back to indexMaster Your Sleep & Be More Alert When Awake | Huberman Lab Podcast #2
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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, and I'm a professor of neurobiology
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and ophthalmology at Stanford School of Medicine.
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Today's podcast episode is all about sleep.
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We're also going to talk about the mirror image of sleep,
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which is wakefulness.
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Now, these two phases of our life, sleep and wakefulness,
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govern everything about our mental and physical health.
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And we're not just gonna talk about
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what's useful about sleep.
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We're also gonna talk about how to get better at sleeping.
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And that will include how to get better at falling asleep,
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timing your sleep, and accessing better sleep quality.
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In doing so, we're also gonna discuss
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how to get more focused and alert in wakefulness.
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So because sleep and wakefulness are related,
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we really can't have a conversation
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about one without the other.
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Now, in keeping with this theme,
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you may catch a few snores in the background.
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Unlike me, my bulldog Costello
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can fall asleep anywhere, anytime,
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and he happens to be sleeping over there in the corner.
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So if you hear snoring, that's what that's about.
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As always, I wanna just mention that this podcast
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is part of my effort to bring zero cost to consumer,
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public education about science and science-related tools.
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It is unrelated to my teaching and research roles
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at Stanford School of Medicine.
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Today's podcast is brought to us by Helix Mattresses.
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Having the proper sleep environment,
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both the environment you're sleeping in
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and the object you're sleeping on,
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is critically important to getting a good night's sleep.
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Helix Mattresses are a little different than most
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because they're matched to your specific sleep needs,
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as well as whether or not you tend to run hot or cold
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as you sleep through the night,
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what position you sleep in, and so forth.
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So if you go to their website,
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they have a quiz that you can take
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that matches you to the particular mattress
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that's gonna be best for your sleep needs.
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I've always had a lot of trouble sleeping.
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I'm one of these people that can fall asleep easily,
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but then I wake up and I have a hard time
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getting back to sleep.
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And once I switched to a Helix Mattress
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that was precisely matched to my sleep needs,
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I found I could sleep through the night,
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which has made a tremendous difference for me.
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If you wanna try Helix Mattresses,
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you can go to helixsleep.com slash Huberman,
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and that will give you up to $200 off on a mattress order,
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as well as two pillows free with your mattress order.
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And of course, having the proper pillows
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is just as important as having the proper mattress.
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Today's podcast is also brought to us by Headspace.
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Headspace is a meditation app
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that teaches you how to meditate.
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It's fair to say that now there's a ton of research out
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there in peer-reviewed journals,
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supporting the fact that mindfulness meditation
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can support mental and physical health.
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But many people find it hard to meditate.
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In fact, I'm one of these people.
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I started meditating in my teens,
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but then I would drop it every few weeks or so,
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and then I'd get back to it maybe the following week
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I just was not very regular about my meditation practice.
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And then a few years ago, I was flying a lot for work
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and I was on JetBlue flights,
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and they have Headspace as part of the choice of things
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that you can watch on the TV screen.
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And as I started meditating more regularly,
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what I found is my sleep was better,
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I would arrive feeling more rested.
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It just had tremendous effects on my work performance
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and other aspects of my life.
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If you wanna try Headspace, you can go to headspace.com
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slash special offer.
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If you do that, you'll get one month
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of all of Headspace's meditations for free.
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That's the best offer right now.
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So if interested, go to headspace.com slash special offer.
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So let's talk about sleep.
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Sleep is this incredible period of our lives
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where we are not conscious.
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We might dream, we might twitch, we might even wake up,
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but in sleep, we are only in relation
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to things that are happening within our brain and body.
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Outside sensory experience, in most cases,
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can't really impact us.
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And yet sleep is this tremendously important period of life
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because it resets our ability to be focused, alert,
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and emotionally stable in the wakeful period.
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So we can't really talk about wakefulness, focus,
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motivation, mood, wellbeing without thinking about sleep.
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And that's why we're devoting this entire month
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to the discussion about sleep.
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But we also can't talk about sleep and think about sleep
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without thinking about wakefulness,
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because it turns out that the period that we call sleep
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and the period we call wakefulness
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are tethered to one another.
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What we do in the waking state determines
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when we fall asleep, how quickly we fall asleep,
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whether or not we stay asleep,
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and how we feel when we wake up the next day.
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And today, we're gonna talk mostly
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about how to get better at sleeping.
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And the reason for starting the conversation that way,
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as opposed to just diving into a lot of biology about sleep,
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is because first of all, there's a lot of information
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out there already about the biology of sleep.
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We're gonna touch on a little bit of this,
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things like stages of sleep and sleep spindles,
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melatonin, and dreaming.
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But I think that by now, most people are aware
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that getting a really good night's sleep
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on a consistent basis is critically important.
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But most people don't know how to do that.
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In fact, I'm guessing that very few of you out there
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are consistently getting seven to nine hours
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of really terrific sleep, waking up feeling rested,
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like you're ready to attack the day,
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and being able to go through the day feeling focused
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and alert without dips in energy or focus.
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So if you're like most people, which includes me,
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you have some challenges with sleep,
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at least every third or fifth night or so,
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and maybe even more often.
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So we're really gonna go tool heavy today
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and talk about tools that can help you fall asleep,
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sleep better, and emerge from sleep feeling more rested.
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And we're gonna do that by grounding our discussion
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of tools in peer-reviewed studies,
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mostly from the last 10 years,
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although some even more recent than that.
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And we're gonna start by discussing what is sleep
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and what governs the timing of the onset of sleep.
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In other words, what makes you get sleepy
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at a particular time of day.
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So what determines how well we sleep
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and the quality of our wakeful state?
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Turns out that's governed by two forces.
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The first force is a chemical force.
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It's called adenosine.
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Adenosine is a molecule in our nervous system and body
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that builds up the longer we are awake.
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So if you've just slept for eight or nine or 10
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really deep restful hours,
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adenosine is gonna be very low in your brain and body.
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If however you've been awake for 10, 15 or more hours,
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adenosine levels are going to be much higher.
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Adenosine creates a sort of sleep drive or a sleep hunger.
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And actually hunger is the appropriate word here
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because for most of what we're gonna discuss today,
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we can think of it in an analogous way to nutrition.
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Your nutrition and how well you feel
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after you eat certain foods,
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your overall level of fitness and your cellular health
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and your heart health isn't governed by any one food item
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that you might eat or not eat.
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It's governed by a number of different factors.
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How often you eat, how much you eat,
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which items you eat, et cetera,
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and what works best for you.
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In the same way, your sleep and your wakefulness
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are the product of kind of the average
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of a number of different behaviors.
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How long you've been awake is a key one
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because of this molecule adenosine.
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So the reason you get sleepy
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when you've been up for a while
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is because adenosine is creeping up steadily
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the longer you've been awake.
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And a good way to remember this and think about adenosine
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is to think about caffeine.
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Caffeine for most people,
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except a very small percentage of people, wakes them up.
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It makes them feel more alert.
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In fact, some people are so sensitive to caffeine
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that they feel jittery if they drink it
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even in small amounts.
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Other people can drink large amounts of caffeine
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and not feel jittery at all.
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Caffeine acts as an adenosine antagonist.
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What that means is that when you ingest caffeine,
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whether or not it's coffee or soda or tea
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or in any other form, it binds to the adenosine receptor.
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It sort of parks there,
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just like a car would park in a given parking slot,
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and therefore adenosine can't park in that slot.
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Now, when caffeine parks in the adenosine receptor slot,
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nothing really happens downstream of that receptor.
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The receptor can't engage the normal cellular functions
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of making that cell and you feel sleepy.
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So the reason caffeine wakes you up
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is because it blocks the sleepiness receptor.
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It blocks the sleepy signal.
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And this is why when that caffeine wears off,
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adenosine will bind to that receptor,
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sometimes with even greater, what we call affinity,
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and you feel the crash, you feel especially tired.
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Now, I'm not here to demonize caffeine.
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I drink it in the morning and I drink it in the afternoon.
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But I'm one of these people
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that either because of my tolerance
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or because of some genetic variations
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that exist among people
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in terms of their adenosine receptors,
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I can drink caffeine as late as four or 5 p.m.
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in the evening and still fall asleep just fine.
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Some people can't have any caffeine at all
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or can't have any caffeine past 11 a.m.
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or else their sleep is totally disrupted.
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All of this has to do with the relationship
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between adenosine and these adenosine receptors,
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genetic variation, things that are very hard to find out
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except experimentally,
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meaning each of you needs to decide
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and figure out for yourselves
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whether or not you can tolerate caffeine
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and at what times of day you can tolerate caffeine
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in order to still fall asleep easily and get good sleep.
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So rather than demonize caffeine,
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or say that everyone can drink caffeine until late,
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you need to figure out what's right for you.
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Caffeine has a lot of health benefits.
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It also, for some people, can be problematic for health.
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It can raise blood pressure, et cetera.
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Caffeine increases this molecule
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that's a neuromodulator that we call dopamine.
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We discussed this in episode one,
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which tends to make us feel good,
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motivated, and give us energy
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because as you may have learned in episode one,
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dopamine is related to another neuromodulator
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called epinephrine, which gives us energy.
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In fact, epinephrine is made from dopamine.
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So let's just take a step back
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and think about what we're talking about
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when we're talking about sleepiness.
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Sleepiness is driven by increases in adenosine
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that happen naturally.
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Caffeine prevents the adenosine
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from having its action of making us sleepy
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by blocking that receptor.
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So it gives us energy and it increases our dopamine levels,
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but some people can't tolerate caffeine very well.
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Other people can tolerate it just fine.
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So you need to determine that experimentally.
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All the data say there's tremendous variation.
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And right now, the only way that I'm aware of
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for you to decide whether or not caffeine
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is a good or a bad thing for you
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and whether or not you should ingest it
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at a given time of day or at all
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is really to figure that out on your own.
