How Sleep Rewires Your Brain, Balances Your Hormones & Extends Your Life | Dr. Matthew Walker

Coming up on this episode of the Dr. Hyman Show.

And what we found is that when people are sleep deprived, you become asocial. You withdraw from society. You just don't want to interact with other people.

You want to watch Netflix.

You just want to shut down.

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You won't go back. Now, before we jump into today's episode.

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If you care about sleep and if.

You'Re having trouble sleeping or you struggle.

With sleep or you know anybody who.

Has had sleep issues, this is the.

Podcast you want to listen to because it's with what I would say is.

Today'S iconic world expert on sleep, Dr. Matthew Walker. He wrote a book that changed the world called why We Sleep. His TED talk on this topic has.

Been seen probably close to 20 million times.

He is a PhD in neuroscience from.

The Medical Research Council in the UK.

And became a professor of psychiatry at Harvard Med School. He's currently a professor of neuroscience and psychology at University of California, Berkeley and the director of the Center for Human Sleep Science.

His focus is mostly on the effect.

Of sleep on human health and disease, brain and bodies. Published over 200 scientific studies, received numerous funding awards from the National Science Foundation.

NIH, and just is an incredible guy.

With a wealth of knowledge who I.

Learn from every single time. And we get into so much about misconceptions about sleep, why we're struggling with sleep, simple sleep hacks, let's call them, or just strategies to optimize your sleep.

Everything from how to navigate your wind down routine to the things that interfere.

With sleep to why sleep is so important.

And I think you're gonna love this conversation.

We could have gone on for probably.

Six hours, which may be a reason.

I'm going to have him back and talk more about this topic, but sleep.

Is a very deep topic. We barely scratched the surface.

But I think you're gonna get a great overview in this wonderful conversation with Dr. Matthew Walker. So let's dive right in. So Matthew, welcome. Great to have you here.

It's lovely to be here. I've been trying to get you on.

For a few years now and finally we did it. We made it work. We did it. It was great. Great to see you. You're looking great, by the way.

Thank you. And you too. You've got the long COVID hair now, which is. Yeah, exactly.

Nobody told you COVID was over, which is apparently not. And, you know, probably no one should trust someone who has hair this long.

So everyone listening or watching, take anything I say with a grain of salt.

Well, that's not true. I actually, I had hair actually longer than this when I was in college.

Really? That was in the 70s when it was. Yeah, you had an excuse.

I don't know what mine is. MidlifeCrisis. But maybe. So, for those who don't know Dr. Matthew Walker, he is the guru of sleep, I would say, in today's world. And, you know, I remember back in Cornell when I took a class with a psychologist, James Maas, It was big intro Psych 101, and there was this whole section on sleep, and it kind of blew my mind. And there was a guy named, I think, William Dement.

Oh, my goodness.

Who wrote this.

Godfather of Sleep.

Yeah, the Godfather of Sleep. And so, you know, nobody else really has come on the scene since he was around. And you wrote this book called why We Sleep.

Yeah, why We Sleep.

And, you know, it's something probably most people have never thought about, and yet sleep, it turns out, is probably one of the most important things that we do. And many people in the longevity space, in the health space, and I'm sort of surprised to hear this, have put it above nutrition, above exercise, right?

It has come on the scene now. I mean, back then, just before I published the book, sleep, and it wasn't the book that did this, sleep was almost the neglected stepsister in the health conversation of that time back in 2018. And now I think people are starting to really embrace it. Maybe it's the wearable movement, maybe it's just more people speaking about it. I don't quite know what it is. But now people, as you said, are not only saying it's the third pillar of good health alongside diet and exercise. In fact, if you look at the data, it's really not. It's the foundation on which those two other things sit.

Yeah.

And so I think that's why it's had this really remarkable ascendancy in some ways. Nevertheless, I would still say, though, that sleep has an image problem in society. Yeah. Meaning that we still apply this label of stigma and laziness so many people will tell you how clean they've been eating this past month, how many days they've got to the gym. I don't know anyone who's sidled up to me and said, I slept nine hours last night. I am consistently saying, because people's response is really? And embedded in that response and the tone is, well, are you not busy? And if you're not busy, you must not be important, and therefore we have this problem. But anyway, whoever the PR agent for sleep has been in the past 20 years, we should probably find them.

Certainly not you, 'cause you've done a great job. And you published a paper recently in a very prestigious medical journal called PLOS Biology called the New Science of Sleep From Cells to Large Scale Societies, which I thought was an incredible framing around sleep because most of us think we sleep 'cause we have to, we get tired, if we don't we feel crappy, and that's what most of us know. And it sleeps in annoyance for some people 'cause it means they can't get enough work done and they wanna watch more TV or they wanna create their business or they wanna go out and party. but they got to do this annoying thing called sleep. And it turns out that it's sort of essential to the fabric of everything that we care about that matters, right down to our biochemistry and cellular physiology, all the way to what happens in society and across a whole spectrum of human experience. So can you kind of walk us through from, maybe start from like the big picture from the large scale impact of sleep and lack of sleep and poor sleep, which is an epidemic. Yeah. And sort of lay out, like, how big of a problem sleep is for us, because I know, I don't think people really realize how big of a problem it is. And then, and then let's kind of walk through during the session and podcast how we get down to the biology of sleep, the cellular impact of sleep or lack of sleep, and then the factors that really are driving a lot of the stuff and, and the things that people aren't even thinking about, for example, like the bacteria in your gut. Like who thinks that the bacteria in your gut actually play a role in your sleep? But they do, and I can tell you they do because I know they have for me. And there's other things like that that people aren't talking about, like nutrition and hormones and other things. So let's start by sort of kind of talking about what inspired you to write this kind of really sweeping view of sleep that you recently published.

What I really wanted to try to do is capture, in a way, the full spectrum, the full panoply of sleep's influence in every single facet of us human beings as a species. And as you said, you can start right at the top some of our most recent work, which I think is to me was the biggest surprise most recently, sleep is essential for our pro-social behavior, meaning there is no major society that has sort of aspect of developed nations that has evolved without human cooperation, for example. That's pro-sociality. And what we found is that when people are sleep deprived, you become asocial. You withdraw from society. You just don't want to interact.

You wanna be watched Netflix.

You just want to, you know, just want to shut down.

Yeah.

Worse still, other people who do not know that you are sleep deprived, when they are asked, would I like to go to coffee with this person when they've watched a video of them, or would I like to make friends with them on Facebook? Even though they know nothing about whether that person is well slept or sleep deprived, they will find the person who is sleep deprived more socially repulsive and they will choose not to interact with them.

I mean just by how they look?

Just by how they look and how they talk. So in other words, and then worse still, when you interact with a sleep deprived individual and we ask you, the sleep rested individual, How are you feeling right now? Are you feeling engaged? Are you feeling lonely? They feel significantly more lonely as a consequence of interacting with the lonely sleep-deprived individual.

I think the sleep-deprived individual is kind of checked out.

They're checked out, but in some ways, it's viral transmission of becoming asocial, of social. There is a social repulsion force from a sleep-deprived individual that not only makes you step away from them and not engage with them, but it makes you feel even more lonely having interacted with them.

That's crazy.

And you can see this in all manner, sleep deprived individual, people who are more sleep deprived are less likely to engage, for example, in voting during elections. So fundamental aspects of how our civilization operates are dependent on the interlaced factor of sleep at a high level. But then you can step down to the level, let's say, of brain function. And here it is.

Before you jump into the brain function, it's true. Because when you think about who you want to hang out with, if someone's depressed, you don't really want to hang out with them. It's kind of a bummer. And if someone's sleep deprived, they're kind of depressed by default.

The profile that you see is a high anxious, socially withdrawn, sort of depressogenic natured, sort of patient or individual. And why would you? Now, there are circumstances where you would, because they're your family member, they're your loved one, and so you will help them. But if it's just another individual, you will shy away from them. So that stunned me in terms of that aspect. And then I can walk you through, I won't bore you, but we can go down to the level of the individual and look at their brain, and their brain networks will start to disintegrate when you are sleep deprived. You lose what's called your prefrontal executive control, which is a very fancy way of saying you go from an evolved Homo sapien to essentially regressing back to your impulsive emotional tendencies because you lose that regulatory break from your high level executive frontal lobe. you're not making good choices, you're starting to become more reward sensitive, you're more risk taking and sensation seeking. You are emotionally unstable, you have pendulum like swings because your brain has lost the emotional break to its accelerated gas pedal. And you're learning in memory, take a nose dive like a dart into the ground.

