#49–Matt Walker, Ph.D., on Sleep (Part 3 of 3): Effects of poor sleep on metabolism & performance...

1. 0:00 – 0:04

   Intro

   1. PAPeter Attia0:00

      [upbeat music]

2. 0:04 – 10:38

   Sleep Restriction and Impaired Glucose Disposal

   1. PAPeter Attia0:04

      Hey, everyone. Welcome to The Peter Attia Drive. I'm your host, Peter Attia. The Drive is a result of my hunger for optimizing performance, health, longevity, critical thinking, along with a few other obsessions along the way. I've spent the last several years working with some of the most successful top-performing individuals in the world, and this podcast is my attempt to synthesize what I've learned along the way to help you live a higher quality, more fulfilling life. If you enjoy this podcast, you can find more information on today's episode and other topics at peterattiamd.com. [upbeat music] Hey, everybody. Welcome to this week's episode of The Drive. I'd like to take a couple of minutes to talk about why we don't run ads on this podcast and why instead we've chosen to rely entirely on listener support. If you're listening to this, you probably already know, but the two things I care most about professionally are how to live longer and how to live better. I have a complete fascination and obsession with this topic. I practice it professionally, and I've seen firsthand how access to information is basically all people need to make better decisions and improve the quality of their lives. Curating and sharing this knowledge is not easy, and even before starting the podcast, that became clear to me. The sheer volume of material published in this space is overwhelming. I'm fortunate to have a great team that helps me continue learning and sharing this information with you. To take one example, our show notes are in a league of their own. In fact, we now have a full-time person that is dedicated to producing those, and the feedback has mirrored this. So all of this raises a natural question. How will we continue to fund the work necessary to support this? As you probably know, the tried and true way to do this is to sell ads. But after a lot of contemplation, that model just doesn't feel right to me for a few reasons. Now, the first and most important of these is trust. I'm not sure how you can trust me if I'm telling you about something when you know I'm being paid by the company that makes it to tell you about it. Another reason selling ads doesn't feel right to me is because I, I, I just know myself. I have a really hard time advocating for something that I'm not absolutely nuts for. So if I don't feel that way about something, I don't know how I can talk about it enthusiastically. So instead of selling ads, I've chosen to do what a handful of others have proved can work over time, and that is to create a subscriber support model for my audience. This keeps my relationship with you both simple and honest. If you value what I'm doing, you can become a member and support us at whatever level works for you. In exchange, you'll get the benefits above and beyond what's available for free. It's that simple. It's my goal to ensure that no matter what level you choose to support us at, you will get back more than you give. So for example, members will receive full access to the exclusive show notes, including other things that we plan to build upon, such as the downloadable transcripts for each episode. These are useful beyond just the podcast, especially given the technical nature of many of our shows. Members also get exclusive access to listen to and participate in the regular Ask Me Anything episodes. That means asking questions directly into the AMA portal and also getting to hear these podcasts when they come out. Lastly, and this is something I'm really excited about, I want my supporters to get the best deals possible on the products that I love. And as I said, we're not taking ad dollars from anyone. But instead, what I'd like to do is work with companies who make the products that I already love and would already talk about for free and have them pass savings on to you. Again, the podcast will remain free to all, but my hope is that many of you will find enough value in, one, the podcast itself, and two, the additional content exclusive for members to support us at a level that makes sense for you. I want to thank you for taking a moment to listen to this. If you learn from and find value in the content I produce, please consider supporting us directly by signing up for a monthly subscription. Welcome back to the final installment, part three of three, of the Matthew Walker series on sleep. If for some reason you haven't yet listened to the first two episodes, I'd recommend going back and listening to those prior to listening to this one. My guest this week is Matthew Walker, professor of neuroscience and psychology at the University of California, Berkeley, and the founder and director of the Center for Human Sleep Science. Matthew earned his undergraduate degree and PhD in neurophysiology in London and subsequently became a professor of psychiatry at Harvard Medical School before moving to Berkeley. His research examines the impact of sleep on human brain function in healthy and diseased populations. To date, he has published over 100 scientific studies. He has received numerous funding awards from the National Science Foundation, National Institutes of Health, and he's a fellow of the National Academy of Sciences. He's the author of the international bestseller Why We Sleep, which also happens to be the favorite book of my not yet two-year-old son. He holds many patents covering various consumer-based sleep recordings, sleep tracking, and sleep simulation. He's a sleep scientist at Google, where he helps the scientific exploration of sleep in health and disease. He is also an enormous fan of Formula One and my hero, Ayrton Senna. In the final part of this series, we discuss the role of sleep and my weight gain, presumably that of others, sleep and blood sugar, sleep's effect on genes, sleep's effect on the food you eat, the effect of sleep on people's productivity, the relationship between alcohol, caffeine, THC, CBD, and sleep, and that's not all combined, of course. What Matthew is doing today at Berkeley at the Center for Human Sleep Science and other startup projects he's working on. And we close this out with a discussion of Formula One, our mutual favorite thing, driving and sleep. As a reminder, at the end of this series, we're going to take questions for a follow-up AMA with Matthew. Asking questions on the AMA forum And listening to the AMA podcast with Matthew, along with all AMAs, will only be available to subscribers. So if you haven't signed up yet, you can do so now at peterattiamd.com/subscribe. So without further delay, here is the finale with Professor Matthew Walker. [upbeat music] I want to talk about another several topics on here, but I want to go back to something that you and I have spoken about before, but I, I think it's so important, I want to make sure we've got it for all the listeners. One of the most compelling things I ever read, I mean, I, I think there were several moments in my journey in, in the sort of, uh, world of sleep that really shook me. One of them was reading this paper out of the University of Chicago, and I believe it was Eve Van Cauter, but it might not have been. It took a group of subjects, and it was a very small study, but it was so well-controlled because they sleep deprived these in-- Well, they did euglycemic clamps on, you know, day zero. So for the listener, that's a, a really rigorous test where you inject glucose and insulin into the patient, and you keep the glucose level steady by titrating the insulin level, and this is an elegant way to measure one of the most important features of metabolism, which is how well you dispose of glucose primarily into the muscle. And I believe the subjects were restricted to four hours of sleep a night for two weeks.

   2. MWMatt Walker7:30

      Yep.

   3. PAPeter Attia7:30

      So, you know, about like-

   4. MWMatt Walker7:31

      And it's been replicated for four, five, and six hours for one week.

   5. PAPeter Attia7:36

      Okay. At the end of that period of time, they repeated the euglycemic clamp, again, the gold standard for measuring insulin resistance, and these patients suffered a fifty percent reduction in their ability to put glucose into their muscle, which again, would certainly rank among the five most important physiologic things to do. Again, to put this in perspective, a normal blood sugar might be a hundred milligrams per deciliter or roughly five millimolar. For a normal-sized individual, that represents five grams of glucose. I'm gonna let the siren go by here.

   6. MWMatt Walker8:13

      Yeah, it's, it may actually be, um, immigration coming to get me finally and [chuckles] deporting me back to the United Kingdom. But sorry. Yeah.

   7. PAPeter Attia8:20

      So, so you've got five grams of glucose in the bloodstream, which is one table- teaspoon. Frank diabetes would be two hundred milligrams per deciliter, ten to eleven millimolar, two teaspoons of sugar. So the amount of glucose you have in your bloodstream is trivial compared to what's in the muscles and in the liver. So imagine losing the ability to put that away by fifty percent. And as I look back at how metabolically deranged I was at the end of my residency, I can't help but realize something that I think eluded me for a great number of years, which is the role that sleep deprivation played in my weight gain, my insulin resistance, my hypogonadism. I know you and I have joked about it, but I think at the end of residency, my testosterone was about two hundred to two hundred and twenty nanograms per deciliter on a scale where two standard deviations below the mean is about three fifty. So, you know, about twice that of a, of a female in terms of testosterone. I now realize that was the sleep deprivation. That wasn't just the cafeteria food.

   8. MWMatt Walker9:36

      That's right.

   9. PAPeter Attia9:36

      Uh, and by the way, it certainly wasn't a lack of exercise. Amazingly, throughout residency, I still managed to figure out a way to exercise like crazy.

   10. MWMatt Walker9:43

       And, you know, the point there is despite all of that exercise, despite the power that that should have had on your metabolic system, my guess is that if we'd done that same glucose tolerance test, it would've been way down. And when you think about, you know, that's essentially taking healthy individuals who show no signs of diabetes, limiting them to an anemic diet of sleep, you know, four or five hours for one week now we've seen, and you can get them into a state where someone like you, if you just read their readings at the end of the week and knew nothing about the experiment, you would probably argue that they may be in a pre-diabetic state at that stage.

   11. PAPeter Attia10:23

       Sure. You're writing the ret-- the metformin prescription. How is this happening, Matt? What is the mechanism by which something so profound, so fundamental and important to our survival is going so awry in such a short period of time?

3. 10:38 – 20:31

   How Short Sleep Disrupts Insulin Signaling in Cells

   1. MWMatt Walker10:38

      We know the evidence. We, we've unpacked this mechanism now. So the way that you regulate y- your glucose, the way that you sort of have glucose homeostasis, is that there are at least two major parts of this equation. The first is that cells in your pancreas called beta cells need to sense the spike in blood sugar, and then they need to release insulin. And then when that insulin is released, it actually tells the cells of the body to reach out and absorb the blood glucose, the blood sugar, and that prevents you from an otherwise dangerous spike in blood sugar. So these two things need to happen. Your beta cells in your pancreas need to release insulin, and then the cells of the body need to be sensitive to that insulin to be then instructed to essentially, you know, suck in that, that blood glucose from the bloodstream. Now, what can happen is that if you have a deficit in one, and, you know, I think, you know, pregnancy may be a good demonstration of this, where sometimes, you know, the cells of the body become less sensitive to that insulin. But what's nice is that the beta cells in the pancreas, they understand that the cells aren't sucking in the glucose that they need, so they just release some more insulin, and your insulin homeostasis remains in balance. So this is what we call the disposition index. How, how good are you at disposing of glucose? And, you know, can you manage that disposition index? So what happens with insufficient sleep is unfortunately bad on both sides of those equations. So firstly, we know that when you are underslept, the beta cells of your pancreas become insensitive to the spike in blood sugar glucose. In other words, your body stops releasing enough insulin to deal with the food that you've just eaten. So you're down on insulin. You haven't released enough insulin. That's a bad thing. But maybe it wouldn't be so bad if the cells of the body were just really sensitive to what little insulin is left, and you could still at least clear some of that blood glucose. Unfortunately, that doesn't happen because what's worse is that the cells of the body actually become insensitive to the signal of insulin. And so the cells of the body stop sucking in as much glucose, as much sugar from the bloodstream. So on both sides of the, the glucose homeostasis balance, you're kind of a little bit screwed that insufficient sleep means that you don't release enough insulin, so you don't have enough of that signal to begin with. What little has been released, unfortunately, is not listened to and heard by the cells of your body. So those cells actually don't end up dragging in the blood glucose, the gushing kind of monsoon of glucose that's now in your bloodstream after a meal, which means that you end up having an inability on both sides of the glucose equation to clear that blood glucose. That's why you have that type of glucose intolerance, problems with glucose absorption. And to get down to even the causal mechanism in humans, some great studies where you can actually say, "Why are the cells so mute to the signal of insulin? Why are your cells not listening to insulin correctly and not responding by bringing that blood sugar into them to drop your blood sugar levels?" And the answer is this. What they did was they took a group of, again, healthy people, no signs of diabetes. They took a biopsy of cells from around the belly button, from the umbilicum, and then you can actually measure how those cells are behaving inside of those cells themselves, so you can kind of like poke around inside and figure out what's happening. They took the biopsy in those same subjects after they'd been limited to just four or five hours of sleep, and then they repeated the biopsy when those participants had been sleeping eight hours. So this is, again, one of those beautifully, carefully controlled studies, same individuals, same process.