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In fact, there's a small subset of people
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that can drink caffeine until very late
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and they have no trouble falling asleep
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because they actually have a mutant form
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of the adenosine receptor.
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So in keeping with the theme of science
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and science-related tools,
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this is one of those cases where I can't give you
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a one-size-fits-all prescription,
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except to say you need to experiment with caffeine
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in a way that's safe for you
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and explore that and figure out what works for you
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and then stick with that.
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Okay, so adenosine is driving the sleep hunger.
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When adenosine is low, it's like we're well-fed,
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we're not very hungry.
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And when adenosine is high,
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it's like we're fasted for a long time
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and we tend to be very hungry.
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So when adenosine is high, we really wanna fall asleep.
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If you want, I'm not suggesting you do this experiment,
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but you can do it,
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you can stay up for four more hours
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than you're used to staying up
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and you'll find that you're very, very sleepy.
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That's because adenosine is building up
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at levels higher and higher
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because you've been awake for those extra four hours.
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However, if you've ever pulled an all-nighter,
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you'll notice something interesting.
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As morning rolls around,
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you'll suddenly feel an increase in your energy
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and alertness again.
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Even though adenosine has been building up
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for the entire night.
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The reason that is, is because there's a second force
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which is governing when you sleep and when you're awake.
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And that force is a so-called circadian force.
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Circadian means about a day or about 24 hours.
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And inside all of us is a clock
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that exists in your brain and my brain
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and the brain of every animal that we're aware of,
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that determines when we want to be sleepy
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and when we want to be awake.
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Just think about it.
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We don't go through the day
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wanting to fall asleep every 30 minutes
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and then feeling like we're wide awake.
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Our sleep and our period of sleepiness
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tends to be condensed into one block.
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Typically one six to 10 hour block.
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Although there's also variation
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in terms of how much people want to sleep.
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And we're going to discuss
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how you can diagnose your absolute sleep need
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as well as how to recover sleep that you've lost.
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That block of sleep and when it falls
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within each 24 hour cycle
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is governed by a number of different things.
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But the most powerful thing that's governing
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when you want to be asleep
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and when you want to be awake is light.
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And in particular, it's governed by sunlight.
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Now I can't emphasize enough how important
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and how actionable this relationship is
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between light and when you want to sleep.
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It's quite simple on the face of it.
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And it's quite simple to resolve
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but people tend to make a big mess
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of this whole circadian literature, frankly.
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So let's just break it down from the standpoint
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of what's going on in your brain and body
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as you go through one 24 hour day.
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Let's start with waking.
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So regardless of how well you slept at night
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or whether or not you were up all night,
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most people tend to wake up sometime
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around when the sun rises.
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Maybe not right at sunrise,
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but within an hour or two or maybe three of sunrise.
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And I realized there are night shift workers
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and there are people traveling and experiencing jet lag
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where this is not gonna be the case.
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We are gonna deal with jet lag and shift work
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at the end of this podcast.
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But for most people, we tend to wake up
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about the time that the sun is rising or so.
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And as we do that, adenosine levels tend to be low
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if we've been asleep for reasons that you now understand.
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And our system generates an internal signal
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that is in the form of a hormone.
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Now I've talked a lot about neuromodulators
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and neurotransmitters.
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I haven't talked a lot about hormones yet on this podcast.
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The definition of a hormone is it's a substance,
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a chemical that's released from one organ in your body
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that goes and acts on other organs elsewhere in your body,
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including your nervous system.
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When you wake up in the morning,
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you wake up because a particular hormone called cortisol
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is released from your adrenal glands.
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Your adrenal glands sit right above your kidneys
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and there's a little pulse of cortisol.
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There's also a pulse of some, and when I say a pulse,
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I just mean that the release of a little bit.
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There's also a pulse of epinephrine,
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which is adrenaline from your adrenals
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and also in your brain, and you feel awake.
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Now that pulse of cortisol and adrenaline
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and epinephrine might come from your alarm clock.
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It might come from you naturally waking up,
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but it tends to alert your whole system in your body
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that it's time to increase your heart rate.
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It's time to start tensing your muscles.
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It's time to start moving about.
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It's very important that that cortisol pulse
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come early in the day,
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or at least early in your period of wakefulness.
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I say that because some people are waking up at 8 p.m.
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and are sleeping all day,
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but it's very important that that pulse of cortisol
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occur early in the day and that it happens all at once.
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It sort of sets a rising tide of cortisol in your system.
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Now, many of you have probably heard about cortisol
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in relation to stress,
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and indeed, as we go through our day and our life,
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different stressors, different events happen in our life
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that make us feel more alert.
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Some of the more stressful ones
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might be looking at your credit card bill
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and seeing what seems to be a fraudulent charge,
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or looking at your phone and suddenly seeing a text
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that something you thought was gonna happen
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at a particular time is not gonna happen,
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or you're running late.
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Those will tend to increase norepinephrine and epinephrine,
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an adrenaline in your system.
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And if they're severe enough,
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you'll start getting some pulses of cortisol
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released from your adrenals throughout the day.
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But there's this normal, healthy, rising tide of cortisol
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that happens early in the day.
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And I say healthy because it wakes you up.
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It makes you feel alert.
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It makes you feel able to move and wanting to move
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and to go out about your day for work, for exercise,
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for school, for social relations, et cetera.
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So when you wake up in the morning
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is when that cortisol pulse takes off
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and something else important happens.
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A timer is set in your body and in your nervous system
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that dictates when a different hormone called melatonin,
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which makes you sleepy, will be secreted
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from a particular brain region.
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So let's talk about that.
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When you wake up in the morning
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and you experience that rise in cortisol,
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there's a timer that starts going,
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and these are cellular timers,
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and they're dictated by the relation
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between different organs in your body
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that says to your brain and body
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that in about 12 to 14 hours, a different hormone,
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this hormone we're calling melatonin,
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will be released from your pineal gland.
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So there's two mechanisms here,
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a wakefulness signal and a sleepiness signal.
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And the wakefulness signal triggers the onset of the timer
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for the sleepiness signal.
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Now that sleepiness signal that we call melatonin
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that's released from the pineal comes only from the pineal.
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Unless you're taking exogenous melatonin,
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you're supplementing with melatonin,
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the only source of melatonin in your body
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is going to be this pineal gland.
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So let's talk about the pineal gland for a second.
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The pineal gland is a gland that sits
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kind of in the little structure
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near for the aficionados out there.
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It's kind of near the fourth ventricle.
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It's about the size of a pea.
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Descartes, the philosopher,
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said that the pineal was the seat of the soul.
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He said that because it's one of the few structures
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in the human brain that there's only one of them.
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Most structures, there's one on either side of the brain,
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so-called bihemispheric,
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but the pineal, there's only one.
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I don't know anything about souls, really.
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Certainly not the science of souls,
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but I think it's very unlikely
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that the pineal is the seat of the soul,
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but it is a very interesting organ
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because it's the only organ in our body
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that releases melatonin.
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And that melatonin makes us sleepy and lets us fall asleep.
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Now I'm guessing that many of you are probably asking,
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should I take melatonin?
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My personal bias on this is, except in rare cases, no,
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for the following reason.
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Melatonin has a second function,
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which is that melatonin also suppresses
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the onset of puberty.
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In kids, and especially in babies,
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melatonin isn't just released in the evening,
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12 to 16 hours after we wake.
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Melatonin is released chronically or tonically
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throughout the day and night.
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And that chronic or tonic release of melatonin
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is known to suppress some of the other hormones
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in other regions of the brain
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that trigger the onset of puberty.
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Now, if you or your child has been taking melatonin,
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As always, any kind of supplement
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or anything that you're going to take or think about taking,
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you really need to consult with your doctor.
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I've said this many times on this podcast
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and it's in the show notes, et cetera.
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But before you remove anything or add anything
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to what you're already doing,
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please do consult with a healthcare professional.
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However, melatonin is known to suppress the onset of puberty
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so much so that regular cyclic cycled periods
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of melatonin release from the pineal
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really correlate with the onset of puberty
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and early adulthood.
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Meaning, as we start secreting melatonin only at night,
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that's also when we tend to transition out of puberty.
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Now, there are a lot of things that correlate
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in our nervous system,
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so it doesn't necessarily mean it controls it,
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but in this case, we know based on lots of data
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and endocrinology and so forth
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that melatonin suppresses the onset of puberty.
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So supplementing melatonin could be problematic
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but if you've already gone through puberty,
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it could also have some impact
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on other hormone systems in your body.
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So that's why I personally don't like to use melatonin
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There's another reason,
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which is that melatonin will help you fall asleep,
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but it won't help you stay asleep.
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And many people who take melatonin find that they wake up
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three to five hours later, unable to fall back asleep.
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Part of the reason for that might be
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that melatonin purchased,
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you can buy it over the counter in most areas of the world,
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even though it's a hormone, which is a little unusual.
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You can't just go into a pharmacy, at least in the US,
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and buy testosterone or cortisol or estrogen.
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You need a prescription,
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but you can go buy melatonin for whatever reason.
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I don't know the reasons for that legality,
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but it's been shown many times,
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and now I'm borrowing from some items
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that were in Matt Walker's book, Why We Sleep,
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where he stated there is evidence
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that in commercially available melatonin,
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the amount of melatonin has been tested for various brands,
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and it can range anywhere from being 15%
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of what's listed on the bottle, okay?
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So if they list up, this is 100 milligrams,
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would be a tremendously high dose.
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It turns out it's only 15 milligrams
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in that particular pill or capsule,
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or up to 400 times more than what's listed on the bottle.
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So it's completely unregulated.
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And so for those of you taking melatonin,
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I will discuss at the end of the podcast
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some other potential alternatives that are probably safer
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and don't have these issues.
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So should you take melatonin?
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My personal bias is no, but for many people,
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they find that it does help them.
