The Dr. Jules Plant-Based Podcast
Hey, I’m Dr. Jules! I’m a medical doctor, teacher, nutritionist, naturopath, plant-based dad and 3X world championships qualified athlete. On this podcast we’ll discuss the latest in evidence-based and plant-based nutrition, including common nutrition myths, FAQs and tips on how to transition towards a healthier dietary pattern and lifestyle that creates little friction with your busy life!
The Dr. Jules Plant-Based Podcast
The Science of Sleep & How Hormones Shape Your Health
Your life literally depends on sleep, and in this eye-opening exploration of sleep science, we reveal why this nighttime process might be the most undervalued health tool in your arsenal.
Sleep isn't merely a passive state where your body shuts down. It's an intricately choreographed series of stages, each with distinct physiological purposes that keep your body and mind functioning optimally.
We journey through the four sleep stages that make up each 60-90 minute cycle, from light sleep transitions to the deep restorative phases where physical healing happens, and finally to REM sleep where emotional processing and memory consolidation occur.
Behind this complex sleep architecture lies a fascinating hormonal dance. Adenosine builds up throughout your day creating "sleep pressure," while melatonin responds to darkness to signal bedtime. Cortisol prepares you for morning alertness, and insulin regulation depends on quality sleep. When this delicate system gets disrupted, the consequences are far more serious than just feeling tired - a single night of poor sleep can reduce immune function by 70%, temporarily induce pre-diabetic conditions, and accelerate aging biomarkers.
For those struggling with sleep, I’ll offer practical, evidence-based strategies you can implement tonight: creating a wind-down routine, limiting blue light exposure, establishing consistent sleep-wake times, optimizing bedroom temperature, and more. The science is clear, prioritizing sleep isn't self-indulgent; it's essential maintenance for your body and brain. Better brain function, stronger immunity, stable mood, and even weight management all depend on those precious hours of rest.
Ready to transform your health? Start with better sleep.
Go check out my website for tons of free resources on how to transition towards a healthier diet and lifestyle.
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Thanks so much!
Peace, love, plants!
Dr. Jules
Hey everyone, welcome to Season 2 of the Dr Jules Plant-Based Podcast, where we discuss everything from plant-based nutrition to the main pillars of lifestyle medicine.
Speaker 1:Yo, plant-based buddies, welcome back to another episode of the podcast. Today we're going to be talking about sleep and how you need to sleep, like your life depends on it, because it kind of does. Sleep is one of the main lifestyle pillars and people tend to underestimate how much sleep or sleep deprivation could impact your health. In fact, it probably impacts your health a lot more than you think and exponentially more than any of the health and wellness trends or fads or hacks that you can find online. So let's start by talking about one of the most powerful yet underrated health tools that you have. So we'll cover what actually happens during the different stages of sleep and how hormones like adenosine, melatonin, cortisol and insulin can actually shape your night and how you sleep, and even shape your health. And then we'll talk about the real risk associated with sleep deprivation and spoiler, it's not just feeling grumpy the next day. And then we'll end with practical and evidence-based tips on how to sleep better, starting tonight, let's start by discussing the actual sleep stages and how all of these sleep stages make up one sleep cycle. Now, sleep isn't just an on and off switch, it's actually a series of complex and restorative cycles, and each stage has its own purpose and its own superpower. Now we cycle through four different stages multiple times per night, with each cycle lasting anywhere from 60 to 90 minutes.
Speaker 1:Now sleep stage one. The first stage of the cycle is what we call N1, or light sleep, and this is kind of a transitional phase where your brain starts to slow down and you might actually feel muscle twitches and sometimes you may actually wake up or feel like you're falling. That's an interesting thing. This concept called proprioception is a term we describe, to use your own self-awareness about your body's position in space. So if you close your eyes and lift your arm, you're probably able to stop it around 90 degrees, and if you lift your right arm over your shoulder, you know in which position your arm is in. So that's called proprioception and it's basically simply an awareness of your body's position in space. That's something that you start losing while you're cycling through that stage one of sleep, and that's where you kind of wake up like you're falling and you're simply just lying in bed. Now this light sleep stage lasts just a few minutes anywhere from 5 to 15 minutes depending on the person and then you cycle to stage two or N2, which is a true light sleep stage. Now, in this stage, your heart rate starts to drop, your actual body temperature starts to fall, and that's how sleep trackers or wearable trackers that you may wear on your wrist or in your ears can actually start measuring in what sleep stage you're in. Now, during N2, brain waves start to slow, but they have what we call bursts of activity, which scientists call sleep spindles. Now this stage will dominate your total sleep time and basically, n2 is the stage that preps you for deep sleep.