   2. PAPeter Attia15:05

      And, and are they looking at adipocyte or myocyte?

   3. MWMatt Walker15:07

      That's right. So it's adipocyte. So this is fat cells.

   4. PAPeter Attia15:11

      Right. So this-- I would expect something different in the adipocyte from the muscle cell.

   5. MWMatt Walker15:15

      I don't think the experiment has been done with the muscle cell yet, but it has been done with the adipocyte. And then they've essentially got these now, these cells outside of the body, and you can play around. You can essentially sort of, you know, drip insulin onto those cells, and you can ask what's going to happen to those cells in terms of the instruction that they receive from the insulin. One of the critical things that happens when insulin binds to the receptor of the cells is the phosphorylation of something called AKT. And when AKT is phosphorylated, it essentially helps something called the GLUT4 transporter inside of the cell to essentially go to the surface of the cell, and it's almost like the metaphorical straw that gets stuck out of the cell, and it, it's bringing glucose in, to simplify it. What you find is that when that cell has been under conditions of insufficient sleep, the amount of insulin required to phosphorylate that AKT to get those cells to start absorbing glucose, you need almost twice the amount of insulin. You need double the amount of insulin to get those cells to do the same thing, which-

   6. PAPeter Attia16:31

      That's counterintuitive, actually. You'd think that the adipocyte would be even more sensitive to insulin as the body works harder to undergo esterification and put fat away, given that the muscle becomes more resistant to insulin. So that's interesting. So of course, this speaks to why many hormones are necessary to drive the metabolic derangement, because also the cortisol level would maybe even oppose that. But in isolation, what you just described would actually oppose re-esterification of fatty acid.

   7. MWMatt Walker17:08

      Yeah, but in my mind, I think what's striking, though, it, it starts to tell you that individual cell types need sleep, though.

   8. PAPeter Attia17:18

      Yeah, what, yeah, what-- I was just gonna say, what do you think is the communication vehicle? What is telling that phosphorylated sign, "Do less of it. Be less effective"? How is that communicated?

   9. MWMatt Walker17:36

      That right now, I think we, at least I don't know of what intracellular mechanisms have transpired to decrease the amount of, or the capacity for the phosphorylation of AKT to bring glucose into the cell. There are clearly some kind of signaling mechanisms that are coming extracellularly and telling intracellularly things to do that are either maladaptive or just much less efficient inside of the cell. But to me, that just blows my mind that, you know, we often think of the impact of a lack of sleep on things like behavior, like driving or, you know, making food choices. We've done some of this stuff with brain scanning and-- but your question is so beautifully nuanced because it's actually asking, there is something about a lack of sleep- That will get even into cells themselves and alter intracellular functioning. So if you can get a, a single factor, sleep, that can have its impact all the way from complex cognitive issues like decision making all the way down to something like intracellular function, my goodness, you need to look out if you're depriving yourself of that one function. And I'll go a step further, because there was a great paper published in something called the Proceedings of the National Academy of Science. It's a very prestigious journal.

   10. PAPeter Attia19:08

       We, we like to call it penis around here.

   11. MWMatt Walker19:10

       Right. Yeah. Penis, the acronym. Um, I, with my students, I'll say PNAS, uh [chuckles] and try to get, navigate around that unfortunate acronym.

   12. PAPeter Attia19:19

       That, that is hilarious because, like, I'm so, you know, far removed that it was just penis. Like, it was-

   13. MWMatt Walker19:25

       Yeah

   14. PAPeter Attia19:25

       ... we never even thought you would have to be politically correct and call it PNAS.

   15. MWMatt Walker19:29

       Yeah. I just published, you know, my biggest girth of research in penis.

   16. PAPeter Attia19:33

       [laughs]

   17. MWMatt Walker19:35

       Well done. That sounds like your parents must be swelling with pride right now. Um, could you imagine? And I actually have, we have published a, a bunch of stuff in penis, but this, this [laughs]

   18. PAPeter Attia19:47

       By the way, this, I just gotta pause for a moment. Why is it, here's another evolutionary question. Why is it that any two guys can be hanging out?

   19. MWMatt Walker19:56

       [laughs]

   20. PAPeter Attia19:56

       Like, you could have the pre- I was gonna say the President of the United States. Bad example.

   21. MWMatt Walker20:00

       [laughs]

   22. PAPeter Attia20:01

       You could take any two male heads of state and put them in the UN on the floor trying to negotiate a resolution, and, like, a penis joke just makes everybody laugh.

   23. MWMatt Walker20:14

       Can I just say that within, I think, and people can tell me the time of this in the comments, I think within the space of about 180 seconds, we went from intracellular cascade mechanisms, from phosphorylation of AKT, to penis jokes. Uh-

   24. PAPeter Attia20:28

       And it's all my fault-

   25. MWMatt Walker20:29

       No, no, no, no, no

   26. PAPeter Attia20:30

       ... because I used the, used the whole...

4. 20:31 – 25:33

   Sleep Loss and Gene Activity

   1. PAPeter Attia20:31

      Now, I wanna go back to this because what you said is, it actually scares me more. Here's why. I think that at the surface, everything you opened our discussion with with respect to Alzheimer's disease, I mean, you led with the best punch, right? To me, that is, you could stop there. If sleep disturbance didn't impair your driving, didn't increase your risk of cardiovascular mortality, didn't trash your immune system and double your risk of cancer, didn't give you diabetes, if you took every one of those things away, just driving your risk of dementia is, that's full stop reason enough. Didn't impair your learning. Take everything away-

   2. MWMatt Walker21:10

      Cardiovascular disease, depression-

   3. PAPeter Attia21:12

      Eh, forget that

   4. MWMatt Walker21:12

      ... anxiety, suicidality.

   5. PAPeter Attia21:13

      Don't worry about it.

   6. MWMatt Walker21:13

      Yeah.

   7. PAPeter Attia21:13

      I'll, I'll take it all. But, but paradoxically, most of those things, because at least we see what the mechanism in, that the mechanism of action is, and even when we don't, like in Alzheimer's disease, I don't think we know exactly the mechanism of action, but there's a plausible theme. But it's this last one that you're bringing up that in many ways scares me the most because it speaks to the ubiquity and the spread and the breadth of that impact. Like, there are other cellular fact- Like, this is so central that it's impacting and regulating the phosphorylation of a series of enzymes that drive something so seemingly unrelated as a GLUT4 transporter to translocate the-

   8. MWMatt Walker21:59

      Right

   9. PAPeter Attia21:59

      ... surface of a cell. Like, why in the world would that happen at a single cell level? That should never happen.

   10. MWMatt Walker22:05

       If you can observe the impact of a process, be it, you know, diet or exercise or food, you know, at that level, the fact that it can transcend almost every biological level of slice that you can do to biology. And to me, I think that the, the final one, which comes back to the, the, the penis, the PNAS paper, takes the final step for me. What they did was they took a group of, again, healthy adults, and they limited them to six hours of sleep for one week.

   11. PAPeter Attia22:34

       So they basically made them average Americans.

   12. MWMatt Walker22:36

       Average Americans, yeah. And then they essentially looked at the change in their gene activity profile. This is from blood.

   13. PAPeter Attia22:44

       You're not gonna tell me there was epigenetic change.

   14. MWMatt Walker22:47

       Well, relative to when those same individuals were getting eight hours of sleep, and there were two critical findings. First, what they found is exactly your fear. They found that a sizable and nontrivial 711 genes were distorted in their activity caused by that insufficient sleep, which by the way, again, six hours of sleep, you know, may even sound luxury to some people, but this is very common. So this is not one of those experiments where you say, oh, they limited them to two hours of sleep, or they did total deprivation, and that's not ecologically relevant. This is an ecologically relevant manipulation. This is six hours of sleep. It's very common in society. And it distorts, you know, well over 700 genes relative to when those same individuals are getting eight hours of sleep.

   15. PAPeter Attia23:34

       Let, let's just put this in context. There's only about 20,000 genes in the human genome. It's not like you said seven genes, or it's not like you said 700 in the presence of two billion genes. This is 3%.

   16. MWMatt Walker23:49

       Right.

   17. PAPeter Attia23:50

       You have an epigenetic change in 3% of your genome?

   18. MWMatt Walker23:53

       And this is with an epigenetic change within seven days at a moderate dose of sleep restriction. [chuckles] What was also interesting was the direction that about half of those genes were actually upregulated, the other half were actually downregulated. Those genes that were impaired in their activity were numerous genes associated with the immune system. Those genes that were actually upregulated were genes that were associated with tumor promotion, genes that were associated with long-term chronic inflammation within the body, and genes that were associated with stress and, as a consequence, cardiovascular disease. And I find that impressive because Many people in society right now feel uncomfortable about the idea of something like genetically modified embryos or genetically modified food, for example.

   19. PAPeter Attia24:52

       Or CRISPR, right?

   20. MWMatt Walker24:52

       Or CRISPR.

   21. PAPeter Attia24:52

       Think of the debate about-

   22. MWMatt Walker24:53

       Yeah, especially here as we are in Berkeley, it's relevant. But to me, I think that if you feel that way, if you feel uncomfortable about sort of GMOs, genetically modified food, or genetically modified embryos, but you're choosing to get insufficient sleep, and here we're talking about six hours of sleep, then I think you must accept then that you are performing firstly a similar genetic modifying experiment on yourself by reducing your sleep amount. And secondly, if you don't let your children get the sleep that they need, you may be inflicting inadvertently a genetic manipulation on them as well.

5. 25:33 – 36:48

   Is It Ever Too Late? Sleep Recovery and CPAP

   1. PAPeter Attia25:33

      Did that PNAS... Sorry. I-- See, to me, I can say PNAS without thinking penis, but, um, now I can't. Um, did that paper show the reverse? In other words, once you restored sleep, could you undo any of that genetic damage?

   2. MWMatt Walker25:48

      Didn't look at it.

   3. PAPeter Attia25:50

      Because, because I'm gonna take the sort of contrarian view here, which is we're all hosed, 'cause there's not a single person that hasn't been restricted to six hours a night. So it's almost like we should throw up our hands and wave.

