How Much Sleep Do You Really Need?

When it comes to sleep, quality beats quantity, which means you can actually get more out of 6 hours of sleep than out of 8 hours of sleep if you know how to maximize sleep efficiency. And today, I promise I'll show you how. But first, let's back up. Why does this matter? Well, as you might know, sleep is foundational for learning and memory, but it's more than that. It's also critical for clearing metabolic waste out of your brain, like your brain's daily shower. And when sleep is impaired, that metabolic waste can accumulate, contributing over time to cognitive decline and even Alzheimer's disease. And to add insult to sleep deprivation, I'm especially vulnerable. I'm part of the 2% of the population at highest genetic risk for Alzheimer's disease, and because my PhD was on neurodegenerative diseases, I've seen the devastation firsthand. Oh yeah, and I'm a terrible sleeper. I always have been. So all this has conspired to make me obsessed with sleep efficiency. I don't need sleep, I need answers. Today I'm going to flood you with practical, science-based, and often overlooked strategies for improving sleep quality. These will include a specific supplement, a sleep position, at least one peptide, and even strange lights and sounds. So lock in because we're about to go deep. Deep sleep is primarily about physical restoration and brain maintenance. Does the position you sleep affect glymphatic clearance? Imagine the brain with a velvet rope. Lights and sounds that can clean your brain? I mean, come on. The brain naturally produces electrical rhythms. What if you didn't need to sleep? Okay, real quick before I begin, a thank you. Over the past year, we've seen a lot of success, including here on the YouTube channel, which has grown dramatically, over 5-fold, and recently crossed the lovely 1 million mark, thanks to you. We've also grown elsewhere, including at the Stay Curious Metabolism Substack, which has arguably grown even faster and is now a world leader in science. And I mention that because that's where you will find all the references, but more than that, including deeper nuances that never make it into these videos. So if you'd like a deeper look at this topic or any other, please join me there as well. The link is below, and it's a great way to support me. But without further ado, let's lay the roadmap for this video. In part 1, we're going to talk about why we even sleep. Part 2, we'll talk about the stages of sleep. And then parts 3 and 4, we're going to get into optimizing deep sleep, then optimizing REM sleep. Part 3 and 4 are really the payoff, but we need to lay the groundwork. So hang in with me, please. First, part 1. Why do we sleep? That's the meta question behind all of this, isn't it? Why do we sleep? And future Nick here with another question: do we even need to sleep? More on that in a moment. The truth is there's probably no single answer. There are several theories though, and the 2 I find most compelling and most important for our discussion are the restoration theory and the neuroplasticity theory. These are important because they map well onto the stages of sleep we'll discuss before we talk about how to optimize them. Okay, the restoration theory is pretty intuitive. Sleep is when the body performs its critical maintenance. So if you've worked out hard, muscles grow and repair themselves. Growth hormone actually increases during sleep, and the brain clears away metabolic waste. The second theory, though, is the neuroplasticity theory, which proposes that sleep evolved, at least in part, to support learning and adaptation. During sleep, particularly REM sleep, memories are consolidated, emotional experiences are processed, and neural connections are refined. Sleep is kind of like psychotherapy that doesn't cost $375 an hour, which I would know because my mom is a psychiatrist, and that's probably why I am the way I am, and also probably why I just made a terrible joke. I shouldn't have said that. I should not have said that. Anyway, if you boil it down, sleep appears to serve 2 broad purposes: repairing and maintaining the body and brain, and strengthening neural circuits that allow us to learn, remember, and adapt neurally. That was a quick and fun reinforcing aside. Looking at sleep through this lens may explain why some animals need less sleep than us. For example, giraffes only sleep about 2 to 5 hours per day. Some sharks spend very little time in what we'd recognize as a classic sleep state. Smaller, less complex brains may generate less metabolic waste and require less recovery and upkeep, which, if true, may mean that one of the prices we pay for having large, complex human brains is the need to spend roughly a third of our lives asleep. Food for thought. Okay, Future Nick back here for a sec to follow up on that prior question: do we even need to sleep? Now, I'm sorry for commandeering my own video, but I absolutely have to because A new paper came out after I recorded the initial video that blew my mind. Basically, it was inspired by nature. There are certain examples of animals like dolphins and certain birds. They don't sleep like we do. They do unihemispheric sleep. So they sleep with one side of the brain at a time, with the other side carrying out