Today is episode three of the podcast, and it is office hours. Office hours are when students come to the office of the professor, sit down and ask questions, request clarification about things that were confusing, or simply go down the route of exploring a topic with more depth and detail. So, let’s cover a couple of different categories, light, exercise, supplementation, temperature, learning, plasticity, mood, and sort of mood-related disorders. I want to point out something that I’m not a medical doctor. I don’t prescribe anything, including behavioural protocols. You should take that information. You should filter it through whatever it is that you currently happen to be dealing with, whether or not that’s health or illness. You should consult with a licensed healthcare professional before you add or remove anything from your daily life protocol. I’m not responsible for your health. You are, so be smart with this information and be a stringent filter.
Moonlight & Fire
The unit for measuring light intensity is typically lux, L-U-X. One lux equals the illumination of one square meter surface at one meter away from a single candle. So somebody actually decided at some point that the amount of illumination at one square meter surface, one meter away from a single candle, equals one lux. So, 6,000 lux of light intensity, you could think of it as 6,000 candles, all with their light intensity shown on one square meter from one-meter distance away. It turns out that moonlight, candlelight, and even a fireplace do not reset your circadian clock at night and trick your brain into thinking that it’s morning, even though a fireplace or even a candle can seem very bright. There are two reasons for that. The first one is that melanopsin ganglion cells adjust their sensitivity across the day, and those cells respond best to the blue-yellow contrast present in the rising and setting sun and the low solar angle sun, but those cells adjust their sensitivity such that they will not activate the triggers in the brain that conveyed daytime signals when they view moonlight, even a full moon a really bright moon or fire. So, providing you’re not going to burn down the structure you’re in enjoy your fireplaces, enjoy your lights from candles.
Red Light: Good & Bad
Viewing red light for a few minutes each morning can have positive effects on mitochondria in a particular retinal cell type, that tends to degenerate or decline in function with age in humans. And that cell type is the photoreceptor. The photoreceptor is a type of cell in your eye that sits at the back of the eye, some distance away from the ganglion cells. It’s the cell that converts light information into electrical signals that the rest of the retina and brain can understand. These are vitally important cells; without them, people are blind. And many people’s vision gets worse with age. In particular, age-related macular degeneration is also related to some other factors, including photo receptor functionality just getting worse with time. Red light flashes delivered early in the day but not late in the day can help repair the mitochondria. In principle, red light will not stimulate the melanopsin retinal neurons that wake up the brain and circadian clock and signal daytime. However, most of the red lights that come from these products that people are supposed to view are way too bright and would definitely wake up your body and brain. So if you’re going to use those products, and I’m not suggesting you do or you don’t, you would want to use those early in the day. Who knows you might even derive some benefit from mitochondria function in these photoreceptors. But if you’re thinking about red light for the sake of avoiding the negative effects of light later in the day and at night, then you want that red light to be very, very dim. Now, do you need red lights? No. Although red lights are rather convenient because you can see pretty well with them on, if they’re dim, they won’t wake up the circadian clock. They won’t have this dopamine-disrupting thing that we talked about in the previous podcast. So there’s a role for red light potentially early in the day, and for mitochondrial repair in the photoreceptors, there’s a role for dim red light later in the day and at night. It brings us back to the blue light issue which is you actually want a ton of blue light early in the day and throughout the day. So don’t wear your blue blockers then, or maybe even don’t wear them at all. And at night, it doesn’t matter if you have blue blockers on; if the lights are bright enough, then you’re still going to be activating these cells and mechanisms. So blue light during the day is great. Get that screen light, get that sunlight especially getting overhead lights. I’ll talk about all this in the previous podcast, but at night you really want to avoid those bright lights. And it doesn’t matter if it’s blue light or something else.
Eyeglasses, Contact Lenses & Windows
Sunlight coming through a window is going to take 50 to 100 times longer, setting your circadian clock. To do this experiment, you can download the free app Light Meter. You can have a bright day outside or some sunlight. Hold up that app, and take a picture. It will tell you how many lux are in that environment, then close the window. And if you want to close the screen or don’t open the screen, you can do all sorts of experiments. You’ll see that it will be at least half the amount of lux. It does not mean that you just need to view that sunlight for twice as long if it’s half as many lux, okay? It’s not like 2,500 lux means you need to look for 10 minutes, and 5,000 lux means you look for five minutes. It doesn’t scale that way just because biology doesn’t work that way. The best thing to do is to get outside; if you can’t, the next best thing to do is to keep that window open. It is perfectly fine to wear prescription lenses and contacts. Why is it okay to wear prescription lenses and contacts, but looking through a window, diminishes the effect? Well, we should think about this. The lenses that you wear in front of your eyes by prescription or on your eyes are designed to focus the light onto your retina. In fact, that’s what near-sightedness is when the image because your lens doesn’t work quite right. In fact, they’re great for this reason they’re actually focusing the light onto the retina. So think about this logically, and all of a sudden, it makes perfect sense your glass window or your windshield or the side window of your car isn’t optically perfect to bring the image and the light onto your retina. In fact, what it’s doing is scattering and filtering light, particularly the wavelengths of light you want.
Adding Up Your Lights
This can really empower you with the ability to change your behaviour in terms of light viewing, depending on the time of year and other lifestyle factors. The important point to understand is that early in the day, your central circadian clocks and all these mechanisms need a lot of light to trigger this daytime signal. Early in the day, there’s this brief period of time when the sun is low in the sky when your brain and body are expecting a morning wake-up signal where it is pretty overcast; just stay outside longer, and when you get inside, turn on the lights really bright and overhead lights in particular, because at least for the first few hours of the day, you can continue to some or add photon activation of the cells in the eye and the brain. In the middle of the day, once the sun is overhead, then you’re in the circadian dead zone; it doesn’t matter if you get a ton of artificial light or even sunlight; you’re not going to get that wake-up signal. And then, in the evening, you want to think about this whole system as being vulnerable to even a few photons of light because their sensitivity to light really goes up at night. You can protect against that sensitivity by looking at the setting sun and watching the evening sun, even if it’s not crossing the horizon around the time of sunset. It adjusts your retinal sensitivity and your melatonin pathway so that light is not as detrimental to melatonin at night.
How the planet controls your energy.
Every cell in your body is tuned to the movement of the planet relative to the sun. So as all of you know, the earth spins once every 24 hours on its axis. So, part of the day is bathed in sunlight, depending on where we are, and the other part of the day, we’re in darkness. The earth also travels around the sun 365 days, which is the time that it takes to travel around that sun. The earth is also tilted. Depending on where we are in that 365 day journey and depending, some days of the year are longer than others. Some are very short, some are very long. If you’re at the equator, you experience less variation in day length and, therefore, nightlife. And if you’re closer to the poles, you’re going to experience some very long days. And you’re also going to experience some very short days depending on which poll you’re at and what time of year it is. Every cell in your body adjusts its biology according to day length, except your brain and body, and cells don’t actually know anything about day length. It only knows night length. And here’s how it works.
A Season For Breeding
Light inhibits melatonin powerfully. If days are long and getting longer, that means melatonin is reduced. The total amount of melatonin is less because light is more, therefore melatonin is less. If days are getting shorter, light can’t inhibit melatonin as much, and that melatonin signal is getting longer. So every cell in your body actually knows external day length and therefore time of year by way of the duration of the melatonin signal. In general, it’s fair to say that in diurnal animals, the longer the melatonin signal, the more depressed our systems tend to be. Reproduction, metabolism, mood, and turnover rates of skin cells and hair cells all tend to be diminished compared to the spring and summer months for some Northern hemispheres, spring and summer months, or the times in which days are very long. And there’s less melatonin that tends to, in almost all animals, including humans, more breeding, more hormone elevation of the hormones that stimulate breeding reproduction and fertility metabolism is up, lipid metabolism fat-burning is up, protein synthesis is up. These things tend to correlate with the seasons, some people are strongly tied to the seasons. They get clinically depressed in winter, and light therapies are useful for those people. some people love the winter and are kind of depressed in summer, however it is rare. Suicide rates tend to be highest in the spring, not in the winter, but that has to do with some of the more complicated and unfortunately tragic aspects of suicide, which is that often people will commit suicide not at the very depths of their energy levels, but as they’re emerging from those depths of low energy. Then why not just get as much light as I can all the time and reduce melatonin? because melatonin also has important effects on the immune system. It has important effects on transmitter systems in the brain, et cetera. Everybody needs to figure out for themselves how much light they need early in the day and how much light they need to avoid late in the day, in order to optimize their mood and metabolism. There is no one-size-fits-all prescription because there’s a range of melatonin receptors; there is a range of everything from metabolic types to genetic histories, family histories, et cetera. But by understanding that light and extended day length inhibit melatonin, which tends to be associated with a more depressed or reduced functioning of these kinds of activity driving and mood elevating signals, and understanding that you have some control over melatonin by way of light, including sunlight but also artificial light.