Speaker 1:Now stage three, or N3, is where the magic happens for a lot of people. That's where physical recovery happens and we enter deep sleep, or what we call slow wave. Sleep and slow wave are simply what we see when people do polysomnography, which is like EEG that you wear in a sleep lab. It'll measure brainwave activity and during this phase of sleep, the brainwave activity will be slow, with high peaks and deep valleys. Now, during N3, that's where physical recovery happens and that's where growth hormone will be released and will help with tissue repair and immune boosting. And deep sleep stage three is vital for physical recovery, memory consolidation and a special form of detox where we clean up cellular debris or metabolic debris that have accumulated throughout the day. Now this is accomplished by our lymphatic system in our brain, which we also call the glymphatic system. It basically removes debris and helps repair and clean out toxins that are circulating in between and inside of our neurons and brain cells. Now, stage three deep sleep is vital, but it's also the hardest to wake from. So sometimes when you nap, if your nap is not well planned and is actually too long over 20 minutes, for example you might actually fall into stage three. Deep sleep. Now that's great for repair.
Speaker 1:But if you wake up during sleep stage three, you may wake up with something called sleep inertia. Basically, you're feeling groggy, you're feeling tired, you're feeling unrested, wondering if the nap was worth it to begin with. But basically that means that either your nap was a little too long or just not long enough. If you're going to nap, you probably want to nap for something like either 20 to 25 minutes to make sure that you stay in sleep stage N2, but you don't enter deep sleep. And if you enter deep sleep, you want to come out of it, which usually takes about 90 minutes to complete the cycle where you go back to N2. So typically sleep would look like N1, then N2, then deep sleep, n3, then deep sleep, n3, then you would enter REM sleep or emotional recovery, and then you would go back to N2 and the cycle continues. So if your nap is either too long or not long enough and you wake up during N3, well, you might wake up feeling a little drowsy, and that's normal. During N3, well, you might wake up feeling a little drowsy, and that's normal. So after sleep stage 3 or N3 or deep sleep, you enter REM sleep or rapid eye movement sleep.
Speaker 1:Now, during this weird sleep stage, your brain is active but your body is paralyzed. So well, your body is paralyzed where every single muscle, skeletal muscle in your body is paralyzed except extraocular muscles, and that's why, if you would open up the eyelids, you would see rapid eye movements. Now, this is the stage where dreams happen and, just like in the way that N3 or deep sleep, stage 3 is mostly for physical recovery, sleep stage 4, or REM sleep, is for emotional recovery. It supports learning, emotional regulation, memory. You're dreaming during that stage and REM sleep length increases as the night goes on. So that means that if tomorrow you put your alarm clock at an extra early time, you are missing out on REM sleep, the stage where mental restoration happens. So basically, each sleep stage has a job. So when someone asks me which sleep stage is most important, they're all important. You need N1 to make it to N2, and you need N2 to make it to N2, and you need N2 to make it to deep sleep, stage N3, where you have body repair, and you need N3 to make it to stage 4, which is your REM sleep, where brain repair or emotional repair happens.
Speaker 1:Now let's talk about how hormones like adenosine, melatonin, cortisol and insulin can actually impact the quality and the quantity of our sleep. Now, sleep specialist and expert, dr Matthew Walker describes four macros of sleep. So basically that would be sleep quantity you want to aim for seven to nine hours per night. Sleep quality, meaning you want to sleep enough, but you want to progress normally and spend enough time in all sleep stages, including N3 and REM sleep. You also want to have sleep regularity, meaning that you try to wake up at the same time every day and go to bed every night so you can develop a strong circadian rhythm where your hormones and your body. Basically, they can anticipate when you're supposed to go to bed, because you basically go to sleep and wake up about the same time every day and then you want to sleep accordingly to your chronotype. Some people are night owls, some people are a morning person. Some people will naturally want to go to bed earlier and wake up early. Some people will naturally want to go to bed late and wake up later and function optimally when they sleep, according to their chronotype, which is primarily genetically determined. So these four will make up the bulk of how optimal your sleep routine can be. But there are a lot of hormones that will influence or impact the quality and the quantity of your sleep.