basically all the functions of a full brain so they can interact with their environment without fully falling asleep. The question then becomes, can you mimic this in animals that don't naturally do it like mice and humans? But that brings us to part 2, the stages of sleep. And I'll try to lay the rest of this foundation pretty quickly. There's stage 1, which is basically falling asleep. It's quite brief. Stage 2, which is stable foundational sleep. Then there's stages 3 and 4, which are deep sleep, and finally REM sleep. For our purposes, the most important and efficient stages of sleep are deep sleep and REM sleep, because they map onto the evolutionary functions of sleep that we just discussed. Deep sleep is primarily about physical restoration and brain maintenance, but I really want to emphasize the brain maintenance piece and a paradox therein. Consider this. Not only are our brains enormous relative to our body size, but they're also incredibly energy intensive. And all that metabolic activity in our brains generates a lot of metabolic waste. But here's something you probably never thought about. Most organs throughout the body have 2 major vessel systems. There are the blood vessels, which deliver oxygen and nutrients, and then there are the lesser discussed lymphatic vessels, which help remove waste. They are the waste removal vessels. And this waste removal system is obviously important because you don't want metabolic debris accumulating in organs But the brain does not have a lymphatic system, at least not a dominant one. It doesn't have vessels to remove waste because the brain is so jam-packed with neurons, glia, and blood vessels, there was literally no space to pack in a glymphatic system. So that presents a major paradox, right? How could we have this massively metabolically active organ generating all this waste during our waking hours without an obvious waste removal network? The answer is something called the glymphatic system. Cleverly named for a combination of the word glia, which means brain support cells, and the lymphatic system that the rest of the body uses. But the glymphatic system in the brain is something totally different. At a high level, here's how it works. During deep sleep, the brain's energy demands decrease. Because there's less blood flow needed, blood vessels in the brain constrict, creating little channels around them, like appearing and disappearing water slides. And through these channels, the brain can literally pump cerebral spinal fluid that bathes the brain through these crevices, washing away debris accumulated during the day. That is the glymphatic system. It's basically the nightly shower for your brain. Let me dig it in the shower! Ow! And I really need to make sure I do not undersell how important this is. If glymphatic flow is impaired and metabolic waste builds up, this lays the groundwork for cognitive decline. In fact, it's well known that in Alzheimer's disease and dementia, there is impaired glymphatic flow. Your brain isn't being properly cleaned, which is why you need sleep, and especially deep sleep, because deep sleep is when the brain is most metabolically quiet and glymphatic flow can occur. The brain is taking that shower. All right, future Nick here, back for the 3rd and final time, I swear. But to finish up my commentary on that study on no sleep, what researchers were actually able to show is that they can biochemically mimic sleep, and particularly deep sleep, in mice through a technique known as optogenetics. But basically what they did is they caused different regions of the brain to take Turns sleeping. And at the synaptic level, this mimicked many of the effects on sleep. At the behavioral level, it proved memory consolidation while the animals didn't actually need to sleep. So in the future, could we redesign sleep so we never actually have to sleep? It's actually possible. More here. And we're about to get to how to improve that process. But first I need to tell you about REM sleep. REM is actually much more metabolically active than deep sleep. In many ways, it resembles wakefulness. Rather than focusing on cleanup and restoration like in deep sleep, REM appears to be critical for memory consolidation, emotional processing, learning, and adaptation. But now we get to the fun stuff: optimizing sleep phases with part 3, how do you optimize deep sleep? Now, some of the things we're going to talk about are mundane. Others are surprisingly weird, and my favorite of few Sound like complete pseudoscience until you see the literature, and it's mind-blowing stuff. The first pillar of deep sleep, or just sleep in general, is maintaining a consistent circadian rhythm and good sleep hygiene. This is common sense, but I do need to mention it in good faith. So, at a high level, maintain a consistent sleep schedule, get morning sun exposure, reduce bright light exposure in the evenings— all things you've heard before, right? Okay, let's dispense with that and get a bit deeper to talk about one key supplement And then we'll get to some weirder stuff, including a strange sound. But the supplement, magnesium threonate. Now, maybe you've heard about magnesium, maybe even magnesium threonate, but has anybody ever told you how it works? Magnesium is involved in hundreds