   4. MWMatt Walker26:01

      Say-

   5. PAPeter Attia26:01

      Which I don't think is the answer, but, but-

   6. MWMatt Walker26:03

      No, I, I don't think it is the, the answer, and I think here's why. Firstly, you know, coming back to this argument that sleep is not like the bank. You cannot accumulate a debt and then hope to pay it off at a later point in time. That's why that binging at the weekend doesn't work. So once you've gone without sleep, whatever has happened during that time when you are underslept doesn't seem to be reversible. However, that doesn't mean that from this point forward, it's a waste of time to start sleeping better, and I have evidence for that. We and others have been looking at cognitive decline in older adults, as we've mentioned before. Now, one study looked at a group of individuals who were in mid to later life, and they had sleep apnea, snoring, which by the way is a devastating condition. If you snore or your partner tells you to snore, please go and see your doctor, get a sleep test, and get on sleep apnea treatment. But the point was this: They gave them this CPAP treatment, which is this sort of face mask to push the airway open so that you don't snore and you don't go without oxygen, and by way of an experiment of nature, about half of those individuals were compliant with the treatment, about half of them weren't. Those individuals who complied to the treatment and started sleeping better because they had their sleep apnea treated ended up staving off the onslaught of Alzheimer's disease by about ten years. So in other words, this is a causal demonstration that if you course correct sleep, you can actually modify your dementia probability risk, and it tells me in some ways a message of hope, which is that perhaps it's never too late to start sleeping better. Because if I've got evidence that in moderate, in mid to late life, that when you start course correcting bad sleep, here it's a sleep disorder with a particular treatment, that can have an observable benefit in terms of reducing your cognitive decline rate, then-

   7. PAPeter Attia28:12

      Although it's hard to know, right? Because the people who are compliant with CPAP presumably are doing so for reasons that might also make them more compliant with other inputs, such as, you know-

   8. MWMatt Walker28:26

      That's right

   9. PAPeter Attia28:26

      ... nutrition and exercise.

   10. MWMatt Walker28:27

       And it could even be, you know, that the sleep is not actually-- So maybe the sleep is the influencing factor.

   11. PAPeter Attia28:35

       Yeah. Yeah.

   12. MWMatt Walker28:35

       But sleep is not the route through which the benefit comes. It's because you're sleeping that you start to eat better, and we can speak about that relationship between sleep and food choices and, and, and caloric intake. And when you are underslept, you are far less likely to be active and motivated to be physically active. When you are physically active, the amount of force pressure that you can generate, the amount of aerobic output that you can generate, the amount that you can resist physical exhaustion when you're sleeping well, all of those things are improved. To your point-

   13. PAPeter Attia29:13

       If I recall, it's about a thirty percent rough... I mean, it's not a-

   14. MWMatt Walker29:16

       That's right

   15. PAPeter Attia29:16

       ... it's a non-trivial reduction in performance with sleep deprivation, right?

   16. MWMatt Walker29:19

       Yeah. I take someone, healthy person who is physically active, and I limit them to six hours of sleep, you get about a thirty percent decrease in your time to physical exhaustion. So the idea would be, let's say that you're training for a ten K, and in the days before, for whatever reason, you're down to six hours of sleep, and you've trained to maintain your point of physical exhaustion, you know, to the ten K level. Well, now, just with six hours of sleep, I'm gonna see you fail at s- at seven K because I've had a thirty percent reduction in your time to physical exhaustion. But I think your point, again, is a very good one, which is maybe it's not the sleep directly, it's the sleep transacting its benefits that we know also play into decreased risk for cognitive decline, such that you start making better food choices, the amount of caloric intake that you have is lower, the amount of calories that you expend is higher, your motivations to be physically active, and when you are active, you work out more intensely and harder. All of those things we know come by way of a benefit of sleep. So maybe sleep is, you know, the root cause, but it's not ultimately the thing that may be transacting it. Now, I think knowing the relationship between sleep loss and Alzheimer's protein pathology that we described, maybe it is playing a part. I don't think we know, but to your point, which is a good one Don't feel as though if you're someone listening to this and you've been on a, a diet of five or six hours of sleep for most of your adult life, that all is lost and you should just cash in your chips and say, "Well, basically, my fate is now sealed." It's not. I don't think it's ever too late to start sleeping better. I honestly don't.

   17. PAPeter Attia31:08

       I think the argument that it's, it's too late almost fails on first principles when you just consider virtually every other intervention, right? If you take someone who has diabetes, type 2 diabetes, and, you know, you dramatically change the way they eat and exercise, it's quite clear what you can do. If you take someone who smokes... I mean, smoking might even be a better example because we have such longitudinal data on risk reduction as time of non-smoking increases after a period of smoking. I mean, those are, that's actuarially mapped up the wazoo, and that's a simple enough intervention that you can attribute it to-- It's actually a very similar intervention, right? Because you would argue that in the individuals who stop smoking, they're more likely to make more positive health decisions for the simple reason that if I'm not gonna smoke, what else am I gonna take seriously in my health?

   18. MWMatt Walker32:02

       That's right.

   19. PAPeter Attia32:03

       And in the end, for the purist who says, "I need a randomized prospective trial to demonstrate this," one, I don't think you're ever gonna get it, and I think the reason is we're really at the point where it's going to become unethical to do draconian studies of sleep deprivation or I, I don't even think it would be ethical to take, to do a longitudinal study of depriving people with apnea of CPAP.

   20. MWMatt Walker32:26

       I think the evidence is so overwhelming that, yeah, you're ethically going to be unable to do those things. You know, and it's the same way with kids in school that I think the only option that we're going to have in terms of proving the importance of sleep for school start times and just health in general for kids is going to be, you know, elongating their sleep. If you look over the past fifty years, what we found is that kids across all ages are sleeping about two hours less now than they did fifty years ago. Two hours less. Now, to put that in context, if I went to my ethics committee and said, "Look, I'd like to take a group of seven-year-olds or six-year-olds, and I'd like to lop off two hours of their sleep, and I'd like to impose that on them for the next month and study it. Is that okay?" I'd probably be, you know, put on academic probation for even suggesting that, let alone they would never let me do that. But that's what's happened in society. So I think your point is, is a great one, too, which is we are probably not going to be able to do the sleep restriction studies increasingly anymore. We're going to have to do, you know, the sleep intervention and the sleep extension studies, and even some of the sleep intervention studies, ethically, you may not be able to do it because it's already so clear that you need to be treating the sleep disorder. And, you know, sleep apnea is a good example there too, that when you treat sleep apnea, and you typically see far higher rates of diabetes in people who have untreated sleep apnea, and when you treat them, you see their diabetic profile improve markedly, but you also see that they start eating less, their choices of food are better, they are far more likely to be physically active once again. So again, I think it's unclear whether it's that direct benefit of sleeping better on things like the pancreas releasing the right amounts of insulin or the cells in the body being instructed by that insulin to suck in the glucose more, or if it's just higher order things such as you're sleeping better, so you make better food choices, you are not as hungry anymore. And, you know, we and others have done these studies where you look at sleep and appetite regulation, and there I think the da- the data is just as causal and powerful as it is for glucose regulation. You know, what we find is that when you start short-sleeping people four, five, six hours a night for one week, the appetite hormones that regulate exactly, you know, that food intake, they're called leptin and ghrelin, they go in opposite directions in ways that you wish they didn't. So leptin is the hormone that essentially is the satiety signal. It tells your brain that you are full, you don't need to eat anymore, you're satisfied with your food, stop eating. Essentially, it's that s-satiety sort of red flag. Ghrelin is the opposite hormone. It essentially says, "No, you're not satisfied with your food. You want to eat more." It's a hunger signal, essentially. So what you find is that when you are under-slept, the leptin, which is saying, "You're full, don't eat anymore," that signal gets turned down, so it's not particularly volumous anymore. So your brain loses the signal of, "I'm full, I'm satisfied," and instead, ghrelin is actually ramped up, so you start to feel unsatisfied by your food, and you will eat more. And so on both sides of that hormonal appetite equation, you essentially downgrade this red flag of satiety, and you upgrade the signal of hunger, which then leads to what we've now demonstrated, which is an increase in your caloric intake. People sleeping six hours a night during the week, they will typically eat about three hundred extra calories during the day, which may not sound very much, but when you add it up week after week, year after year, it comes to about seventy thousand calories if you look at the actual numbers.

6. 36:48 – 43:06

   Appetite Hormones, Food Choices and the Brain

   1. PAPeter Attia36:48

      And I think it's even more pronounced than that because, uh, you know, the caloric arithmetic is complicated because of the compensatory components. But I think anybody-- I mean, I do this natural experiment of doing too much flying across the country. And the east to west, which is a very long day, and it's a sleep-deprived day because you're us- at least for me, I always want the earliest flight out to have the most time back. That is unquestionably one of the worst eating days of my life if I let it be. So one of the tricks I've learned for that day, which I now do very well, but I had to be very deliberate about it, was so you're gonna fly out of JFK at 6:00 AM, which means you're waking up at about 4, and you didn't go to bed at 8, right? So that sucks. I go to the airport, and I get a really good breakfast, a proper breakfast. Like, I eat, you know, the, exactly what I would want to eat. I don't eat a single thing on the plane, despite all of the dumb snacks that keep coming your way. And I also manage to exert enough self-discipline to get on the plane without buying trail mix, which is my absolute airport kryptonite. [laughs] But here's the thing, then, you know, you land in California, it's like 10:00. And what I do is basically have a tiny snack that is also, like, well-scripted. Like, I know exactly what it's gonna be. It's like sort of avocado and macadamia nut, highly satiating, and then I don't eat again till dinner, and then I go to bed really early. So super early dinner, 5:00 PM, super early bedtime, 8:00. And if I do that, it's, it's awesome, but it... Like, that requires a lot of work. It just requires a lot of planning and, and, and momentary moments of discipline. But if you don't, if you just do that on autopilot, which is basically what you would be doing if you were living that way every day, I mean, I'm amazed at the food choices I wanna make. Like, I, I have literally, if I look back, there are moments when I caught myself eating a pizza in the airport for breakfast.

   2. MWMatt Walker38:54

      Yeah.

   3. PAPeter Attia38:55

      Like, under no circumstance would you, would you do that regularly. And yet, like, the cravings you get for the craziest things under these sleep-deprived... I mean, any college, any college kid will know this, right?

   4. MWMatt Walker39:07

      Right.

   5. PAPeter Attia39:07

      You're pulling the all-nighter. Like, you will eat-

   6. MWMatt Walker39:09

      What do you-

   7. PAPeter Attia39:09

      Yeah.

   8. MWMatt Walker39:10

      Right. And so, you know, imagine someone like you, who has the knowledge that they have about sleep and then has this maniacal discipline to be able to fast for long periods of time, and even you with that arsenal of benefit in place can struggle under the weight of sleep deprivation. No wonder the majority of, you know, us non-demigods of control will, will implode so quickly.