Melatonin / Serotonin.
Melatonin is synthesized from serotonin. Serotonin is a neurotransmitter that is associated with feelings of well-being of a particular kind associated with quiescence and calm and the feeling that we have enough. Its the kind of thing that comes from a good meal, sitting down with friends, holding a loved one, or conversing with somebody that you really bond with. Serotonin tends to stimulate stillness. Very different from the neuromodulator dopamine, a reward, feel-good neuromodulator that stimulates action. And actually dopamine is the cursor to epinephrin, to adrenaline which actually puts us into action. Light is powerful for modulating things like sleep and wakefulness but also serotonin and melatonin levels. Light in the middle of the night reduces dopamine levels to the point where it can start causing problems with learning, memory and mood. That’s one powerful reason to void bright light in the middle of the night. Seasonal rhythms have a number of effects, but humans are not purely seasonal breeders. Unlike a lot of animals, we breed all year long. In fact, there’s a preponderance of September babies, which means that they were conceived in December; without knowing the details, we can fairly assume that. And December, at least in the Northern Hemisphere, days tend to be shorter, and nights tend to be longer. So clearly, humans aren’t seasonal breeders, but there are shifts in breeding and fertility that exist in humans, but also much more strongly in other animals. Some of you will experience very strong seasonal effects others of you will not. I think everybody should be taking care to get adequate sunlight and to avoid bright light at night throughout the year if possible.
Epinephrine vs Adrenaline: Same? Different?
Throughout this podcast and in previous episodes, I’ve been mentioning neuromodulators, things like serotonin and dopamine which tend to buy a certain brain circuits and things in our body to happen in certain brain circuits and things in our body not to happen. One of the ones I’ve mentioned numerous times is epinephrin which is a neuromodulator that tends to put us into action, make us want to move. In fact, when it’s released in high amounts in our brain and body, it can lead to what we call stress or the feeling of being stressed. Several people ask me, what’s the difference between epinephrin and adrenaline. Adrenaline is secreted from the adrenal glands which sit right above our kidneys. Epinephrin is the exact same molecule except that it’s released within the brain. And so people use these phrases or these words rather interchangeably, epi means near or on top of sometimes and neph, neph Anytime you see nephron or ph it means kidney. So it means near the kidney. So epinephrin actually means near the kidney. So it was used originally to describe adrenaline, but epinephrin and adrenaline are basically the same thing and they tend to stimulate agitation and the desire to move. That’s what that’s about. Which brings us to the topic of exercise. Got a lot of questions about exercise. What forms of exercise are best for sleeping well? When should I exercise et cetera. There’s a lot of them individual variability around this, but I can talk about what I know from the science literature
Exercise & Your Sleep
and what I happened to do myself. There are basically two forms of exercise that we can talk about although, of course I realize there are many different forms of exercise. There’s much more nuance to this, but we can talk about cardiovascular exercise, where the idea is to repeat a movement over and over and over continuously. So that’d be like running, biking, rowing and cycling this kind of thing. Or there’s a resistance exercise where you’re moving, lifting, presumably putting down also things of progressively heavier and heavier weight that you couldn’t do continuously for 30 minutes. So cardiovascular exercise is typically the more aerobic type exercise and resistance exercise of course is the more anaerobic type exercise. And yes, there’s variation between the two. Most studies of exercise have looked at aerobic exercise because that’s basically the thing that you can get a rat or a mouse to do. You know what’s really weird about rats and mice, they like to run on wheels so much, that someone actually did this study, it was published in science they put a wheel, a running wheel in the middle of a field and mice ran to that wheel and ran on the wheel. They turns out that what they like is the passage of the visual image of the bars in front of their face, which I find kind of remarkable and troubling because it seems so like trivial, but anyway they love aerobic exercise. And so most of the studies were done on these mice that love running on wheels. Whereas so far as it’s been challenging to find conditions in which mice really liked to lift weights or we’ll do it in a laboratory. So any weight bearing exercise studies really have to be done in humans. And since humans are what we’re interested in, there are some studies looking at these two things and when they tend to work best. Now you will see some places aerobic exercise is best done in the morning and weight training is best done in the afternoon. I think there’s far more individual variation than that. I think there are however, a couple of windows that the exercise science literature and the circadian literature points to as windows related to body temperature in which performance, injury, in which performance is optimized injury is reduced and so on. And those tend to be 30 minutes after waking. And that probably correlates with the inflection in cortisol associated with waking whether or not you’ve gotten light or not, three hours after waking, which probably correlates to the rise in body temperature sometime right around waking. And the later afternoon, usually 11 hours after waking which is when temperature tends to peak. So some people like to exercise in the morning. Some people like to exercise in the afternoon. It really depends. I think for those of us with very busy schedules, it’s advantageous to be able to do your training whenever you have the opportunity to do it, unless you can really control your schedule. And so I would never want these recommendations to seem like recommendations, what I’m really describing are some opportunities, 30 minutes after waking, three hours after waking or 11 hours after waking has been shown at least in some studies to optimize performance, reduce injury and that sort of thing. But you really have to figure out what works for you. A note about working out first thing in the morning. Last time we talked about non-photo phase shifts. If you exercise first thing in the morning, your body will start to develop an anticipatory circuit. There’s actually plasticity in these circadian circuits that will lead you to want to wake up at the particular time that you exercised the previous three or four days. So that can be a powerful tool but you still want to get light exposure. Because it turns out that light and exercise converged, so giving even bigger, wake up signal to the brain and body. So you might want to think about that. Some people find if they exercise late in the day they have trouble sleeping in general intense exercise does that, whereas the kind of lower intensity exercise doesn’t. I found some interesting literature that talked about sleep need and exercise. I found this fascinating that if one is waking not feeling rested and recovered from and yet sleeping the same amount that they typically have, it’s quite possible that the intensity of exercise in the proceeding two or three days is too high. Whereas if one can’t recover no matter how much sleep they get, they’re just sleepy all the time, I realized these things are correlated that the volume of training might be too high. Now I’m not an exercise scientist. We should probably get Andy Galpin or somebody else on here, who’s really an expert in this kind of stuff. I do realize as soon as anyone talks about exercise or nutrition publicly, they’re basically opening themselves up to all sorts of challenges because you can basically find support for almost any protocol in the literature. What I’ve looked at was two journals in particular, International Journal Chronobiology and journal Biological Rhythms. Excuse me, to assess these parameters that I I’ve mentioned just just a moment ago because the studies tended to be done in humans. They were fairly recent and they came from groups that I recognized as well as knowing that those journals are peer reviewed. Many of your questions were about neural plasticity which is the brain and nervous system’s ability to change
Neuroplasticity & Food/Chemicals/NSDR
40:30in response to experience. There was a question that asked whether or not these really deep biological mechanisms around wakefulness, time of waking sleep, et cetera were subject to neuroplasticity and indeed they are. Some of that plasticity is short-term and some of it is more long-term. There’s a really good analogy here which is, if you happen to eat on a very tight schedule where every day say it 8:00 AM, noon and 7:00 PM is when you eat your food not suggesting you do this but let’s say you were to do that for a couple of days. After a few days, you would start to anticipate those meal times where no matter where you were in the world, no matter what was going on in your life about five to 10 minutes before those meal times, you would start to feel hungry and even a little agitated, which is your body’s way of trying to get you to forage for food. And that’s because of some peptide signals that come from the periphery from your body, things like hypocretin norexin that signal to the hypothalamus and brainstem to make you active and alert and look for food and feel hungry. So there’s kind of an anticipatory circuit, that’s a chemical circuit, but eventually over time, the neurons, the neural circuits that control hypocretin orexin would get tuned to the neural circuits that are involved in eating and maybe even smell and taste to create a kind of eating circuit that’s unique to your pattern, to your rhythms. The same thing is true for these waking and exercise and other schedules, including all trade-in schedules. If you wake up in the morning and start getting your sunlight, you start exercising in the morning or you exercise in the afternoon, pretty soon, your body will start to anticipate that and start to secrete hormones and other signals that prepare your body for the ensuing activity of waking up or going to sleep. So if you get onto a pattern or a rhythm, even if that rhythm isn’t down to the minute, you’ll find that there’s plasticity in these circuits and it becomes