of enzymatic reactions throughout the body, including many in the brain, where it plays roles in neurotransmitter regulation, synaptic plasticity, how your neurons wire together, and the activation of what's called the GABA receptor system. This is the system that helps your brain quiet down, calm down, and facilitates deep sleep. But here's the problem. Most forms of magnesium don't cross the blood-brain barrier very efficiently. That is why we have magnesium threonate. It was specifically designed by researchers at MIT to increase magnesium levels in the brain, which it's been shown to do. The threonate component helps shuttle magnesium across the blood-brain barrier more efficiently. Or if you want a cute analogy, imagine the brain with a velvet rope and some bouncers. This is the blood-brain barrier. And magnesium gets stuck in the general admission line. But magnesium threonate has a VIP pass to get through the velvet rope and past the bouncers. Okay, now what about in humans? Does magnesium threonate work? Well, there are human data suggesting, yeah, it does, particularly for deep sleep. For example, in one double-blind randomized placebo-controlled trial, participants receiving magnesium threonate reported improvements in energy, productivity, and even my favorite, grouchiness. I love that the researchers measured grouchiness. Even better, the participants also demonstrated improvements in deep sleep scores measured objectively using a sleep tracker. The authors of this paper concluded that magnesium threonate improved sleep quality, particularly deep sleep and even REM sleep to some extent, while improving mood, energy, alertness, and daily productivity. Sounds like a win, right? Now, to quickly hit you with the practicals I know you want, if you're looking for dosing and timing protocols, typically people take 1 to 2 grams of magnesium threonate 30 to 60 minutes before bed. Now, I am trying to respect your time in this video, so if you want specific product ideas, what I look for when choosing a magnesium threonate supplement, and a deep dive into deep sleep boosting peptides that are at the frontier of human experimentation, you can find that information below at the Stay Curious Metabolism Substack. Stay curious, side quest. Real quick, a little side quest in this video. I don't talk about sleep trackers. That was intentional. This is my Oura Ring. This is not an ad for Oura. In fact, I'm going to level with you. I don't use it that much. The reason being, it can stress me out when life happens and I don't get perfect sleep. Having it quantified just in my brain starts this negative vicious loop, which is counterproductive to me getting better sleep. So one of the theses behind this video is to control what you can control, and you can't control everything. The pursuit of perfection is endless. And if tracking your sleep and doing the experiments is helpful for you, fantastic, but you don't need to. Just do the best you can. Now let's come back to the science. But now let's shift, literally, to something even simpler and more accessible. Does the position you sleep affect glymphatic clearance? The best answer we have is probably. So in 2015, researchers did a kind of fun experiment where they took rodents, put them asleep, and put them in an MRI machine, then flipped them around like little pancakes on their side, on their back, face down. And what they were looking for was glymphatic efficiency. How well does the brain shower? How efficiently in different sleeping positions? And the winner was... Side sleeping. The high-level idea is that gravitational forces and tissue mechanics may collectively create a more favorable environment for glymphatic flow, more efficient brain cleaning in the side sleeping position. Now, we cannot say for 100% certain that the same effect exists in humans, the study just hasn't been done, but there is an interesting observation I want to bring to your attention, which is that side sleeping is by far the most common sleeping position in humans. Is that a coincidence? Maybe. Or maybe this is one of those situations where evolution figured out something long before modern neuroscience has caught up. What do you think? Drop a comment below to let me know your hypothesis. But finally, now we arrive at what I personally find to be the most fascinating part of this entire discussion. And when I first heard about it, I thought it sounded like pseudoscience, to be honest. Flickering lights and sounds that can clean your brain? I mean, come on. But then I started reading papers published in top journals like Cell, Neuron, and Nature that blew my mind. The idea is actually pretty simple. The brain naturally produces electrical rhythms. It's what it does. And one of those rhythms oscillates at about 40 hertz, which is just 40 cycles per second. This is called gamma rhythms, not to be confused with gamma rays like those that made the Hulk. Anyway, they sound like this. And gamma rhythms are thought to enhance glymphatic flow. So maybe you can see where we're going. Can we use sensory inputs, lights and sounds, to make the brain vibe at this gamma rhythm? And will this enhance the ability of the brain to clean itself? Well, yeah! Researchers at MIT discovered that exposing mice to light and sound