And your performance.

And then your performance in terms of your cognitive speed your speed of processing, all of those things degrade. And then you can also look at what happens for brain clearance. This has been a stunning, I think, finding. It's one that we've been doing a lot of work on aging Alzheimer's disease at night when we sleep, if we are allowed to get enough of it, or we give ourselves the chance to get it, your brain cleanses itself of the metabolic detritus that's been building up during the day. And It's hubristic, I mean, it's, well, it's hype, I should say it's hyperbolic in the sense to say that wakefulness from a brain perspective is low level brain damage biochemically, but sleep is your sanitary salvation. And two of the pieces of toxic metabolic byproducts that are washed away by sleep at night, beta amyloid and tau protein, two protein culprits underlying Alzheimer's disease. this is why we see that short sleep across the lifespan is predictive of a high risk of Alzheimer's disease. So your brain is affected downstairs in the body. We can speak about every major organ system from your metabolic system, your reproductive system, your cardiovascular system, your thermoregulatory system, your immune system, every one of those. We can experimentally just tweak your sleep and we can measure mark changes in those systems. But then the article went on to demonstrate that it's not just organ systems, it's individual cells. And even when you go inside of a cell, the specific componentry of a cell, even the nucleus itself is affected. There was a great study from the UK. They took people, healthy people, limited them to six hours of sleep a night for one week. Now, for most people, they're thinking six hours of sleep, that sounds almost luxurious. This was their version of sleep restriction.

Oh, that's sleep restriction.

And then what they did was they measured the change in the gene activity profile within that individual compared to that same individual when they'd been getting a full eight hours of sleep opportunity. So everyone acted as their own control. And there were two stunning results. First, what they found was that a sizable 711 genes were distorted in their activity caused by that short sleeping profile.

So, you know, it causes adverse expression of certain genes that lead to more illness.

Well, and that was the second result. About half of those genes were what we call upregulated. They were overexpressed. And those were genes that were associated with the promotion of tumors, genes that were associated with inflammation and long-term chronic inflammation, and genes that were associated with cellular stress and as a consequence, cardiovascular disease. whereas those genes that were actually down regulated were genes that were promoting the support of your immune system. So even at a DNA genetic level, you could see your immune deficiency caused by one week of short sleep. So I can take you from a societal level and how we operate together as a human society all the way down to say that there is no aspect of your physiology that can retreat at the sign of sleep deprivation and get away unscathed. It will even tamper with the very DNA nucleic alphabet that spells out your daily health narrative. Incredible.

And everything in between.

It's incredible. So, yeah, I think, but think about it from this perspective too. It shouldn't surprise us because sleep is the most ridiculous dumb thing you could ever have designed. I know, right? Evolutionary perspective. You're not eating, you're not finding a mate, you're not reproducing, you're not caring for your children. And you're vulnerable to being eaten. You're vulnerable to being eaten. Now, on any one of those grounds, but especially as a collective, sleep should have been strongly selected against in the course of evolution. And it's once been said that it's-.

Dolphins only sleep like one half of their brain at a time, which is- that's right.

They can keep coming. They have to keep coming up for air. Now, you could have designed a system where they just didn't need sleep so that they would never have to worry about surfacing. Sleep was so incredibly necessary for those aquatic mammals. They had to figure out how to sleep with one half of their brain.

Right.

They couldn't get around this non-negotiable thing called sleep. And so I think for me, what that really tells us is that if sleep doesn't serve an absolutely vital set of functions, it was probably the biggest mistake the evolution process ever made. And now we realize it didn't make a spectacular blunder. It is- We need cleanup. It's cleanup. Sleep is Mother Nature's best effort yet at immortality based on everything that I've seen.

Rip Van Winkle lived for a long time.

Yeah. So you just sleep rather well.

I think what's so fascinating to me about sleep is that for me, it's really been a neglected science in medicine. We've sort of not paid much attention to it. You don't sleep, take the sleeping pill, and it's really a wrong approach because there are so many root causes of sleep dysfunction. Great point. And I really think they've been under-evaluated and under-understood. But before I want to get into the root causes, I just wanted to sort of Give us a broad overview of how big of a problem is sleep deprivation and dysfunctional sleep in our population.

If you look at the data, there has been a pernicious erosion of sleep time over the past 100 years. Now, if you look at it over the past 10 years, that creep has maybe not been so demonstrable. But really think about it. We evolved over millions and millions of years for our evolution. And it's taken Mother Nature millions of years to put this necessity of a seven to nine hour sleep need in place. And then within the space of 100 years, we've gone from something that seems to be based on the data around about 8.4 hours of sleep a night that we used to be getting 100 years ago. Now, if you look at the data on average, Americans are sleeping about six hours and 40 minutes. Now, don't forget, that's the average. That means that there's a good proportion of people who sit to the left side of that distribution who are getting even less than that. America is not the worst culprit, by the way.

Is that why we're all at each other's throats and not thinking clearly? And so it's kind of divided.

We think about that and we giggle about it. But I don't think it's a factor to be discounted in our emotional dysfunction. Your empathy, for example, we did a great study and we were looking at how empathetically sensitive a human being is. And boy, do you just simply start to ignore other people's pain and their needs?

No, you feel like crap, so it's hard to care, right? You feel like yourself.

Why? Because you've got to take care of you. You know that your brain, or let me put it this way, human beings are the only species that will deliberately deprive themselves of sleep for no apparent good reason.

Like doctors, you mean?

And like doctors, exactly. But what does that tell us? tells us is that Mother Nature has never had to face this challenge of sleep deprivation. So no wonder there are no safety nets in place. So no wonder that we firstly go down very quickly biologically in terms of our health. But also, don't forget that that is such a rare circumstance that when it happens, when the brain starts to sense, I'm not sleeping enough, now it doesn't know why because we're watching Netflix. It just says, red alert, break glass in case of emergency. I'm not going to care about you, the people that I love. I've got to go into essentially low battery status and take care of myself. So you lose your empathetic sensitivity. We looked at doctors and there's great study from a team in Israel too. And what they found was that they started to prescribe less, it was necessary, less pain medication for their patients. the more sleep deprived they were. Why? Because they lost their empathy. They did not care. And so patients are suffering. They are more sort of ensconced in nociceptive, you know, drench of pain because the doctors just don't see it.

I mean, I remember honestly, Matthew, because I was in, you know, residency and working hard and I was living babies, working as a family doctor. I mean, I spent many, many, many nights not sleeping at all. So not even having two hours of sleep, just not sleeping and working 36 hours straight. One shift was 60 hours. And, you know, I remember how I would feel and I was like, you know, when you force yourself at first, you're like, your body's just like shutting down. And then you learn how to caffeinate and override your body's sense of needing to sleep. And then you kind of will yourself through. And, you know, the idea is, you know, you're a doctor, you have to be ready to go at any time, you have to deal crisis and pick the right answer and do the right thing and be able to function in the worst conditions, which it's kind of like a Navy SEAL, you know?

Yeah. It's almost like a hazing that we went through it and you're gonna have.

To go through it. But it's horrible. I mean, my daughter's in medical school now, and she, you know, she called me one morning after one of her first shifts where she had to do this. She's like, I don't want to do this. This is horrible. And I'm like. And I think it's a, you know, this, the Sleep deprivation crisis in America, it's like, It's sort of parallel to the lack of exercise, the crappy diet we have, it's degrading our health. And you combine all those things together with all the chronic stress, it's no wonder we're the sickest and fattest nation in the world, pretty much.

And if you look at the curve, the decline in sleep over the past really 70 years for which we have good data, and if you look, for example, at the rise in obesity over the same duration of time, those two things go in opposite directions. as sleeping is coming down, obesity is going up. And we know that a lack of sleep changes your appetite hormones. It changes your ability to dispose of food and specifically regulate your blood sugar. So you are more obesogenic in terms of your profile of weight gain.

Crave more carbs and sugar. Craves sugar. I remember that. I mean, when I was like, you know, two in the morning and working the ER, I'm exhausted and like, give me the sugar.

Yeah, where's the sugar? That's all you want. and that's exactly it's not just that you eat more, which you do, it's what you eat. That's the problem. You go after the heavy hitting, stodgy carbohydrates, simple sugars, and you shy away from the sort of, you know, the leafy greens, the nuts and the good proteins because you are just on a junk food binge. Well, you want to get energy.