easier to wake up early. If that’s your thing or exercise at a particular day if that’s your thing. That’s the beauty of neuroplasticity. A number of people ask, “What can I do to increase plasticity?” And that really comes in two forms. There’s plasticity that we can access in sleep to improve rates of learning and depth of learning from the previous day or so. And there’s this an SDR non-sleep deep breaths that can be done without sleeping, to improve rates of learning and depth of retention, et cetera. So let’s consider those both and you can incorporate these protocols if you like. Again, these are based on quality peer reviewed studies. First, let’s talk about learning in sleep. This is based on some work that I’ll provide the reference for that was published in the journal Science. Excellent journal, Matt Walker also talks about some of these studies done by others in his book “Why We Sleep”. The studies just to remind you are structured in he following way an individual is brought into a laboratory, Lowe does a spatial memory task. So there tends to be a screen with a bunch of different objects popping up on the screen in different locations. So it might be a Bulldog’s face that might be a cat, and it might be an Apple than it might be a pen in different locations. And that sounds trivial easy but with time you can imagine it gets pretty tough to come back a day later and remember, if something presented in a given location was something you’ve seen before and whether or not it was presented in that location or a different location. If you had enough objects and changed locations enough, this can actually be quite difficult. In this study, the subjects either just
Using Sound & Smell To Learn Faster
went through the experiment or a particular odor was released into the room while they were learning or a tone was played in the room while they were learning. And then during the sleep of those subjects the following night and the following night, so this was done repeatedly for several nights, the same odor or tone was played while the subjects were sleeping. They did this in different stages of sleep non-REM sleep and rapid eye movement, sleep REM sleep. They did this with just the tone in sleep. If the subjects had the odor but not the tone, they did it with putting the tone, if they had had the odor while learning. So basically all the controls, all the things you’d want to see done to make sure that it wasn’t some indirect effects, a modulatory effect. Okay. And what they found was that providing the same stimulus, the odor, if they smelled an odor or a tone if the subjects heard a tone while learning if they just delivered that odor or tone while the subject slept, rates of learning and retention of information was significantly greater. This is pretty cool. What this means that you can cue the subconscious brain, and the asleep brain to learn particular things better and faster. So how might you implement this? Well, you could play with this if you want. I don’t see any real challenge to this provided the odor and is a safe one and then doesn’t wake you up and the tone is a safe one, and doesn’t wake you up. You could do this by having a metronome, for instance, while I’m learning something, playing in the background or particular music and then have that very faintly while you sleep. o you could apply this if you like and try this. There are a number of groups I think now that are trying this using tactile stimulation. So slight vibration on the wrist during learning and then the same vibration on the wrist during sleep. It does not appear that the sensory modality, whether or not it’s odor or auditory tone or tactile stimulation, some as a sensory stimulation, whether or not it matters. It’s remarkable because it really shows that sleep is an extension of the waking state. We’ve known that for a long time but this really tethers those two in a very meaningful and actionable way. So I think I’ll report back to you as I learned more about these studies, but that’s what I know about them at this point. As long as we’re there we might as well talk about dreaming ’cause I got so many questions about dreams. A couple of you, we want to ask me what their dreams meant.
Dream Meaning & Remembering
Look, I don’t even know what my dreams mean half the time. I occasionally will wake up from a dream and remember it. If you want to remember your dreams better, if you’re somebody who has challenges remembering your dreams, you can set your alarms that you wake up in the middle of this one of these 90 minute cycles which toward morning tend to be occupied almost exclusively by REM sleep. Remember early in the night, you have less REM sleep than later in the night. But you want to get as much sleep as you can ’cause that’s healthy. So I don’t know that you want to wake yourself up. Some people find that writing down their thoughts immediately first thing in the morning allows them to relater spontaneously remember their dream they had. There’s some literature on that. The meaning of dreams is a little bit controversial. Some people believe they have strong meaning other people believe that they can be just spontaneous firing of neurons that were active in the waking state and don’t have any meaning. There are good data to show that when you learn spatial, new spatial environments that there’s a replay of those environments, so-called place cells that fire in your brain only when you enter a particular environment, that those are replayed in sleep in almost direct fashion to the way that things were activated when you were learning that spatial task. Dreams are fascinating, they’re were paralyzed during dreams which brings us to another question. Somebody asked about sleep paralysis. We are paralyzed for much of our sleep, so-called atonia so presumably so we don’t act out our dreams. Some people wake up and they’re still paralyzed.
Waking Up Paralyzed
I’ve actually had this happen to me not very many times, but a few times. And then they jolt themselves awake and it actually is quite terrifying. I can say from personal experience to wake up be wide awake and you cannot move your body at all. It’s really quite frightening. There are a couple of things that will increase the intrusion of atonia into the wakeful state which is essentially means you’re waking up but you can’t, you can’t move. One is marijuana, THC, a I’m not a marijuana smoker. I’m not a copper. I don’t know the legality where you live. So I’m not saying one thing or another about marijuana. I’m just, the fact that I had that experience without marijuana means that it can happen regardless, but marijuana smokers, for whatever reason maybe it has something to do with the cannabinoid receptors or the serotonin receptors downstream of the motor pathways. I don’t know. I couldn’t find any literature on this but marijuana smokers report, higher frequency of this kind of paralysis and wakefulness as you transition from sleep to wakefulness. I suppose probably one could learn to get comfortable with it. For me, it was terrifying, ’cause I’m just used to being able to move my limbs fortunately and I wasn’t able to, and it’s a quite a thing, let me tell you, okay. some other questions about neuroplasticity. So the other form of neuroplasticity
Nap/Focus Ratios For Accelerated Learning
is not the neuroplasticity that you’re amplifying by listening to tones or smelling odors in sleep, but the neuroplasticity that you can access with non sleep deep rest. So NSDR, non sleep deep rest as well as short 20 minute naps, which are very close to non sleep deep rest because people rarely drop into deep States of sleep during short naps, unless they’re very sleep deprived. NSDR has been shown to increase rates of learning when done for 20 minute bouts for a proxy- to match an approximately 90 minute about of learning. So what am I talking about? 90 minute cycles are these ultradian cycles that I’ve talked about previously. And we tend to learn very well by taking a 90 minute cycle transitioning into some focus mode early in the cycle, and it’s hard to focus and then deep focus and learning feels almost like agitation and strain and then by the end of that 90 minute cycle, it becomes very hard to maintain focus and learn more information. There’s a study published in Cell Reports last year. Great journal, excellent paper showing that 20 minute naps or light sleep of a sort of non sleep deep rest taken immediately after or close to it, doesn’t have to be immediately after you finished the last sentence of learning or whatever it is, or bar of music. But you know, a couple of minutes after transitioning to a period of non sleep deep rest, where you’re turning off the analysis of duration path and outcome has been shown to accelerate learning to a significant degree. Both the amount of information and the retention of that information. So that’s pretty cool, because this is a cost-free, drug-free way of accelerating learning without having to get more sleep. But simply by introducing these 20 minute bouts. I would encourage people if they want to try this to consider the 20 minutes per every 90 minutes of ultradian learning cycle, there you’re incorporating a number of different neuroscience backed tools 90 minute cycles for focused learning. It could be motor, it could be cognitive, it could be musical, whatever, and then transitioned to a 20 minute non sleep deep rest protocol. I just want to cue you the fact that in last` episode in the caption on YouTube, we provided links to two different yoga nidra, non sleep deep rest protocols as well as hypnosis protocols that are clinically backed from my colleague David Spiegel at Stanford Psychiatry Department. All those resources are free. There are also a lot of other hypnosis scripts out there. I like the ones from Michael Sealey S-E-A-L, I think it’s E-Y, maybe it’s just L-Y, you can find them easily on YouTube, clinical hypnosis scripts meaning not stage hypnosis. They’re not designed to get you to do anything. In fact they’re just designed to help rewire your brain circuitry. Now, how does hypnosis work that way? This has a lot to do with sleep because it engages neuro-plasticity by bringing together two things that normally are separate from one another, one is the alert focused wakeful state
Hypnotizing Yourself
