Newsletter #021: A pathway to longevity and disease prevention ♾️
Welcome to the newest edition of the humanOS newsletter! Here, once again, is where we share our own work plus the interesting media and studies that we stumbled upon this week. 🤓
This week on humanOS Radio, Dan interviewed Kristine Wilckens, whose research focuses on how sleep structure can be modified to enhance cognitive performance. We all know from personal experience that it’s hard to think clearly and remember things when we haven’t gotten enough sleep. But we’re now realizing that sleep quality - and specifically, how much time you spend in deeper restorative stages of sleep - also plays a role in brain function.
In this interview, we review the role of slow-wave sleep in learning and memory consolidation, and what we can do to enhance slow-wave sleep. In general, activities that increase brain energy consumption during the day seem to correspond to a rebound decrease in metabolic rate at night, which produces greater slow-wave activity during sleep. As an example, simply elevating body temperature activates warm-sensitive neurons in the hypothalamus, which can promote slow-wave sleep. This can be done through intense exercise, or just passive heat exposure (yet another benefit of saunas, perhaps? 🤔). Check out the interview to learn other techniques for getting the deep sleep you need, and perhaps boosting your brainpower!
This Week’s Research Highlights
Researchers analyzed data from 68273 Swedish men and women who provided dietary data and who were followed for an average of 16 years. The research team estimated the inflammatory potential of each person's diet using a validated inventory of anti-inflammatory and pro-inflammatory foods, and divided subjects into four quartiles based on the calculated adherence to an anti-inflammatory diet. Compared to those in the lowest quartile, individuals in the highest quartile had an 18% lower risk of all-cause mortality, a 20% lower risk of cadiovascular mortality, and a 13% lower risk of cancer mortality. Even greater mortality benefits were observed in current smokers who followed an anti-inflammatory diet compared to smokers with a pro-inflammatory diet.
Researchers at the Autonomous University of Baja California randomly assigned participants to consumed either 2 grams of dark chocolate (containing 70% cocoa) or 2 grams of milk chocolate daily for six months. The researchers took epithelial cell samples from inside the cheeks of participants throughout the duration of the study to examine how the treatments affected genotoxicity. At the beginning of the study, 14.4% of the buccal epithelial cells on average had abnormalities in the nuclei. However, after consuming dark chocolate for six months, abnormalities dramatically lowered to less than 2%. The milk chocolate group showed no change in the percentage of abnormalities in their cell samples. The researchers attribute this to antioxidant effects of cocoa flavonoids, which are found abundantly in dark chocolate but not in milk chocolate. Indeed, when the researchers performed chemical analysis of the chocolates, they found that the antioxidant capacity of the dark chocolate was 3-fold greater than the milk chocolate. The dark chocolate group also experienced significant reductions in LDL cholesterol, triglycerides, and fasting blood glucose.
💊 Supplementation with lutein and zeaxanthin increases xanthophyll levels in the central nervous system and improves cognitive function.
Researchers recruited 51 young (18-30) healthy adults and randomly assigned them to either take 10 mg of lutein + 2 mg of zeaxanthin or a placebo. Over the course of a year, supplementation with the macular xanthophylls led to increased macular pigment optical density (MPOD). Cognitive testing, administered before and after supplementation, revealed significant improvements in spatial memory, reasoning ability, and complex attention, which was correlated with increased MPOD.
Videos We Loved This Week
- Mark Williams: Mindfulness. Via Oxford Mindfulness.
- Jon Kabat-Zinn: The healing power of mindfulness. Via Dartmouth.
Products We Are Enjoying
Ginny says: Avocado oil has the highest smoke point of any oil of which I am aware (520 degrees Fahrenheit / ~271 degrees Celsius), making it the safest choice for roasting and stir-frying. Avocados are also a rich source of monounsaturated fats and antioxidants, which seem to keep your coronary arteries happy, so the oil seems like a wise choice. I like this spray in particular because it diffuses the oil in a thin layer, so it’s evenly distributed and you don’t use too much.
New humanOS Content
- humanOS Radio: Can Enhancing Slow Wave Sleep Boost Your Brain Function? Podcast with Kristine Wilckens.
humanOS Catalog Feature of the Week
This week, we’d like to highlight one of the courses from the Ideal Weight Program, developed by Stephan Guyenet. Much of the Ideal Weight Program is centered around nutrition, as you would expect, but research has shown that multiple aspects of our lifestyle play an important role in body weight. Sleep is one of the most important, and perhaps most underappreciated.
In this course, Stephan reviews the basics of sleep and circadian rhythms, then zooms in on how insufficient or misaligned sleep specifically influences body fatness. He looks at a few key studies that have examined the impact of altered sleep on food intake, which largely mirror the findings that we described above. But it actually gets even worse - sleep loss can also adversely affect nutrient partitioning, making it harder for you to hold onto muscle! Fortunately, this is for the most part a solvable problem. Stephan covers realistic ways for you to obtain restorative sleep, and hopefully achieve your body composition (and health) goals.