Yeah. And you want it quick. Yeah, yeah, yeah. I remember that. So, you know, it's the question is, you know, is the sleep deprivation a big part of the cause. And because of the decline in sleep, it seems like it may because I've read these studies. They take young college kids and they basically sleep deprive them and they're healthy, but then the ones who get sleep.

Deprived just eat more and eat more sugar and carbs. That's right. And you can see that same replication of failure across multiple organ systems. So for example, I take a young healthy set of males, I limit them to let's say four or five hours of sleep for five nights. they will have a level of testosterone, which is that of someone 10 years their senior. So I can age a healthy young man by 10 years by short sleeping them for a week. You can take people who have perfectly regulated blood sugar, no problems with their blood glucose whatsoever, put them on that same regiment of four or five nights of short sleep, and at the end of it, someone like you would look at their blood work and you would say, you are bordering on being pre-diabetic right now. Again, that's within the space of days.

Days, yeah.

So I think it's, again, a demonstration to us that sleep, we don't have any real wiggle room.

It's not negotiable.

Yeah.

So in terms of the reasons we're not sleeping, it's clear we're not sleeping. Is it because we're too busy, too stressed, do we have too many obligations? Is it because we're watching too much Netflix? Is it because we're scrolling on our phones? some other factors, like what are the main factors that are leading to the sleep deprivation crisis and that are causing, you know, last I heard it was like 70 million Americans having serious sleep issues.

Yeah.

Right?

What are the main causes?

All of the above plus more. So there's not necessarily just one cause. Let's start at the hierarchical government level. There is no first world nation that I know of that has had a major public health campaign regarding sleep.

Why not?

We've had it for drunk driving, we've had it for safe sex, we've had it for, you know, all of these different things. But there's nothing there for sleep. And yes, you could argue from a cynical perspective, it's because we want you, you know, from a capitalist society, we really want you to be doing two things. You're either, you know, producing things or you're buying things or you're consuming things. And if you're asleep, you're not doing either of those two. So you could argue conspiracy. I don't think it's that. Yeah, probably not. But, and, and we've actually, I've actually just recently started a public charity, a foundation specifically designed for global sleep education. Take it a step down. There is the World Health Organization that I spoke to recently. There is no educational module for children translated into 37 different languages across different age ranges that educates them on the importance of sleep. So no wonder there is a parent to child transmission of sleep neglect. We have to change that too. Some of it is about education. The second part is mental health. We have a rising tide of anxiety in society. People are so stressed and we get people coming into the center at UC Berkeley and they'll say, I am so tired. I am just so tired. But I'm so wired that I can't fall asleep. It's this tired but wired phenomenon. So the anxiety epidemic is causing sleep problems.

And that's adrenal too, right? And that's adrenal.

Cortisol rise at night. It's cortisol rise at night. It's because of that, what we call the HPA axis, the sort of the cortisol descending chain. It's also because the nervous system almost is forced into a locked position of the fight or flight branch, what we call the sympathetic nervous system, which is anything but sympathetic. It's very agitating. And we cannot sleep when we are wired into the fight or flight branch. we have to switch over to the quiescent branch, the parasympathetic. So I think those two factors, the adrenal sort of nation, as it were, together with this fight or flight stance of the nervous system, is a royal roadblock to good sleep at night. I think it's one of the biggest factors. We've then also got the combative forces of entertainment and social media, which are on the, of course, consuming, trying to get my wife to stop scrolling on.

X every night to figure out what's happening in the world. I'm like, why are you doing that before bed?

And it's the worst time because In this modern era, we're constantly on reception. Very rarely do we do reflection. And the only time we do reflection is when our head hits the pillow. And that is the worst of times to do reflection. Because when you do that, you start to ruminate. When you ruminate, you start to ruminate. When you ruminate, you catastrophize. And when you catastrophize, you're dead in the water for the next two years. Because, you know, everything seems twice as bad in the dark of night. than it does in the light of day. And if we're doing that right before bed. So I think there are issues there. Sleep disorders are on the rise. Insomnia, which I think is a consequence of- It's a symptom of the anxiety and the stress. You know, I often think that insomnia is the revenge of things that we've not processed during the day and got resolution to. We've got sleep apnea, snoring. I think that's heavy snoring or can be an indicator of that. that's certainly comorbid with diabetes and also obesity. So I think you've got all of this collection of factors together with the stigma that we described earlier, which is, well, I'm not really that proud of sleeping more. Why should I be? Because society doesn't reward it. You know, it's the type A, the early bird catches the worm. Maybe that's true, but I would say based on the data, the second mouse gets the cheese.

Yeah.

And what's strange is that we... Never heard that one.

Wait, now he's got the genes.

But I find it funny that we chastise people who wake up late as being lazy. But we never say, oh, you go to bed early, you're lazy.

Yeah.

Well, that's night owl and that's morning lark. It's not your fault. So I think there are a whole collection of conspiring factors that together conflate to this enormous sleep challenge that we have in society. right now.

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Yeah, there's a couple things I want to drilled down into because I think that in your article, you talked about gut dysbiosis and gut dysfunction and the microbiome is playing a role in sleep, which is something that most people have never thought of. And it was a substantial part of your article and we'll link to the article in the show notes, but it was interesting to me because I think that inflammation plays a big role in sleep disruption and the gut microbiome plays a role. And also environmental toxins may play a role, nutritional deficiencies may play a role, and there are things hormonal dysregulation plays a role. And these are things that are not really well investigated by conventional doctors and not well understood. But sometimes it's as simple as just giving someone magnesium because 45% of the population is low in magnesium and you get magnesium at night and they're sleeping like a baby. Right. Or their iron's low and they have iron deficiency and people don't realize that a low ferritin is correlated with sleep. Yeah, restless leg syndrome and sleep deprivation and nobody checks that. So can you kind of walk us through some of those unusual kind of things that may be contributing besides the social factors and the stress and the adrenal and the, you know, the things that we just talked about?

Yeah, I think, you know, all of those factors that you just described will all feed into gut dysbiosis. there is, I think, a bidirectional, and this is what we spoke about in the article, a bidirectional relationship between your gut health and your brain sleep health, meaning that when your gut is in balance with that sort of collection of the flora and the fauna in your gut microbiome, it can send a health-related signal through the nervous system by way of a major highway that connects your gut to the brain called the vagus nerve. And that can happen.

That's not like Las Vegas. That's M-A-G-U-S. That's for relaxation. That's the relaxation nerve.

That's the relaxation nerve, but it's also a major informational highway bidirectional communication path between your brain and your gut. That's how we think that the gut can influence the brain. And that's how we think that if you get the gut right, it may be a new approach to a sleep aid because then you can get the brain right. And it works in the opposite way. which is that when you are sleeping well, it can communicate a signal for improved gut health through the vagus down into the body. But when you are not sleeping well, there's been some great studies, for example, in the extreme with jet lag, my goodness, do you see that when the brain becomes deficient in its sleep through this communication pathway, you will get significant gut dysbiosis. And many people will tell you one of the things that happens when I'm jet lagged, is that my tummy is just off. Oh, right. Oh my goodness, things don't go well for me and I don't quite understand why. I'm eating the same things, but it's probably because of this gut dysbiosis caused by a lack of sleep.

Interesting, you know, I'm wondering, this thought popped in my head because we know as we get older, our sleep degrades. That's right. And we also know that as we get older, our gut microbiome degrades and the diversity degrades.

Yeah.

I wonder if there is a link there because why do people who get older not sleep as well? It's an interesting question if it's been answered.

But maybe we should- so it's not been answered yet. I suspect that we have enough data to do the correlation study that you just described, which is, are these two things related? For example, if you look across a longitudinal study, and if we, I mean we haven't been assessing the gut microbiome for probably long enough to have good longitudinal data yet in the gut microbiome, But we've got plenty of longitudinal data in sleep, meaning we've started off assessing people in their 30s or their 40s, tracked them over 15, 20 years, and then asked, is the sleep that they've been having across their life predictive of their all-cause mortality, cardiovascular mortality, cancer mortality? And we've got that data. What we now need is to look at GUT health and ask, as that sleep is declining across the lifespan, longevity-- what happens to their gut?

What happens to the gut? I just was listening to Lee Hood's talk for the Human Longevity Institute yesterday.

You know Lee Hood?

Yeah, yeah. Amazing. Fantastic. Yeah. Systems biologist. And he was talking about how pretty soon we'll be able to look at just a few metabolites in your blood to look at the diversity and health of your microbiome.