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And so if you do find it helps you,
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then just consider what I'm saying
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in light of the other practices that you're doing
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and talk to your healthcare professional.
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Okay, so the rhythm of cortisol and melatonin
link |
is what we call endogenous.
link |
It's happening in us all the time
link |
without any external input.
link |
In fact, if we were in complete darkness,
link |
living in a cave with no artificial lights whatsoever,
link |
or we were in complete brightness,
link |
where we never experienced any darkness,
link |
these rhythms of cortisol and melatonin would continue.
link |
You would have a bump in cortisol or a pulse in cortisol
link |
that would drop off with time,
link |
and then melatonin would come up about 12 to 14 hours later.
link |
But these endogenous systems of our body,
link |
which are both hormonal and neural,
link |
were set so that external things
link |
could govern when they happen.
link |
Now, this takes us back to episode one of the podcast
link |
that if you haven't listened to already,
link |
you might wanna listen to,
link |
where we talked about sensation and perception and all that.
link |
I'm not gonna review it again here,
link |
but there's one particular sensory event,
link |
one particular influence on your nervous system
link |
that determines when that cortisol is going to start to rise.
link |
So if you were in complete darkness,
link |
it would happen once per 24 hour cycle,
link |
but it would be somewhat later and later each day.
link |
Whereas under normal circumstances,
link |
what happens is you wake up,
link |
and what happens when you wake up?
link |
You open your eyes.
link |
When you open your eyes, light comes into your eyes.
link |
Now, the way this system works
link |
is that you have a particular set of neurons in your eye.
link |
They're called retinal ganglion cells.
link |
You don't have to remember that if you don't want to,
link |
but these retinal ganglion cells are brain neurons.
link |
Again, the retina is just the one piece of your brain,
link |
actually two pieces,
link |
because most of you have two retinas that resides
link |
outside the skull per se.
link |
When light comes into the eye,
link |
there's a particular group of retinal ganglion cells
link |
or type of retinal ganglion cells
link |
that perceives a particular type of light
link |
and communicates that to this clock
link |
that resides right above the roof of your mouth
link |
called the suprachiasmatic nucleus, okay?
link |
So I know this can get a little complicated,
link |
but these retinal ganglion cells,
link |
when you open your eyes, light comes in,
link |
and an electrical signal is sent to this central clock
link |
we call the suprachiasmatic nucleus.
link |
And the suprachiasmatic nucleus has connections
link |
with essentially every cell and organ of your body.
link |
Now, it's vitally important that we get light
link |
communicated to this central clock
link |
in order to time the cortisol and melatonin properly.
link |
When I say properly, I can say that with confidence,
link |
because we know based on a lot of evidence
link |
that if you don't get your cortisol
link |
and melatonin rhythms right,
link |
there are tremendously broad and bad effects
link |
on cardiovascular health, dementia, metabolic effects,
link |
learning, depression, dementia.
link |
In fact, there are so many negative effects
link |
associated with getting this wrong
link |
that I don't want to go into it in too much detail.
link |
In fact, I feel like we've been bombarded
link |
with all this information about how we're not sleeping well,
link |
we're not sleeping at the right times,
link |
we're not sleeping enough
link |
to the point where people now have sleep anxiety.
link |
If they can't sleep well for a night,
link |
they're feeling overwhelmed by that
link |
and sort of now they're stressed
link |
about not being able to sleep,
link |
which is making it harder to sleep, et cetera.
link |
I really want to focus on what we can do
link |
to anchor these systems properly.
link |
So let's think about what happens when we do this correctly
link |
and how to do it correctly.
link |
When we wake up, our eyes open.
link |
Now, if we're in a dark room,
link |
there isn't enough light to trigger the correct timing
link |
of this cortisol-melatonin thing, these rhythms.
link |
You might say, well, why won't any light do it?
link |
Well, it turns out that these neurons in our eye
link |
that set the circadian clock
link |
and then allow our circadian clock
link |
to set all the clocks of all the cells and organs
link |
and tissues of our body responds best
link |
to a particular quality of light and amount of light.
link |
And those are the qualities of light
link |
and amount of light that come from sunlight.
link |
So these neurons, what they're really looking for,
link |
although they don't have a mind of their own,
link |
is the sun at what we call low solar angle.
link |
The eye and the nervous system
link |
don't know anything about sunrises or sunsets.
link |
It only knows the quality of light
link |
that comes in when the sun is low in the sky.
link |
The system evolved so that when the sun is low in the sky,
link |
there's a particular contrast between yellows and blues
link |
that triggers the activation of these cells.
link |
So if you wake up and you look at your phone
link |
or you flip on a bunch of artificial lights,
link |
will these cells be activated?
link |
And the answer is sort of.
link |
They'll be activated, but not in the optimal way.
link |
What you want to do is get sunlight in your eyes
link |
as close to waking as possible.
link |
Now, I want to be really clear about this
link |
because I've talked about it on other podcasts
link |
when I was a guest,
link |
and I've talked about it on my Instagram feed,
link |
and there seemed to be the same questions
link |
coming up again and again.
link |
These neurons don't know sunlight per se.
link |
They don't know sunrise or sunset for that matter.
link |
They don't know artificial light from sunlight.
link |
What they respond best to, however,
link |
is the quality and amount of light that comes in
link |
when the sun is low in the sky.
link |
That means that if you can watch the sunrise, great.
link |
That's perfect for triggering activation of these cells.
link |
However, if you wake up a few hours after the sunrise,
link |
which I tend to most days, personally,
link |
you still want to get outside and view sunlight.
link |
You don't need the sunlight beaming you
link |
directly in the eyes.
link |
There's a lot of photons, light energy,
link |
that's scattered from sunlight at this time.
link |
But the key is to get that light energy
link |
from sunlight, ideally, into your eyes.
link |
Now, I know many of you are already asking,
link |
well, I live in Scandinavia or I can't get sunlight.
link |
There's buildings around me, et cetera.
link |
We will get to all of that.
link |
But it's critically important that you get outside
link |
to get this light.
link |
I had a discussion with a colleague of mine,
link |
Dr. Jamie Zeitzer,
link |
who's in the Department of Psychiatry
link |
and Behavioral Sciences at Stanford,
link |
a world expert in this.
link |
And he tells me that it's 50 times less effective
link |
to view the sunlight through a window,
link |
through a car windshield or through a side window of a car,
link |
than it is to just get outside with no sunglasses
link |
and view light early in the day.
link |
Now, if you can't see the sunrise, like I said,
link |
you can see this within an hour or two of sunrise,
link |
but it has to be low solar angle.
link |
Once the sun is overhead, the quality of light shifts
link |
so that you miss this opportunity
link |
to time the cortisol pulse.
link |
And that turns out to be a bad thing to do.
link |
You really want to time that cortisol pulse properly
link |
because we'll get into this a little bit more later,
link |
but a late shifted cortisol pulse,
link |
in particular in 9 p.m. or 8 p.m. increase in cortisol,
link |
is one of the consequences and maybe one of the causes
link |
of a lot of anxiety disorders and depression.
link |
So it's kind of a chicken egg thing.
link |
We don't know whether or not it's the correlated with,
link |
it's the cause or the effect,
link |
but it's a signature of depression and anxiety disorder.
link |
Bringing that cortisol pulse earlier in your wakeful period,
link |
earlier in your day, has positive benefits
link |
ranging from blood pressure to mental health, et cetera.
link |
I'm not going to list them all off
link |
because there's just so many of them,
link |
but many, many positive things happen
link |
when you are getting the cortisol early in the day,
link |
far away from your melatonin pulse.
link |
Okay, so how long should you be outside?
link |
Well, this is going to vary tremendously
link |
because some people live in environments
link |
where it's very bright.
link |
So let's say it's Colorado in the middle of winter,
link |
there's a snow field, there's no cloud cover,
link |
and you walk outside.
link |
There's going to be so much photon light energy
link |
arriving on your retina
link |
that probably only takes 30 to 60 seconds
link |
to trigger the central clock
link |
and set your cortisol and melatonin rhythms properly
link |
and get everything lined up nicely.
link |
Whereas if you're in Scandinavia in the depths of winter
link |
and you wake up at 5 a.m.
link |
and the sun is just barely creeping across the horizon
link |
then goes back down again a few hours later,
link |
you probably are not getting enough sunlight
link |
in order to set these rhythms.
link |
So many people find
link |
that they need to use sunlight simulators
link |
in the form of particular lights
link |
that were designed to simulate sunlight.
link |
However, I'm not out to attack the companies
link |
that produce those.
link |
There's another solution to that.
link |
You can simply go outside for longer.
link |
Even if there's a lot of dense cloud cover,
link |
you're probably getting
link |
anywhere from 10,000 to 50,000 lux, L-U-X,
link |
which is just a measure of light energy.
link |
And that should be sufficient to set the circadian clock.
link |
You could say, well, the lights in my house
link |
or my phone are really, really bright, right?
link |
Everyone's telling us to stay off our phones at night
link |
because they're really bright.
link |
It turns out that early in the day,
link |
your retina is not very sensitive,
link |
which means you need a lot of photons,
link |
ideally coming from sunlight,
link |
to set these clock mechanisms.
link |
So looking at your phone or artificial lights is fine
link |
if you wake up before sunrise,
link |
but it's not going to work to set these clock mechanisms.
link |
And this is supported by dozens, if not hundreds,
link |
of quality peer-reviewed studies.
link |
So you want to use sunlight.
link |
If you can't see sunlight because of your environment,
link |
then you are going to have to opt for artificial light.
link |
And in that case, you're going to want an artificial light
link |
that either simulates sunlight or has a lot of blue light.
link |
Now, without going off course here,
link |
you might be saying, wait, I've heard blue light
link |
Actually, blue light is great for this mechanism
link |
We can talk about blue light and blue blockers,
link |
but you really want a lot of blue and yellow light
link |
arriving on the retina early in the day.