where you activate the learning. And then there’s the deep rest where the actual reconfiguration of the neurons and synopsis takes place. Hypnosis brings both the focus and the deep rest component into the same compartment of time. It’s a very unique state in that way. So hypnosis kind of maximizes the learning about and the non sleep deep breasts bow and combines them. But of course that requires some guidance from a script or from a hypnotist clinically, a trained hypnotist and it becomes hard to acquire detailed information. It’s more about shifts in state, like fear to states of calm or smoking to quitting smoking, anxiety around a trauma to release of anxiety around a trauma rather than specific information learned in hypnosis, okay? So hypnosis seems more about modulating the circuits that underlie state as opposed to specific information. Although I would not be surprised if there weren’t certain forms of hypnosis that could increase retention and learning of specific information, but I’m not aware of any of those protocols out there yet. Which brings us to the next thing about learning and plasticity which is nootropics, AKA smart drugs. [sighs] This is a big topic that sigh was a sigh of concern about how to address nootropics
Smart Drugs
in a thorough enough, but thoughtful enough way. Look, I have a lot of thoughts about nootropics. First of all, it means smart drugs, I believe. And I don’t like that phrase because let’s just take a step back and think about exercise. You just say, I want to be more physically fit. What does that mean? Does it mean I would ask for more specificity, I’d say, Do you want to be stronger? Okay, maybe you need to lift heavier objects progressively. Do you want more endurance very different protocol to access endurance. Do you want flexibility? Do you want explosiveness or suppleness? Huge range of things that we call physical fitness. Maybe you want all of those. If we were talking about emotional fitness we would say, well, inability to feel empathy but probably also to disengage from empathy because you don’t want to be tethered to other people’s emotions all the time. That’s not healthy either. You would think about being able to access a range of emotions, but for some people their range into the sadness regime is really quite vast but their range into the happiness regime might be kind of limited. For other people who are in a manic state, it might be, they can access all that happy stuff but not the sadder stuff. So I’m speaking by way of analogy here. But if we say we’re talking about cognitive and cognitive abilities we have to ask, okay, creativity, memory. We tend to associate intelligence with memory. And I think this goes back to like spelling bees or something, the ability to retain a lot of information and just regurgitate information which will get you some distance in some disciplines of life. But it won’t allow you creative thinking, it’s necessary for creative thinking. You need a knowledge base, right? You can’t just look up everything on Google, despite what you know, certain educators or so-called educators say, you need a database so that you can have the raw materials with which to be creative. So necessary to have memory but not sufficient to be creative, right? The creative could have a poor memory for certain things but certainly not for everything. They can’t have anterograde and retrograde amnesia. They’d be like the goldfish that every time around the tank, it, yo by the way, but you know, so no disrespect to goldfish but you know, so you get the idea. You’ve got creativity, you have memory, you have the ability to task switch, right? You have the ability to strategy development, strategy implement. So the problem I have with the concept of a nootropic or a smart drug is it’s not specific as to what cognitive algorithm you’re trying to engage. We need more specificity. That said, there are elements to learning that we’ve discussed here before that are very concrete things like the ability to focus and put the blinders on to everything else that’s happening in around you and in your head mainly, right? Distractions about things you should be doing, could be doing or might be doing and focus on what you need to do. And then that’s required for triggering the acetylcholine neuromodulator that will then allow you to highlight the particular synopsis that will then later change in sleep. So no nootropic allows you to bypass the need for sleep in deep rest. That’s important to understand. So I daydream about a day when people will be able to access compounds that are safe, that will allow them to learn better meaning, to access information, focus better, as well as to sleep better and activate the plasticity from the learning about. Right now most nootropics tend to bundle a bunch of things together. Most of them include some form of stimulant, caffeine. Episode two, I’ll tell you more probably than you ever wanted to know about caffeine, adenosine and how that works. So refer there for how caffeine works. But stimulants will allow you to increase focus up to a particular point. If you have too little alertness in your system, you can’t focus, too much however, you start to cliff and focus drifts, okay? So you can’t just ingest more stimulant to be more focused. It doesn’t work that way. Most nootropics also include things that increase or a desire to increase acetylcholine. Things like alpha GPC and other things of that sort. And indeed, there’s some evidence that they can increase acetylcholine. I refer you again to examine.com the website to evaluate any supplements or compounds for their safety and their effects in humans and animals, free website as well as with links to studies. So we need the focus component. We need the alertness component. The alertness component comes from epinephrin, traditionally from caffeine stimulation. 7The acetylcholine stimulation traditionally comes from Coleen donors or alpha GPC, things of that sort. And then you would want to have some sort of off switch, because anything that’s going to really stimulate your alertness, that then provides a crash. That crash is not a crash into the deep kind of restful slumber that you would want for learning, it’s a crash into the kind of, let’s just call it lopsided sleep, meaning it’s deep sleep but it lacks certain spindles and other elements of the physiology sleep spindles, that really engage the learning process and the reconfiguration of synopsis. So right now, my stance on nootropics is that maybe, maybe for occasional use, provided it’s safe for you, I’m not recommending it, but in general it tends to use more of a shotgun approach than is probably going to be useful for learning and memory in the long run. A lot of people ask about Modafinil or armodafinil which was designed for treatment of narcolepsy. So right there, it tells you it’s a stimulant. And yes, there is evidence, it will improve learning memory. Modafinil is very expensive. Last time I checked our Modafinil I think is the recent released a generic version of this that’s far less expensive. Most of these things look a lot like amphetamine and many of them have the potential for addiction or can be habit forming. But more importantly, a lot of those things also can create metabolic effects by disruption to insulin receptors and so forth. So you want to approach those with a strong sense of caution. Now, there are the milder things that act as nootropics that I mentioned, some of them like alpha GPC. Some people like Gingko. Gingko gives me vicious headaches, so I don’t take it. So people really differ. Last podcast, I recommend magnesium threonate if you were exploring supplements I’m not recommending anything directly. I’m just saying if you’re exploring supplements, magnesium threonate seems among the magnesium to be one of the more bioavailable and useful for sleep. I recommended it actually to a good friend of mine it gave him at very low dose, he had stomach issues with it. He just had to simply stop taking it.
Magnesium: Yay, Nay, or Meh?
So there’s variability there. You just, it gave him some stomach cramping and just didn’t feel good on it. Stopped it, he felt better.
1:01:19Other people take magnesium threonate and feel great. I was asked, do magnesium need to be taken
1:01:25with or without food or before sleep? If you’re going to go that route it should be taken 30 to 60 minutes before sleep,
1:01:31’cause it’s designed to make you sleepy. And I’m not aware that it has to be taken with food,
1:01:36but again all of this has to be run by your doctor and this is your healthcare to govern not,
1:01:42these are not strict recommendations so look into it. But magnesium threonate, most people I recommend it to
1:01:50have benefit from it tremendously. Some people can’t tolerate it, so you have to find out.
1:01:55There were a number of questions about other supplements designed to access deep sleep, in part to access neuroplasticity,
1:02:01but now I’m just sort of transitioning from neuroplasticity to these compounds that can regulate sleep.
1:02:07One of them that I discussed at the end of the last podcast, I got a lot of questions about is apigenin A-P-I-G-E-N-I-N, apigenin.
How Apigenin Works
1:02:15If you will look in the literature the way it works is it increases some of the enzymes associated with GABA metabolism.
1:02:21It actually, GABA’s an inhibitory neurotransmitter. It’s the neurotransmitter that is increased
1:02:27after a couple alcohol drinks containing alcohol. And that shut down the forebrain.
1:02:34Apigenin is a derivative of the camomile. I think that the proper pronunciation
1:02:39of this is metric caria kemo mila. Although I always feel like I should be using a Spanish accent.
1:02:44Whenever I say something like that other related things that impact the GABA system and increase GABA or things like passion flower
1:02:51which is [speaks in foreign language]. [chuckles] I don’t know why the Italian, is that Italian.
1:02:57Anyway, my Italian colleagues, please forgive me. I have some very close Italian friends
1:03:02and colleagues in Genoa. I butchered the Italian, sorry. In any event apigenin and passion flower found in a lot of,
1:03:12a lot of supplements designed to increase sleepiness and sleep because, and they work presumably
1:03:17because they increase GABA. Actually they work on chloride channels rather than give you a whole lecture on membrane biophysics in neurons.
1:03:24I’ll just say that when neurons are really active it’s because sodium ions, salt rushes into the cells
1:03:31and causes them to fire electrically. The cells tend to become less active as more chloride which is a negatively charged ion.
1:03:40This is probably taking some of you back to the either the wonderful times or traumas of high school physics.
1:03:46The chloride is negatively charged so, it tends to make cells less electrically positive,
1:03:51’cause carries a negative charge and hyperpolarizes the neuron. So apigenin works through these increasing the activity
1:03:58of these chloride channels. Passionflower works by increasing the activity of these chloride channels and GABA transmission.