So through a simple blood test rather.

Than collecting your poop, which isn't really.

Fun for most people. No, yeah.

Of a certain type to really enjoy that type of stuff. Exactly. So, I mean, there's- I think we're getting that. Actually, Steve see these patterns and see the biomarkers. And also the gut dysbiosis drives inflammation and it drives activation of an irritable brain.

That's right.

I think we used to think that irritable bowel in medical school was what we called a supratentorial problem, which in English means it's all in your head. It's above the part of your brain called the centorium, which just keeps your brain on the top. And it was a pejorative view that we doctors had, which is if you're if you have irritable bowel, it's because you're just a neurotic person and it's sort of, you're crazy and that's why your tummy's upset. And it turns out that the opposite is true, that it's the imbalances in the gut flora that are causing the brain to become irritable. And that that's really what you're talking about here is that if you've got.

Imbalanced flora, that your sleep isn't good. That's right. And that's, and to me, that's one of the exciting parts of it. Is that treatable? Is that it's both treatable and it's a novel, you know, is it a novel sleep aid pathway? I don't know. I don't know if it's powerful enough to come close to that. It may not be.

I had a patient and NF1, or maybe actually NF2 now, because both people have said this to me, there's probiotic companies making sleep probiotics.

Yeah. I've seen them too.

And they said it dramatically increased their deep sleep. And I was like, wow, that's crazy. And I was like, how does that work?

I mean, I love to see the data, you know?

Yeah, yeah, yeah.

But it's interesting. And even, I'm not trying to be, too skeptical, because as scientists and doctors, you and I both know absence of evidence is not evidence of absence. So don't judge too quick.

But right now, I think the jury's out. Yeah, for sure. And I think, you know, inflammation also will drive dysfunction of the brain. And most of the brain diseases, and you could argue that sleep is a brain disease, right? Yeah.

I mean, it's the brain not doing.

What it's supposed to do. Yeah, when you have sleep disruption, depression, anxiety, bipolar, schizophrenia, autism, ADD, depression, Parkinson's, Alzheimer's, these are all inflammatory brain diseases.

So I'm- and Alzheimer's disease, there's some really fascinating data regarding inflammation and Alzheimer's disease as a causal relationship now. Oh, for sure.

For sure. Rudy Tanzi, actually, you know Rudy Tanzi? Yeah, he presents an amazing set of data which has to do with a certain population that they've studied that have a gene mutation that prevents inflammation. And on autopsy, at death, these people were cognitively perfectly normal. On autopsy, their brains were just filled with amyloid, like the worst end case terminal case of Alzheimer's, but they were perfectly normal cognitively. Which was so striking to me, and it was the inflammation that's really the trigger.

Right. And I think we don't yet know what's happening with tau, which is the other tau protein, which is the other sort of culprit there. with inflammation, I suspect it may be the same story. It may be even more powerfully explanatory of cognition. But, you know, it's all of this just once again teaches us, I think you and I and maybe people listening, that for so long in medicine and science, we took a siloed organ or system specific approach. I was a cardiologist. I was a neurologist. You know, I was an immunologist. We are an embodied species, brain and body.

I'm an everythingologist.

Yeah, exactly. And that's what, if your doctor says that, you're with the right doctor.

Yeah, yeah. I mean, this is how the body works. It's just common sense, right? We're one integrated ecosystem, and that's what Lee Redwood has really pioneered, which is the idea of systems medicine and systems biology, where we're a big network of networks, and everything's talking to everything all the time. And so, a sleep disruption is sort of the thing that actually, I think, is influenced by so many different factors like toxins. And I personally had this happen to me. I was the greatest sleeper in the world and then I got mercury poisoning. And we know mercury toxicity, one of the symptoms is insomnia. And I don't know how it works. I don't know how it causes it. But we were talking earlier before the podcast started about mitochondria and how many of the things that we are exposed to in the environment are mitochondrial toxins and that it's energy and the body needs energy to run everything.

And I imagine it's critical in sleep regulation as well. Fundamental. Yeah, I mean, and during sleep we have, you know, a metabolic reduction. Part of the, one of perhaps the restorative functions of sleep is to have a metabolic downturn to a degree. But I think the other point is there is, you spoke about all of these different, you know, I'm a multi-system doctor. And yes, what we find is that all of those different systems, each by themselves, can all independently affect sleep. if you're in inflammation, if you have high blood pressure, if you have abnormal hormonal profiles, if you have poor blood sugar, all of these will disrupt your sleep. So it's feed up to the brain, disrupt sleep, but it also is feed down. And I've often thought, and it works both ways for health and ill health with good sleep versus bad sleep, if you've gone into one of those fancy music studios, and there's that mixing deck with all of those little dials on it.

That makes me so intimidated.

And yeah, and I look at it, oh my goodness. And you can move all of the different dials, they're all of the different systems, but you know that there's that one white dial all the way to the far left, that if you move that up, all of the other dials go up with it. That to me is sleep. It is the Archimedes lever of health. So that's why when you move sleep up in the right direction, you cascade down this whole, you know, it's the single tide that rises all other health boats in my mind. And I think it's not my mind, it's the data. The data is pretty clear.

Yeah, I mean, this connection to shift workers and increase in mortality and cardiovascular disease and diabetes.

Yeah. Teens who are sleep deprived because of early school start times. And the link between a lack of sleep and suicide now, I think that's been one of the things that has just exploded on the scene in the past five years. Certainly, I didn't have anything in the book about that because it was just nascent at the time. Now that data is so compelling, insufficient sleep in teens will predict suicide ideation, meaning thinking about suicide. It will predict suicide attempts, and tragically, it will predict suicide completion. And it's not just sleep. What we're finding is that a lack of sleep will have maybe a twofold increased risk for suicidality in teens, meaning you may be twice as likely based on a cutoff of insufficient sleep. And they're sitting up late, they're getting up early. Right. And it's not their fault because their biology, as they become adolescents, forces them to have an appetite, a predilection for sleeping much later into the night. They're not trying to be rebellious, it's just their biology. But then early school start times have them waking up far too early. So the one thing that gets squeezed like vice grips in the middle of the night for these teens, is a sufficient night of sleep. And but what we've also found is that it's not just sleep. Dreams seem to be, and bad dreams in teens seem to be even more predictive of suicide than insufficient sleep itself. We've got no idea why. It tells us something about dreaming above and beyond sleep that is predictive of our mental health.

Interesting. Yeah, I mean, I just came back from Ecuador and there's a culture called the Ashura culture. one of the last sort of untouched cultures down there. And every morning they have a ritual. You wake up at like, they wake up at like four in the morning. I guess they go to bed really early, but they wake up and they drink this thing called yucca tea, which they drink large volumes of and it makes you kind of vomit, which I didn't drink enough to vomit, but I drank a little ceremonial. And then they sit around and they share their dreams. Really? And depending on what their dreams are, they decide either go back to bed and skip the day or go out in the world and do whatever they got to do. Because if their dreams are auspicious, they'll have a good day. And if their dreams are bad, they're going to not go out and take.

A risk of something bad happening. I should look into that.

There's another book you should read. It's called the Kin of Attar, Waiting for your. It's all about a culture that's, their whole world is all about sleep. And everything that happens in sleep is what matters. And when you're awake, it's stuff that really doesn't matter. So I think you'd like that.

Okay.

What I want to get into now is sort of the practical things that people are listening and thinking, you know, I don't sleep great or I'm a little sleep deprived or, you know, my sleep quality is not good, everybody's wearing devices, tracking their numbers, and we're seeing stuff. And I think, you know, we talked about a lot of different things from hormonal dysfunction, you know, obviously menopause is a big factor. We talked about even thyroid. Hormones can affect sleep, low thyroid function, nutritional factors like magnesium, ferritin. We talked about inflammation, the gut microbiome. We talked about just our stressful culture, a lot of factors. So how do we start to, on an individual basis, start to tease apart what's going on, evaluate our sleep, and.

