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The Tim Ferriss Show
#650: Dr. Matthew Walker, All Things Sleep — How to Improve Sleep, How Sleep Ties Into Alzheimer’s Disease and Weight Gain, and How Medications (Ambien, Trazodone, etc.), Caffeine, THC/CBD, Psychedelics, Exercise, Smart Drugs, Fasting, and More Affect Sleep
Jan 19, 2023
10:10:00
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Quick takeaways
- Caffeine disrupts sleep and reduces deep sleep, especially in the first two hours of the night.
- Stress, anxiety, light exposure in the evening, and caffeine intake can decrease deep sleep.
- Temperature and exercise can enhance deep sleep, while avoiding caffeine and limiting light exposure can support it.
- Caffeine has similar benefits to sleep, such as increased alertness, but can disrupt the transition to restful sleep.
- Sleep deprivation increases appetite and cravings for carbohydrate-rich and obesogenic foods.
- Classic sleep medications sedate the cortex and can lead to tolerance and increased health risks, while newer medications like trazadone provide more natural sleep.
Deep dives
Effect of Caffeine on Sleep
Caffeine blocks adenosine receptors, preventing the sleepiness signal from reaching the brain. It also increases anxiety, disrupts the transition to restful sleep, and destabilizes sleep, making it more fragile. Caffeine can reduce deep sleep, especially in the first two hours of the night.
Factors That Decrease Deep Sleep
Factors such as stress, anxiety, light exposure in the evening, and caffeine intake can decrease deep sleep. Stress and anxiety activate the flight-or-flight response, making it harder to fall asleep. Exposure to light, even during sleep, disrupts sleep, and caffeine blocks sleepiness signals.
Factors That Increase Deep Sleep
Temperature plays a role in increasing deep sleep. Taking a hot bath or shower before bed raises body temperature and facilitates a drop in core temperature, promoting deep sleep initiation. Exercise, especially aerobic exercise, also enhances deep sleep. Avoiding caffeine and limiting light exposure in the evening can support deep sleep.
Caffeine and Sleep Benefits
Caffeine is associated with similar health benefits as sleep, such as increased alertness and improved mood. It acts as a stimulant, blocking adenosine receptors and reducing sleepiness signals. However, it can disrupt sleep and make the transition to restful sleep more challenging. Caffeine has a half-life of 5-6 hours, affecting sleep duration and stability.
Effect of Sleep Loss on Appetite-Regulating Hormones
Sleep loss leads to a decrease in the appetite-suppressing hormone leptin and an increase in the hunger hormone ghrelin. Leptin levels drop by about 18%, while ghrelin levels increase by 28%, resulting in an increased appetite and desire for food.
Preference for Obesogenic Foods
Sleep deprivation also leads to an increased preference for carbohydrate-rich foods, sweet treats, and salty snacks. This can contribute to weight gain and increase the risk of conditions like obesity and hypertension.
Endocannabinoids and Hunger
Sleep deprivation increases the levels of endocannabinoids in the brain, which can stimulate hunger and lead to overeating. This mirrors the effects of exogenous cannabinoids like THC, which are known to induce the munchies.
Overall Impact on Weight Gain
The combination of disrupted appetite-regulating hormones, increased preference for obesogenic foods, and heightened hunger due to elevated endocannabinoid levels can contribute to weight gain and make it more difficult to maintain a healthy weight.
The Role of Sleep Deprivation in Hunger
Sleep deprivation can increase hunger due to changes in endocannabinoids and hormonal patterns. Depriving oneself of sleep can mimic conditions of starvation and trigger the release of weight-promoting chemicals. This leads to an increased drive to search for food and consume more calories. The brain's control regions are affected, making obesogenic foods more desirable while reducing impulse control. Lack of sleep also affects the brain's decision-making processes, favoring unhealthy food choices.
The Impact of Sleep Medications on Sleep Quality
Classic sleep medications, known as sedative hypnotics, sedate the cortex but do not produce naturalistic sleep. These medications work by targeting the brain's inhibitory system and can lead to tolerance, next-day drowsiness, and increased risks of accidents, dementia, and falls. Cognitive behavioral therapy for insomnia is recommended as a first-line treatment, while newer medications like trazadone offer a different mechanism that switches off wake-promoting regions and allows for more natural sleep. The long-term health risks of sleep medications are still unclear.
The Benefits and Mechanism of Trazadone
Trazadone, originally developed as an antidepressant, is now used as a sleep aid in lower doses. It works by reducing noradrenaline, serotonin, and histamine activity in the brain. Trazadone has been shown to improve sleep latency, reduce wakefulness during the night, and increase deep non-REM sleep without affecting REM sleep. It provides sleep benefits for both younger and older individuals, making it a potentially valuable sleep medication.