pulsing at 40 Hz enhanced the gamma activity throughout the brain. And it did help the brain clean itself! Various animal studies with 40 Hz light and sound treatment caused the hallmarks of Alzheimer's disease, like amyloid and tau, to decrease, perhaps owing to a combination of improved glymphatic function— brain cleaning— and also changes in immune cell activity in the brain that allowed them to gobble up some of the amyloid and tau. And tack onto that, the animals' memories improved on multiple validated memory tests. So now we have research showing light and sound can get the brain to vibe at the right frequency to help clean itself out, a remarkable advancement that could genuinely improve sleep efficiency. Are you excited about this? I know I am. But we do need to be honest and ask the question, does this work in humans? And the humble answer is... We don't know for sure, at least not for prevention of Alzheimer's disease and dementia. Human studies are underway, but to do true preventative studies would take decades and many millions of dollars, and those studies haven't been done, they may never be done. The research that's been done so far was mostly on safety and feasibility, and this is a safe intervention. But at a high level, I still find the idea of entraining the brain to certain rhythms using specific light and sound techniques as a preventative form of medicine against Alzheimer's dementia to be extremely promising. And if I do say so, researchers at Harvard, MIT, and elsewhere— pretty smart cookies— agree with me. That said, the research has progressed enough that there are now many commercial devices that exist that can get you this gamma entrainment. I'll mention a few below in the video notes and also at the newsletter if you want to check them out. But now I want to get into part 4: REM. Losing my religion. No, not that REM. REM sleep. Recall, deep sleep is primarily when the brain maintains itself, and cleans up— the glymphatic flow phase. But REM sleep is more like the brain's integration phase. This is where memories are consolidated, emotions are processed, and neural circuits are refined. It's also where you have the most vivid dreams, which can be kind of fun. Anyway, the question then turns to, can we improve REM sleep efficiency? Well, beyond the basics we've already discussed, like consistent circadian rhythm, light management, and basic sleep hygiene, there's one compound that's receiving a surprising amount of attention: melatonin. It's called pinealon, and there are people reporting it consistently improves their REM sleep, even doubling their REM sleep on sleep trackers. Never before have I found something that can improve the amount of rapid eye movement sleep that I get. But what is pinealon? Pinealon is an extremely small peptide, just 3 amino acids. It was first developed in Russia from researchers based on peptides isolated originally from the pineal gland, hence its name, which is a small structure deep in the center of the brain which is responsible for producing melatonin, and helping regulate circadian rhythms. So at a high level, it starts to make sense, but how does it work? Pinealon's small size allows it to penetrate into your body when taken orally, get into cells, and literally latch onto DNA like a tiny koala which happens to sleep 22 hours a day. Anyway, pinealon influences gene expression through DNA modification, and this is gene expression related to neuroprotection, circadian regulation, and yeah, melatonin signaling, you know, the sleep hormone. At least in animal models, it improves sleep efficiency and improves melatonin signaling. And when you combine this with the growing anecdotes of people saying it's doubling their REM sleep and then showing their sleep tracking data, I find that pretty compelling. And it is something I've been using since I first learned about it. The brand I personally use is called Your Protocols. Yes, I do have a discount code for it if you want. Stay curious. It came recommended by a trusted colleague and meets the quality standards I look for, including third-party testing, and manufacturing transparency. I'll put more information below, but that is what I used. And I can honestly say that while taking paneolone, I've had the most restorative and most memorable sleep I've had in recent years, although not necessarily longer sleep. If you want more on my experience, see this timestamp at this video on the Russian peptides. Where can I get my hands on these miracle peptides? I was actually having dreams within dreams within dreams. I felt like I was in Inception. But now let's put this video to bed because we reviewed a lot of high-yield and some unconventional tips. Including how magnesium threonate works, with its little VIP pass to get into the brain to calm it down, how side sleeping can improve glymphatic flow and brain cleaning, how 40 Hz lights and sound treatment can also enhance glymphatic flow, including products you can access today, and even how tiny little peptides, pinealon, can bind onto your DNA like a micro koala to improve REM sleep. So when your head hits the pillow tonight, don't stress. Consider that there's only so much you can control. But what you can control might be more than you think. Sweet dreams and stay curious.