link |
Let me be clear about something.
link |
You never ever want to look at any light,
link |
sunlight or artificial light, that is painful to look at.
link |
If you find that your eyes are watering
link |
or you're having challenges maintaining,
link |
looking at this thing for a while because it's painful,
link |
that light is too bright
link |
and you do not want to damage your retina.
link |
So you don't want to gaze at the sun,
link |
refusing to blink and burn your retina.
link |
That's actually possible to do.
link |
You don't want to do that.
link |
You have a proper blink reflex installed in you since birth.
link |
And if you feel like something's too bright
link |
and you need to blink, it means you need to blink,
link |
that it's too much light.
link |
So please don't beam your eyes with really bright light.
link |
But blue light, in particular blue light
link |
and yellow light coming from sunlight is ideal.
link |
If you're going to get it from artificial light,
link |
because you can't get enough sunlight,
link |
well then artificial lights that are rich in blue,
link |
blue wavelengths are going to be ideal
link |
for setting this mechanism.
link |
A lot of people will say,
link |
oh, I should be wearing blue blockers throughout the day.
link |
No, that's the exact wrong thing.
link |
If you're going to use blue blockers,
link |
we can talk about that.
link |
That should be reserved for late in the evening
link |
because light suppresses melatonin.
link |
I've been asked many times before about this pineal gland.
link |
And there are a lot of ancient practices
link |
that map to some of the things that I'm saying.
link |
And people always say,
link |
oh, I heard that sunlight is great for the pineal.
link |
Well, perhaps, but we have to be careful about that phrase.
link |
Sunlight inhibits the pineal.
link |
It prevents it from releasing melatonin.
link |
Darkness allows the pineal to release melatonin.
link |
So the pineal is not the gland or the organ of sunlight.
link |
It is the gland of darkness.
link |
In fact, melatonin can be thought of as a sleepiness signal
link |
that's correlated with darkness.
link |
So get up each morning, try and get outside.
link |
I know that can be challenging for people,
link |
but anywhere from two to 10 minutes of sunlight exposure
link |
is going to work well for most people.
link |
And you want to do this on a regular basis
link |
and you don't have to do it exactly at sunrise.
link |
I realize I'm repeating myself,
link |
but somehow despite barking at people about this
link |
for a couple of years now,
link |
I keep getting the same questions.
link |
And somehow it hasn't been sinking in,
link |
which could be related to some circadian disorder.
link |
If it's not sinking in,
link |
it's probably that I'm not being effective
link |
in communicating the information.
link |
But get that bright light early in the day from sunlight.
link |
And if you can't get it from sunlight,
link |
get it from artificial light.
link |
What kinds of artificial lights will work?
link |
Well, there are these sunrise simulators,
link |
but the ring lights that people use for selfies
link |
and this sort of thing for posting on Instagram,
link |
those generate a lot of blue light.
link |
If you want to get experimental about this,
link |
there's a free app.
link |
I have no relationship to the app,
link |
but it's a great app called Light Meter
link |
that you can use your phone
link |
and you can measure the amount of photon energy
link |
in your environment.
link |
And it's kind of a fun experiment to do.
link |
You can go outside in the morning
link |
and you'll see that there's 10,000, 20,000 lux,
link |
even though it might seem like it's kind of dim
link |
or there's tree cover or cloud cover,
link |
you go inside and you shine that artificial light
link |
at your phone, press the button on Light Meter
link |
and you'll find that it's only 500 or 1,000 lux.
link |
And you realize that even though it seems really bright,
link |
the artificial light is very condensed,
link |
whereas the outside light is scattered in the atmosphere.
link |
And so you can think that you're not getting much sunlight,
link |
but you're actually getting much more outside.
link |
So get outside, get that sunlight early in the day
link |
and try and do it on a consistent basis.
link |
If you can't do it every day
link |
or you sleep through this period of the early day,
link |
low solar angle, don't worry about it.
link |
The systems in the body,
link |
these hormone systems and neurotransmitter systems
link |
that make you awake at certain periods of the day
link |
and sleepy at other times are operating
link |
by averaging when you view the brightest light.
link |
Now, that can immediately tell us
link |
that what most people are doing is terrible.
link |
They're waking up and they're looking at their phone,
link |
which isn't triggering activation of these cells in the eye
link |
and the central circadian clock.
link |
Then a few hours later,
link |
they might get in their car with sunglasses and drive.
link |
Now, a note about sunglasses and prescription lenses.
link |
Absolutely never, ever, ever compromise safety
link |
for the sorts of things I'm talking about.
link |
So if you need to wear sunglasses for safety reasons,
link |
Absolutely, if you wear prescription lenses or contacts,
link |
They won't filter out the wavelengths of light
link |
that are necessary for setting these central clocks.
link |
So safety first, of course.
link |
If you have a retinal degenerative disorder,
link |
retinitis pigmentosa, macular degeneration, or glaucoma,
link |
or those run in your family,
link |
you want to avoid excessively bright light all the time.
link |
You want to be very cautious about that.
link |
You're going to want to get your light exposure
link |
by through seeing dimmer light, including sunlight,
link |
but for longer periods of time, perhaps.
link |
You might immediately ask,
link |
what about low vision or blind people?
link |
How do they set these central clocks?
link |
Well, it turns out that low vision and blind people,
link |
most of them, provided they still have eyes,
link |
that the eyes weren't removed
link |
because of a burn or tumor or something like that,
link |
still maintain these neurons that set the circadian clock,
link |
which brings me to a really important point.
link |
It's not about seeing and perceiving the sun.
link |
This is a subconscious mechanism by which these neurons,
link |
which are called melanopsin ganglion cells,
link |
these neurons set your central clocks
link |
by getting activated by the particular wavelengths of light
link |
that are present in the atmosphere,
link |
even coming through cloud cover.
link |
And you don't need to see or perceive the sun
link |
in order to get this mechanism to start.
link |
Now, it's such a vitally important mechanism
link |
because it dictates how well and what time
link |
you will want to fall asleep later in the day.
link |
So for those of you that are night owls
link |
and you insist that you're a night owl
link |
and you have the genetic polymorphism
link |
that makes you a night owl,
link |
you may very well have that genetic polymorphism,
link |
those genes that make you want to stay up late
link |
But chances are about half of you
link |
that think that you're night owls
link |
are just not getting enough sunlight early in the day.
link |
So viewing light early in the day, ideally sunlight,
link |
is key for establishing healthy sleep-wake rhythms
link |
and for allowing you to fall asleep easily at night.
link |
Now, it's not gonna make sure
link |
that all that happens every single time,
link |
but it is the foundation of proper sleep
link |
and what we call circadian health.
link |
It governs metabolism and so many other things
link |
that are supposed to exist on a regular 24-hour cycle.
link |
Some of you, many of you might be asking,
link |
what else can help set this rhythm?
link |
Well, it turns out that light
link |
is what we call the primary zeitgeber, the time giver.
link |
But other things can help establish this rhythm
link |
of cortisol followed by melatonin
link |
12 to 16 hours later as well.
link |
The other things besides light are timing of food intake,
link |
timing of exercise, as well as various drugs
link |
or chemicals that one might ingest, not illegal drugs,
link |
although those will impact circadian mechanisms as well.
link |
But the reason we focus so heavily on light
link |
is that light is the main way that the central clock,
link |
the suprachiasmatic nucleus was supposed to be set.
link |
We know that because it's the only direct input
link |
These neurons in the eye that are also part of the brain
link |
that we call melanopsin ganglion cells
link |
that not so incidentally were discovered
link |
by my friend and colleague David Berson
link |
at Brown University and others,
link |
Samir Hatar, King Wayao, et cetera,
link |
worked out the mechanisms, the molecular mechanisms,
link |
but it was really David Berson
link |
that discovered these incredibly fascinating non,
link |
these are cells that aren't important for sight
link |
like pattern vision, but are for setting our clocks.
link |
David's really credited with making that discovery.
link |
Those cells are the main way
link |
and the only direct way to set the clock.
link |
In fact, it's fair to say that light
link |
viewed by these melanopsin cells, particular sunlight,
link |
is 1,000 to 10,000 times more effective
link |
than say getting up in darkness and just exercising.
link |
That doesn't mean that you shouldn't exercise
link |
early in the day in darkness if that's what you like to do.
link |
It will have somewhat an effect
link |
on raising your wakefulness early in the day
link |
and setting these rhythms.
link |
And this is because of some other pathways.
link |
For the aficionados out there
link |
who want to know more neuroscience, here's how it goes.
link |
You've got this clock above the roof of your mouth
link |
that churns out this 24-hour rhythm
link |
and is communicated to all the other organs
link |
and tissues of your body.
link |
But there's another structure, has a cool name.
link |
It's called the intergeniculate leaflet,
link |
which sits a few millimeters away in the brain,
link |
and it's involved in regulating the clock output
link |
through what's called non-photic, non-light type influences
link |
like exercise and feeding, et cetera.
link |
So if you are not feeling awake during the day
link |
and you're having trouble sleeping,
link |
get the sunlight exposure that we just talked about.
link |
But in addition to that,
link |
if you want to become an early riser, for instance,
link |
and you want to feel more awake
link |
during the early part of the day,
link |
by getting that light exposure
link |
and exercising early in the day,
link |
you will, after two or three days,
link |
you will naturally start to wake up earlier in the day.
link |
And that's because these clock mechanisms have shifted.
link |
It's like setting the clock earlier
link |
as opposed to delaying the clock.
link |
And that takes us to a somewhat complicated
link |
but very important aspect to all this,
link |
which is what sets the clock and keeps it anchored.
link |
The main thing is that bright light early in the day.
link |
The other thing is sunset.