   9. PAPeter Attia39:42

      Love to see what Jocko would do under sleep-deprived conditions with respect to food.

   10. MWMatt Walker39:46

       Right, and a gentleman who, by the way, I have such incredible respect for in many areas, um, and I would love to have a conversation and just an honest, frank conversation about sleep with him, but it's someone who, you know, I just... My goodness, what an incredible human being. But to come back to your point about food choices, it's not just that you overeat when you are underslept, which you do, and if you pull the all-nighter, you will typically eat probably about 450 more calories than when you're well rested. It's also the profile of food that you eat. And what I mean by that is if you give people, and these are the studies that have been done, essentially an ad lib food buffet, where at the end of the sleep deprivation period or sleep restriction, where you kind of limit them to four or five hours of sleep for the week, and then at the end of that, you give them this food buffet and you say, "Eat whatever you want. It's up to you." And there's everything from kind of leafy greens to, you know, avocados and macadamia nuts, all the way down to Oreos, ice cream, and pizza. What you find is that not only do you eat more, but you eat more of the things that you should not eat. So people will actually eat more from the heavy-hitting carbohydrates, the stodgy carbohydrates, together with simple sugars. So they'll be going after pizza, cookies, uh, ice cream, and they stay away from things like protein as well as, you know, leafy greens. So in other words, it's not just that you eat more, but what you're eating in terms of both micro and macro groups of food is actually also distorted in the wrong direction that you want. So we understand at the hormonal level what's causing these changes. We understand that it leads you to overeat in the excess of probably about 70,000 calories each year, which is about 10 pounds of additional obese mass that you would put on each year, which for some people may be painfully familiar. But we also know what happens in your brain, and we did a study where we took a group of people, we limited them, we restricted their sleep, and then we gave them a full eight hours of sleep, put them in a brain scanner, showed them a whole bunch of different food images, desirable foods, non-desirable foods. What you find is that when you are underslept, the centers of the brain that keep your hedonic desires in check, and it's a part of the brain that we call the prefrontal cortex, that part of the brain was actually taken offline by sleep deprivation, and that led to the more primitive areas of the brain, regions, um, such as the amygdala, for example, that just erupted in terms of its hedonic response to desirable foods. So you can see that essentially you're losing impulse control networks within the brain.

   11. PAPeter Attia42:48

       Which by the way, brings us right back to the five-year-old.

   12. MWMatt Walker42:51

       Yes.

   13. PAPeter Attia42:51

       It's so obvious when we see the kid that missed his or her nap, especially his nap, it seems. And look, as adults, maybe we're not gonna throw temper tantrums in the grocery store, but You know what? We're probably a hell of a lot more likely to buy Pringles

7. 43:06 – 49:24

   Sleep, Work Performance, Leadership and Attractiveness

   1. MWMatt Walker43:06

      Right, and you can scale this up. We've just described the litany of causal evidence from circulating hormones to food choices to changes in network brain activity. This idea of sleep leading you on a path towards obesity and diabetes is very clear. Input regulation equation of energy balance. That I think is, is, is just unquestionable. But your point is a good one about impulsivity. You know, think about other sectors where impulsivity is probably not great, yet sleep deprivation is rife: military, aviation, stock markets. I was speaking to a, a- another author who lives, um, here in Berkeley called Michael Lewis, who's written some fantastic books, and he was describing how rife sleep deprivation is, you know, down on Wall Street in terms of trading and money markets. I can only imagine the types of poor decisions and deficits that come by way of your brain shifting into impulsivity when you are underslept, and we're starting to do some work in those financial market sectors as well with choice and decision. I'd love to at some point do a survey of sleep in McKinsey and see exactly what the efficacy of insufficient sleep is, and there's already work out there. We've done some of these studies, and Chris Barnes has done some of these studies in Washington. If you look at employees who are sleeping six hours or less, the impact is probably fivefold. Firstly, those employees who are underslept will select less challenging problems. So you give them the experiment where you give them a range of problems, and they just typically will choose listening to voice messages or doing email rather than digging into hard project work. Secondly, of the problems that they do select, they end up producing fewer creative solutions to those problems, and that's an issue because it's supposed to be creativity and ingenuity that's driving businesses forward, but you lose that with a lack of sleep. The third thing that we found is that when underslept employees are actually working in groups, working in teams, they just slack off, and they just let other people work. It's riding the coattails of other people's hard work. It's called social loafing. Doesn't breed good atmosphere. The fourth thing that they found was that the less and less sleep that an employee has had, the more and more deviant and unethical they became, which comes back to impulsivity and deep emotional sort of eruption uncontrolled. So for example, they started to falsify data in spreadsheets. They started to claim the work of other people, even falsify reimbursement claims. And then the final study, which we didn't do, but it was a great study, this was from Christopher Barnes, they looked at the sleep of a business leader, and then they asked their employees how charismatic and inspiring was that business leader from one day to the next. And what they found is that the less sleep that that CEO had had from one night to the next, the less inspiring and charismatic their employees rated that business leader from one day to the next, even though they knew nothing about the sleep of that leader. It was evidential in their behavior. So here again, you know, we've gone from intracellular networks and the impact. We've gone from genes out to changes in food consumption, energy consumption, food choices, changes in brain networks, all the way back up to, you know, the workforce.

   2. PAPeter Attia46:40

      And that last one, by the way, is to me one of the most interesting, which is when you consider what that message is, right? 'Cause that's a great blinding, uh, in the sense that the employees have no idea how much sleep... They, they might not even recognize what the purpose of the experiment was. I'm sure that if the study-

   3. MWMatt Walker47:00

      They were not told

   4. PAPeter Attia47:01

      ... was done correctly, they were blinded-

   5. MWMatt Walker47:02

      They did not know

   6. PAPeter Attia47:03

      ... as to even the reason.

   7. MWMatt Walker47:04

      That's right.

   8. PAPeter Attia47:05

      If something so socially important, because that goes beyond just being the CEO and being the person that works for the CEO, right? That, that speaks to a much broader network of communication and interpersonal skill. You know, you think about that from the standpoint of dating, mating, like all of these other things, parenting.

   9. MWMatt Walker47:25

      Yep.

   10. PAPeter Attia47:26

       Like I think about, God, what a, what kind of a horrible parent am I when I'm sleep deprived? Because I, I mean, I just, I can't imagine that I'm doing the same job.

   11. MWMatt Walker47:36

       And what's interesting, you know, there about sort of dating, mating, and parenting, it brings me onto sort of that similar control. One of the interesting things, and this really actually does impact reproductive fitness and reproductive health. It's a great study from Sweden, a colleague of mine there, and they took some individuals, and they gave them a full night of sleep, and they sleep deprived them, and then they took essentially a portrait shot, beauty picture under both conditions. And then they took a group of independent judges who knew nothing about the sleep that those individuals had got or had not obtained, and they just simply asked them to rate those pictures essentially like a beauty contest. How attractive does this person look? How sickly does this person look? And how sleepy does this person look? So these, it's the same individual just under two different experimental conditions, and the judges in this beauty contest have no idea what those two images are. They just see the two images. Despite being blind to the experimental manipulation, you are consistently rated as looking more sickly, looking sleepier, but especially looking less attractive when you have not slept. So there is scientific proof of this thing called beauty sleep, but, you know, in truth, it's, it's a real issue regarding, you know, attractiveness if you're trying to find a mate or if you've got a mate. And you're trying to get intimacy and move towards reproduction, you're not going to be looking your best when you are underslept in that regard. So I think you, you know, these things consistently keep playing out under very carefully controlled experimental conditions. You just can't get around it. You know,

8. 49:24 – 53:45

   Sleep as Swiss Army Knife and Why We Weren't Prepared

   1. MWMatt Walker49:24

      sleep is, it is a life support system, and I often think of sleep as the Swiss Army knife of health. Whatever ailment you face, it's more than likely that it's got a tool in its box that's going to help out. And this decimation of sleep throughout industrialized nations, I think is having a real demonstrable, and I mean that as in literally a demonstratable impact on our health, our productivity, our safety on the roads, and the education of our children. You know, there is, there is truly no aspect of a human being's wellness that we've been able to discover that isn't eroded by a lack of sleep. Lack of sleep, it's almost like a broken water pipe in your home in the sense that it will leak down into every nook and cranny of your physiology.

   2. PAPeter Attia50:24

      That is actually an elegant way to state what I've been struggling to wrap my mind around over the past few hours. Taking a step back, we've gone through so many aspects of the pathology of sleep deprivation from what I would consider, we started at a somewhat macro level, which is big chronic diseases that are multifaceted. We went really, really, really micro into something for which we can't even elucidate the mechanism of AKT's phosphorylation, then brought it out to arguably the most macro, which is suitability for leadership and appearance. I mean, you can't get more macro. And a great analogy is water. I mean, as anyone who's ever had a leaky roof has known, and I had a leaky roof in residency that tormented me for two years, water will always find a way. And that's, I, I sort of picture sleep as if you interrupt this system, it is always going to track into something negative. And sometimes it'll be water gushing through the ceiling, and sometimes it'll be a slow drip that streaks your wall, and you barely know where it's coming from.

   3. MWMatt Walker51:40

      Yeah. The just... It's very, it's been very hard to find something that is resistant. There are few things in your biology or your psychology that can retreat at the sign of sleep deprivation and get away unscathed.

   4. PAPeter Attia51:56

      I think it goes back to the point you made earlier, Matt, which is it is such a ridiculous proposition to sleep that the fact that it is here, the fact that we spent probably when you consider, you know, our origins at the very beginning, call it half a billion years, keeping this strange thing around that on the surface makes no sense and, and we've had no pressure to get rid of it, I mean, that we haven't already resisted, right? Meaning, like all the pressure that would get rid of it that we discussed, you know, the inability to get food while you're sleeping, the inability to find a mate, the inability to protect yourself, the inability to care for your children. We, we resisted all of those things, but it's only in the last hundred and fifty, two hundred and fifty years, and really in the last forty years, that a totally new pressure has come on board that we didn't have anything to prepare for, that it could be so devastating. Whereas starvation, excess food, we've had lots of time to prepare for that. And again, even though the excess food we have today doesn't look anything like the binging that we would have done years ago, and, and, and Rick Johnson has written very eloquently about some of the genetic changes in fructose metabolism that really saved us and enabled us to fatten up in the fall when the fruit were sweeter. At least that prepared us a little bit of, you know, what we would do with excess nutrients in this modern era. At least we had a relatively safe place to store excess energy.

   5. MWMatt Walker53:31

      Right.

   6. PAPeter Attia53:31

      And we certainly have a safe way to handle not having energy. I mean, ketosis, starvation ketosis.

   7. MWMatt Walker53:37

      Yeah.

   8. PAPeter Attia53:37

      If not for that ability, our species wouldn't exist. So we, we've got that one pretty covered. We just, I, I... For sleep, we just didn't have the chance.