1:04:04It tends to increase this inhibitory neurotransmitter that shuts off our thinking our analysis of duration path and outcome.
1:04:12So if you’re going to explore these things I suggest you at least know how they work. You at least go to examined.com
1:04:19that you talked to your doctor about them. Some people asked about serotonin for getting to sleep and staying asleep.
1:04:26Now I understand the rationale here. Just like I understand the rationale of taking something like Macuna Purina or L-DOPA to increase dopamineSerotonin:
Slippery Slope
1:04:34but sometimes what works on paper doesn’t really work in the real world. I personally have tried taking a supplement
1:04:41which was Al tryptophan, which is the precursor to serotonin or five HTP, which is designed to increase,
1:04:48it is serotonin basically. You’re just a one biochemical step away from actually taking actual serotonin.
1:04:55And I’ll be honest the sleep that I had with increased serotonin by way of tryptophan or five HTP was dreadful.
1:05:01I fell asleep almost immediately. You say, well, that’s great. And 90 minutes later, I woke up and I couldn’t sleep almost for 48 hours.
1:05:08Now that was me, I have a pretty sensitive system to certain things and not to other things. Some people love these things.
1:05:13So you really have to be thoughtful and explore them with that kind of awareness of being thoughtful and realizing that what works for you
1:05:22might not work for everybody and what works for everybody might not work for you. Okay? I’d like to continue by talking about
1:05:27the role of temperature in sleep, accessing sleep, staying asleep and wakefulness.
The Frog Experiment
1:05:36But first I want to tell a joke. Because I think this joke really captures some of the critical things to understand
1:05:42about any self-experimentation that you might do. So this is a story that was told to me
1:05:48by a colleague of mine who’s now a professor of Caltech not to be named.
1:05:53So there’s a scientist and they’re in their lab. And they’re trying to understand
1:05:59how the nervous system works. So they go over to a tank and they pick up a frog,
1:06:04and they take the frog and they put it down on the table And they clap. [claps]
1:06:10And the frog jumps. So they think for awhile, they pick up the frog, okay.
1:06:16They go over to the cabinet and they take out a little bit of a paralytic drug and they inject it locally
1:06:24into the back leg, set it down and clap. [claps]
1:06:29And the frog jumps, but it kind of like jumps to the side a little bit. They pick it up, they inject the paralytic
1:06:36into the other back leg. They clap again, the frog jumps, but it really doesn’t jump well that time,
1:06:42it kind of drags itself forward. So they pick it up and they inject the paralytic into the remaining two legs.
1:06:49They set it down and they clap and the frog doesn’t jump.
1:06:54And they go, “Oh my goodness! The legs are used for hearing.”
1:06:59Now they publish the paper. Paper comes out in a great journal, news releases.
1:07:05It’s a really big deal, their career takes off. 20 years later, a really smart graduate student
1:07:11comes along and says, “Yeah but that’s loss of function. It doesn’t really show gain of function.”
1:07:17So let’s take a closer look. So they repeat the first experiment and checks out,
1:07:22everything happens the same way, but then they take the frog and they inject a drug into all four legs that turns off
1:07:32the paralytic, right? It’s an antagonist. They set the frog down, they clap, and the frog jumps
1:07:40and they go, “Oh my goodness! It’s true. The legs really are for hearing.” Now, first of all, I want to make the point that
1:07:48this is not to illustrate that science is not a good practice, it is. We need to do loss of function
1:07:54and gain and function experiments. But just to show that correlation and causation is complicated.
1:08:00You need to do a variety of control experiments, and you really need to figure out what works for you. And so while science can provide answers about what works
1:08:08under very controlled conditions, it doesn’t and can never address all the situations
1:08:14in which a given compound, a given practice will or won’t work. And it’s not just individual variability
1:08:19is that there are a number of different factors. You all of course know that light can activate and shift your circadian rhythm, but so can exercise,
1:08:26so can food. The last point I want to make is an important one, which is that no frogs were hurt
1:08:32in the telling of this joke. Okay. So let’s continue. I want to talk about temperature.
Temperature
1:08:37Temperature is super interesting as it relates to circadian rhythms and wakefulness and sleep.
1:08:44First let’s take a look at what’s happening to our body temperature across each 24-hour cycle.
1:08:51In general, our temperature tends to be lowest right around 4:00 AM and starts creeping up around 6:00 AM,
1:08:598:00 AM and peaks sometime between 4:00 PM and 6:00 PM.
1:09:05Now that varies from person to person, but in general if we were to continuously monitor or occasionally monitor
1:09:10temperature that’s what we would see. Now what’s interesting is that even in the absence of any light cues or meal cues, we would have a shift.
1:09:19We would have an oscillation or a rhythm in our temperature. They would go from high to low. This is why the idea that we’re all 96.8
1:09:26and that’s our correct temperature. Forget that. That is no longer true. It never was true. It depends on what time of day you measure temperature.
1:09:34However, there is a range which is within normal range, I think most of us associate fever with somewhere around
1:09:40100, 101 103, that’s concerning. And we will be very concerned if temperature drop too low as well.
1:09:46The way that the temperature rhythm that’s indogenous, that’s within us and rhythmic no matter what,
1:09:52the way it gets anchored to the pattern I described before, or being lowest at 4:00 AM and increasing again around,
1:10:00through the day until about four to 6:00 PM is by way of entrainment or matching to some external cue,
1:10:09which is almost always going to be light, but also exercise. Now you may have experienced this temperature rhythm
1:10:17and how quickly it can become uninterested or it can fall out of entrainment.
1:10:23Here’s an experiment I wouldn’t want you to do but you’ve probably experienced this before, where you wake up, it’s sunny outside,
Morning Chills
1:10:31and maybe you have some email or some things to take care of or maybe you didn’t sleep that well the night before and so you stay in doors.
1:10:37You don’t change anything about your breakfast, you don’t change anything about your within home temperature or anything like that.
1:10:43And somewhere right around 10 or 11 o’clock you start feeling kind of chilled, like you’re cold. Well, what happened was the oscillators, the clocks
1:10:52in your various tissues that are governed by temperature and circadian rhythm are starting to split away
1:10:58from your central clock mechanisms. So it’s actually important that your temperature match day length.
1:11:04Now there’s another way in which temperature matches, oh daytime, excuse me. There’s also an important way
1:11:09in which temperature matches day length in general as days get longer, it tends to be hotter out.
1:11:15Not always, but in general, that’s the way it is. And as days get shorter, it tends to be colder outside.
1:11:21So temperature and day length are also linked metabolically. They’re linked biologically they’re linked, excuse me,
1:11:29and atmospherically they’re linked for the reason that we talked about before about duration of day length and other climate features and so forth.
1:11:37So one of the most powerful things about setting your circadian rhythm properly is that your temperature will start to fall
1:11:44into a regular rhythm. And that temperature has a very strong effect on things like metabolism
1:11:50and when you will feel most willing and interested in exercising, typically the willingness to exercise
1:11:57and engage in any kind of activity mental or physical is going to be when that rise in temperature is steepest.
1:12:03When the slope of that line is greatest. That’s why 30 minutes after waking is one of those key windows, as well as three hours after waking.
1:12:10And then when temperature actually peaks which is generally, generally about 11 hours after waking.
1:12:17So this is why we say that temperature and circadian rhythm are linked but they’re actually even more linked than that.
1:12:25We’ve talked before about how light enters the eye, triggers activation of these melanopsin cells, which then triggers activation
1:12:31of the super charismatic nucleus, the master circadian clock. And then I always say the master circadian clock
1:12:36informs all the cells and tissues of your body and puts them into a nice cohesive rhythm.
1:12:41But what I’ve never answered was how it actually puts them into that rhythm. And it does it two ways.
1:12:48One is it secretes a peptide. And peptide is just a little protein that floats through the bloodstream and signals to the cells.
1:12:54Okay, we’re tuning your clock. Kind of like a little, we know watch store, the watch store owner would tune the clocks.
1:13:00But the other way is it synchronizes the temperature under which those cells exist.
1:13:05So temperature is actually the effector of the circadian rhythm. Now this is really important because
1:13:12changes in temperature by way of exercise, by way of eating, but especially by way of exercise
1:13:18can start to shift our circadian rhythm pretty dramatically. But let’s even go to in a more extreme example.
1:13:24Nowadays, there’s some interest in cold showers and ice baths, not everybody is doing this I realize.
