Newsletter #060: Performance-Enhancing Gut Bacteria & Sauna for Heart Health 🦠
Welcome to the newest edition of the humanOS newsletter! Here is where we share our work, plus the various studies and media that captured our attention this week. 🤓
This Week’s Research Highlights
Researchers recruited 19 volunteers and exposed them to a 25-minute sauna session, while having their blood pressure and heart rate assessed. Both rose immediately during the sauna. Notably, both blood pressure and heart rate dropped below baseline levels after leaving the sauna. On a separate day, the same participants performed a short workout on a stationary bicycle. During the exercise session, blood pressure and heart rate rose to the same levels that they had during the sauna session.
Researchers analyzed outcomes in 16741 older women who wore activity monitors for one week. Participants were followed for an average of more than four years. Subjects in the bottom 25% of steps walked (on average 2700 steps per day) were at the greatest risk of dying during the study period. Women who walked on average 4400 steps per day were at 41% reduced risk of mortality, compared to the lowest quartile. Risk of death continued to decrease up to 7500 steps per day.
Researchers analyzed fecal samples from Boston Marathon runners, as well as a cohort of sedentary individuals. They identified a particular genus of bacteria, Veillonella, which was found in higher abundance in runners generally and was especially enriched immediately after the marathon. A rodent model revealed that supplementation with Veillonella increased running ability, confirming that this genus is linked to greater exercise capacity.
♻️ The average American consumes many thousands of particles of microplastics - with unknown health effects.
Researchers reviewed 26 previous studies that analyzed the amounts of microplastic particles in fish, shellfish, added sugars, salts, alcohol, tap/bottled water, and air. The team then assessed approximately how much of these foods people typically eat from the recommended dietary intakes of the 2015-2020 Dietary Guidelines for Americans. From this analysis, the researchers estimated that the average American consumes more than 70,000 particles of microplastics per year (this value is likely an underestimate). People who drink only bottled water could consume an additional 90,000 microplastics annually compared with those who drink only tap water.
Videos We Loved This Week
- Robert Sapolsky: On Depression in the US. Via Stanford.
- John Ioannidis: In scientific method we don’t just trust - or why replication has more value than discovery. Via NIH Videocast.
- Cory Zapatka: The real reasons why the US refuses to go metric. Via Verge Science.
Products We Are Enjoying
Ginny says: This bottle is perfect for quickly mixing protein powders, creatine, other supplemental powders - you can even carry it with you and mix on the go. I have mostly been using it for matcha and for other cold tea/coffee beverages, and it would also work well for cocktails. 🍸 This one takes two AAA batteries, but they also make a model that charges via USB if you prefer that.
humanOS Catalog Feature of the Week
This week, we’d like to highlight our how-to guide for chrononutrition. We often fixate on what we are eating, when we are discussing diet and lifestyle, but we are gradually appreciating that when we eat also has a significant impact on our health and our daily performance.
This guide will help show you how to optimize your food timing, in alignment with the latest scientific research, to maintain robust circadian alignment and to ensure you are performing at your very best.
(PS: If you’re looking for a deeper dive into the subject of nutrient timing and other aspects of circadian physiology, please refer to our Circadian OS Program.)