9. 53:45 – 1:05:52

   Alcohol and Caffeine as Sleep Aids

   1. MWMatt Walker53:45

      There's just, there's just nothing there. And I think, you know, part of this now comes to the bleed out of what's happening, which is where people are either so stressed or the diet, exercise, substance intake is such that they are finding all manner of sleep aids. You know, we know for a fact that ten million American adults in the past month have swallowed some kind of a sleep aid. Ten million.

   2. PAPeter Attia54:16

      I, I'm actually surprised it's not higher.

   3. MWMatt Walker54:17

      Which... Well, and that's all that we can get people to admit to and we know of. You know, I think there's probably a lot of over-the-counter things that are, you know-

   4. PAPeter Attia54:27

      Yeah, that wouldn't include necessarily someone taking Benadryl for sleep or-

   5. MWMatt Walker54:30

      Right. Exactly. Tylenol PM, whatever. And so, you know, I think this is where we're starting to see... And people have a very, I think, complex misunderstanding about what sleep aids actually are. Alcohol is probably the most misunderstood of all of those sleep aids, and it comes back to our discussion about sleeping pills a little bit too, that what I often hear from people are saying, you know, "I'm pretty stressed in the evening. I can't fall asleep. Um, I, when I get into bed, I'm too awake," perhaps because they're not getting enough darkness or perhaps because of use of caffeine too much or because of that anxiety. One of the problems with alcohol is that, well, it does three things to your sleep. Firstly, alcohol, as we sort of mentioned before, is also a drug that is a sedative, so it works on the same class of receptors that sleeping pills actually does. And when you have a nightcap, what you're doing is again just sedating your brain. You're just knocking yourself out. So that's the first thing. You think you fall asleep faster. You don't. You're just losing consciousness quicker. You're not falling asleep quicker. The second thing is that alcohol will fragment your sleep, so you wake up many more times throughout the night. Now, typically, they're so brief that you don't remember them, but they have a measurable impact on your sleep physiology and, as a consequence, your own wellness biology. The final thing that we've discovered is that alcohol is actually very good at blocking your dream sleep, your rapid eye movement sleep. And so what happens is that you end up waking up the next morning feeling unrefreshed and unrestored by your sleep. And some of the times you may think, "Well, I don't remember waking up with the alcohol, so maybe it wasn't the alcohol. I don't know what's going on." But now you start to feel lousy the next morning. You start to feel that you have this, like, kind of sleep inertia where sleep is still with you, and it won't let go of you, so now you start abusing caffeine.

   6. PAPeter Attia56:31

      Or by its more technical name, adenosine reducing substance. [laughs]

   7. MWMatt Walker56:35

      Correct. Yeah, a- adenosine muting substance. If you are taking caffeine, you know, before midday, I think a good question is to ask why, because that naturally should be your peak level of alertness around 11 or 12. You know, I often used to look before on planes now where you can now use your phones on takeoff. You know, five years ago, you couldn't do that, and it was a great experiment for me 'cause I'd get on a flight at 10:00 when everyone on that plane, for the most part, depending on their chronotype, they should be, you know, getting into the nice sweet spot of their alertness. They should be wide awake. And when finally people could not do anything, they weren't allowed to use their phones, they could... They just had to sit with the boredom of taking off. Boredom unmasked their state of chronic sleep deprivation, and I would look around, and half of the plane was fast asleep. So, uh, what then happens with, you know, alcohol is that you start using caffeine, and caffeine is a problem because everyone knows caffeine, you know, makes you awake. And the way that caffeine works comes back to our discussion of adenosine, which is that adenosine builds up. It's a sleepiness signal. It's telling your brain, "Get to sleep, get to sleep," the longer, the more that you have. Caffeine rushes into the brain, and it latches on. It hijacks those adenosine receptors, and it just blocks them. So essentially, it acts like a remote control for your TV, and it just hits the mute button on the sleepiness signal. So your brain thinks, "Oh, I haven't been awake for 16 hours. Maybe I've only been awake for eight hours 'cause I've just slammed, uh, an espresso after dinner." But then the problem with caffeine is that it actually has a half-life of about six hours. It has a quarter life of 12 hours. So in other words, if you have a cup of coffee at midday, a quarter of that caffeine is still in your brain at midnight. So the equivalent would be, you know, getting into bed, and before you go to sleep, before you turn the light out, you swig a quarter of a cup of Starbucks, and you hope for a good night of sleep, and it's not going to happen for, for some people. Other people will tell me, "Well, you know, I'm one of those people with caffeine. I can have an espresso after dinner, and I fall asleep, and I stay asleep, so no harm, no foul, presumably. Isn't that okay?" And the danger there, and we've done these studies too, where if you give someone a standard 200 milligram dose of caffeine in the evening and then you measure their sleep architecture, what you see is about a 20% reduction in deep sleep as a consequence of that caffeine being in the system. To put that in context, to drop your deep sleep by about 20%, I'd have to artificially age you by about 20 to 30 years to get that type of a reduction of a loss of deep sleep.

   8. PAPeter Attia59:28

      And is this, is this independent of the caffeine metabolism SNP differences that exist? Is everybody equally... Like, I've always felt like caffeine doesn't do anything to me. I mean, I love coffee, so I make, most days I'll make a coffee in the morning as a French press more-

   9. MWMatt Walker59:43

      Yeah

   10. PAPeter Attia59:44

       ... more as the ritual, and I just love the taste and the aroma. But when I'm tired, caffeine does not wake me up, and it just seems to have zero impact on me in any way, positive or negative.

   11. MWMatt Walker59:57

       And I think that's where we, you know, we don't know. We know that people have different genes that are associated with the enzyme that decomposes caffeine, and that's why some people are very caffeine sensitive or less caffeine sensitive.

   12. PAPeter Attia1:00:11

       Yeah, like we, we, we actually run this on most of our patients. If they-

   13. MWMatt Walker1:00:15

       You do? Yeah

   14. PAPeter Attia1:00:15

       ... if they've done a 23andMe-

   15. MWMatt Walker1:00:16

       So if you do a 23andMe, you'll get the gene. Yeah

   16. PAPeter Attia1:00:17

       ... yeah, you can, you can run it into Prometheus and see that. And, and I-

   17. MWMatt Walker1:00:20

       Right

   18. PAPeter Attia1:00:20

       ... I mean, truthfully though, Matt, you know, the association isn't as, as clear as I experience it clinically with people. I've always kind of been jealous of those people who can use caffeine as a true performance enhancer.

   19. MWMatt Walker1:00:33

       Yeah.

   20. PAPeter Attia1:00:34

       Um, but on the flip-

   21. MWMatt Walker1:00:34

       'Cause it just doesn't have that effect on you.

   22. PAPeter Attia1:00:36

       It has no effect on me whatsoever.

   23. MWMatt Walker1:00:38

       But what we don't know is those people who have those particular gene profiles that may have the ability to more quickly decompose caffeine, are they the same people who also don't suffer the same type of deep sleep reduction?

   24. PAPeter Attia1:00:50

       Yeah, I don't think, I don't think we know.

   25. MWMatt Walker1:00:52

       We don't know. And-

   26. PAPeter Attia1:00:53

       A- and this gets to something interesting, right? So, you know, going back to the alcohol point, I would add two points. The first is there are a handful of things that my wearing the Oura Ring for the past three years has, has, has done for me, and I, I want to disclose that I'm an investor, too, and an advisor to Oura, so please understand that. You, it's important you know that so that you can take what I'm saying with a grain of salt. But But what I'm about to say, every single one of my patients has said, and we buy this ring for every single one of our patients. There is no greater behavioral tool to show you the deleterious effects of alcohol than this ring.

   27. MWMatt Walker1:01:33

       Hmm.

   28. PAPeter Attia1:01:34

       I mean, you see the effect, and for most people, it is somewhere between zero and two drinks.

   29. MWMatt Walker1:01:43

       Yeah.

   30. PAPeter Attia1:01:44

       So in other words, um, for me, it appears that a single drink th- four to five hours before bed doesn't appear to have a, an, a difference that I can discern.
10. 1:05:52 – 1:16:58

    THC and CBD for Sleep

    1. PAPeter Attia1:05:52

       I want to go to another compound that I get asked about a lot, and truthfully, I just don't know the data. And that is, well, we'll start with THC and we'll move to, to CBD. And then the THC touches, I guess you could think about it through two lenses, right? Which is the developing brain versus the, quote unquote, "developed brain."

    2. MWMatt Walker1:06:11

       Mm-hmm.

    3. PAPeter Attia1:06:12

       So let's start with the latter, since I think it's more clear in the former that the developing brain probably is not benefiting from THC, so it's probably not even worth asking the question, is THC a good sleep aid in a teenager? I think the answer would be clearly no. But you and I, is THC a pro-sleep compound?

    4. MWMatt Walker1:06:36

       No. I, I don't think I'd feel comfortable in suggesting that it's a pro-sleep compound. I think-

    5. PAPeter Attia1:06:42

       And would you say that independent of strains? I mean, you know, anybody who's experimented these things will tell you, you know, well, sativa maybe not, but indica yes.

    6. MWMatt Walker1:06:51

       Right. I mean, firstly, I don't think we have enough data to, you know, pinwheel out the different strains and sort of parametrically slice the, the strain pie, as it were, and ask that. But what I do know from the evidence, firstly, I should say that, you know, acute use of THC typically has a, quote unquote, "beneficial effect" such that it will decrease the amount of time it takes you to fall asleep, what's called your sleep latency.

    7. PAPeter Attia1:07:17

       That's the only thing it impacts is latency?

    8. MWMatt Walker1:07:19

       So it reduces the latency, and it Makes it feel as though, well, and you are essentially-

    9. PAPeter Attia1:07:25

       And that would give you more duration.

    10. MWMatt Walker1:07:26

        So yeah. So you're falling asleep faster. Total duration, not so much. But what is happening, however, unfortunately, is that that THC, just like alcohol, has been shown to be a very robust blocker of your dream sleep, of your REM sleep. Add that to the fact that with chronic use of THC, you build up a tolerance to the benefit on falling asleep faster, so that now you actually have to start using more of the compound to get the same reduction in sleep onset time, means that that tolerance and dependency, I don't think is necessarily a good thing. When you then cease the use of THC, what you find in the studies is a pretty horrific insomnia rebound, where people then actually have miserable sleep, and it usually typically leads to then falling off the bandwagon of abstinence, if that's their goal, and people then start having to use again to gain back that crutch that you may not necessarily have needed otherwise. So I think the, the evidence right now, especially with the REM sleep blocking effect of THC and the importance of REM sleep that we know of, I just don't feel comfortable in thinking that THC itself is really the sleep aid of the future, and that there is more evidence on the THC side. CBD is starting to gain more research traction. I don't think there's enough studies done. I think part of the reason with CBD is-- and THC, it's just, it's hard to do these studies because they're hard to get funded because of still some of the moral-- And now I am not, again, I'm not puritanical about this. I'm not casting any judgment at all. And I've often thought, "Well, you know, what would it take? Maybe, you know, I should do, like, a Kickstarter and try and crowdsource enough money to do the appropriate CBD studies," because I think CBD is more promising on the data right now. The data for CBD is that you get that benefit of falling asleep faster.

