Newsletter #90: Nature’s Candy, Walnuts, and Eating Jet Lag 🍊
Hello Friends!
Welcome to the latest edition of the humanOS newsletter! Below is our work, plus the assorted studies and media that captured our attention this week. 🤓
This Week’s Research Highlights
🧠 Blue light exposure therapy may enhance recovery from mild traumatic brain injury by re-entraining the circadian rhythm.
Researchers recruited 32 adults with a recent mild TBI and randomly assigned them to either blue light or amber (placebo) light, exposed in 30-minute pulses every morning. After six weeks, participants who used the blue light showed improved sleep timing, reduced daytime sleepiness, and improved executive functioning, compared to the placebo group. Brain imaging also revealed that the morning blue light was linked to increased volume of the posterior thalamus, greater thalamocortical functional connectivity, and increased axonal integrity of these pathways.
🦠 Walnuts may promote heart health through the gut microbiota.
Researchers recruited 42 participants with overweight or obesity, and randomly assigned them to three different study diets, all of which included less saturated fat than the run-in diet to which the subjects had been adhering previously. One of these diets incorporated 57-99 grams of walnuts per day, which replaced the saturated fat content of the prior diet. After six weeks, the walnut group showed reductions in LDL cholesterol, as well as changes in the composition of the gut bacteria. Interestingly, shifts in gut microbes were linked to changes in risk factors. For instance, greater increases in Eubacterium eligens and Lachnospiraceae were associated with greater reductions in blood pressure and cholesterol.
⏰ Variability in meal timing on the weekend versus weekdays may increase risk of overweight and obesity.
Researchers analyzed anthropometric and meal timing data from 1121 students enrolled in universities in Mexico and Spain. Participants were asked when they eat meals on weekdays and weekends, and the researchers used the eating midpoint on weekends and eating midpoint on weekdays to calculate the variability in the timing of the eating period, or “eating jet lag.” The results revealed that higher eating jet lag was linked to higher BMI, independent of chronotype and social jet lag.
☕ Short bouts of exercise may boost memory like coffee.
Definitely my favorite study of the week. Researchers had subjects perform either acute moderate-intensity exercise (20 minutes of brisk walking on a treadmill) or consume a single dose of caffeine (equivalent to about one cup of coffee), then perform a working memory assessment. They found that the exercise and the caffeine produced comparable improvements in accuracy. As an added bonus, a second phase of the study revealed that exercise may help alleviate symptoms of caffeine withdrawal.
Researchers had 25 habitual caffeine consumers go through a deprivation period, then take either a single dose of caffeine or perform exercise. Both moderate exercise and caffeine administration improved working memory accuracy and reduced caffeine withdrawal symptoms to a similar degree.
Podcasts We Loved This Week
- Michael Grandner: Societal, Social, and Psychological Influences on Sleep. Via Sigma Nutrition Radio.
- Meeta Singh: Sleep as a Competitive Advantage. Via Where Others Won’t.
Products We Are Enjoying
Glucosamine.
Obviously, most folks out there take glucosamine to prevent or alleviate joint pain (though the research is inconclusive on how effective this really is). But preliminary evidence suggests that it may have other benefits. Glucosamine has been shown to interfere with the breakdown of glucose, mimicking some of the effects of calorie restriction. An analysis of data from the VITAL cohort in Washington found a ~20% reduction in mortality in subjects taking glucosamine, compared to those who did not. That’s pretty damn impressive if you ask me, especially for such a cheap supplement. Check out our past interview with Michael Ristow to learn more.
