on in your body,
link |
02:16:18.220
that can change the absorption
link |
02:16:20.400
of natural sort of tryptophan and serotonin uptake
link |
02:16:24.160
within the brain itself.
link |
02:16:26.180
So I'm always thoughtful when you're playing around
link |
02:16:29.640
with that mother nature dynamic, as it were.
link |
02:16:32.820
The data, as you described,
link |
02:16:34.240
is a little bit all over the map.
link |
02:16:35.820
Some people say that it knocks them out.
link |
02:16:37.720
Other people say, just like you do,
link |
02:16:39.760
it has a terrible impact on my sleep.
link |
02:16:42.280
And when I stop, it's pretty bad for a couple of days.
link |
02:16:46.440
It seems to have this lingering after effect.
link |
02:16:51.320
I think what could be happening here is
link |
02:16:54.560
we need serotonin to, just as you described,
link |
02:16:57.280
be modulated in very specific ways
link |
02:16:59.540
during the different stages of sleep.
link |
02:17:01.220
If you look at the firing of the brain epicenters
link |
02:17:05.880
where serotonin is released,
link |
02:17:07.960
and there's a bunch of them in the brainstem,
link |
02:17:11.520
what you find on the release of serotonin too,
link |
02:17:15.240
when we're awake, it's usually in high concentrations.
link |
02:17:18.200
As we start to drift off to sleep,
link |
02:17:20.440
it lowers some, but not necessarily dramatically
link |
02:17:23.800
as we're going into non-REM sleep.
link |
02:17:26.520
But then when we go into REM sleep, serotonin is shut off.
link |
02:17:32.760
One of the other neuromodulators, noradrenaline,
link |
02:17:35.540
also shut off.
link |
02:17:37.360
REM sleep is the only time during the 24-hour period
link |
02:17:41.340
where we see noradrenaline and serotonin,
link |
02:17:43.960
or norepinephrine, completely shut down.
link |
02:17:46.800
When I say serotonin, we're also talking 5-HTP,
link |
02:17:49.640
sorry, 5-HT, that's just its chemical name here.
link |
02:17:52.640
So whether it, speaking about serotonin or 5-HT,
link |
02:17:56.120
it's the same thing, norepinephrine, noradrenaline,
link |
02:17:58.320
both of those need to be shut down
link |
02:18:00.840
for you to produce REM sleep.
link |
02:18:03.200
The other, one of the other neuromodulators
link |
02:18:05.460
that then ramps up to produce REM sleep is acetylcholine.
link |
02:18:10.620
So these three neuromodulators
link |
02:18:13.340
have this incredible reciprocal dance that they have
link |
02:18:17.880
for you to generate what is called a natural architecture
link |
02:18:21.120
of sleep throughout the night.
link |
02:18:22.360
It's the push-pull again.
link |
02:18:23.400
It's a push-pull again.
link |
02:18:26.240
It's chest and back, it's whatever you want to think of.
link |
02:18:30.880
That's why I think if you're trying to increase,
link |
02:18:34.180
dramatically drive up your serotonin levels at night,
link |
02:18:37.800
and that sustains throughout the night,
link |
02:18:39.460
when you're trying to get into REM sleep,
link |
02:18:41.360
you could be artificially fragmenting REM sleep.
link |
02:18:43.600
Now, I don't know the data.
link |
02:18:44.680
I don't think anyone's really got good data,
link |
02:18:47.120
but that's why I would be,
link |
02:18:49.680
you know, if you were to say, Matt, two years time,
link |
02:18:52.840
that's the data, help me understand the potential mechanism,
link |
02:18:55.880
or let's design some experiments, where would you go first?
link |
02:18:58.880
I would say, let's look at the disruption of REM sleep,
link |
02:19:01.900
non-REM sleep reciprocal regulation,
link |
02:19:04.520
because, you know, you need serotonin to be, you know,
link |
02:19:07.880
up at one time, down at another, so.
link |
02:19:11.000
I agree with everything you said,
link |
02:19:13.480
and I'm personally never taking tryptophan or serotonin
link |
02:19:17.640
again, unless there's some clinical reason for that,
link |
02:19:20.520
that I would need to do that.
link |
02:19:21.880
I want to ask about some other pro-sleep behaviors,
link |
02:19:26.440
but before I do that, let's talk about naps.
link |
02:19:30.260
I love naps.
link |
02:19:31.520
I come from a long history of nappers.
link |
02:19:34.720
My dad always took a nap in the afternoon.