    11. PAPeter Attia1:09:42

        By the way, would you-- Just to interject for a second, would you be able to get an IRB approval to do a real world study where a bunch of people were just using wearables and you could homogenize and uniform the wearable and the CBD and things like that, but without having to do it as an in-house sleep study? Do you think the wearables are good enough-

    12. MWMatt Walker1:10:02

        In-house is, is harder

    13. PAPeter Attia1:10:02

        ... that you could get enough data in the community?

    14. MWMatt Walker1:10:06

        I would probably do a hybrid. I mean-

    15. PAPeter Attia1:10:09

        No, that makes sense. You, you-

    16. MWMatt Walker1:10:09

        The irony of, of THC and CBD often being used as hybrids is not lost on me, but I would probably do a hybrid where I would do some tracking of sleep ecologically in the, in the home setting, as it were, and then have a couple of nights where they would actually come in and we would measure their high-grade sleep quality. Because the trackers out there right now, you know, they're just not quite accurate. They're not clinical grade enough for me to understand the quality and the stages of your sleep. I think trackers are not bad right now and-

    17. PAPeter Attia1:10:39

        But even those metrics, you'd get a clue, right? Like even with the ethanol-

    18. MWMatt Walker1:10:42

        Somewhat of a clue. Yeah, you can see it. I think, you know, people often ask me, "What's the best sleep tracker?" And I would say it's the sleep tracker that you wear every night. You know, I think m- most of them are much of a muchness in terms of their current inaccuracy. So I would do a hybrid study probably where I would do some tracking outside with things like wristwatches or rings, and then I would do some in-laboratory studies. But I think for CBD, things are actually looking more promising. CBD does give you that same benefit. You fall asleep faster. You don't seem to get the hit on REM sleep. Now, I don't think there's enough studies for me to yet feel comfortable in saying definitively you don't. But for the small handful of non-placebo controlled trials, for whatever it's worth, and we are talking about hands up here, everyone, no recommendations, no promissory notes, this is just very early tentative preliminary evidence suggests that you may not get the REM sleep deficit, which is good. The other thing is that you typically don't see the dependency issues, nor do you get the insomnia rebound when you stop using CBD. And the final thing I think that's interesting with CBD is that it may actually have some benefits in certain sleep disorders. There's some-- There's a little bit of evidence that it may reduce the severity of sleep apnea, but I think that that's just, you know, one or two studies. There's some benefit that's happening in PTSD with CBD treatment to help with PTSD sleep problems, and sleep problems are real problematic issues with PTSD patients. So I think anything there that could be of help, as long as it's medically safe and doesn't compromise your sleep, unlike THC, would be a good thing too. Probably two caveats, or at least one caveat. It does seem to be somewhat dose dependent. Um, it-- I don't think it's very clear right now what the optimal dose is. There have been some times where people have actually suggested that the use of CBD at a certain dose is actually wake promoting rather than sleep promoting. So I think there may actually be this U-shaped function when it comes to CBD that what-- or some kind of a, of a function. I don't know what the function is going to be. But there's going to be perhaps a sweet spot of a dose concentration that is optimal for CBD's benefit on sleep, and there may be other doses that are actually detrimental to sleep, and we need to stay away from them. How is CBD doing that and having that kind of benefit of sleep? There was actually even some evidence that it may actually increase the amount of deep sleep, which was interesting, and that was just one single study, small study, again. I'm not believing it. I'm not going to go out there and start telling people to, to take CBD on the basis of that single study. I am saying that I think it's got promise right now, but we don't know how could it be doing that. Well, one of the interesting things could actually be thermoregulation. In some of those studies, they were actually finding that the core body temperature decreased with CBD administration, and we were just describing that when you drop core body temperature, you sleep better. When you increase core body temperature by way of something thermogenic like alcohol, or it's just a hot room or a big meal, that increase in core body temperature is worse for sleep. So CBD may actually be having its mechanistic benefit through the thermoregulatory system is one of my hypotheses. The other is that it's indirect through its anxiolytic benefits. I think probably the greatest, strongest evidence right there, out there right now for CBD's clinical efficacy is for anxiety. And I actually think, and I've tried to read as much of that data as I can, I think it's actually pretty interesting. I think one of the major causes of insufficient sleep and poor sleep right now is that everyone is just cranked in terms of anxiety and that they wake up or... You know, we are constantly on reception in this modern day of life, and the only time that our brain goes from reception to reflection is when our head hits the pillow, and that's the last time that you need to be ruminating and catastrophizing and having that Rolodex of anxiety. So I think if CBD is efficacious for lowering anxiety, and anxiety is one of the causes of poor sleep in society, then part of that benefit may not be through a direct mechanism on sleep-regulating centers, but instead a secondary benefit of lowering anxiety, which perhaps lowers that sympathetic fight or flight branch of the nervous system, which means that you shift into a more parasympathetic state and or it drops core body temperature. Both of those routes, I think, are, in my mind, the tenable hypotheses that in, you know, a crowdsourced study that I would want to do. And I don't know if people want to do that study. You know, comments in wherever comments can be, but if people-

    19. PAPeter Attia1:15:54

        I, I would, I'll, I'll speak for myself. I would love to see that study because anecdotally, not so much in myself, but I also think I'm, I sleep reasonably well. But in people who don't sleep that well, I have anecdotally seen some pretty impressive results with CBD.

    20. MWMatt Walker1:16:15

        Yeah.

    21. PAPeter Attia1:16:15

        Uh, and other times I've seen nothing. And what's interesting is in some of the people in whom I've seen impressive results, it's people who have been largely recalcitrant to other big guns. Again, I think whenever you can sleep without pharmacology, you're doing a good thing, but-

    22. MWMatt Walker1:16:31

        I agree

    23. PAPeter Attia1:16:31

        ... when you look at things like trazodone, Thorazine with their anti-ruminative properties, and you see patients who even at twenty-five and fifty milligrams, doesn't matter.

    24. MWMatt Walker1:16:43

        That's right.

    25. PAPeter Attia1:16:43

        You know? Doesn't-

    26. MWMatt Walker1:16:44

        And, you know-

    27. PAPeter Attia1:16:44

        It's not helping them sleep. And yet, you know, CBD does.

    28. MWMatt Walker1:16:47

        CBD ends up having... Yeah.

    29. PAPeter Attia1:16:49

        A- a- and at that point, you start to think, "Well, it's less likely to be the placebo effect because you've tried all of these other things that didn't work. Why would this silly little oil work?" And, you know,

11. 1:16:58 – 1:24:15

    Anxiety, Mental Health and Sleep

    1. PAPeter Attia1:16:58

       I'll share a, a sort of unrelated story that speaks to this role of anxiety, 'cause this kind of brings it back to this idea of mental health that I, I think is such an important part of longevity. I have a patient whose sleep has really eroded in ways that I, I can't even imagine, and it's been quite devastating to watch, and this is an individual who's done everything that you would ask someone to do, right? This means we-- you know, you control the room temperature, you control the light, you control the nutrients, you control-- you eliminate the alcohol, you eliminate the caffeine, an hour of meditation a day. I mean, this is everything. But, you know, this person's in the midst of a very difficult personal struggle, and that's... So, so by the time you're at, you know, fifty milligrams of Thorazine to just try to shut off the ruminative properties, and you would get some intermittent benefit, but not long term. So in the end, what he was able to do was enter into a clinical setting under which he was able to therapeutically utilize MDMA to deal with some of the issues that were predisposing. And again, I want to be very clear what I'm saying here. I'm not saying he went to a party and did ecstasy, right? To the listener. This is a clinical administration with a therapist of MDMA to address the underlying trauma and anxiety and depression of the situation. The next day, and for months to follow, and we're still at that standpoint, his sleep is fixed. Now, I think that is an outlier situation, but sometimes these outlier situations provide an insight into a mechanism. And I think in this person's individual, because we had already fixed all of the sleep hygiene metrics, I mean, we had literally done everything in our toolkit, and that's a toolkit that has about ten tools in it. To see this one thing, this one intervention work, and, you know, the patient would describe this as a transformational life experience, was just another example of the power of the mind and how the mind can sort of get in its own way at times.

    2. MWMatt Walker1:19:13

       And the power of the mind in terms of it essentially deconstructing this thing called a full night of sleep is, I think, so critical. And more and more now, we are seeing that the causes of sleep difficulties and sleep problems are shifting from You know, typical biological problems to increasingly psychological problems. I think that rise in anxiety has walked in lockstep with a rise in insomnia, and I think we've got enough evidence to suggest that those two are probably not coincidental, but are significantly interrelated, is probably the, the strongest thing I could say right now. So it doesn't surprise me that if you have something that essentially is, you know, a mental health reset on your Wi-Fi router in a demonstr-- you know, in a marked way, that could lead to essentially the same type of reset in that physiological thing called sleep. It doesn't surprise me. You know, whether or not, you know, that is the, the treatment for everyone, you know, is-- and you are very clear about that, and I enjoy that, but it doesn't surprise me that if you fix mental health, you fix-- And we've seen this bidirectionally. We do a lot of work on sleep and mental health, and it's very clear that I can take people who don't have any problems with mental health, depression, poor mood, anxiety, suicidality, and when you sleep deprive them, you can instigate many of those conditions. In fact, I can, within one single night of sleep loss, I can put someone who is non-clinically anxious to a level of anxiety where they would have a clinical anxiety disorder diagnosis. That's how quickly it can happen. So yes, sleep can impact your mental health. And what's interesting is that psychiatry, in the past twenty-five years, I have not been able to discover a single psychiatric condition in which sleep is normal. Which to me was quite profound when we added it up. That I can manipulate sleep in mentally well people and then produce, by way of the excising of sleep, mental ill health, tells me that there is a causal direction from insufficient sleep to poor mental health, that sleep is essentially emotional first aid in that regard. However, don't mistake that for the fact that it's a two-way street as well, and I think what you're describing here is a state of m-mental ill health, and when you course correct that mental ill health, you then correct the sleep. And so I think the relationship between sleep and mental health is bidirectional. I think is-- it's a two-way street. Is the traffic flowing more in one direction than the other? Perhaps, and perhaps psychiatry has had it wrong for the past fifty years. They used to think that the poor sleep in their patients that they knew about long before we published, you know, scientific data, that was a symptom of the disorder rather than considering it a potential predisposing cause of the disorder. So I think psychiatry is un- starting to undergo a revolution when it comes to sleep and understanding how fundamental sleep is to the maintenance of good mental health. I think it's, I think it's the bedrock of it. You can stack up the different physiological body systems and the different operations of the mind, but I would put mental health pretty high up there in terms of one of the things that falls apart quickest. And the reason I can say that is because essentially we start with these sleep deprivation studies, and we can just keep sampling the organism, which is the patient, the individual, you know, every hour, and we can just look to see the further you go into sleep deprivation, what is the trajectory of impairment in brain and body systems? And some, you know, come on tap later in the sleep deprivation, others very, very quickly. Essentially what we're trying to ask is: What is the recycle rate of a human being? And after about sixteen hours of wakefulness, things start to go wrong, and the things that start to go wrong soonest and perhaps most severely, one of those things certainly is your mental health, anxiety being one of them, mood being the other, depression.