Upgrade the quality of our sleep? I think most people can probably tell you to a degree, am I getting the sleep that I need? and you can ask at least one of two questions to answer that. If your alarm didn't go off tomorrow morning, would you sleep past your alarm? If the answer is yes, you're not done with sleep yet. You're not satiated. Another good example would be, how much are you sleeping during a working week? And how much are you sleeping at a weekend? And this is not a perfect test for a number of different reasons, but if you are sleeping more at the weekend than you are during the week, then what I know is that you have the capacity to generate more sleep and you have a sleep need that is higher than that which you are giving yourself the opportunity to get during the week. So it's not as though you just are someone who actually needs six hours of sleep because at the weekend you get more sleep than you would do during the week. So I think the first thing is ask yourself some honest questions Am I getting enough sleep? The next question then is to say, even if the quantity of sleep I'm getting is sufficient, maybe I still do not feel restored or refreshed by my sleep the next day. And that comes on to quality over quantity. It's not just about how much sleep you're getting. It's about how well that sleep restores you the next day. In fact, that's one of our new metrics of insomnia. You can fall asleep fine, you can stay asleep, but if you don't feel restored or refreshed by your sleep the next day, you can still receive a diagnosis of unrestorative sleep leading to insomnia. Insomnia is much more a waking day disorder than it is a sleeping night disorder.

What do you mean? Because you feel bad during the day.

Because you feel bad during the day. And so we've now tried to upgrade, or at least refine the complexity that is insomnia to represent the patient themselves and their true experience. So understanding that your quantity and quality are good or bad then leads to the next set of questions, which is, well, what do I do about it? Should everybody be measuring that through like.

Aura rings or watches? Are those very accurate? Are they helpful? I think that, no, take what I.

Say with a grain of salt. I'm wearing two aura rings right now. Two of them. I know, yeah, one is sort of a next gen and the reason why is that I'm a scientist. advisors to the company. So say, take anything I say with a grain of salt. Absolutely. So complete, and they look very much similar. But so complete disclosure, and that's important. I would say though that for most people, tracking your sleep can be a very worthwhile thing. And it's simply because sleep in part is a non-conscious process. I can ask you, look, Mark, in the past week, have you been eating well or not eating well? And you can tell me. Have you been exercising consistently or not? Yes, you can. But if I then said to you, how much deep sleep did you get last Tuesday night?

4 hours and 37 minutes and 22 seconds.

I have no idea. No one has any idea. Unless you have the historical record of your sleep. So I think it can be very helpful. Are they accurate? You know, I only know about Aura and I think it's probably I know the algorithm and I've helped with that algorithm. It's going to be about close to 80, maybe more percent accurate at determining wake from sleep. And then when you split it four ways, light non-REM, deep non-REM, REM sleep, or wakefulness, which are really the four states that you can be in, which is a four-class algorithm, then the accuracy is about maybe 75%. And that seems to be about best in class right now. Now, you may say, well, hang on a second. That doesn't sound so impressive, 75%. Think about this though. I have about $50,000 worth of a spaghetti monster at my sleep center to get 100% accurate gold standard sleep recording. And then you can come along and within the space of some development cycles of technology, you can boil it down to a ring this size for several hundreds of dollars and you can get 75% of the way there. Bloody remarkable, you know?

But they're different. Like, I have a Garmin watch and I have an Oura ring and I wake up and they have widely different readings.

I'm like, different algorithm and unfortunately different site of location. So I think the reason that Oura and I wasn't with the company when they first made the choice to go with a ring. By the way, the other reason I like the company and the ring itself is because of the form factor. We don't put wristwatches on when we go to sleep.

Yeah.

Or headbands or chest straps. We take things off.

Yeah, yeah.

But rings, we're accustomed to that. So I like the form factor too, which is a low friction, no friction device. I would say though that for the aura ring in terms of its sensing capacity, when you get closer to the vasculature of the finger, it's more accurate than it would be necessarily on the wrist itself and the sensor. So that's why firstly, because the, the, so you get a better sensing location, number one, and number two, I think the algorithms are different. So that's why you'll get probably quite wildly different numbers from those two devices. But again, I think overall, Sleep Tracker is largely good. Two more caveats. The first is that that absolute accuracy of 75% is its absolute accuracy. However, its relative accuracy is much higher. What I mean by that is If.

It'S consistent day to day.

Correct, you've nailed it. So don't follow nightly headlines, absolute accuracy, follow weekly trend lines, which is to say that this thing is 75% accurate at separating all of those different categories, but it's consistently inaccurate night after night after night. So its power is when all of a sudden you see deviations in your trend because it can't be the ring that's deviating. It's consistent. It must be you. That's when you should pay attention.

It's still off, but it's off by.

The same amount every time. Exactly, yeah.

So whatever is changing it, it's not the ring. So you think people should be tracking?

Because otherwise, how do you know what's going on, right? I think almost all people should be tracking, except those who- and there's a now- Obsessive about it. who obsess about it and become- it becomes a challenge. And sleep now has this term that's floating around called orthosomnia. so ortho- Orthorexia, yeah. So you've heard of, yeah, ortho sort of straightening. So orthodontic, straightening teeth, orthopedic, straightening bones, you know, orthosomnia is getting my sleep so straight and I get so anxious about it that it crucifies my sleep. Yeah. And at that point, I say one of two things. If it's really causing you distress, take it off, put it in a drawer, we'll come back to it, we'll fix your sleep and we'll get back on track later. Or keep it on and only look at your data once a week or have someone else look at your data once a week. And the discipline there is hard. I agree. But you know, you may not need to throw the baby out with the bath water.

Okay, so we get a sense of what's going on with our sleep. You know, how do we start to unpack what to do to fix our sleep? Like what are the, give us the kind of Matthew Walker take home collection list. You know, like what are the things we're doing wrong and what do we have to fix and how do we get to we call it sleep hygiene or sleep practices or even tests that we should do to figure out what's going on if we're not sleeping well.

I think the first thing we have to do, and sleep is so idiosyncratic that different people will have different problems. First thing that we would want to do with an individual who comes in with complaining of sleep problems, do sleep test assessments. Do you have insomnia? Do you have sleep apnea? Do you have restless leg syndrome? Let's discount the sleep disorders. Let's say that you don't have any of those. Let's now take a step down. I would say in terms of recommendations, and it's going to be different as I said for different people, there are probably a collection of calm things that you can do now. Don't worry so much about the sleep supplements and we can come to those later. But if you're focusing on supplements as your first line approach to getting your sleep corrected, you are majoring in the minors. and you are not, you know, and you're minoring in the majors, you should be focused on firstly, regularity. You would be surprised.

Same time going to bed and waking up.

Everything just falls in place when you go, I am, I am the most boring individual, I get that. But I am so metronome like in my regularity, just because I know how powerful that anchor to my circadian rhythm is. to make sure that my sleep is healthy.

You go to bed and you wake up at the same time every day.

No matter weekday, weekends for the most part. When you're traveling, when I'm traveling, or sometimes we'll go out with friends, we'll have a later night. Of course, you know, I don't want to be puritanical about this. Life is to be lived, Joaquin de Viv. No one wants to be the healthiest person in the graveyard. Live life, of course, for goodness sake. But overall, if, you know, 90% of the time, you can be consistent, you would be surprised. I would say the next big challenge is have a way- Before you jump.

Off, is it matter like when? Because I've heard if you get sleep before midnight, it's better quality sleep.

There is nothing special whatsoever about the stroke of midnight and sleep. It's not as though all of a sudden, the two minutes of sleep that you get after midnight are so much less powerful and utility beneficial and the two minutes that you got before, that's not true at all.

But getting to sleep earlier, like 9-10, is that better?

You should go to sleep like 1-2. No, it's not. Absolutely not. And it can be problematic in at least two ways. The first is that if you are having insomnia and you suffer from sleep onset insomnia where you can't fall asleep, forcing yourself to go to bed earlier.

Is the worst thing you can do.