Speaker 1:Adenosine is the first one. Now people know what adenosine is if they've read up on caffeine. People who drink a lot of coffee or consume caffeine understand that caffeine is an adenosine receptor blocker. So adenosine is actually a metabolic byproduct that accumulates when you're waking up. So as soon as you wake up in the morning and start to do physical or brain activities, adenosine starts to accumulate. Now people describe adenosine as the sleep pressure hormone. As your adenosine levels go up during the day, your sleepiness kind of increases in the same direction, right, so it builds up all day while you're awake. It makes you feel sleepy by binding to receptors in the brain and then when you drink caffeine, it simply blocks adenosine at the door. But it blocks the effects of adenosine, but it doesn't block it from getting higher or from accumulating more, which means that as soon as the caffeine wears off, the adenosine that you've accumulated throughout the last four or five hours is ready and able to bind to receptors that will make you feel tired. So the longer you're awake, the more adenosine builds and the stronger your need to crash and take a break or take a nap, or the more you'll feel sleepy. And that's why people call adenosine the sleep pressure hormone. It builds throughout the day and it makes you feel sleepy. So right before bed your adenosine is super high and then when you go to sleep, the adenosine clears and then it resets in the morning.
Speaker 1:As for melatonin, melatonin is like the timekeeper it's secreted by the pineal gland when it gets dark. So it's actually a hormone that responds to light or to darkness and it regulates your circadian rhythm. Your circadian rhythm is the internal clock that's telling you when it's time to sleep. Now, it doesn't knock you out, it just cues your system. So, basically, when people take melatonin and then go to bed five minutes later and say melatonin supplements aren't working, I wasn't feeling drowsy Well, that's not melatonin's job and that's not how it works. Melatonin is simply a hormone that, within 30 to 90 minutes after it peaks, it cuesues your system for sleep. So the most important thing is that you understand. Melatonin will also increase when it gets darker, and for thousands or even millions of years, we didn't have artificial lights in our rooms or screen time at midnight.
Speaker 1:So what happens now is that when people have bright lights on after supper or at 10 pm, or they're on their iPad or they're on their phones, the blue light emitted by these devices actually suppress the production of melatonin, actually suppress the production of melatonin. So what happens then is that your melatonin that gets suppressed by all these artificial lights, is not able to cue your system to relax and unwind and go to sleep. And that's why that a lot of influencers are recommending that people maybe wear glasses that block blue light, or that you dim the light after supper or, even better, that as soon as you wake up, you get exposed to light from the outside, because this light will suppress melatonin and that's what you want when you're waking up. If you suppress melatonin consistently at the same time at each morning and that you suppress light exposure at the same time at night, it helps you reinforce that circadian rhythm, which will help you get to sleep naturally. Now the other hormone that's quite important is the morning wake-up call, or cortisol.
Speaker 1:Cortisol, also known as the stress hormone, is not a bad thing. We need cortisol to naturally rise in the morning to help us feel alert, but we also need it to drop at night to allow melatonin to rise. Now, chronic stress keeps cortisol high and if you have high cortisol that blocks melatonin's effect to help you cue your sleep and your sleep will feel light. It will feel easily disrupted and basically think of cortisol and melatonin as a seesaw. Your cortisol is supposed to rise as your melatonin falls in the morning and your cortisol is supposed to plummet as your melatonin rises at night. So watching CSI or crime investigation documentaries right before going to bed is probably not a good idea, not just because of the blue light emitted by screens, but also because these things physical or psychological stressors can absolutely increase cortisol right before you go to bed, and that's probably why you want to develop a routine that helps you unwind, and you probably want to avoid reading emails or doing work right before going to bed, because if your body perceives that as a stressor, it will increase your cortisol and this will suppress melatonin just as bright lights would, and this basically makes it so that your body can't fall asleep and your mind keeps racing. So if you're one of these persons that are constantly ruminating or reflecting on things and worrying about tomorrow likely if you're doing these things right before going to bed your cortisol levels are high and you're probably having challenges with falling asleep Now.