The Effects of Pregabalin and Gabapentin on Sleep
Pregabalin and Gabapentin, primarily used for pain and seizures, have been found to increase deep non-REM sleep and reduce light non-REM sleep. Their mechanism of action is different from sedative hypnotics, as they impact calcium channels and neuronal firing rather than targeting the GABA system. These medications may indirectly improve sleep by reducing anxiety and stress-related hormonal activity. Their long-term health risks and potential side effects are still being studied.
Brought to you by Eight Sleep’s Pod Cover sleeping solution for dynamic cooling and heating, Athletic Greens all-in-one supplement, and LMNT electrolyte supplement.
Matthew Walker, PhD (@sleepdiplomat), is professor of neuroscience at the University of California Berkeley and founder and director of the school’s Center for Human Sleep Science. Dr. Walker is the author of the New York Times and international bestseller Why We Sleep: Unlocking the Power of Sleep and Dreams, which was recently listed by Bill Gates as one of his top five books of the year. His TED Talk, “Sleep is Your Superpower,” has garnered more than 17 million views.
He has received numerous funding awards from the National Science Foundation and the National Institutes of Health and is a Kavli Fellow of the National Academy of Sciences. In 2020, Dr. Walker was awarded the Carl Sagan Prize for Science Achievements. Dr. Walker’s research examines the impact of sleep on human health and disease. He has been featured on numerous television and radio outlets including 60 Minutes, Nat Geo TV, NOVA Science, NPR, and the BBC. Dr. Walker is also scientific advisor to Oura, a sleep-tracking ring.
Dr. Walker hosts the 5-star-rated podcast The Matt Walker Podcast, which is all about sleep, the brain, and the body.
Resources from this episode: https://tim.blog/2023/01/18/matthew-walker-sleep/
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[05:55] Sleep and Alzheimer’s disease.
[19:55] What causes the decline of deep sleep as we age?
[24:36] Are there any known species that don’t require sleep?
[29:15] Brain stimulation for more deep sleep, less insomnia.
[41:01] Tips for better sleep without laboratory budget or access.
[51:45] Ideal types of exercise for promoting deep sleep.
[53:51] Matt’s updated thoughts on caffeine and sleep.
[1:11:12] Cannabis (CBD, THC, CBN) and sleep.
[1:30:18] A crowdsourcing request of listeners.
[1:36:17] If the bed’s a-rocking…
[1:41:45] The Da Vinci Code magic sleep device.
[1:46:04] DARPA innovation.
[1:46:32] Ensuring proper function in the glymphatic system.
[1:50:42] Psychedelics and sleep.
[2:01:20] How sleep affects food intake and weight fluctuation.
[2:10:46] Orexin, I reckon.
[2:22:11] Fainting goats and narcolepsy.
[2:25:36] Modafinil.
[2:30:32] How sleep medications affect sleep quality.
[2:36:16] Trazodone.
[2:46:26] Perilous polypharmacy.
[2:49:04] Pregabalin and gabapentin.
[2:54:33] The psychological value of emergency sleep medicine for insomniacs.
[2:58:16] CBTI and the balancing role of pharmacology.
[2:59:56] Parting thoughts and what to expect from a future round two.
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For show notes and past guests on The Tim Ferriss Show, please visit tim.blog/podcast.
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Past guests on The Tim Ferriss Show include Jerry Seinfeld, Hugh Jackman, Dr. Jane Goodall, LeBron James, Kevin Hart, Doris Kearns Goodwin, Jamie Foxx, Matthew McConaughey, Esther Perel, Elizabeth Gilbert, Terry Crews, Sia, Yuval Noah Harari, Malcolm Gladwell, Madeleine Albright, Cheryl Strayed, Jim Collins, Mary Karr, Maria Popova, Sam Harris, Michael Phelps, Bob Iger, Edward Norton, Arnold Schwarzenegger, Neil Strauss, Ken Burns, Maria Sharapova, Marc Andreessen, Neil Gaiman, Neil de Grasse Tyson, Jocko Willink, Daniel Ek, Kelly Slater, Dr. Peter Attia, Seth Godin, Howard Marks, Dr. Brené Brown, Eric Schmidt, Michael Lewis, Joe Gebbia, Michael Pollan, Dr. Jordan Peterson, Vince Vaughn, Brian Koppelman, Ramit Sethi, Dax Shepard, Tony Robbins, Jim Dethmer, Dan Harris, Ray Dalio, Naval Ravikant, Vitalik Buterin, Elizabeth Lesser, Amanda Palmer, Katie Haun, Sir Richard Branson, Chuck Palahniuk, Arianna Huffington, Reid Hoffman, Bill Burr, Whitney Cummings, Rick Rubin, Dr. Vivek Murthy, Darren Aronofsky, Margaret Atwood, Mark Zuckerberg, Peter Thiel, Dr. Gabor Maté, Anne Lamott, Sarah Silverman, Dr. Andrew Huberman, and many more.
DISCLAIMER: I’m not a doctor, nor do I play one on the Internet. None of the content in this podcast constitutes medical advice. Please consult your doctor before considering anything we discuss in this episode.
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