1:13:30People seem to either love this or hate this. I don’t mind the cold dunk thing.
1:13:35I get regular about this from time to time and I’ll do it. I haven’t been doing it recently. It’s always painful to do the first couple of times
1:13:41then you get kind of used to it. However, I’ve taken people to a cold, dunk or an ice bath. I have a family member who wouldn’t get in
1:13:48literally passed her toes. She was like, this is just too aversive for me. Some people really like the cold, people very tremendously.
1:13:55Getting into an ice bath is very interesting because you have a rebound increase in thermogenesis.
1:14:01Now you should know from the previous episode that as that temperature increases, it will shift your circadian rhythm
1:14:08and which direction it shifts your circadian rhythm will depend on whether or not you’re doing it during the daytime or late in the day. If you do it after 8:00 PM,
1:14:14it’s going to make your day longer, right? Because your body and your central clocks
1:14:21are used to temperature going up early in the day and throughout the day and peaking in the afternoon.
1:14:26If you then increase that further or you simply increase it over its baseline at 8:00 PM
1:14:32after temperature was already falling, even if it’s just by a half a degree or a couple of degrees or you do that with exercise
1:14:37doesn’t have to be with the ice bath, you are extending, you are shifting forward your phase,
1:14:42delaying your clock. You’re convincing your clock and therefore the rest of your body that the day is still going, right?
1:14:49You you’re giving it the perception, the cellar and physiological perception that the day is getting longer.
1:14:54And you will want to naturally stay up later and wake up later. Now you might say, “Wait
1:15:00I do an ice bath late at night, and I feel great. And I fall deeply asleep.” Well, cold can trigger the release of melatonin.
1:15:07There’s a rebound increase in melatonin. So that could be the cause of that effect. You have to see what works for you,
1:15:13but if you do the ice bath early in the day and then get out you will experience a more rapid rise
1:15:20or cold shower early in the day, a more rapid rise in your body temperature that will phase advance your clock
1:15:27and make it easier to get up early the following day. So for those of you that are having trouble getting up
1:15:32and this is going to almost sound laughable but a cold shower first thing in the morning will wake you up, but that’s waking you up in the short term
1:15:40because of a different mechanism which I’ll talk about in a moment, but it also is shifting your clock, it’s phase advancing your clock
1:15:47in a way that makes you more likely to get up earlier the next day, okay?
1:15:52So in other words, increasing your temperature by getting in an ice bath or cold shower or exercising
1:15:59which causes a compensatory increase in body temperature. Think about the normal pattern of body temperature.
1:16:05Low around 4:35 AM starts to peak right around waking start, excuse me, starts to increase right around waking
1:16:11then steep slope, steep slope to a peak around four to 6:00 PM and then drops off. If you introduce an increase in body temperature
1:16:18by way of cold exposure early in the day, let’s say 6:00 AM or 5:00 AM
1:16:24if you’re masochistic enough to get into a cold shower at that time more power to you, it’s going to make, you want to wake up about half hour
1:16:31to an hour earlier the next day than you normally would. Whereas if you do it while your temperature is falling,
1:16:37it will tend to delay and make your body perceive as if the day is getting longer. These are phase advances and phase delays.
1:16:43We’re going to get into this in far more detail when we talk about jet lag and shift work in episode four
1:16:48as well as other other things. But temperature is, again is not just one tool to manipulate
1:16:55wake up time and circadian rhythm and metabolism. It is the effector. It is the way that the central circadian clock
1:17:02impacts all the cells and tissues of your body. If you want to read further about this and you’re really curious about the role of temperature
1:17:08work by Joe Takahashi who used to be at Northwestern University and is now at UT Southwestern in Dallas,
1:17:15incredible scientist and has really worked out a lot of the mechanisms around temperature
1:17:20in circadian rhythms. You can just Google his name and you’ll see a whole bunch of studies there.
1:17:27I want to talk about cold and cold exposure because there’s a great misconception about this
1:17:32that actually you can leverage once you understand how to use cold to either increase thermogenesis
1:17:39and fat loss, metabolism, or you can use it for stress, mitigation and mood.
1:17:45And it really depends on one simple feature of how you approach the ice bath or cold shower.
1:17:51If you get into an ice bath or cold shower and you are calming yourself you’re actively calming
1:17:57the autonomic nervous system. Maybe through some deep breathing, maybe through visualization, maybe you sing a song.
1:18:02You know, people do this stuff. They use various tools. Some people find paying attention to an external stimulus is more helpful.
1:18:09You know, thinking about something not the experience of the cold, other people find that directly experiencing the cold
1:18:14in its most intense form and kind of “going into the cold” is the best way to approach it. It really varies for people.
1:18:21There’s no right or wrong way to go about this. But the goal of using cold exposure for stress inoculation
1:18:28and to raise your stress threshold to be able to tolerate heightened levels of real life stress, not the ice bath, but real life stress
1:18:36like work stress and relational stress, et cetera is by suppressing the activation
1:18:43of the so-called sympathetic nervous system, meaning the alertness or stress system.
1:18:49That involves buffering or trying to resist the shiver response. The shiver response is an autonomic response
1:18:56designed to generate heat, presumably, and actually that is what it does in order to counter the cold.
1:19:03So when you use cold exposure and you’re kind of muscling through it, or you’re learning to relax within it
1:19:09as a form of stress inoculation, that’s great and works quite well for that purpose.
1:19:14And there’s a reason why cold exposure is used in a variety of forms of military stress inoculation,
1:19:20most famous of which of course is the Navy seal buds, a strep test really,
1:19:26which is screening procedure for becoming a seal involves a lot of exposure to cold water.
1:19:31However, if you’re interested in using cold exposure for fat loss and thermogenesis,
1:19:37you want to do the exact opposite thing. There was a paper published in nature two years ago
1:19:43which showed that cold induced shiver, the actual physical shiver activates the release of
1:19:52a chemical in the body from muscle called succinate S-U-C-C-I-N-A-T-E.
1:19:59Succinate travel in the bloodstream and then goes and activates a particular category of fat
1:20:05not the typical kind pink or white fat that we think of is like blubber in humans. That the stuff that people will seem to
1:20:11generally want less of, except for those genetic freaks that seem to have none of it
1:20:16depending what they consume. Congratulations. Brown fat is called Brown fat
1:20:23because it’s actually dark under the microscope. It’s rich with mitochondria and it exists mostly
1:20:29between the scapulae and in the upper neck. And it generates thermogenesis and heat in the body.
1:20:35It’s rich with a certain category of agile anergic receptor,
1:20:40in insanely epinephrin binds to adrenergic receptors.
1:20:46These Brown fat cells increase metabolism, it’s called Brown fat thermogenesis
1:20:52and cause fat burning, burning of other kinds of fat, the pink and white fat.
1:20:57So what does this all mean? This means if you want to use the ice bath in order to increase metabolism, shiver away.
1:21:04If you want to use the ice bath or cold shower in order to stress inoculate, resist the shiver
1:21:10and learn to stay calm or “muscle through it”. I mean, I don’t know that anyone’s ever really talked
1:21:15about this publicly because I think the data are so new. And I think that people assume that the ice bath
1:21:22or cold exposure is just one thing. Here I’ve talked about it three ways to shift your circadian rhythm depending on whether or not
1:21:28you’re doing it early in the day while your temperature is still rising or at its peak
1:21:34or after that peak, in order to extend the perception of your day as continuing and make you want to go
1:21:41to sleep later and wake up later. Now, and then the third way of course is to either
1:21:48activate brown fat thermogenesis and increase metabolism. I suppose the fourth way would be to
1:21:55increase stress tolerance or stress threshold, okay? But remember, temperature is the effector
1:22:01of circadian rhythms. Light is the trigger. The super charismatic nucleus is the master circadian clock
1:22:08that mediates all these changes, also influenced by non-photic influence like exercise and feeding and things of that sort.
1:22:15But temperature is the effector. Now you can also shift your circadian rhythm with eating.
1:22:21When you travel and you land in a new location and your schedule is inverted 12 hours.
1:22:27One way that we know you can shift your rhythm more quickly is to get onto the local meal schedule.
1:22:32Now that probably has to do with two effects. One or changes in temperature inducer, eating induced increases in body temperature.