link |
02:19:36.960
I take a 20 or 30 minute nap, or I do a practice,
link |
02:19:40.280
which I took the liberty of coining NSDR,
link |
02:19:43.200
non-sleep deep breaths,
link |
02:19:44.160
some sort of just passive laying out there,
link |
02:19:46.960
feet up, elevated, sometimes people do you,
link |
02:19:49.300
or I'll do yoga nidra,
link |
02:19:50.640
I'll do hypnosis or something of that sort,
link |
02:19:52.360
but 20 or 30 minutes of that has been very beneficial
link |
02:19:57.120
for me to get up from that nap
link |
02:19:59.360
or period of minimal wakefulness, we'll call it,
link |
02:20:03.120
and go about my day quite well,
link |
02:20:04.960
and also fall asleep just fine.
link |
02:20:07.080
What are the data on naps?
link |
02:20:10.400
Do you nap, and what are your thoughts
link |
02:20:13.480
about keeping naps short, meaning 20 to 30 minutes,
link |
02:20:17.120
versus getting out past 90 minutes, two hours?
link |
02:20:20.560
So for you personally, naps, yay, nay, or meh?
link |
02:20:25.040
I don't nap, and I've just never been a habitual napper.
link |
02:20:31.040
Is that because you don't feel sleepy in the afternoon,
link |
02:20:33.140
or because- I typically don't feel sleepy.
link |
02:20:35.200
So you're just hardier than I am.
link |
02:20:36.680
I wouldn't say hardier.
link |
02:20:38.000
I may be less capable of falling asleep.
link |
02:20:44.640
My sleep drive- But you're not
link |
02:20:45.480
dragging through the afternoon.
link |
02:20:46.360
No, no, I don't drag through everything.
link |
02:20:47.920
So you don't nap because you don't feel a need to nap.
link |
02:20:50.140
That's right, yep.
link |
02:20:51.120
Now, it's not that I am immune
link |
02:20:53.320
to what we call a postprandial dip in alertness.
link |
02:20:56.520
I definitely feel as though there can be
link |
02:20:58.280
this kind of afternoon lull,
link |
02:21:01.200
where I'm not quite as on as I was
link |
02:21:04.600
at 11 o'clock in the morning.
link |
02:21:06.120
And we know the physiology to that,
link |
02:21:07.880
which brings us back to whether we were designed to nap.
link |
02:21:11.920
So for naps, we've done lots of different studies,
link |
02:21:15.140
and other colleagues have done these studies too.
link |
02:21:17.200
Naps can have some really great benefits.
link |
02:21:19.580
We found benefits for cardiovascular health,
link |
02:21:22.200
blood pressure, for example.
link |
02:21:23.720
We found benefits for levels of cortisol.
link |
02:21:26.020
We found benefits for learning and memory,
link |
02:21:28.360
and also emotional regulation.
link |
02:21:30.880
How long are the naps typically in those studies?
link |
02:21:33.440
Anywhere between 20 minutes to 90 minutes.
link |
02:21:36.240
Sometimes we like to use a 90 minute window
link |
02:21:38.680
so that the participant can have a full cycle of sleep.
link |
02:21:42.000
And therefore they get both non-REM and REM sleep
link |
02:21:44.560
within that time period.
link |
02:21:45.680
Then when we wake them up,
link |
02:21:47.160
we usually wait a period of time
link |
02:21:48.840
to get them past what we call sleep inertia,
link |
02:21:51.200
which is that kind of window of grogginess
link |
02:21:53.060
where you say to your better half,
link |
02:21:54.800
look, you know, darling,
link |
02:21:56.200
please don't speak to me for the first hour.
link |
02:21:59.080
Don't anything right now.
link |
02:22:00.240
After the first hour of waking up,
link |
02:22:01.800
you know, I'm just not the best version of myself.
link |
02:22:05.320
So we wait for that time period,
link |
02:22:06.740
and then we do some testing.
link |
02:22:08.480
And we've done some testing before and after,
link |
02:22:10.160
and we look at the change.
link |
02:22:11.360
And that's how we measure what was the benefit of naps.
link |
02:22:13.720
And the reason why we sometimes do 90 minutes
link |
02:22:15.800
so that they get all of those stages of sleep.
link |
02:22:17.800
And then we correlate how much benefit did you get
link |
02:22:21.000
from the nap and how much of that benefit
link |
02:22:23.640
was explained by what REM sleep you got,
link |
02:22:26.440
what deep sleep you got, what light sleep you got.
link |
02:22:29.080
So that's the only reason that we use that
link |
02:22:30.880
as an experimental tool.
link |
02:22:33.200
What we've also found is that naps
link |
02:22:35.840
of as little as 17 minutes
link |
02:22:37.760
can have some quite potent effects on,
link<