    3. PAPeter Attia1:23:57

       It's interesting, right? How long it can take for certain things to, to ravage the brain, neurodegenerative disease that manifests clinically in dementia, and yet how quickly certain elements of the brain will demonstrate the limitation, memory consolidation and anxiety as two examples.

12. 1:24:15 – 1:32:56

    Walker's Current Projects, StimScience and Sleep Research Funding

    1. PAPeter Attia1:24:15

       You're in your sabbatical year, correct?

    2. MWMatt Walker1:24:18

       I am. I'm finishing it up right now. Yeah.

    3. PAPeter Attia1:24:21

       So what else are you doing with your time besides being incredibly generous and sitting here with me?

    4. MWMatt Walker1:24:28

       [chuckles] So I still, even though I don't teach, I still am here at the sleep center. Um, I'm the director of the Center, uh, uh, for S- for Human Sleep Science here at Berkeley, and we continue to do all of our research, so I'm still, you know, directing the center. I'm s- writing grants. I've been doing a lot of public advocacy. I've been doing a lot of public speaking now that the book has come out, and I'm doing sort of television media. I've also got a couple of startup companies that are emerging. One of them has just gone public. It's a brain stimulation company. This comes from work that's out there in the literature showing that if you can try to essentially electrically sing in time with deep sleep brainwaves, you can boost the amplitude and the size of those deep sleep brainwaves. We're hoping to try and transfer that same technology into older adults and those with dementia. Can we salvage some aspects of their learning and memory by way of boosting back their deep sleep? That's one of those, um, possibilities.

    5. PAPeter Attia1:25:32

       Can you say how the device works? Is it a device that sits in the room?

    6. MWMatt Walker1:25:35

       No, it's actually a device that you place on your head. Um, and it's actually-

    7. PAPeter Attia1:25:38

       I see. So it actually measures the waves.

    8. MWMatt Walker1:25:40

       It both measures the waves, and then it inserts electrical voltage into the brain. And essentially what we're trying to do is measure when you're having those sleeping brainwaves and almost act like a, a choir to a flagging lead vocalist, that you're trying to sing in time with the electrical stimulation of the deep sleep of older adults, which is diminished by fifty to eighty percent. But giving them an electrical sort of, you know, stimulation to try and every time they have a, a s- a deep slow wave, boost the size of that slow wave, and in doing so, try to almost double the amount of memory benefit that you get from sleep because that's what we've already been able to demonstrate in young healthy adults. So that's one of the, the, the companies.

    9. PAPeter Attia1:26:25

       What's that company called?

    10. MWMatt Walker1:26:26

        It's called StimScience, and that's together with a set of co-founders that we just recently got seed funding for from Koshla Ventures. Then I'm starting to think about writing a second book and unclear exactly what it will be. I think there's probably three candidates right now. The other thing that we're trying to do as well, though, is raise funds for the sleep center. We've just moved to this beautiful new building that we're in with the new sleep center, so we're trying to raise philanthropic funds because, you know, and I think you've done this, you know, wonderfully, and you've done work with Gary Taubes to try and, you know, create this, this vision for how you can fund science in ways that typical funding mechanisms will never do, and that's what we need at, at my sleep center is that we need philanthropic support, um, and there is now currently through the university, they've granted the ability to name the sleep center for a philanthropic donation. So I'm now just trying to move that work out. So I guess this is a shameless plug that should anyone out there wish to have a legacy name to name the center that is there. But just to give you a sense of some of these, you know, studies, one of these other studies that w- I'm fascinated by in our elderly cohorts is not just the deficit in deep sleep that happens as you age, which it does. There is also this strange cluster of outliers of people in their 70s and 80s that when I put their data of sleep and deep sleep plotted against all of the young healthy adults that we've studied, some of those older adults seem to be incredibly resistant to age-related sleep decline. Why? No one is willing to kind of give me the money to do the studies, which is the inverse. You know, it's easier to get money to explore when things go wrong. But you can get insights into those critical questions by looking at also when things go anomalously right. And a good example of this is the blue zones, you know, this work that was done starting by National Geographic, where they looked at longevity, and they found that there were these pockets throughout the world where people seem to live longer. Now, I think some of the c- the data there is controversial, but it was a good idea that you could look, is there something about their social fabric? Is there something about their diet, their exercise? The... No one in terms of these blue zones has asked the fundamental question about sleep. Why? You know, and that's gonna be fiendishly difficult for me to get funding for. So one of the things that I'm trying to do right now is raise money for the sleep center to do what would be otherwise impossible fundamental research to make critical discoveries on the flip side of where I think we can make real inroads into understanding sleep, which are usually typically very difficult to get funded, or these are kind of more blue sky research questions, but could make real impacts. But sorry, I interrupt.

    11. PAPeter Attia1:29:32

        Where does sleep reside within NIH? Which of the 17, uh...

    12. MWMatt Walker1:29:37

        It resides in most of those branches. You know, it resides in the National Institute of Aging. It's there for neurology. It's there for cardiovascular disease. It's there for metabolism, glucose, and it's there for NIDA, which is the institute for drug abuse. So it's prevalent in all of them, but I would say that-

    13. PAPeter Attia1:30:00

        But, but paradoxically, it doesn't have its own institute.

    14. MWMatt Walker1:30:02

        No, it doesn't.

    15. PAPeter Attia1:30:03

        Which it seems like it ought to.

    16. MWMatt Walker1:30:07

        Well, if you were to think that exercise, nutrition, and sleep are the three fundamental ingredients that as best we can tell from the science that we've done as a human species keeps us alive and longer living and living longer well-

    17. PAPeter Attia1:30:21

        And yet those things all spread across the entities as opposed to stand in their own, which there's benefit to that. You would argue they shouldn't be siloed, they should be studied. But of course, you could almost argue for a matrix-

    18. MWMatt Walker1:30:35

        That's right

    19. PAPeter Attia1:30:35

        ... as opposed to-

    20. MWMatt Walker1:30:36

        So yeah, what you really want is horizontals and verticals, and when you put those together, well, you create the matrix that you've just described. So I would say, you know, I think NIH has done, has definitely supported a, you know, a huge amount of sleep research, and they support some r- the research or some of the research that we do here at the sleep center, and, and I'm incredibly grateful and very fortunate to have those grants. They're very hard to come by. But there's also, I keep running into these fundamental questions that when I write these grants, they're difficult to get money for. And, and I understand why, because you've got government policies, you've got particular institutional mandates that you have to fill. They're just not going to fund these, these research programs. So that's another thing that I'm doing is trying to raise money for the sleep center, then with these startup companies, and then also just doing our fundamental basic science. And-

    21. PAPeter Attia1:31:31

        Now, are you formally involved with Google in some way as well? I've seen some of your talks there, but I... Are, do you work with Verily? Do you work with Google?

    22. MWMatt Walker1:31:39

        Yeah, so I do. So right now I'm also a scientific advisor for Verily, which is formerly known as Google Life Sciences. So I do help Verily to try and help shape their mission of sleep, and, you know, I've also been a consultant for, um, many of the other large tech companies out there and many of the fitness trackers as well. But right now, yeah, I do also do some time at Verily to try and help with many of their exciting visions regarding how you could use the resources of a big technology company like Alphabet to try and do things differently than the way that the government does health. I think we'll need both of those forces, and both of those forces will be for good. But- It's a wonderful place to be. You've got incredible people there, and the way in which they see problems is different. The time course over which they want to solve those problems is different, and the solutions and the expertise that they bring to those health problems are different. So when I got the chance to work at Google Life Sciences there, or, uh, essentially be an advisor there, you know, I jumped at the chance. It was, it was great to try and help shape that mission.

    23. PAPeter Attia1:32:56

        You know,

13. 1:32:56 – 1:45:14

    Formula One Talk: Season Predictions and Favorite Cars

    1. PAPeter Attia1:32:56

       Matt, I, I had a list of, uh, probably five pages worth of things that I wanted to discuss with you, and we covered many of them, but I, I would say we covered half of them truthfully.

    2. MWMatt Walker1:33:06

       [laughs]

    3. PAPeter Attia1:33:06

       And I think the only, the only solution is we, we probably have to sit down again sooner rather than later. And amazingly, we were pretty good about not getting into cars, which is... I mean, like, we could have spent this entire time talking about Formula 1.

    4. MWMatt Walker1:33:23

       Maybe that's the second half of the second conversation should people not generally lose the will to live when they hear my voice for, you know, several hours, which is what most people do, unfortunately. But I would be so thrilled to come back at any time you would wish me to, um, and same for the audience. And if that second time did involve a little discussion of all things cars and car racing, including Formula 1, it is one of the few thing... You know, I, I've never been a big fan of alcohol, not because I'm down or against it, it's just I've never really liked the taste, so I, I typically don't drink. I'm caffeine free just 'cause I'm one of those people who's sensitive to caffeine. But the one vice that I have, my biggest weakness is cars, car racing. Oh, it's, it's a te- it's a wonderfully terrible affliction. I adore all things automotive.

    5. PAPeter Attia1:34:18

       The next time we do this, let's do it in San Diego so we can sit in the simulator and, I don't know, maybe just do 100 laps of COTA or something like that, and-

    6. MWMatt Walker1:34:29

       God, I'd love that

    7. PAPeter Attia1:34:30

       ... yeah, it's, it's, uh-

    8. MWMatt Walker1:34:31

       That would be such a gift.

    9. PAPeter Attia1:34:34

       Yeah, yeah.

    10. MWMatt Walker1:34:34

        That really would be.

    11. PAPeter Attia1:34:35

        Well, we'll, we'll do that.

    12. MWMatt Walker1:34:36

        I'll take you up on that.

    13. PAPeter Attia1:34:36

        You know, it's possible that by the time this comes out we'll already know the answer to this question, but given where we are right now, which is in late February, what is your take on this year's season? I mean, early testing looks really good for Ferrari. Looks like that front wing is giving Mercedes a little bit of difficulty.

    14. MWMatt Walker1:34:56

        Yeah, they, they struggled, didn't they?

    15. PAPeter Attia1:34:58

        Um, if, if you had to predict one, two, and three this year in both constructor and driver, how would you handicap it now? And, and these are impossible questions to be kn-

    16. MWMatt Walker1:35:09

        I-

    17. PAPeter Attia1:35:09

        ... to be clear.