If you're not tired enough. Because you're not tired enough, and therefore you remain in bed longer awake and that only reinforces your anxiety around this place called my bed being the place where I am always awake. So don't do that if you're suffering from insomnia. The rule of thumb there is, and it's just a rule of thumb, only go to bed when you're tired. Don't worry about the clock. Insomnia patients, only go to bed when you're tired. The second reason that going to bed earlier and you sort of hear this this edict coming down from maybe influencers or people saying, you know, just go to bed early, wake up early, get a jump start on the day. That's the most effective way to be productive and healthy and it changes your life forever. Nonsense. If you are an evening type, let's say you're a night owl who normally has a biological, hardwired predilection to go to sleep at 12:30 at night, you can get into bed at 10:00 PM and you are going to think that you have insomnia because you're wide awake for the first two hours. And you don't have insomnia, you have a mismatch between your chronotype and your lifestyle. And we see that quite often too. So the advice of always going to bed early or trying to go to bed before midnight is completely dependent on your chronotype and people can do a chronotype test or your morning type, evening type, or somewhere in between. Easy to do. You can just Google the MEQ test, which stands for morningness, eveningness questionnaire. Takes about three minutes. And it will tell you pretty close to your genetics, which truly determine it. And it turns out, by the way, that if you are an evening type and you want to be a morning type, it's not that simple. You don't get to decide. It's gifted to you at birth. There are at least 22 different genes that we know dictate your morningness and eveningness. But this questionnaire comes quite close in terms of its kind of proxy. So I would say that good sleep, what is good sleep? Good sleep for me is about four macros. I've sort of thought about this and come up with this principle that there are four macros of good sleep. And you can remember it by the acronym QQRT, quantity, quality, regularity, Timing and we've really covered all of them. Quantity, seven to nine hours. Quality, are you sleeping consistently or is your sleep littered with all of these awakenings at night? So you're sort of waking up. That's poor quality. And the way that we measure that is efficiency. You can see it in your sleep trackers. Of the time that you're in bed, what percent of that time is sleep? What's a good efficiency? 85% or above. Once you drop below that, We'd like to correct it. So, quantity, quality, regularity, going to bed at the same time, waking up at the same time, regularity carries as if not more predictive power over your all-cause mortality than quantity does. That's a recent finding. And literally, a paper came out today that replicated that finding of about two years ago. The final one is timing. And you think, well, hang on, Q-QRT, quantity, quality, regularity, Timing sounds like regularity. Timing is your chronotype. So, if you are an evening type, sleep as best you can with your lifestyle. And I know that I'm talking about the ideal world and no one lives in that. We all live in the real world. So, as best you can, try to sleep closer to your natural chronotype. Because if you sleep against your chronotype, sleeping out of harmony with your biology, when you Fight biology you normally lose. The way you know you've lost is disease and sickness. And we see that in night owls who are forced to sleep like morning larks. So that's why to me, I think you've, I would come on to say, firstly, give yourself the right opportunity to sleep. Get regular, understand your chronotype, realize it's not your fault and it's not your choice. Try to get good with your chronotype. as best you can. And then finally, just make sure that the quality of your sleep, the consistency is good. If the quality is not good, you're waking up a lot, let's drill down into that for recommendations. Think about your alcohol and caffeine. Those are probably the two lowest hanging fruit that will cause poor quality of sleep.

I mean, the R-ring is like definitely a metronome for like if I drink something, Devastation, isn't it? Yeah, it's like, there is a blast.

Radius that is non-trivial. And it is sort of...

The roaring has kind of caused alcohol.

Consumption to go down. And, you know, I wonder if they've changed alcohol sales, you know, I don't know among their users, that would be an interesting study.

But I would say that the two of them... I tell you, I'm sure it has, because everybody who owns an OraRing tells.

Me they noticed the same thing, and it's changed their amounts of alcohol intake. Now, you can complain about devices or subscription fees or whatever about all of these different gadgets, all you like, but if that's the only thing that they've done in society, I think that your liver is gonna be outside of your body next day. I'm thanking you to the high heavens for saying, thank you for not drinking as much. So, let's- It's alcohol caffeine. Alcohol caffeine. I would say be mindful of light. We are a dark deprived society in this modern era and we get junk light at night. And light will stamp the brakes on melatonin, which is a natural hormone that times our sleep. And it will make you, it will fool your brain into thinking, I'm not tired. Even though there's all of that tiredness built up inside of you, your overhead lighting I'm stimulated. And so your brain gets thoroughly confused. We don't have strong enough daylight during the day to ramp us up and make us awake. So we're sleepy during the day and we don't have enough darkness at night to make us sleepy. So we're awake at night. I would say recommendation in the last hour before bed, switch off half the lights in your home. Just do me the experiment for the next 10 days. Try it. If it doesn't feel any different, great.

But does it matter if you like in your bedroom you have incandescent lights? Is that a problem or should you change those red light bulbs or?

You can go for red light bulbs, but just keep it, you don't have to worry about that fancy stuff.

The dimmer matter.

Dimness. Try to get below about 10 lux and you can just on your phone go to the App Store, download a Lux Meter, L-U-X. And then just sit in your bed and look to say, you know, or walk around your house. I do this.

This is how I measure my house in Austin. And I'm literally putting in dimmer lights because there's no dimmers in the house. I'm like, it's like $3,000 to put.

All these-- no, but imagine spending that to guarantee sleep for the next years. It's a small cost to pay. Yeah, for sure. So I would say grab a Luxmeter if you want to be nerdy about it, but just get dim light. Don't have to be too nerdy. Just turn down half the lights in your house.

Next thing for timing, by the way, I should go back to it.

But the light thing, did you buy this whole red light thing? Yeah, the data there is quite strong on melatonin. However, in terms of the blue light from our devices being the catastrophic force on sleep decline that we used to think it was is probably not true.

So if you're on your phone or night or if you're on your computer.

Blue light is not the villain that we thought.

So you shouldn't be buying those blue blocker glasses or?

There's been a great, there's been a guy in Australia almost pioneered this. Michael Gradisar, he started to get skeptical of this whole blue light thing. And there's been a couple of powerful studies that, yes, it definitely blocks your melatonin. Yes, it can disrupt your sleep. But what he demonstrated is that it's not the blue light itself. It's that these devices that we use.

That emit blue light.

It's what we're reading on them. Activating, they are attention capture devices. They are hugely activating. And their sole purpose now is to capture your attention economy. And they do it ruthlessly well.

And they stimulate dopamine. And the dopamine is the awake switch.

Switch on your cortex. And that results in this thing that we call sleep procrastination, where you know that you're tired, but then you think, oh gosh, I'll just look at Facebook one last time. Oh, I'll just check X one more time. And oh, I should have ordered that from Amazon, let me just go through that. And you look up and it's 40 minutes later. And what he's really arguing, and I think the data is compelling now, is that you just need to try to do a digital detox, not for the blue light, but for the demonstrable capturing of your brain's cortical activation.

Yeah, I use the Kindle. And I think that when you do the Kindle, it's got the black thing.

I would suggest that for people, there are two rules of thumb, if you can, desaturate your phone to black and white. There are some apps that will do it. Big difference. The second is if you have to use your phone in the bedroom and I know that genie is out the bottle, no matter what I say, it's not going back in anytime soon. The rule of thumb from another friend of mine, Michael Grandner, said and the following, if you have to take your phone into the bedroom, you can only use it standing up. And after about seven or eight minutes, you're standing there, I'm just gonna sit down. And at that point, sorry, phone goes away, you're done. That's it.

I tell my wife that. She's not gonna like that at all.

I would say just coming on to some other points of suggestion.

Yeah.

Wind down routine. We all fail to recognize that sleep is not like a light switch and it shouldn't be that way. Sleep is much more like landing a plane. It takes time to come down onto the sort of the terra firma of good sleep at night. And then, and so you can't be answering emails then. And then, no, don't ex, why would you expect that? It's like driving into your garage and your sort of your driveway, you know, at still 60 miles an hour and then slamming the brakes on and think it's gonna be a good outcome. You go down the gears and then gradually you're braking and you come to a stop. That's sleep for you. So we obviously when we, you know, if you have kids, you will know that you have a bedtime routine. You figure what it is out for your child, you figure out what it is for your child, and then you stick ruthlessly to it, because if you don't, bad things happen. Why do we think that as adults? We don't also need a wind-down routine.

And what did that look like?

It can be hot baths or showers, works very well for sleep, and we can speak about why from a thermal perspective. You can do meditation, data on that, very strong indeed. you can do sleep stories. We read stories to our children. It turns out that sleep stories, and the reason that they've saved meditation companies like Calm and made them a unicorn billion dollar company, which it did, the sleep stories, is because we also like to listen to stories ourselves. And I'll come back to why that is in a second.

Corey Booker, a friend of mine, said he listens to my podcast tonight to put himself to sleep.

I'm like, well, I've had that from, I've, so many people, and I deeply despise my own voice. I loathe it. But so many people have said that listening to my voice, I have a podcast, Matt Walker podcast, Shameless Plug, but they actually use it as a sleep aid. And in some ways, it's very devastating like you. But that's lovely for me, in truth. And so I'm actually going to start releasing an that has sleep stories because people just kept slamming me. So, but do a sleep story. I don't care what it is. Hot baths, whether it's meditation, whether it's journaling, whether it's listening to an audiobook, whether it's yoga, whether it's light stretching, whether it's meditation. The goal is simple. Get your mind off itself. That is the principal reason why most people are not getting shut down that.