link |
When the sun is also at low solar angle,
link |
low, close to the horizon,
link |
by viewing sunlight at that time of day in the evening
link |
or afternoon, depending on what time of year it is
link |
and where you are in the world,
link |
these melanopsin cells, these neurons in your eye,
link |
signal the central circadian clock
link |
that it's the end of the day.
link |
And there's a really nice study that was published last year
link |
and I will put links to these references on a website
link |
not too long from now.
link |
There was a really nice study that showed
link |
that viewing sunlight around the time of sunset
link |
doesn't have to be just crossing the horizon,
link |
but circa sunset within an hour or so of sunset
link |
prevents some of the bad effects of light
link |
in preventing melatonin release later that same night.
link |
So let me repeat this.
link |
Viewing light early in the day is key.
link |
Viewing light later in the day when the sun is setting
link |
or around that time can help protect these mechanisms,
link |
your brain and body against the negative effects
link |
of light later in the day.
link |
So let me talk about how you would do that.
link |
You'd go view the sunset,
link |
or you would go outside in the late afternoon or evening.
link |
Again, if you safely can do that with sunglasses off,
link |
If you need to wear sunglasses, fine,
link |
but it will take probably a hundred to a thousand times
link |
longer with dark sunglasses than if you take them off.
link |
Again, if you want to do this through a window at work,
link |
that's fine, but it'll take 50 times longer.
link |
So the best thing to do is just to get outside
link |
for a few minutes, anywhere from two to 10 minutes
link |
also in the afternoon.
link |
Having those two signals arriving to your central clock
link |
that your body, your internal world,
link |
knows when it's morning and knows when it's evening
link |
is tremendously powerful.
link |
Maybe think about it this way.
link |
Every cell in your body needs glucose and energy.
link |
It needs, whether or not it gets that from meat
link |
or it gets it from ketones or it gets it from carbohydrates
link |
or fruit or vegetables, it doesn't matter.
link |
It is eventually converted into a certain form of energy
link |
that all your cells use.
link |
But you don't take glucose,
link |
you don't take a bread or a steak or a nice orange
link |
and shove it in your ear.
link |
You put it in your mouth, it goes into your stomach,
link |
it's digested, and then that resource is distributed
link |
to all the cells of your body.
link |
Every cell in your body needs oxygen
link |
and you don't put a hose through your nostril
link |
or through your ear or through some other orifice
link |
You inhale air and it's then distributed via the lungs
link |
to the cells in your bloodstream
link |
and that's distributed to all the organs of your body.
link |
Every cell and organ in your body needs light information.
link |
And the way to get that light information
link |
to all those cells, because you have a thick skull
link |
and inside of you is dark inside your skin,
link |
there's no sunlight getting in there,
link |
is by viewing sunlight with your eyes
link |
at the two times a day that I'm referring to, okay?
link |
That's the only route.
link |
There was a study published in Science,
link |
an excellent journal well over 10 years ago
link |
that showed that light shown on the back of the knee
link |
could set these circadian rhythms.
link |
That study was retracted
link |
and unfortunately most people don't know
link |
that it was retracted.
link |
There were some experimental flaws
link |
that people were actually viewing light through their eyes.
link |
That study was repeated.
link |
Turns out there is no extra ocular photoreception in humans.
link |
Whatever somebody tells you that light to the skin
link |
or light to the wherever is beneficial for your health,
link |
we can talk about that,
link |
but there's no way that light information
link |
is setting your clocks.
link |
You need these cells in your eyes to perceive
link |
or to see light at the particular times of day
link |
that I'm referring to.
link |
Some animals like snakes and other reptiles
link |
actually have a hole in the top of their skull
link |
to get light information directly to their pineal
link |
where to suppress melatonin.
link |
We don't have that hole.
link |
I mean, most of you don't have holes in your skull.
link |
These holes in your skull that we call
link |
the sockets for the eyes are actually there
link |
primarily to allow light information to the central clock.
link |
And then vision and pattern vision and color vision
link |
came much later in evolution.
link |
We know this on the basis of genetic studies
link |
we get to discuss in a future podcast.
link |
So get that light information
link |
to the cells of your brain and body
link |
by viewing sunlight at the two times a day
link |
that I referred to.
link |
There's always a lot of questions about how long,
link |
how much, how do I know if I've had enough?
link |
You'll know because your rhythm will start to fall
link |
into some degree of normalcy.
link |
You'll start to wake up at more or less
link |
the same time each day.
link |
You'll fall asleep more easily at night.
link |
Generally it takes about two or three days
link |
for these systems to align.
link |
So if you've not been doing these behaviors,
link |
it's gonna take a few days
link |
but they can have tremendous benefits
link |
and sometimes rather quickly on a number of different
link |
mental and physical aspects of your health.
link |
Now let's talk about the bad effects of light
link |
because light is not supposed to arrive in our system
link |
And nowadays, because of screens and artificial light,
link |
we have access to light at times of day and night
link |
that normally we wouldn't.
link |
Now, earlier I said that you need a lot of light
link |
in particular sunlight to set these clock mechanisms.
link |
That's true but there's a kind of diabolical feature
link |
to the way all this works
link |
which is the longer you've been awake,
link |
the more sensitive your retina and these cells are to light.
link |
So that if you've been awake for 10, 12, 14 hours,
link |
it becomes very easy for even a small amount of light
link |
coming from a screen or from an overhead light
link |
to trigger the activation of the clock
link |
and make you feel like you wanna stay up later,
link |
make it harder to fall asleep
link |
and disrupt your sleep pattern.
link |
Okay, so the simple way to think about this
link |
is you want as much light as is safely possible
link |
early in the day, morning and throughout the day,
link |
including blue light.
link |
So take those blue blockers off during the day
link |
unless you have a real issue with screen light sensitivity.
link |
And you want as little light coming into your eyes,
link |
artificial or sunlight after say 8 p.m.
link |
And certainly you do not want to get bright light exposure
link |
to your eyes between 11 p.m. and 4 a.m.
link |
David Berson, who I mentioned before
link |
and another friend and colleague, Samir Hattar,
link |
who's director of the Chronobiology Unit
link |
at the National Institutes of Mental Health,
link |
published a paper in Cell, which is a journal,
link |
another excellent journal, very high stringency,
link |
showing that light that arrives to the eyes
link |
between 11 p.m. and 4 a.m. approximately
link |
suppresses the release of dopamine,
link |
this neuromodulator that makes us feel good
link |
as sort of an endogenous antidepressant
link |
and can inhibit learning
link |
and create all sorts of other detrimental effects.
link |
It does this through a mechanism,
link |
for those of you who want to know the neural pathways,
link |
that involves light to the eyes
link |
that then signal to a structure called the habenula.
link |
The habenula looks like two little bat ears
link |
sitting right in the middle of you,
link |
structuring your brain called the thalamus.
link |
Don't worry about these names
link |
if you're not interested in this stuff.
link |
If you are, these are just avenues to explore.
link |
When that habenula gets activated,
link |
it's actually called the disappointment nucleus
link |
because it actually makes us feel less happy
link |
and more disappointed
link |
and can lead to certain forms of depression
link |
in the wakeful state.
link |
Now, if you wake up in the middle of the night
link |
and you need to use the bathroom
link |
or you're on an all night flight
link |
and you need to read or whatever it is, fine.
link |
Every once in a while, it's not going to be a problem
link |
to get bright light exposure to your eyes
link |
in the middle of the night.
link |
But if you think about our lifestyle nowadays
link |
and being up late looking at phones,
link |
even if you dim that screen,
link |
you're triggering this activation
link |
because your retinal sensitivity
link |
and the sensitivity of these neurons has gone up
link |
Now, I'm not here to dictate what you should or shouldn't do
link |
but for those of you that are experiencing challenges
link |
with mood, those of you that have anxiety,
link |
learning problems, issues focusing,
link |
the questions I usually get are, how can I focus better?
link |
Well, we will get to that.
link |
But one of the best ways you can support your mechanisms
link |
for good mood, mental health, learning, focus,
link |
metabolism, et cetera, is to take control
link |
of this light exposure behavior at night
link |
and not get much or any bright light exposure
link |
in the middle of the night.
link |
Red light won't trigger this pathway
link |
but very few people have the kind of infrared lights
link |
that are set up or floor lights.
link |
And that brings me to an important point
link |
which is about the location of light.
link |
This hasn't been discussed much out there, I don't think.
link |
These cells in our eye, these neurons
link |
that signal the central clock reside mostly,
link |
not exclusively, but mostly in the bottom half
link |
And because we have a lens in front of our retina
link |
and because of the optics of lenses,
link |
that means that these cells are actually viewing
link |
our upper visual field.
link |
There's an inversion of the visual image, et cetera.
link |
You can look that up if you wanna learn more
link |
about retinal optics, it's fascinating
link |
but not the topic for today.
link |
These cells are in the bottom half of your retina mostly
link |
and so they're viewing the overhead visual space around you.
link |
This is probably not coincidental
link |
that these cells were essentially designed
link |
to detect sunlight, which is overhead, of course.
link |
So if you want to avoid improper activation
link |
of these neurons, it's better to place lights
link |
that you use in the evening low in your physical environment
link |
so on desktops or even the floor,
link |
if you wanna go that way, as opposed to overhead lights.
link |
So overhead fluorescent lights would be the worst.
link |
That would be the worst case scenario.
link |
Lights that are overhead that are a little bit softer
link |
of the sort of yellow or reddish tints
link |
would be slightly better.
link |
But dim lights that are set low in the room
link |
are going to be best because they aren't going
link |
to activate these neurons
link |
and therefore shift your circadian clock.
link |
Some people like Samir Hatar that I mentioned earlier,
link |
he turns his home basically into a cave in the evenings.
link |
Candlelight actually does not trigger
link |
activation of these cells.
link |
So candlelight and fireplaces and campfires are fine.
link |
Dim lights, very dim lights are fine
link |
and lights low in the physical environment.
