Newsletter #038: High-Intensity Exercise Boosts Brain Protein in Obese Individuals 🧠
Hello Friends!
Welcome to the latest edition of the humanOS newsletter! Here, we’ll share our work, plus some of the cool studies and media that we reviewed this week and that found their way onto our social media channels. 🤓
This Week’s Research Highlights
🥤 High levels of dietary phosphate may reduce physical activity.
Researchers fed mice either a high-phosphate (2%) diet or a normal (0.6%) diet for 12 weeks. Mice that were fed the high phosphate diet ran less, exhibited lower exercise capacity, and showed impaired ability to burn fat. In addition, the researchers analyzed data from human participants in the Dallas Heart Study and found that higher phosphate levels were linked to less time exercising and more time sitting. Most phosphate in the modern Western diet comes in the form of inorganic phosphates. This matters, because they are used extensively in processed foods and are more readily absorbed than those that naturally occur in fruits, vegetables, and organic food protein sources.
🧠 Acute high-intensity interval exercise elicits greater levels of serum brain-derived neurotrophic factor (BDNF) in obese individuals.
BDNF is a protein in the brain that stimulates production of new brain cells and helps maintain existing ones. Obesity is thought to attenuate expression of BDNF, raising interest in lifestyle interventions that might ramp up BDNF levels. Researchers assigned twelve subjects (six obese and six normal weight) to either high-intensity intervals or continuous moderate-intensity exercise. In obese subjects, the BDNF response to high-intensity interval exercise was greater than moderate-intensity exercise.
💊 Melatonin dosing in over-the-counter supplements varies wildly.
Researchers systematically analyzed the actual melatonin content in 31 supplements purchased from groceries and pharmacies. They found that melatonin content varied from −83% to +478% of labeled melatonin, and 70% had a melatonin concentration that was ≤ 10% of what was claimed. Perhaps most alarming, the content of melatonin between lots of the same product varied by as much as 465%.
Videos We Loved This Week
- David Nutt: Psychedelic Research, From Brain Imaging to Policy Reform. Via MAPS.
- Michael Pollan: The Science of Psychedelics. Via The Royal Institution.
- James Fadiman & Sophia Korb: Microdosing - The Phenomenon, Research Results & Startling Surprises. Via MAPS.
New humanOS Content
- Blog: Microdosing Psychedelics for Creativity and Intelligence: Hope or Hype? By Greg Potter.
This week on the blog, Greg addressed a subject that has been growing in hype (as well as controversy): micro-dosing psychedelic drugs. In a previous blog, we talked about using psychedelics therapeutically to treat mood disorders. But oddly enough, some folks out there have been utilizing extremely small doses of these drugs (too low for the mind-altering effects for which they are best known) as a means to enhance cognitive performance. Many such individuals report improved focus and motivation, and other benefits. But it’s hard to assess the validity of such claims. You’d really like to see published research examining this phenomenon, which we didn’t have...until just now. Check out the blog to find out what was revealed in the very first studies examining the effects of micro-dosing psychedelics in healthy volunteers.
The humanOS Bookshelf
Catching Fire: How Cooking Made Us Human by Richard Wrangham.
Ginny says: How much time did you spend eating today? Humans are major outliers among primates, in terms of how much time they devote to this activity. Great apes, like chimpanzees, typically spend about 48% of their day just chewing (compared to 4.7% for humans - an order of magnitude less!). The major reason why we are able to eat so much more efficiently - and thus have more time available to do other things with our lives - is because of how we cook and process our food.
In this book, primatologist Richard Wrangham lays out his cooking hypothesis, arguing that the control of fire opened the door for a suite of cultural and anatomical changes, which ultimately made us who we are now. The energetic significance of thermal processing is massive. Cooking renders food more digestible and bioavailable by destroying cell walls, denaturing toxins, modifying the structure of proteins and starches, etc. You can get way more calories by cooking - for less time and effort.
In addition, this substantial boost in nutrients helped fuel encephalization - the increase in the relative size of our brains in proportion to our body mass. Our powerful brains are metabolically costly, particularly early in life, and could only be developed and maintained with a steady source of high-quality food. So in this sense, cooking certainly did make us human. Further, into the book, Wrangham also hypothesizes about the potential effects of cooking on social dynamics in early human societies, which is quite a bit more speculative and should be taken with a grain of salt. But overall the book is a solid introduction to how early technological innovation may have transformed us, both inside and out.