Crazy person in between your ears.

Correct. And sleep is like trying to remember someone's name. The harder that you try, the more you force it away. And when you stop trying, it comes back to you. And I can't, I mean, another trick that I recommend people use, if you don't like meditation or any of that kind of stuff, it feels like a bit woo-woo, just close your eyes and take yourself on a mental walk that you know with exquisite detail. So let's say, I'm going to take the dog out for a walk. I clip him in, I open the door, I go down the steps, I take a left, go to the end of the driveway, and then sort of go through a little gate there, and then we take a right, but I always look to the right because the traffic is coming far too quickly. It's in that level of granularity. What's the color of the leash that I'm using today for the dog?

That's the level of-- Distracting your mind.

And I'm just-- and I'm just distracting my mind, and then usually the next thing I remember It's my alarm going off in the morning. Why? Because I got my mind off itself. So have a wind down routine, I would say, is absolutely critical. It's one of the lowest hanging fruits that you can really do. Tell us about the hot bath thing.

Because I've heard different theories about this, but it's like when you heat your body temperature up and then when it's coming down, it helps you fall asleep. But I've also heard people saying cold plunges before bedtime, which seems like the opposite of what you'd want to do, also help with sleep.

So, I'd love your thoughts on that.

Data not so strong for cold plunges.

In truth, warm bath and warm shower, it's so reliable that we have a statement called the Warm Bath Effective in.

Sleep Science, because it's been replicated so many times. I mean, I do Epsom salt, which is magnesium, it gets into your skin.

I use lavender drops. I call my ultra bath because the lavender drops reduce cortisol. Right, and also just the scent of it, is calming. And that's a calming signal to the brain, which puts you back out of the fight or flight into the restful state, the parasympathetic state. But you're right with the first explanation that when we have a hot bath or a shower, what we do is we encourage all of the blood to race to the surface of the skin. So someone like me, I'll have sort of rosy cheeks when I come out the bath. And essentially the bath has acted like a snake charmer, that it's charmed all of the trapped hot blood at the core of my body. and it's brought it to the surface so that when I get out, you think, or I think that the reason I sleep so well after a bath at night is because I'm all warm and toasty. It's the opposite. When I get out the bath, all of the blood at the surface of the skin radiates the heat very quickly, and my core body temperature absolutely plummets. And temperature and sleep is not quite as simple as we've been led to believe. It's a three-part equation. You have to warm up to cool down, to fall asleep. You have to stay cool to stay asleep. You have to then warm up to wake up. And the first part seems oxymoronic. How can you warm up to cool down, to fall asleep? Just as we've said.

Take a bath.

Warm up the surface of the skin to radiate heat to get cold at your core, and that promotes sleep onset. Then the cooler you get at night, and that's the reason that these smart mattresses now are working so well, as you get cold.

They ate sleep.

They ate sleep, yeah. I recently, together with Andrew Huberman and my good friend Peter Attia, we joined the company because I've been using it for so long. And everyone I speak to, all of my sort of concierge clients, they all say it really radically changed life for them. So I thought, if I can help them, I'd love to help join them.

I was using it, but then I hadn't said it wrong, and then I got too cold and then I was.

Like, but if you switch on the autumn, the sort of the AI agent, it will gradually, you know, learn when your thermal sweetspot is. So as you get colder during the night, you get more deep sleep. But then you have to reverse engineer the trick. You have to warm up to wake up. And it's not light that wakes us up, really. It's the warming of our core brain and body that is the true force that wakes us up. Case in point, when you, you know, let's say you come through in the morning, and your significant other is there and they look at you and you say, I know I left the dishes in the sink. I'm so sorry. But just give me two minutes. I just need a couple of mouthfuls of my hot coffee and then I'll be right with you. And within five minutes, you feel like a much better version of yourself. It's got nothing to do with the caffeine. Why? Plasma peak concentration of caffeine isn't going to hit you until about 15 or 17 minutes later.

What is it?

It's the warmth. It's the warmth. and that much more rapidly rises your core temperature, and that's where you get a first hit after the warm beverage in the morning, and then the caffeine kicks in. So you get a second benefit.

Okay, that's good. So if I tried tea, I'd get the same benefit. Yeah. Interesting. So the cool temperature at night is important. Yes. I would say the best sleep I've had in decades was when I went winter camping a couple of years ago, and it was like, you know, The yurt was covered completely in snow. You had to dig yourself out and go in. But I was, it was, you know, there was no wood stove or anything. I'm in my sleeping bag and I was warm, but I was, it was cold. And I slept like 10 hours, which.

I don't think I've ever done. Stunning, isn't it? It was really, really cold. And that's a combination of both the.

Temperature, but also don't forget that you didn't have much electric light polluting you. There was no Wi-Fi, there was no.

Electric light, EMS, and I had just, I sent snow skied with cross country.

Skis up a mountain to get to the top.

So you've done all of the right things. Daylight during the day, physical activity, darkness at night, coldness at night, and you probably not has as much digital stimulation as you would otherwise too. That is the perfect sort of prescription in a quote unquote manner for a good night's of sleep. And that's exactly what you got.

And dark matters too, right? Not just correct. 'Cause I think, you know, we think your eyes are closed, so it's dark.

But it's not, doesn't matter, right? If your eyes are closed, it doesn't matter. It showed that even if you were to sort of, you know, have low level overhead lighting still on during sleep, even though you still sleep, the quality of your sleep is worse because it's still penetrating through your eyelid onto your retina and essentially light infecting your sleeping brain at night. So, no light sound? Blackout curtains, the data on noise machines.

Earplugs.

Equivocal. Earplugs, I will do eye mask, earplugs. I will have a sound machine if I'm in a noisy environment, because if you look at the data, it's only where you get, you only get efficacy, meaning a benefit of these sort of white noise machines at least, in conditions of urban high noise. That's where they seem to be useful. if you're in a beautiful, you know, if you're camping in a yurt, a white noise machine isn't gonna do a thing 'cause it's, you know, there's no noise whatsoever, maybe occasionally, but nothing. But I would say that absolutely the reason that you had that collection of benefits was because of this juicy menu set of options. It was really good.

You had finger buffeted your way through the night.

But I like to keep the room at like 65 degrees at night. I think that's perfect. The problem is that it's different for men and women, and that's why I also like these smart mattresses. Yeah. Because you can find your own individual tailored solution.

I tell you, my wife and I are the same, which is fantastic.

Oh my goodness. You are, it's like, right now you are the envy of so many people.

I call her my was wife or whatever. My ex-wife, she had the opposite. She liked it hot, I liked it cold. And so she did a whole comedy skit about it. It was very funny.

And you will always struggle with those problems. I would absolutely say, I think that type of thermal intervention is fairly well replicated in some sense.

These are really simple practices. All the things you talked about.

The.

Timing and the regularity and the quality and the quantity, the temperature, the wind down routine, the light reduction, these are things that are pretty simple and they work. And it's not rocket science, but the science is actually there. What about EMS? Is that a thing?

We have not seen much data right now to suggest that sort of, you know, electromagnetic sort of, you know, pollution in the environment is going to be a sleep disruptor. I think there's probably some, you know, anecdata.

I mean, I noticed when the power goes out in our house for some reason, there's a tornado or something, and I'm like, wow, I slept so good last night.

But I think that that's got much more to do with absent light, absent technology. Yeah. I know that when, so I live in Northern California, just outside of San Francisco, and up in the Berkeley Hills, which is where I live behind my campus, trees will go down in the winter, they will take down the power lines, and you lose electricity for maybe two or three days. At that point, I've just got maybe my phone left. I'm trying to save the battery, so I'm not on it much. I'm reading journals with candlelight. And I know for a fact that I think my natural bedtime, I'm a desperately vanilla person, I'm deeply boring, I'm vastly uninteresting, but I'm kind of like an 11:30 to kind of 7:30 kind of guy in terms of my rhythm. I'm just slap bang in the middle neutral. But I know that when those nights happen, all of a sudden I'm thinking, it's 10:25 and I'm actually sleeping.

Sleepy, yeah.

And what happens is that modernity comes in and it hits the mute button on my sleepiness. And I think I'm an 11 to 7:30 kind of guy, when actually I'm probably closer to a 10:15 kind of guy. And so you've got to be a bit mindful of that too.