link |
Of course, the problem with candlelight and fireplaces
link |
is the fire hazard, but you're smart people.
link |
You know what to do about that.
link |
Don't burn down whatever structure you're in,
link |
including forests, please.
link |
So keep the lights low in your environment.
link |
What if you wake up in the middle of the night
link |
and you find yourself watching TV or on the computer?
link |
And well, in that case, you might want to wear blue blockers
link |
and you certainly would want to dim the screen,
link |
but ideally you're not doing that.
link |
It's remarkable the positive effects
link |
of getting that bit of sunlight early in the day,
link |
maybe even also around sunset and avoiding bright lights
link |
and especially overhead bright lights
link |
between about 11 p.m. and 4 a.m.
link |
Now I'm not talking about shift work.
link |
I'm realizing that we're probably going to have to have
link |
an entire discussion devoted just to shift workers
link |
because there's some good information there
link |
about how they can protect themselves
link |
against some of the very bad health effects of shift work
link |
of getting light in the middle of the night.
link |
But we rely on shift workers and they're super important
link |
to culture and society and the economy.
link |
So I want to acknowledge them and let you know
link |
that we will do a discussion about shift work and jet lag.
link |
But let's talk about what light can do
link |
in terms of shifting us in healthy ways.
link |
So the way to think about this whole system,
link |
again, is you've got adenosine building up
link |
depending on how long you've been awake
link |
and it's making you sleepy.
link |
And then you've got the circadian mechanisms
link |
that are timing your wakefulness
link |
and timing when you want to be asleep,
link |
mainly through cortisol and melatonin.
link |
But there are a bunch of other things
link |
that are downstream of cortisol and melatonin.
link |
Like we tend to be hungrier during our wakeful period
link |
than late at night.
link |
Some people like to eat late at night,
link |
but if you're finding that you can't become a day person
link |
or a morning person, shifting your light exposure,
link |
exercise and food intake to the daytime will help.
link |
Some people like to stop eating around six or 8 p.m.
link |
because of metabolic reasons
link |
or they're trying to maintain their weight or lose weight.
link |
That's actually not supported so well by the literature.
link |
The literature around nutrition essentially says
link |
that it's best to restrict your feeding
link |
to a certain period of each 24 hour cycle
link |
to not be eating around the clock.
link |
And whether or not that's four hours or eight hours
link |
or 16 hours is a much lengthier discussion
link |
than we have time for now.
link |
I would refer you to Sachin Panda's book,
link |
The Circadian Code, which talks all about that.
link |
He's an expert, a former colleague of mine
link |
from the Salk Institute in San Diego.
link |
You can explore intermittent and circadian fasting,
link |
so to speak, through Sachin's literature.
link |
We'll talk about that.
link |
We might even get Sachin in here
link |
if we're lucky at some point in the future.
link |
But you can actually use light to wake up earlier.
link |
Jamie Zeitzer and colleagues did a beautiful study
link |
showing that if you turn on the lights before waking up,
link |
so around 45 minutes to an hour before waking up,
link |
even if your eyelids are closed,
link |
provided you're not under the covers,
link |
after doing that for a few days,
link |
that increases your total sleep time
link |
and shifts forward the time at which you feel sleepy.
link |
It makes you want to go to bed earlier each night.
link |
Now, in a kind of a diabolical way,
link |
they did this with teenagers who are notorious
link |
for wanting to wake up late and stay up late.
link |
And what they found was bright light flashes,
link |
just turning on the lights in their environment,
link |
because they're trying to activate the system,
link |
and that's why they're using overhead lights.
link |
Even through the eyelids, before these kids woke up,
link |
then made those kids naturally want to go to bed earlier
link |
and they ended up sleeping longer.
link |
So that's something you could try.
link |
You could put your lights on a timer to go on
link |
early in the day before you wake up.
link |
You could open your blind so that sunlight is coming through.
link |
And again, if you curl up under the covers,
link |
then it's not going to reach these neurons,
link |
but it's remarkable the light can actually penetrate
link |
the eyelids, activate these neurons,
link |
and go to the central clock.
link |
That study illustrates a really important principle
link |
of how you're built,
link |
which is you have the capacity for what are called
link |
phase advances and phase delays.
link |
And I don't want to complicate this too much.
link |
So the simplest way to think about phase advances
link |
and phase delays is that if you see light late in the day,
link |
and in particular in the middle of the night,
link |
your brain and body for reasons that now you understand
link |
will think that that's morning light,
link |
even though it's not sunlight
link |
because you have this heightened sensitivity,
link |
and it will phase delay,
link |
it will delay your clock.
link |
It will essentially make you want to get up later
link |
and go to sleep later.
link |
So if you get light exposure too late in the evening
link |
or in the middle of the night,
link |
it's going to make it hard to want to wake up
link |
the next morning early and to go to bed early.
link |
The opposite is also true.
link |
If you wake up early,
link |
say 6 a.m. or 7 a.m. and get light exposure,
link |
or even earlier, 4 a.m., and get light exposure,
link |
it will phase advance your clock, okay?
link |
It's going to make your clock think it's earlier
link |
and you'll want to wake up earlier.
link |
So the simple way to think about this
link |
is if you're having trouble waking up early
link |
and feeling alert early in the day,
link |
you're going to want to try and get bright light exposure
link |
even before waking up because it will advance your clock.
link |
It's sort of like turning the clock forward.
link |
Whereas if you are having trouble waking up early,
link |
you definitely don't want to get too much light exposure
link |
or any light exposure to your eyes late in the evening
link |
and in the middle of the night
link |
because it's just going to delay your clock more and more.
link |
So rather than get into the specifics
link |
of everybody's situation,
link |
because there are many of you out there
link |
with different situations
link |
and lifestyle requirements, et cetera,
link |
the way to think about this
link |
is that you have these internal mechanisms
link |
of adenosine and circadian clocks,
link |
and they're always operating.
link |
And what you're trying to do is provide them anchors.
link |
You're trying to provide them consistent, powerful anchors
link |
so that your cortisol, your melatonin,
link |
and then everything that cascades down from that,
link |
like your metabolism and your ability to learn
link |
and your sense of alertness, your dopamine, your serotonin,
link |
all that stuff is timed regularly.
link |
One of the reasons why there's so much challenge out there
link |
with focus and anxiety and depression,
link |
there are a lot of reasons for that,
link |
but one of the reasons is that people's internal mechanisms
link |
aren't anchored to anything regular.
link |
Now, this doesn't require being neurotically attached
link |
to getting up at a very specific time,
link |
going outside, viewing the sunlight, same time every day.
link |
These systems, again, will average,
link |
but if you can provide them consistent light anchors
link |
early in the day and in the evening
link |
and avoiding light at night,
link |
you will be amazed at the tremendous number
link |
of positive effects that can come from that
link |
at the level of metabolic factors, hormones,
link |
and just general feelings of wellbeing.
link |
In fact, most of us are familiar
link |
with what it is to not sleep well
link |
and all the terrible effects that has.
link |
Maybe one night you're fine,
link |
two nights even for the new parents out there,
link |
I sympathize with you,
link |
but most people are not familiar with what it is
link |
to sleep really, really well on a consistent basis.
link |
And when you start doing that
link |
by controlling your sleep environment, right,
link |
get the proper sleep surface, get the proper pillow,
link |
get the temperature in the room right,
link |
get your light exposure right,
link |
start timing your exercise at normal periods or times
link |
throughout the day and week.
link |
It's amazing how many other biological systems
link |
just naturally fall in line.
link |
And this is why whenever people ask me,
link |
what should I take,
link |
which is one of the most common questions I get,
link |
what supplements should I take?
link |
What drugs should I be taking?
link |
What things should I be taking?
link |
The first question I always ask them is, how's your sleep?
link |
And 90% of the time they tell me
link |
they either have trouble falling asleep or staying asleep,
link |
or they don't feel rested throughout the day.
link |
A brief note about naps.
link |
Naps, provided that they're less than one ultradian cycle,
link |
provided they're 20 minutes or 30 minutes or even an hour,
link |
can be very beneficial for a lot of people.
link |
You don't have to take them,
link |
but many people naturally feel a dip in energy
link |
and focus late in the afternoon.
link |
In fact, if we were gonna look at wakefulness,
link |
what we would find is that
link |
you get that morning light exposure,
link |
hopefully your cortisol goes up,
link |
people will start feeling awake,
link |
and then around two or three or four in the afternoon,
link |
there's a spike in everything from alertness
link |
to ability to learn, some metabolic factors drop,
link |
and then it just naturally comes back up,
link |
and then it tapers off as the night goes on.
link |
So for some of you, naps are great.
link |
I love taking naps.
link |
Some people, they wake up from naps feeling really groggy.
link |
That's probably because they're not sleeping as well
link |
as they should at night,
link |
or as long as they should at night,
link |
and so they're dropping into REM sleep
link |
or deeper forms of sleep in the daytime.
link |
And then they wake up and they feel kind of disoriented.
link |
Other people feel great after a nap.
link |
So that's another case where just like with caffeine,
link |
you sort of have to evaluate for yourself.
link |
As we discuss this, you're probably realizing
link |
this is a lot like nutrition,
link |
where nowadays it's just crazy.
link |
I mean, if you go on social media,
link |
it's like you've got people who are pushing carnivore,
link |
you've got other people who are pushing vegan,
link |
other people who are pushing paleo,
link |
every variation of every diet.
link |
And there's a lot of data to support any and all of those,
link |
and the arguments go on and on.
link |
And there's probably a lot of genetic variation
link |
and lifestyle variation that's going to dictate
link |
whether or not something is good for you,
link |
whether or not you like it,
link |
whether or not you'll stick to it.
link |
The same thing is true for circadian
link |
and sleep and wakefulness behaviors,
link |
except the light viewing behavior
link |
that I talked about before.