Speaker 1:The other hormone that can impact sleep, or that sleep can impact, is insulin. Now, insulin people know it as the blood sugar boss. It is the hormone that helps blood sugar go from the bloodstream inside of your cells so that you can use it Now. Sleep helps regulate insulin sensitivity and if you have poor sleep, it increases insulin resistance and it makes your blood sugar higher, and one single poor night of sleep can absolutely impair blood glucose metabolism and make people pre-diabetic. We know that people who have sleep apnea and do not sleep well because they wake up frequently during the night, they have impaired blood sugar regulation, and these patients are at higher risk for having insulin resistance diabetes, all the way to type 2 diabetes. Now, over time, these things increase the risk of gaining weight and of having metabolic dysfunction. Basically, your hormones aren't just chilling while you snooze, they're running a night shift and they're very important for helping you regulate sleep.
Speaker 1:So what we would expect is that when you wake up in the morning, adenosine starts to rise as a metabolic byproduct. Cortisol starts to rise as you're getting ready to feel more alert and to take on the stressors of your day. Exposure to light will suppress melatonin, which will go down, and also insulin will typically start going up as your melatonin goes down, as your cortisol goes up and as you get exposed to calories. Now, late at night, your insulin should be going down in preparation for sleep. Since you're not ingesting calories, you should also see your cortisol go down as you're cuing your body to go to sleep. Your melatonin should start to rise as you're reducing your exposure to bright lights and your adenosine will start plummeting as you're going through your normal sleep stage cycles. For most people, the issue is related directly to chronic stress, where exposure to high stress will increase stress hormones, increase insulin and this will negatively impact the clearance of of adenosine and the production of melatonin.
Speaker 1:Now there are real risks of being sleep deprived, and it's okay to have an occasional late night, but consistent sleep deprivation is actually no joke, and the science says that one night of bad sleep can reduce immune function by up to 70%. Some studies have shown that natural killer cells the immune cells that fight off cancer can drop by up to 70% after one night of bad sleep. Sleep deprivation increases cortisol, it increases inflammation, it impairs memory, attention and even decision making. It disrupts hormonal balance, increases hunger hormones like ghrelin and decreases satiety hormones like leptin. And sleep deprivation is directly linked to obesity, heart disease and increases the risk of Alzheimer's, depression and type 2 diabetes.
Speaker 1:Chronic sleep debt is associated with higher blood pressure, higher insulin resistance, mood disorders and impaired testosterone and estrogen balance. A few nights of bad sleep can reduce testosterone in men by 10 to 15%, and considering that the typical decline in testosterone seen in men is about 1% per year, that's the equivalent of aging you 10-15 years in a few bad nights sleep. So let's not forget the micro-sleep danger also. Just a few seconds of nodding off at the wheel could lead to very poor outcomes and fatal accidents. Now sleep isn't just a matter of self-care. It's there for survival and throughout millions of years of evolution sleep has been sustained and maintained in all species.
Speaker 1:Now what can we do to sleep better? Practical, science-backed tips that could improve the quality and quantity of our sleep. Firstly, set a wind-down routine, maybe an hour or 90 minutes before bed. Start dimming the lights, disconnect your screens, stretch, read, do things that help reduce your exposure to light. This will naturally help your melatonin increase and it'll also help your cortisol go down. Help your cortisol go down. The combination of high adenosine from the day with low cortisol from a wind-down routine and high melatonin from avoidance of bright lights will set the stage for a good night's sleep. And when your brain knows that this ritual has worked before, you have positive reinforcement and that can help have confidence that you will have a restful night's sleep.
