Newsletter #102: Chocolate for Breakfast and Hard Exercise for Immunity 🏃♀️🍫
Hello Friends!
Welcome to the latest edition of the humanOS newsletter! Below is our work, and a roundup of the various studies and media that have captured our attention this week.
This Week’s Research Highlights
🏭 HEPA air filters placed in bedrooms can significantly improve breathing in asthmatic children.
During a period of moderately high air pollution in Shanghai, researchers gave 43 children with asthma two air filters to use in their bedrooms. One was a HEPA filter capable of removing PM2.5 (fine particles with diameters smaller than 2.5 micrometers); the other was a sham filter. Each filter was used for two weeks in random order with a two-week interval in between. PM2.5 concentrations inside the children's bedrooms were a third to two-thirds lower when the HEPA air filters were in use. This drop was accompanied with significant improvements in how easily air flowed in and out of the children's airways and lungs. This included a 24% average reduction in total airway resistance, a 43.5% average reduction in small airway resistance, a 73.1% average increase in airway elasticity, and a 27.6% average reduction in exhaled nitric oxide (a biomarker of lung inflammation).
🐁 Regular aerobic exercise instills youthful muscle repair capabilities in old mice.
Researchers took two groups of mice - one around 20 months old (equivalent to 60-70 years in humans) and another around 3-4 months old (equivalent to 20-30 years in humans), and gave all of them access to exercise wheels. The rodents were allowed to run as much as they desired. The older mice ran around 5 kilometers per night, while the younger ones ran around 10 kilometers. Other mice in the same age groups were given a wheel that didn’t rotate as sedentary controls. The older mice that exercised regularly showed accelerated muscle repair and improved muscle stem cell function, compared to those that didn’t run. Further investigation revealed that the rejuvenation was likely due to increased expression of the signaling protein cyclin D1, which maintains muscle stem cell activation capacity and whose expression declines with age.
🦠 Depression is associated with a reduction in anti-inflammatory gut flora.
Researchers analyzed the gut microbiota of 90 young adults, comparing 43 participants with major depressive disorder and 47 healthy controls. Participants with depression generally had reduced phylogenetic diversity in their microbiota, with lower levels of Firmicutes and higher levels of Bacteroidetes. At the genus level, the depression group had lower levels of anti-inflammatory bacteria, including Faecalibacterium. Functional differences in microbiota included reduced abundance of short-chain fatty acid production pathways. Magnitude of taxonomic changes in bacteria was associated with the severity of depressive symptoms.
🍫 Chocolate consumed early in the day (breakfast) helps with circadian re-entrainment and desynchrony in rodent models.
Three groups of rats were exposed to a sudden 6-hour advance of their light/dark cycle. One group of rats was given 5 grams of milk chocolate at the start of their day. Rats in another group were given chocolate at the end of their day. Finally, the rats in the third group were given no chocolate (controls). The rodents in the chocolate for breakfast group were able to adjust more rapidly to their new “time zone” than the controls. The group that ate chocolate for dinner adjusted more slowly than both groups. Additionally, the rats eating chocolate for breakfast showed increased thermogenesis, and gained 17% less body weight than the control group and 24% less than the shift-work group.
Podcasts We Loved This Week
- Charles Eisenstein: The Coronation. Via the Rich Roll Podcast.
- Meeta Singh: Sleep, Immunity & Mental Health. Via Sigma Nutrition Radio.
- Christian Benedict: Sleep, Diet, Obesity, and Weight Gain - Part 2. Via Sleep Junkies Podcast.
Products We Are Enjoying
Gochujang fermented chili paste. 🌶️
You can use this stuff on almost anything - it is really good in stir fries, as a spread for sandwiches/wraps, or as a dipping sauce for veggies. I like to slather it on sweet potatoes and other starches. Highly recommended.
New humanOS Features
- Course Enhancement: We have added Talking Points to the following course
FYI: Talking Points is a feature that is unlocked once you complete a course (just click on the achievement badge), and offers a useful recap of key takeaways from the lessons to aid memory retention, and hopefully enhance your ability to use that information and convey it to others. No point in studying something if you can’t use that info later, right?
New humanOS Content
- humanOS Blog: Does Hard Exercise Increase Your Risk of Getting Sick?
We have known for some time that moderate exercise is linked to improved immune function, and this is particularly true for regular daily activity. For instance, people who walk 40 minutes per day have been shown to have half as many sick days due to upper respiratory infections. This is probably why government officials have continued to allow us to go to parks and take exercise outside, even during the lockdowns.
But what about strenuous, prolonged exercise? You might have heard before that people who exercise very hard are actually more prone to getting sick. As someone who likes doing high-intensity interval training, this notion gave me pause. Was it possible that an ambitious exercise program could actually put someone at greater risk of catching an infectious disease?
We didn’t know the answer to this question, and it seems more relevant now than ever before, so we decided to take a quick look at what the observational research said. Here’s what we found.