1:22:39Now you should understand why that would work as well as eating has this anticipatory secretion
1:22:45of beta, of hyper cretin orexin that I talked about it earlier. So, if this is getting a little too down in the weeds,
1:22:51don’t worry about it. I will get more into this in episode four of how to shift one’s rhythm. But I would love for people to understand that light
1:22:59and temperature are the real heavy duty leavers when it comes to moving your circadian rhythm and sleep times and activity schedules
1:23:06and exercise and feeding can help, but really temperature and light, with light being the primary one are the most important
1:23:13when it comes to sleep and wakefulness. Many people asked questions about food and neurotransmitters
1:23:20and how those relate to sleep, wakefulness and mood, which is essentially 25 hours of content for me to cover.
1:23:28But I’m going to try and distill out the most common questions. We’ve talked a lot about neuromodulators like dopamine,
1:23:34acetylcholine and norepinephrine. You may notice in those discussions that the precursors
1:23:40to say serotonin is tryptophan. Tryptophan actually comes from the diet. It comes from the foods that we eat.
1:23:47tyrosine is the precursor to dopamine. It comes from the foods that we eat.
1:23:53And then once we ingest them those compounds are circulated to a variety
1:23:59of different cells and tissues, but it is true that our food and the particular foods we can influence,
1:24:06things like neuromodulator levels to some extent, it’s not the only way, because there are also enzymes
1:24:12and biochemical pathways that are going to regulate how much tyrosine gets converted into dopamine and there are elements of the dopaminergic neurons,
1:24:19the dopamine neurons themselves that are electrical that have influence on this as well. But there are a couple fair assumptions that we can make.
1:24:28First of all, nuts and meats in particular red meats, tend to be rich in things like tyrosine, right?
1:24:36That tells you right there, that because tyrosine is the precursor of dopamine, and dopamine is the precursor of norepinephrine,
1:24:42and epinephrine that those foods tend to lend themselves toward the production of dopamine
1:24:50and epinephrin and the sorts of things that are associated with wakefulness. Now, of course, the volume of food that we eat
1:24:58also impacts our wakefulness. If we eat a lot of anything, whether or not it’s ribeye steaks, rice, or cardboard,
1:25:05please don’t eat cardboard, your stomach if it’s very distended it will draw a lot of blood into your gut and you will divert blood
1:25:12from other tissues and you’ll become sleepy. So it’s not just about food content, it’s also about food volume, all right?
1:25:18Fasting states generally are associated with more alertness, epinephrin so forth and fed states are generally associated
1:25:28with more quiescence and relaxation, serotonin, and the kind of things that lend themselves more towards
1:25:34sleep and less toward alertness. Foods that are rich in tryptophan tend to be things
1:25:39like white meat, turkey, also complex carbohydrates. So if you like you can start experimenting
1:25:46depending on what foods you eat. You can start experimenting with carbohydrate rich meals
1:25:53for accessing sleep and more depth of sleep. This is actually something I personally do.
1:25:59I tend to eat pretty low carbs during the day. I actually fast for until about noon. Not because I have to work to do that,
1:26:05but because I’d rather just drink caffeine and water during that time. And then sometime around noon I can’t take it anymore and I’m hungry.
1:26:12And I eat and I try and eat low carb-ish unless I’ve worked out extremely hard in the previous two hours, which I rarely do,
1:26:19although I do it sometimes. And that meal is then designed to prolong my period
1:26:25of wakefulness into the late afternoon. And then sometime around dinner time which for me is around 6:37 PM, 8:00 PM.
1:26:31Sometimes as late as 9:00 PM, I tend to eat things like white meat, fish, pastas, rice, that kind of thing.
1:26:39My favorite food of all for accessing tryptophan is actually a starch. It’s actually a vegetable.
1:26:44And it’s the croissant, which is my favorite vegetable. I don’t eat those all the time, but I love them
1:26:50and they seem to increase dopamine as well. I’ve never actually done the mass spectrometry on a croissant, but they definitely increase tryptophan
1:26:57and relaxation for me. In all seriousness, low carbohydrate/fasted/ketogenic diets
1:27:05tend to lend themselves toward wakefulness by way of increasing epinephrin, norepinephrine, adrenaline
1:27:11dopamine, and things of that sort. Carbohydrate rich meals. And I suppose we talked about meals as opposed to diet
1:27:19tend to lend themselves more toward tryptophan, serotonin and more lethargic states.
1:27:26There is very limited evidence that I am aware of that carbohydrates should be eaten at one time a day
1:27:32as it relates to metabolism, et cetera. I’m sure that will open up a certain amount of debate.
1:27:39If you work out very hard and you deplete glycogen, then this all changes. So some people are working out very hard
1:27:44in depleting glycogen and other people are not. That gets way outside the context of this particular podcast, but yes indeed different foods
1:27:51can bias different neuromodulators and thereby can modulate awaking
1:27:57or our feelings of lethargy and sleepiness.
Eating For Heating
1:28:02There are a couple effects of food that are independent or I should say a couple of facts of eating,
1:28:07’cause the food won’t do it when it’s sitting across the table, but of eating that are powerful
1:28:13for modulating circadian, rhythm, wakefulness, et cetera. And that’s because every time we eat we get eating induced thermogenesis
1:28:20regardless of what we eat. Now that eating induced thermogenesis and increase in metabolism, which is an increase in temperature really,
1:28:28is probably greatest for amino acid rich foods like meats,
1:28:34but also other types of foods. It’s a minimal increase in body temperature compared to say cold exposure or exercise.
1:28:42Now, whether or not it’s a quarter of a degree or half a degree or a degree, it really depends on the individual.
1:28:48And of course there are blood sugar effects. There are things like whether or not
1:28:53you are type one or type two diabetic, whether or not you’re insulin resistant, whether or not like there’s a kid who
1:28:59interns on the podcast here, who’s 17 years old and I’m convinced that he can eat anything
1:29:05and he just seems to like burn it up and he’s growing it every time. Actually the other day, he walked into the other room
1:29:11and two days later, he walked out of the same room. He came out in between of course, but and I was like, you’re grow?
1:29:18And he was like, you know, but he’s at that stage where he’s just growing. Food is going to affect a teenager very differently
1:29:23than it’s going to affect a full-grown person. So, in general, starchy carbohydrates, white meat,
1:29:31such as turkey, some fish increased tryptophan, therefore serotonin, therefore more lethargic states more calm.
1:29:39Meat, nuts and there are probably some plant-based foods that I’m not aware of and I apologize,
1:29:44I should read up on this that also are high in tyrosine that can increase things like dopamine,
1:29:50norepinephrine, epinephrin alertness. So you can vary these however you like.
1:29:56Most people I think are eating a variety of these things in a given meals. And there are other parameters of nutrition
1:30:02that are important too. Volume of food for the reasons that I mentioned before, the volume of food in the gut, less food in the gut
1:30:09whether or not it’s empty or a small amount of food which tend to correlate with wakefulness. Large volumes of food of any kind will tend to correlate
1:30:18and drive the calming response and that’s by way of this nerve pathway called the vegas. We actually have sensory fibers in the gut that communicate
1:30:25to a little protrusion of neurons that sit right next to the juggler called the nodose ganglia N-O-D-O-S-E unlike Costello,
Vagal Pathways For Gut-Brain Dialogue
1:30:34it’s no dose right now he’s all dose. Nodose actually means having many protrusions
1:30:39and it’s like kind of a lumpy collection of neurons. A ganglia is just a collection of neurons. And then it goes into the brain stem and then forward
1:30:47in the brain to the areas of the brain they’re involved in production of various neuromodulators.
1:30:53So what we eat and the volume of food are both signaling to the brain.
1:30:59It’s not just one or the other. And then there’s also this eating induced thermogenesis.
1:31:04And now, you know, from the discussion about temperature that if you’re eating early in the day you’re tending to shift your rhythm earlier.
1:31:10So that you’ll want to wake up earlier the next day if you’re eating very late in the day,
1:31:15even if you can fall asleep after that, there’s a tendency for you to want to sleep later the next day.
1:31:20Now this of course is all going to be constrained by when your kids need to eat, and when your spouse needs to eat,
1:31:25and when your friends need to eat, or if you live alone or what other things you’re doing, if you’re like me and you kind of don’t eat until noon
1:31:31then eat sometime around noon. And then I’m terrible about meals. I just start eating the ingredients while I’m supposed to be cooking and then eventually they’re all gone
1:31:37and I guess that’s a meal. It varies. Some people are neurotically attached
1:31:43to a particular meal schedule. Some people are not. I take my light exposure schedule far more seriously
1:31:49than I take my meal schedule. Although in general, try and eat healthy foods for the most part croissants included.