That's a really amazing set of simple practices that people can have. What about supplements? You know, Andrew talks about Apigenin and different things. how good is the data on that? Magnesium for sure I know is something that about 45% of the population is low and I call it the relaxation mineral. It relaxes your muscles, your nervous system, your brain. And I know anecdotally that my patients all say that if I sleep so great with it. Tell me what does the data show about magnesium and other supplements?

Magnesium is an interesting one. I mean, if you look on Amazon or a like, magnesium sleep formulations is rife across the board, and they're getting very good ratings. So you don't need a scientific study to suggest that something's going on there. But if you dig into the history of magnesium and sleep, you get an interesting kind of paper trail that goes all the way back. The story emerged from people who were magnesium deficient, and they had really quite profound sleep problems. And when you made them magnesium normative with supplementation, their sleep got better. That's very different than saying, okay, Matt, we've looked at your blood work. You are magnesium normative. And then taking vast doses of magnesium, I expect to get even better sleep. It's not going to happen. It's a little bit like saying, I tell you, I've got this amazing new blood oxygen saturation machine. It's stunning. and you say, but my blood oxygen saturation is 98-99%. Right. Do you think that I'm going to push you where, no, you're at ceiling. So you've got to be a bit thoughtful. I think there is a cluster of individuals, the magnesium deficient individuals.

It's about 45% of the population who.

Will respond to magnesium for sleep. If you look at the data, magnesium citrate not so much, magnesium oxide, oxate certainly does seem to be the more, if there's going to be a form of magnesium that carries the vote so far. Not three and eight, which is well.

I'll come on to three and eight.

But magnesium oxide is definitely the one that seems to promote it. It's just a little tougher on the tummy.

And it's harder to absorb.

Correct, and it's harder to absorb. But I would say that the problem with those two as an explanation, standard forms of magnesium, not magnesium L-threonate, is that none of those cross the blood-brain barrier. And so if you're thinking magnesium helps your brain to sleep, how could it? Because it doesn't get into the brain. And I think it does it indirectly through relaxation of the body, which sends a signal through the vagus nerve up to your brain to say, you,'re quiet, you're calm, your body is at peace, and your brain says, Great, I'm checking out its sleep time. that's the indirect mechanism. However, there is a form of magnesium, magnesium L-threonate that based on some animal data from MIT does seem to cross the blood-brain barrier. Now, there are no randomized control studies that I know of that have looked at magnesium L-threonate and sleep improvement. So I think the jury is out. If you put a gun to my head and said, which form would you recommend for a patient? I would probably say magnesium threonate, because at least it's going to potentially get into the brain. so magnesium, I think under certain circumstances, it can be quite useful. I think the data on GABA is not particularly strong right now. So sort of the GABA supplements, I don't think they're great. I think phenine has some supportive data to it right now. Again, it's just not that consistent.

If you want to buy melatonin.

Melatonin, for people who are not in the 50s or older, and people who are in a stable time zone, magnesium, sorry, melatonin doesn't seem to move the needle.

So it doesn't work for older people?

No, it does seem to potentially work for older people.

It's better for older people, not for younger people.

And under circumstances of jet lag, if you are younger and you're not in a state of jet lag, melatonin, just doesn't seem to be that beneficial. I think there was a meta-analysis that said it only improved the speed with which you fell asleep by about 3.9 minutes, not much, and it only improves your sleep efficiency by about 2.2%, not much more than placebo. Now, don't forget the placebo effect is the most reliable effect in all pharmacology. So I'm shy of an effort, you know, adrenaline shot to the heart. So I would say melatonin, I probably wouldn't favor it. Right now, if you're going to do it, you're probably taking too much right now. You're taking maybe 10-20 milligrams. Get below five, 10-20, that's a super physiological dose.

Melatonin, yeah.

That's a dose that the body never would normally release itself. And we don't know what the consequences of that are. Could be fine, may not be fine. Other things I would say for the tired but wired phenomenon, you can try it, although Some people respond and some people don't. Ashwagandha.

Yeah.

The other one, phosphatidylserine. Not phosphatidylcholine, but phosphatidylserine. Both of those have got pretty good data, not with sleep. There are some data studies on sleep. And here we're talking about 300 to 400 north of those values, milligrams in each dose. But I would say that may certainly help.

400 milligrams of phosphatidylserine.

Phosphatidylserine and also ashwagandha, sort of 400 to 600. You can add, if you would like, some glutamate seems to, sorry, glycine. Glycine at probably around two grams seems to potentially help regulate the circadian rhythm. That may be useful too. So you may want to try magnesium, ashwagandha, phosphatidylserine, and then maybe add glycine in the mix as well.

Man, man, I can see why all these podcasters have you on for like six part series. I could talk to you for hours and hours about this. I got like a thousand more questions.

But again, I would say for the supplements, just be careful. Go back and listen to all of the things that we just said about the majors. major in the majors, minor in the minors. Don't major in the minors. If you're looking straight away to supplements, you're majoring in the minors.

And listen, if you're listening out there and you have sleep problems, which I know a lot of you do because it's rampant, definitely read Matt's book, While.

We Sleep, check out- I would say the podcast is probably the best place. The book may scare you if you're not sleeping well, which is fine. But the podcast now, there's over 70 different episodes on the amazing podcast. And probably whatever question that you have will be answered there in a way. And it's a podcast, by the way, I'm nowhere near as elegant and erudite as you are to be an interviewer. My podcasts are usually, there are short form podcasts, somewhere between 20 to 40 minutes. They are short form monologues from yours truly. And they just are a little bite of sleep goodness to accompany your waking day. And most of what you're probably going to ask about is somewhere there on the episode list so far.

And because your voice is so great, if you put it on at night.

It'S the perfect sleep aid. Apparently most people almost want to lose the will to live when they're listening to me. I think it's mostly because I'm so deeply uninteresting. I don't know about that. I think someone once said that my personality was the best prophylactic known to man.

So anyway, that's not true. I know you, and I can verify that is not true. And Matt's website is WhyWeSleep.org?

Yes, go to WhyWeSleep.org if you would like to support the Public Foundation, which is a global sleep education foundation, please visit us there. You can also take the global sleep assessment that you can get your global sleep score. It is just what we spoke about. QRT, quantity, quality, regularity. Get your four macros of sleep score. And if you feel good about it, you can click on a button. It will tell you Not just your score, but tips for what you can do to change your specific score. And then if you really want it, it will give you a four-week action plan as to how to try to change that. And all we ask for, we don't force it, but we simply ask for that component, please just consider a wee little donation to the foundation.

Very grateful for your work, Matt. And the place they can do that, QRT is at thesleeptdiplomat.com actually, no, it's.

If you just everything, if you just go to whywesleep.org, and that's Y-W-H-Y, rather than the letter Y. whywesleep.org, you can get all of that information there, and I would so appreciate any little gift that you could provide the foundation.

Well, I know you've changed so many people's lives, including mine, and your work is just tremendous, and I am definitely gonna have to have you back when you're in Austin in my new studio, because you're gonna also be living there.

And I will spend some time there. Absolutely.

Cannabis, and I want to ask you about dreams. I want to ask you about a lot of things we didn't get to today. You're the best, Matt.

Absolutely. When I'm there, my much better half in life is out there, so I will be there frequently. I would love to stop by. And if people have not had a vomiting reaction to this first podcast, have me back on, I would be delighted. And I would say, too, in return, thank you for what you do, what you have done in terms of a public service gift. in terms of medical education should not be underestimated.

Thank you.

It doesn't come without a toll. I understand what it takes to do these things. And when you put your head above the public parapet, you can also get some criticism too. And it doesn't feel so nice sometimes. But you still do it. So for what you've done for society and what I hope you continue to do, thank you. And thanks for having me on the show.

Thank you. I do all this because, honestly, I was so sick. and I know how much people suffer and how much needless suffering is out there and how many answers we actually do have. And so, you know, just talking to you and learning what you've done to sort of investigate the nature of sleep and what it role it plays in our health and our life is, is so important. And for me, it's like, you know, it makes my work easier cuz I don't have to know everything. You know it. I can just kind of talk about it. So, Matt, thanks for being on the podcast. We'll have you back soon. And good luck with everything you're doing. I'm so excited about what you're going to be doing next, which I can imagine is going to be something really fun we talked about, but we'll talk.

About on the next podcast.

Thanks again, Mark.

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