Speaker 1:So it's important to ditch blue lights. The blue lights that are emitted by screens or by iPads or iPhones can absolutely impact the rise in melatonin that's supposed to happen. So some people go as far as putting red lights in their rooms or in their bathrooms. Just try to maybe have some dimmers if you can, or soft lights or lamps. That would avoid that melatonin suppression that happens with bright lights. You also want to have a caffeine curfew. Caffeine blocks adenosine, so you just want to not drink caffeine after maybe 12 pm or sometimes in the afternoon. Caffeine's half-life, depending on the person, can be anywhere from six to eight hours. So if you drink two cups of coffee at 2 pm, that means that with a half-life of six to eight hours at eight or nine pm is almost like you still have a cup of coffee in you and that could absolutely impact your sleep. And if you say, well, I can drink coffee at suppertime and still sleep seven hours, we know that caffeine impacts the progression through the normal sleep cycles. So if you drink caffeine in the afternoon and we would put you in a sleep lab, we could still determine that your sleep quality, the normal progression through the different sleep cycles, is negatively impacted. Now, another factor that's commonly minimized is having the same bedtime and the same wake time, even on weekends, as often as possible. Now, regularity, one of the sleep macros, actually anchors your circadian rhythm and think of it as setting your own internal clock to auto-sync. Basically that means that at the same time every day in the morning and at night. That means that at the same time every day in the morning and at night, that same cycle happens reliably with all of the hormones that are related to cuing your sleep or to cuing alertness.
Speaker 1:Other things that you can do to help you sleep better is to sleep in a cool, dark, quiet room. The ideal temperature for a room during sleep is probably around 20 degrees Celsius or 64 to 68 Fahrenheit. Consider using blackout curtains or white noise if needed. Make sure to avoid alcohol. Alcohol may help you fall asleep, but it fragments REM sleep, and REM sleep is where the emotional healing happens.
Speaker 1:So even if you can fall asleep because you're sedated into sleep, remember that sedation is not the same thing as sleep. It leads to a lighter and less restorative sleep. Basically, it negatively impacts sleep quality in the deep sleep and REM stages, even though you might feel like it helped you fall asleep quicker. Also, keep in mind that you want to keep your meals or your snacks before going to bed as light as possible. Heavy meals can absolutely lead to poor sleep and try to not eat for two to three hours before going to bed.
Speaker 1:As soon as you wake up from a good night's sleep, make sure to get good morning light exposure. Now, 10 to 20 minutes of natural light will help reset your circadian rhythm by suppressing melatonin and increasing cortisol and bonus, it improves your mood and vitamin D levels. Also keep in mind that moving during the day, like regular exercise, will improve sleep latency, the time needed to fall to sleep, and it'll also improve sleep quality. But also avoid super intense workouts too close to bedtime, because physical activity increases cortisol levels that could negatively impact the quality and quantity of your sleep. And also make sure to find time to manage stress maybe mindfulness, journaling, gratitude journal, meditation, things like this. If you can include them during that wind down ritual before going to bed, it'll help reduce your cortisol levels and cue your body for good sleep Right on.
Speaker 1:So what I want you to take away from this podcast episode is that sleep isn't a passive process. It's highly active and it's metabolically demanding, and it's essential for your body to heal both physically and emotionally In deep and REM sleep. Each play unique yet crucial roles in healing memory and metabolism. Adenosine builds sleep pressure, melatonin cues your body and signals that sleep is coming, cortisol wakes us up in the morning and insulin keeps things metabolically steady. In chronic sleep it increases your risk for basically everything from insulin resistance to mood swings, and sleep deprivation is so dangerous that the World Health Organization actually classified night shift work as an unofficial carcinogen, because people who work night shifts have higher rates of cancer than the general population.
Speaker 1:Now you can fix your sleep with small intentional changes that you hopefully will start tonight. Sedation from sleeping pills does not reproduce the sleep quantity and quality that you can have naturally through a good sleep hygiene routine, wind down routine and behaviors that help set the stage for all of the hormones impacted by your circadian rhythm. If you want a better brain, a stronger body, a calmer mood and a leaner waistline, get more sleep Right on. Thanks so much for listening. I hope that you've learned something during this podcast episode. Sweet dreams, stay curious, stay rested, peace. Hey, everyone, go check out my website plantbaseddoctorjulescom to find free downloadable resources and remember that you can find me on Facebook and Instagram at DrJulesCormier, and on YouTube at Plant Based Dr Jules Cormier, and on YouTube at Plant Based Dr Jules.