link |
There's no way around that.
link |
That's hardwired into our system.
link |
The same way we could factually say
link |
that everybody needs some nutrition at some level
link |
from some source, everybody needs light information
link |
arriving in their system in some way at regular intervals.
link |
So that's really what this is about.
link |
Okay, so naps are going to be good
link |
for some people, not for others.
link |
I have a colleague, a very accomplished neuroscientist
link |
who likes to take naps just after lunch.
link |
I personally like to take a nap around three or 4 p.m.,
link |
but there's a practice that I've adopted
link |
in the last five years
link |
that I've found to be immensely beneficial
link |
that is sort of like napping, but isn't napping.
link |
It's a thing that they call yoga nidra.
link |
Yoga nidra actually means yoga sleep.
link |
And it's a sort of meditation that you listen to.
link |
There are a number of scripts.
link |
I've talked about this on podcasts before,
link |
but I'm going to post a link to the two that I like most
link |
that allows you to consciously bring your entire body
link |
and mind into a state of deep relaxation.
link |
And sometimes you fall asleep and sometimes you don't.
link |
This is done for 10 to 30 or even 60 minutes at a time.
link |
The other thing that works really well is meditation.
link |
So I'm talking about naps,
link |
but I'm also talking about yoga nidra,
link |
which is sort of a form of meditation,
link |
and then more standard forms of meditation.
link |
All three of those do something powerful,
link |
which is that they bring our mind
link |
into a state of less so-called
link |
sympathetic nervous system activation.
link |
Go back and listen to episode one
link |
if that doesn't make any sense,
link |
which is what governs your alertness.
link |
And instead it activates cells and circuits in your body
link |
that promote the parasympathetic nervous system
link |
or the calming system.
link |
A lot of people are not good at falling asleep
link |
because they're not good at calming down.
link |
So some people have no trouble falling asleep,
link |
but many people have a hard time falling asleep
link |
or at least every once in a while
link |
experience challenges falling asleep.
link |
I don't have problems falling asleep most nights,
link |
but I've noticed that if I'm working very hard
link |
or if the world is particularly stressful,
link |
my mind gets into a bit of a kind of OCD loop
link |
where I tend to ruminate on things.
link |
And I'm not even thinking about anything in particular.
link |
It's just challenging for me to disengage and fall asleep.
link |
Meditation and yoga nidra scripts
link |
have been immensely helpful for me
link |
in terms of accelerating the transition to sleep.
link |
So they involve taking a few minutes,
link |
10 to 30 minutes or so, just like you would for a nap,
link |
and just listening to a script almost passively.
link |
And it has you do some particular patterns of breathing
link |
and some other kind of body scan-like things
link |
that can really help people learn to relax,
link |
not just in that moment, but get better at relaxing
link |
and turning off thinking in order to fall asleep
link |
when they want to do that at night.
link |
There's another thing that's similar to this,
link |
which is certain forms of hypnosis for sleep.
link |
For that, I'll just refer you to the website
link |
of a colleague and collaborator of mine, David Spiegel,
link |
who's our Associate Chair of Psychiatry
link |
and Behavioral Sciences at Stanford.
link |
He's developed a website, which is reverie,
link |
R-E-V-E-R-I-E, health.com, so reveriehealth.com,
link |
that has a lot of science-supported,
link |
clinically-supported hypnosis scripts
link |
that essentially take the brain
link |
into states of deep relaxation
link |
for sake of rewiring the brain and neuroplasticity.
link |
But one of those scripts that's there
link |
and is available free is for sleep.
link |
And we'll talk more about hypnosis at a later time
link |
because it has a ton of other effects
link |
that aren't just limited to sleep.
link |
So a period of time each day that you devote
link |
to getting better at falling and staying asleep
link |
is actually a really good practice to adopt.
link |
The other thing about these practices like meditation,
link |
yoga nidra, and hypnosis is people always say to me,
link |
well, when should I do them?
link |
And I always say, well, the best time of day to do it is
link |
when you first wake up in the morning,
link |
provided you've gotten your sunlight already,
link |
anytime you wake up in the middle of the night
link |
or any time of day.
link |
In other words, they're always good for you
link |
because it's a training mechanism
link |
by which you self-train your nervous system
link |
to go from a state of heightened alertness
link |
that you don't want to heightened relaxation
link |
And so it's really teaching you to hit the brake.
link |
And that brings us to an even more important point perhaps,
link |
which is we've all experienced
link |
that we can stay up if we want to, right?
link |
If we wanna stay up late on New Year's
link |
or we wanna push an all-nighter,
link |
some people can do that more easily than others,
link |
but we're all capable of doing that.
link |
But it's very hard to make ourselves fall asleep.
link |
And so there's a sort of asymmetry
link |
to the way our autonomic nervous system,
link |
which governs this alertness calmness thing,
link |
the sympathetic and parasympathetic nervous system,
link |
there's an asymmetry there where we are more easily able
link |
to engage wakefulness and drive wakefulness.
link |
We can force ourselves to stay awake.
link |
Then we are able to force ourselves to fall asleep.
link |
And one of the things that I say over and over again,
link |
and I'm gonna continue to say over and over again,
link |
is it's very hard to control the mind with the mind.
link |
When you have trouble falling asleep,
link |
you need to look to some mechanism that involves the body.
link |
And all the things I described, meditation, hypnosis,
link |
yoga nidra, all involve exhale emphasized breathing,
link |
certain ways of lying down and controlling the body.
link |
We're gonna get into breathing
link |
in real depth at another time.
link |
But all of those involve using the body to control the mind
link |
rather than trying to wrestle your mind
link |
into a certain pattern of relaxation.
link |
So earlier in episode one, I talked about the Mobius strip,
link |
this continuous loop that is the brain-body relationship
link |
or the mind-body relationship.
link |
And when we're having trouble controlling the mind,
link |
I encourage people to look towards the body,
link |
look toward sunlight, avoid sunlight and bright light
link |
if that happens to be late at night.
link |
So there's a theme that's starting to emerge,
link |
which is in order to control this thing
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that we call the nervous system,
link |
we have to look back to some of the things
link |
we discussed earlier, like sensation, perception, et cetera.
link |
But we have to ask, what can we control?
link |
Well, I'm talking about controlling light exposure,
link |
controlling your breathing and body.
link |
I'm not going into details right now,
link |
but you can see the yoga nidra script
link |
or the reveriehealth.com or Headspace would be a great place
link |
to adopt the meditation practice.
link |
Any of those are really teaching you to use your body
link |
to control your mind and to allow you
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to explore the mind-body relationship in a way
link |
that gives you more control over your mind
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and the mind-body relationship, okay?
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So we talked about light,
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we talked about activity and timing of light,
link |
talked about the usefulness of naps
link |
and these things that I'm calling non-sleep deep rest,
link |
which include meditation, yoga nidra and hypnosis.
link |
Non-sleep deep rest, or what I hear after
link |
we will refer to as NSDR,
link |
not to be confused with EMDR,
link |
I don't think I've ever heard NSDR,
link |
so I'm planting a flag for NSDR, non-sleep deep rest,
link |
as a way to reset one's ability to be awake
link |
after you emerge from NSDR,
link |
so to get some more wakefulness and ability to attend,
link |
some emotional stability reset,
link |
as well as make it better and easier to fall asleep
link |
when you wanna go to sleep at night.
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Now, non-sleep deep rest does have some research
link |
There's a beautiful study done
link |
out of a university in Denmark,
link |
I will later provide a link to that study,
link |
that showed that this meditation
link |
and yoga nidra type meditation
link |
allows dopamine and other neuromodulators
link |
in an area of the brain called the striatum
link |
that's involved in motor planning and motor execution,
link |
In other words, this NSDR can reset our ability
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to engage in the world in a way that's very deliberate,
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not to throw in another acronym,
link |
but NSDR resets your ability to engage in DPOs,
link |
duration, path, and outcome.
link |
So now you're probably rolling your eyes,
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like, oh my goodness, the number of acronyms,
link |
but just bear with me because NSDR is so powerful
link |
because first of all,
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it doesn't require that you rig yourself to any device,
link |
it doesn't require that you take much time out of your day,
link |
it doesn't require that you ingest anything except air,
link |
and it can have so many positive effects,
link |
right down to the neuromodulator level.
link |
So I think in the years to come,
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my lab's exploring this in collaboration
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with David Spiegel's lab,
link |
but other labs are looking at this as well.
link |
I think NSDR is going to start to play a more prominent role
link |
in what we call wellness and health,
link |
both mental health and physical health.
link |
So I encourage you to explore those practices.
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Okay, so what about things that we can and maybe should
link |
or should not take in order to control
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and access better sleep and better wakefulness?
link |
We've talked about things you can do or not do.