Sex Differences
1:31:56I was asked several times whether or not men and women or males and females differ in terms of these neurotransmitter phenotypes
1:32:03and the rhythms of sleep and temperature, or we could probably devote a whole month
1:32:09and we probably will devote an entire month to what are called sex differences because those tend to be related to things
1:32:14we absolutely know like XX, or XY chromosomes or XYY in some cases are double X chromosomes
1:32:21as opposed to gender, sex and karyotype as we call it genetic makeup is crystal clear.
1:32:28There are things that correlate with one or the other but it’s complicated and it’s not something that’s been explored in
1:32:36what I think is enough detail. Actually recently, I guess it was about five years ago,
1:32:42the national institutes of health made it a mandate that all studies use sex as a biological variable,
1:32:48and actually explore both sexes of mice, both sexes of humans when doing any kind of study because there was a bias towards only using male animals
1:32:56or male subjects prior to that time. So a lot of data now coming out revealing important sex differences
1:33:02that I think are going to have powerful impact on health practices, et cetera. Response to drugs,
1:33:07response to just different sleep schedules, et cetera. Perhaps the most salient and obvious one
1:33:13is that during pregnancy females experience a whole range
1:33:18of endocrine and neuro effects and we definitely will devote a month to pregnancy
1:33:23and childbirth and child rearing. And for that, I’d really like to bring in some experts.
1:33:29I’ve got terrific colleagues at Stanford and elsewhere that work on these things, so that we can go into those in more depth. So I’m not blowing off those questions.
1:33:35I’m just, I’m kind of pushing them down the road a little bit where I can give you a more thorough answer.
1:33:42So as we finish up, I just want to offer you the opportunity to do an experiment.
1:33:48We’ve talked about a lot of variables that can impact sleep and wakefulness. And in keeping with the theme of the podcast
Self Experimentation
1:33:53we are going to continue to talk about sleep and wakefulness and tools for those, and the science behind those tools
1:34:00as we go forward. But there are really just four simple parameters
1:34:05that you have control over, that you can immediately start to record
1:34:11and take note of just to see how you’re doing with these things. With no judgment or perhaps no change
1:34:18to what you’re actually doing. It might be interesting, just a suggestion to write down
1:34:24for each day when you went outside to get sunlight and when you did that, relative to waking.
1:34:31So you would write down, like the way I do this in my calendar is I’ll write down that I don’t get exact about it.
1:34:36I might say, I woke up at 6:15 and then I, as I’ll put a W 6:15, and then SL for sunlight
1:34:45and you’ll sometimes get outside right away. Other times I’m less good at that. And I’ll go out around, let’s say seven
1:34:51and for how long, I don’t maybe like 10, 15 minutes or so. And then I’ll put a little check
1:34:56at the times that I eat my so-called meals. Although, as I mentioned, sometimes my meals are a bunch of small checks that just kind of extend
1:35:03through the late hours of the day. Yours might be more confined to certain times.
1:35:09And then you might just take note of when you exercised, just put down an E for when you exercise.
1:35:16Weight training or aerobic exercise. And you might note when you might’ve felt chilled or cold
1:35:23if you do, or you might’ve felt particularly hot, or if you woke up in the middle of night, when you felt particularly hot. And then the last thing you might want to do
1:35:29is just write down if and when you did a non sleep deep rest protocol, an STR protocol, that could be meditation,
1:35:35that could be yoga nidra, that could be hypnosis. Anything that you’re using to deliberately
1:35:42teach your nervous system, how to go from more alertness to more calmness in the waking state,
1:35:48even if it’s waking up in the middle of the night and doing an SDR protocol or in the afternoon, or first thing in the morning to recover some sleep
1:35:54and ability to perform DPOs that you might’ve lost from a minimal or poor night’s sleep. So you’re going to rite down when you woke up,
1:36:01when you viewed sunlight, that might be in the morning and the evening, or just the morning, hopefully it’s the morning and the evening, when you exercised,
1:36:08when you eat your meals and using a simple record keeping scheme like W for waking, SL for sunlight
1:36:16maybe you come up with a system where it’s a check or an X or something for exercise. This is not designed to make you neurotically attached
1:36:22to tracking all your behaviors and everything you do.
1:36:28I for instance, don’t track what I eat. In particular, I kind of know what works for me and I’d just try and stay within that range.
1:36:35But by doing this you can start to reveal some really interesting patterns. Patterns that no answer that I could provide you about
1:36:43any existing tool or protocol could counter. It’s really about taking the patterns of behaviors,
1:36:51of waking, and light viewing, and eating, and exercise and superimposing that on
1:36:58what you’re learning in this podcast and elsewhere of course and what you already know and trying to see where
1:37:03certain problem or problems or pain points might be arising. Maybe you’re eating really late in the day and you’re waking up
1:37:09in the middle of the night, really warm. Well, now you would say, “Well, that could be due to kind of an increase in temperature that is extending my day
1:37:17or maybe you start to find that using cold exposure early in the day is great for you,
1:37:22but using it late, if it’s too late in the day, that’s not great. Or if you’re into the sauna or it’s even
1:37:29like some people, including myself, if I take a hot shower or sit in a hot tub or a sauna late at night,
1:37:34well then I get a compensatory decrease in body temperature and I sleep great provided I hydrate well enough,
1:37:40’cause that can be kind of a dehydrating thing to sit in hot, hot conditions. But if I do the sauna early in the day,
1:37:46unless I exercise immediately afterward then I tend to get the temperature drop, which makes sense
1:37:52because when you get in the sauna, you’re get vasodilation. You throw off a lot of heat and then you generally get a compensatory drop in temperature.
1:37:58If you do that early in the day, that’s right about the time that temperature is trying to entrain the circadian clocks of your body.
1:38:04That’s what happens to me. Other people, it might be slightly different and some people have more resilient systems than others.
1:38:12So I just encourage you to start becoming scientists of your own physiology of your own brain and body
1:38:19and seeing how the various tools that you may or may not be using are effecting your patterns of sleep,
1:38:25your patterns of attention and wakefulness. It’s vitally important that if you do this, that you know that it’s not about trying to get
1:38:32onto an extremely rigid schedule, it’s really about trying to identify variables
1:38:38that are most powerful for you, and that push you in the direction that you want to go. And changing the variables that are pushing your body
1:38:45and your mind in the directions that you don’t want to go. Self experimentation is something that should be done slowly, carefully, you don’t want to be reckless about this.
1:38:54And this is where I would say manipulating one or two variables at a time is really going to be best
1:38:59as opposed to changing of a dozen things all at once to really identify what it is that’s most powerful for you.
1:39:06As always, thank you so much for your questions. We are going to continue to answer questions.
1:39:12I certainly didn’t get to all of them but we tried to get to most all of the ones that were frequently asked.
1:39:17Episode four of the podcast, I’m going to get into, shift work, jet lag and age dependent changes
1:39:24in sleeping and wakefulness and cognition. So for those of you with kids,
1:39:30for those of you that are kids for those of you with older relatives or who might be older
1:39:36meaning probably when you start to get into late ’60, ’70 and ’80 is when there’s some marked
1:39:42biological shifts in temperature regulation and things that relate to sleep.
1:39:47And for those of you that travel, we’re going to talk about jet lag. The shift work discussion might seem only relevant
1:39:53to those that work nights, but actually that’s not the case. Most people because of the way they’re interacting
1:39:58with devices are actually in a form of shift work now, where the days are certainly not nine to five,
1:40:05the so-called banker’s hours, and then the lights are out at nine and they’re asleep until 5:00 AM.
1:40:10Some people have that schedule, most people do not. So episode four, we will go deeply into shift work, jet lag
1:40:17age dependent changes in sleep alertness and cognition and I will touch back on a few of your questions
1:40:22but don’t think that if your question wasn’t answered during these office hours that we won’t get to it, I absolutely will at some point.
1:40:30In addition to that, several of you have graciously asked how you can help support the podcast.
1:40:35And we very much appreciate that. You can support the podcast by liking it on YouTube,
1:40:41by subscribing on YouTube, by recommending the YouTube videos to others, as well as subscribing and downloading the podcast on Apple
1:40:50where you can also leave a review and on Spotify, we’re all three, if you like.
1:40:55you can also help us by supporting our sponsors. So check out some of the sponsor links that were described at the beginning of the episode.
1:41:02And in general, recommending the podcast to people that you know and that you think would benefit from the information would be terrific.
1:41:08As always I will be continuing to post on Instagram. You can expect another podcast episode out next Monday
1:41:15about the topics that we’ve been discussing this month and above all, [upbeat music] thank you for your interest in science.