    18. MWMatt Walker1:35:10

        Yeah, I, I don't know about driver. I think I'm gonna put Ferrari one and three, Mercedes two, and I think I, I feel at least-

    19. PAPeter Attia1:35:20

        Well, so the huge question then is Vettel, Leclerc. I mean, where, where are you going on one and three?

    20. MWMatt Walker1:35:24

        Okay, if you're gonna push me, I would say Vettel one, and I, I think Hamilton, you know-

    21. PAPeter Attia1:35:28

        Yeah, yeah. Obviously Hamilton, yeah

    22. MWMatt Walker1:35:29

        ... obviously is gonna probably be number two there-

    23. PAPeter Attia1:35:32

        Wow

    24. MWMatt Walker1:35:32

        ... with Mercedes. That's my suggestion. Or I would at least say that that's gonna be the first half of the season. You know, Mercedes as a team technologically, they are fantastic too, and I think that they could rebound. You know, if this first... All, all the data I've seen is just the one set of testing data that y- you know, you and I have both seen here now in February, and it looks like Mercedes has got a rip-roaringly hot car on their hands. But I think Mercedes is capable-

    25. PAPeter Attia1:36:00

        You mean Ferrari.

    26. MWMatt Walker1:36:01

        Sorry, Ferrari.

    27. PAPeter Attia1:36:02

        Yeah, yeah.

    28. MWMatt Walker1:36:02

        Sorry, sorry, sorry, Ferrari. I think Mercedes is capable technically though of coming back in the second half of the season to make sure that that car performs so they've got a good chance. And Hamilton with the skill that he has, I think may be able to hang in there until that technology and the engineers come good. I would also just love as a British man to see McLaren do-

    29. PAPeter Attia1:36:24

        Oh

    30. MWMatt Walker1:36:24

        ... a little bit better. I love them as a car brand. I've never had the opportunity to, to be in one of their cars. I've only had the chance to look at them, and usually that means that I become a even more incoherent human being-
14. 1:45:14 – 1:57:11

    Sleep, Reaction Time and Performance in Racing

    1. PAPeter Attia1:45:14

       Talk about another sport where, like all sports, sleep really matters. I mean, I can't, I, I can't imagine any athlete that's under more difficult sleep conditions than a Formula One driver because, you know, it's one thing if you play in the NBA, you're gonna fly a lot, but you have a three-hour time zone max. And based on how the conferences work and how the schedules work, it's not like you're going plus three, minus three, plus three, minus three, plus three, minus three. When you look at Formula One, first of all, it's a 10-month season basically. I mean, it's, you know, when you include pre-season testing. And it's truly a global sport. And it's not even like it's structured perfectly well. It's not like they comb through Europe-

    2. MWMatt Walker1:45:55

       Mm-hmm

    3. PAPeter Attia1:45:55

       ... then go over to Asia-

    4. MWMatt Walker1:45:56

       Yeah

    5. PAPeter Attia1:45:57

       ... and then, you know, hit a little Australia and Melbourne on the way over to North America, and then hit South America. Like, it's not even done in the logical way that you would do it if you were optimizing for continental jump.

    6. MWMatt Walker1:46:08

       Right.

    7. PAPeter Attia1:46:09

       It's completely out of control.

    8. MWMatt Walker1:46:11

       Jet lag imposed is horrific. And there, in that sport, if you're talking about margin of error and reaction time, we don't currently have essentially a breathalyzer for sleep deprivation, which we should, and I think, you know, there's ways that we can think about that too. But if there is one gold standard measure of insufficient sleep, it's not only just your response time, your basic reaction time, but it's the number of times that you miss a response, what we call a lapse or an error of omission. You omitted a response that should've been happening. It is so obvious that insufficient sleep impacts your basic reaction time and your missing of choice response times. And in Formula One or in any vehicle racing at high speeds, you know, response times and reaction times, you're talking about margins of error here that are .00X, you know? And six hours of sleep for one week can drop your reaction time by up to three to 400 milliseconds. Now, three to 400 mil- you know, almost a half a second in terms of slowed response times in Formula One can make the difference between you being first and you being somewhere basically nowhere.

    9. PAPeter Attia1:47:35

       Yeah, the other thing I've noticed, and this is one of the things I enjoy about having a simulator, is I get to test stuff out. I mean, I've, I've figured out that even after one drink, I drive worse in a simulator, even though I am not legally drunk, right? I probably have a blood alcohol of .03, .02. I mean, a very low blood alcohol after one drink in someone my size who metabolizes things so quickly. But I don't drive well.

    10. MWMatt Walker1:48:01

        Yeah.

    11. PAPeter Attia1:48:02

        And I, and I know this as clear as, you know, as clear as day because when I drive with my coach, you know, we drive virtually inside of iRacing together, so he's in the cockpit with me, seeing my telemetry, seeing the drive, the whole thing, and it's just a different game. And it's not actually just reaction time. The other thing I've noticed is there's something about my spatial coordination-

    12. MWMatt Walker1:48:24

        Yes

    13. PAPeter Attia1:48:24

        ... that goes down. So I actually think that that's a bigger problem than the reaction time. I think the bigger issue is you're just, you're never quite hitting the right apex. You're never quite finding the right grip in the track, and this is even when you know the track like the back of your hand. You're just off. So, so it's, it's-

    14. MWMatt Walker1:48:43

        So spatial attention-

    15. PAPeter Attia1:48:44

        Yes

    16. MWMatt Walker1:48:45

        ... is one of the things that we s- can study. We do it with brain scanners very quick-

    17. PAPeter Attia1:48:50

        I, I think that's what's killing me

    18. MWMatt Walker1:48:51

        ... to go down with sleep deprivation.

    19. PAPeter Attia1:48:52

        Yeah.

    20. MWMatt Walker1:48:53

        Yep. That, I think together with also just specific choices. You know, if you're racing, you know, you can, if you're by yourself and you're on the clock, that's one thing to worry about. As soon as you put other cars on the track, you make it strategic. When you make it sh- strategic, you make it about decision choices. Do you dive into that apex when you know that you've got someone on your flank? Do you not? When is the time to brake? Do I want to brake later? Do I have the downforce? Where am I with my tires? You, you can go through a whole litany of decision-making that has to happen within split seconds of time. Decision making, again, you know, sleep, critical component of that too, so-

    21. PAPeter Attia1:49:37

        Yeah, and ju- and just judgment. I mean, I think ju-

    22. MWMatt Walker1:49:39

        That's right

    23. PAPeter Attia1:49:40

        ... even having a microscopic miscue on your judgment, and as you said, it's hard enough when you are on a track by yourself just trying to bang out best lap times. The moment someone else is there, and it's incredible how much your judgment can be impaired even subtly to do something stupid. For me, you know what it is? It's impatience. I am much more impatient under that situation.

    24. MWMatt Walker1:50:03

        Impulsivity.

    25. PAPeter Attia1:50:04

        Yeah, very impulsive, and-

    26. MWMatt Walker1:50:05

        Compares to the child in the supermarket.

    27. PAPeter Attia1:50:07

        Yeah, yeah. Just much more likely to... You know, for example, you think about it. You, let's say you have 10 laps to go, and there's one car you need to pass. You know, you think about that for a moment. You've got all the time in the world to figure this out. You, you wanna wait until it's perfect, and yet I can see it in myself, there's this Belief with like, "Well, I just got to do it now. It's got to be on this lap. It's this lap or never," that I... Totally irrational thinking.

    28. MWMatt Walker1:50:36

        Yeah.

    29. PAPeter Attia1:50:36

        And I have to wonder, because it's not... We do see these guys who are gods. I mean, you know, you've, you've driven race cars, I've driven race cars, so we can watch that sport and appreciate it maybe more than the casual observer. Like, we know how good they are.

    30. MWMatt Walker1:50:53

        Yeah.
15. 1:57:11 – 2:01:02

    Closing Reflections on Translating Sleep Science

    1. PAPeter Attia1:57:11

       Well, Matt, until next time, this has been, I mean, really, really insightful. And when I think about how much I probably know about sleep to begin with and how much I have learned even from this discussion and certainly from reading your work, I'm incredibly grateful. And I do think that this is probably the single biggest deficit within the toolkit of most physicians. And I'm, you know, few people are more critical of the absolute dearth of rigor in the nutrition field, but I think this is worse. And it's not the dearth in the quality of the research, it's the dearth in the translation of that research to clinical application.

    2. MWMatt Walker1:57:53

       I agree.

    3. PAPeter Attia1:57:53

       I think the research in nutrition is the worst research of all things. Just, and again, it's not to be critical of the people doing it, it's the difficulty in studying it. But at least there's a greater effort to translate what is known into practice. But here, this is the biggest chasm. That said, I think your work has had a greater impact here than anything I'm aware of. And I wish you all the continued success. I think you could argue part of our humanity depends on it.

    4. MWMatt Walker1:58:18

       Thank you for giving me firstly that affirmation because I am on a mission to try to reunite humanity with I think the sleep that it is so desperately bereft of. And having this type of forum where you can disseminate that knowledge. I mean, what you described there is that the research is not being translated to the clinical practice. You're absolutely right. And that's part of the work that I do with trying to be a sleep advocate. But another part of that is just the transmission of that sleep knowledge to the general public as well. And I think people, you know, I'm not, I can't speak for any of my colleagues, but early on in my career, I don't think I did a very good job at communicating science, the importance of sleep to the public through the science. And that's what I've been desperately trying to course correct with the book and then just trying to be out there and having this type of a forum, this type of an opportunity, a long form discussion with, you know, just a fascinating, intelligent mind like yourself who has an incredible listenership. To be given that platform is such a privilege. And so I have an immense amount of gratitude for this time that you've been providing me with. Thank you, Peter. Thank you very much.

    5. PAPeter Attia1:59:35

       Pleasure is mine. Thanks, Matt. You can find all of this information and more at peterattiamd.com forward slash podcast. There you'll find the show notes, readings, and links related to this episode. You can also find my blog at peterattiamd.com. Maybe the simplest thing to do is to sign up for my subjectively non-lame once a week email where I'll update you on what I've been up to, the most interesting papers I've read, and all things related to longevity, science, performance, sleep, et cetera. On social, you can find me on Twitter, Instagram, and Facebook, all with the ID PeterAttiaMD. But usually Twitter is the best way to reach me to share your questions and comments. Now for the obligatory disclaimer. This podcast is for general informational purposes only and does not constitute the practice of medicine, nursing, or other professional healthcare services, including the giving of medical advice. And note, no doctor-patient relationship is formed. The use of this information and the materials linked to the podcast is at the user's own risk. The content of this podcast is not intended to be a substitute for professional medical advice, diagnoses, or treatment. Users should not disregard or delay in obtaining medical advice for any medical condition they have and should seek the assistance of their healthcare professionals for any such conditions. Lastly, and perhaps most importantly, I take conflicts of interest very seriously. For all of my disclosures, the companies I invest in and or advise, please visit peterattiamd.com forward slash about.

Episode duration: 2:01:05