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We've talked about nutrition and the timing of nutrition.
link |
Now let's talk about compounds.
link |
Those could be prescription drugs,
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those could be supplements.
link |
There are a number of different things
link |
that will affect your circadian timing and behavior.
link |
In fact, almost everything that you could take
link |
will affect your circadian timing and behavior.
link |
So years ago, when I was in graduate school,
link |
I had a professor,
link |
unfortunately he passed away now,
link |
but his name was Ted Jones, the late Edward Jones,
link |
who was a world-class neuroanatomist.
link |
He wrote the book on the thalamus,
link |
in fact, it's called The Thalamus,
link |
and an expert on patterns of activation
link |
in the brain during sleep.
link |
And I'll never forget that during one of these lectures,
link |
someone asked Ted the question,
link |
what is the effect of some drug
link |
on these waves of activity in the thalamus or something?
link |
And his answer was incredible.
link |
He was a pretty gruff guy.
link |
And so his answer was delivered
link |
in the form of a kind of aggressive direct statement.
link |
He said, a drug is a substance
link |
that when injected into a person
link |
produces a scientific publication.
link |
And what he was saying is actually quite true,
link |
which is that most every compound
link |
will have some effect on some aspect of biology.
link |
This is why it's hard to sort through everything
link |
If you put any molecule or compound or drug into PubMed,
link |
and then you put sleep next to it or alertness next to it,
link |
you're likely to find a paper where there's an effect.
link |
But that's not necessarily telling you
link |
that that drug is useful or helpful for that.
link |
What it's telling you is that anytime you change
link |
what you take or you stop taking something,
link |
say you're taking sleeping pills,
link |
Ambien or whatever it is, and you stop taking them,
link |
your sleep behavior will change.
link |
Let's say you take an aspirin,
link |
you don't normally take aspirin,
link |
you will shift your circadian rhythm.
link |
Now you might not shift it perceptibly,
link |
you might not create problems for yourself,
link |
but anytime you ingest a compound at high potency,
link |
you're going to provide some shift to your circadian rhythm.
link |
Now, that said, there are a couple of things
link |
that are directly in line with the biology
link |
related to falling and staying asleep
link |
and directly in line with the biology of wakefulness.
link |
There's a whole category of things like stimulants,
link |
cocaine, amphetamine, and prescription stimulants,
link |
the prescription ones were designed
link |
for the treatment of narcolepsy.
link |
So things like modafinil or armodafinil
link |
that are designed to create wakefulness,
link |
they are all essentially chemical variants
link |
of things that increase epinephrine and dopamine.
link |
Now, of course, I'm of the standpoint
link |
that things like cocaine and amphetamine
link |
are just across the board bad,
link |
they have so many addictive and terrible effects.
link |
In the proper setting prescribed by the proper professional,
link |
things like modafinil for narcolepsy might be appropriate.
link |
I know that a lot of people out there take Adderall,
link |
even though they haven't been prescribed Adderall
link |
in order to increase wakefulness.
link |
That is essentially, well, it's illegal for one,
link |
but it's also, it's abusing the system
link |
in the sense that you're pushing back
link |
on the adenosine system slightly differently
link |
than you do caffeine.
link |
It will make you feel more alert.
link |
There tends to be a heavy rebound
link |
and they do have an addictive potential.
link |
There are also some other effects of those
link |
that can be quite bad.
link |
So we're going to explore stimulants
link |
in a whole month related to drugs,
link |
but there are some supplements and some things
link |
that are safer, certainly safer,
link |
and that in cases where you're doing
link |
all the right behaviors,
link |
you're exercising and eating correctly,
link |
and you're still having trouble with sleep,
link |
that can be beneficial for falling and staying asleep.
link |
Now, I want to be very clear.
link |
I am not pushing supplements.
link |
I'm just pointing you towards some things
link |
that have been shown in peer-reviewed studies
link |
to have some benefit.
link |
The first one is magnesium.
link |
There are many forms of magnesium,
link |
but certain forms of magnesium can have positive effects
link |
on sleepiness and the ability to stay asleep,
link |
mainly by way of increasing neurotransmitters like GABA,
link |
which help turn off the DPO,
link |
the kind of thinking about the future,
link |
duration path outcome analysis,
link |
and make one's mind kind of drift in space and time
link |
and make it easier to fall asleep.
link |
There are a lot of forms of magnesium out there,
link |
but one in particular is magnesium threonate, T-H-R-E-O-N-A-T-E,
link |
which you have to check to see if this is right for you,
link |
check with your doctor,
link |
but magnesium threonate is associated with transporters
link |
in the body that bring more of it into cells
link |
that allow people to feel this kind of drowsiness
link |
and help them fall asleep.
link |
So I personally, I can only talk about what I personally do.
link |
I personally take three or 400 milligrams
link |
of magnesium threonate about 30 to 60 minutes before sleep,
link |
and it helps me fall asleep.
link |
The other thing is theanine, T-H-E-A-N-I-N-E, theanine,
link |
100 to 200 milligrams of theanine for me
link |
also helps me turn off my mind and fall asleep.
link |
I take it 30 to 60 minutes throughout the day.
link |
Interestingly, theanine is now being introduced
link |
to a lot of energy drinks
link |
in order to take away the jitters that are associated
link |
with drinking too much caffeine
link |
or with some other things that are in the energy drinks.
link |
Energy drinks can be problematic.
link |
They can contain a lot of L-Taurine.
link |
I'll just tell you an anecdote.
link |
When I was a postdoc,
link |
I was drinking a lot of a particular energy drink,
link |
has a lot of taurine in it.
link |
And actually the whites of my eyes, the sclera,
link |
as it's called in my eyes, turned beet red.
link |
And I went to a friend who's an ophthalmologist.
link |
I said, look, I'm not a marijuana smoker.
link |
I haven't been hit on the head.
link |
I don't know what's going on.
link |
And he looked and he said,
link |
I think you've got some microvascular damage.
link |
And we walked through what I was taking and doing.
link |
And he said, oh, it's probably the taurine,
link |
excessive levels of taurine
link |
can create some microvascular damage.
link |
So if you're having the microvascular damage in your eye,
link |
you'll probably have microvascular damage deeper
link |
That's the reason why I don't take energy drinks.
link |
So just a consideration.
link |
Again, I'm not here to tell you what to do or not do,
link |
but just want to arm you with information.
link |
The thing about theanine and magnesium is taken together.
link |
They do, for some people,
link |
they can make them so sleepy and sleep so deeply
link |
that they actually have trouble waking up in the morning.
link |
So you have to play with these things and titrate them
link |
if you decide to use them.
link |
Again, if you decide to go this route.
link |
I would not start by taking supplements.
link |
I would start by getting your light viewing behavior correct
link |
and then think about your nutrition
link |
and then think about your activity
link |
and then think about whether or not you want a supplement.
link |
We already talked about melatonin earlier.
link |
There's another supplement that could be quite useful,
link |
which is apigenin, A-P-I-G-E-N-I-N,
link |
which is a derivative chamomile.
link |
50 milligrams of apigenin also can augment
link |
or support this kind of creation of a sleepiness
link |
to help fall asleep and stay asleep.
link |
A note about sleepwalkers
link |
and people with very vivid dreams.
link |
Theanine can often make your dreams very vivid.
link |
Sleepwalkers should be careful about taking theanine.
link |
Everyone should be careful about taking anything
link |
and don't take anything without consulting
link |
your board certified MD or healthcare professional first.
link |
Your health is your responsibility.
link |
I am not going to take responsibility
link |
for what you decide to do experimentally in any case,
link |
but especially as it relates to supplementation and drugs.
link |
As a important point,
link |
apigenin is a fairly potent estrogen inhibitor.
link |
So women who want to keep their estrogen levels high
link |
or at whatever levels they happen to be at
link |
should probably avoid apigenin altogether.
link |
And men take that into consideration as well.
link |
Men need estrogen also.
link |
You don't want to completely eliminate your estrogen.
link |
That it can create all sorts of bad effects
link |
on libido and cognition, et cetera.
link |
So apigenin in some people
link |
is going to be a pretty strong estrogen inhibitor.
link |
So keep that in mind.
link |
There are other things you can take to help you sleep better.
link |
Those are the legal ones that at least I'm aware of
link |
have pretty broad safety margins.
link |
But again, you need to explore your safety margins
link |
with any compound.
link |
I think a great website that I can refer you to
link |
Examine the word, just as it sounds,.com is a website.
link |
I have no relation to them,
link |
but there you can find links to peer-reviewed studies
link |
for any compound or supplement,
link |
as well as some important warnings
link |
related to the things I discussed,
link |
as well as any other thing
link |
that you might decide to supplement with or ingest
link |
to help improve your sleep.
link |
That was a lot of information
link |
about how to get better at sleeping, falling asleep,
link |
wakefulness, et cetera.
link |
An important feature of this podcast, as you know,
link |
is that we dive deep into topics
link |
for several episodes at a time,
link |
at least a month at a time.
link |
So by stopping here,
link |
I recognize that there are probably many more questions
link |
that you still have.
link |
And the great thing about that
link |
is that we have another episode coming up soon.
link |
I'm going to hold office hours
link |
where I'm going to answer your specific questions
link |
about episodes one and two.
link |
So if you have questions about this episode,
link |
you have questions about episode one,
link |
write them down, put them in the comments.
link |
I'll also do a post on Instagram
link |
where you can put them in the comments there,
link |
but put them in the comments to this episode.
link |
As well, please recommend the podcast if you like it.
link |
Please subscribe to it here on YouTube.
link |
Please subscribe to it on Apple.
link |
We're now on Spotify as well.
link |
Recommend it to a friend.
link |
The community that we're creating here
link |
around these topics of sleep and wakefulness
link |
and other neuroscience and health-related themes
link |
is best supported by your involvement and your questions.
link |
And so I'm going to be reading all of your questions,
link |
distilling those into the most commonly asked questions
link |
and liked questions.
link |
So if you see something below
link |
that you are particularly interested in,
link |
you don't have to put that question in again,
link |
you can just give it a like, the little thumbs up tab.
link |
And if you're listening to this on Spotify or Apple,
link |
please go to YouTube,
link |
subscribe and put your question there,
link |
or check out the Huberman Lab Instagram,
link |
and you can put your questions there
link |
so that next episode I can answer those questions
link |
and then we can move forward even more deeply
link |
into these critical topics around sleep and wakefulness
link |
so that you can be armed with all the information
link |
and resources that you need.
link |
Last but not least,
link |
a number of you have very graciously asked
link |
how you can support the podcast.
link |
The best way to support the podcast
link |
is to subscribe on YouTube or one of the other platforms.
link |
We're now on Spotify and Apple.
link |
And the other way you can really support the podcast
link |
is to check out our sponsors,
link |
which were discussed at the beginning.
link |
So thank you so much for your time and attention,
link |
and above all, thank you for your interest in science.
link |
And I'll see you in the next one.