Newsletter #122: Green Space and Green Vegetables for Brain Power 🧠
Hello Friends!
Welcome to the Labor Day edition of the humanOS newsletter! We hope everyone has a safe and healthy holiday weekend.
This week, we learned that higher exposure to BPA is linked to increased all-cause mortality; it’s incredibly hard to get a good night of sleep when you’re in space; and caffeine naps might help you stay awake and alert when working overnight shifts. We also discovered that living in areas with more green space may improve intelligence and behavior in children (adding to past research showing that proximity to green space may augment the gut microbiota in young kids), and that specific nutrients found in green leafy veggies might elevate levels of BDNF and in turn boost cognitive performance.
Scroll down for more info, and stay safe everyone. 👇
This Week’s Research Highlights
🥫 Higher exposure to BPA was associated with increased risk of death from all causes.
Researchers analyzed data from a representative sample of American adults who participated in NHANES 2003-2008, and who provided urine samples for BPA measurements. Participants were linked to mortality data through the end of 2015. After adjustment for age, sex, race/ethnicity, socioeconomic status, dietary/lifestyle factors, body mass index, and urinary creatinine levels, the hazard ratio comparing the highest vs lowest tertile of urinary BPA levels was 49% higher for all-cause mortality during approximately 10 years of observation.
🚀 Spaceflight causes major changes in sleep duration, continuity, and architecture.
Researchers studied the sleep patterns of four cosmonauts and one astronaut before, during, and after spaceflight. Preliminary results revealed that they slept an average of only 5.7 hours in space (compared with 6.7 hours on Earth). They also experienced a 17.7% reduction in sleep efficiency (meaning that they spent more time awake in bed). The structure of their sleep changed as well - their time in non-REM sleep decreased by 14.1% and their time in REM sleep dropped by 25.8%.
☕ “Caffeine naps” may help boost alertness during night shift work.
Six healthy adults completed two 36-hour lab visits at a university sleep laboratory, each visit separated by one week. At 3:25 in the morning, participants consumed either decaffeinated coffee (placebo) or decaffeinated coffee with 200 mg of caffeine anhydrous added to it (caffeine nap). Participants in both conditions were then presented with an opportunity to nap and were administered tests of vigilance and fatigue in the subsequent 45 minutes. The caffeine-nap group showed better alertness and less fatigue than the control group, suggesting that this may be a useful tactic to fight sleep inertia during night shifts.
🏞️ Greater residential green space is associated with higher intelligence in children.
Researchers examined data on intelligence, behavior, and residential proximity to green space from 620 children in Belgium. Prenatal and childhood residential addresses were geocoded and used to assign green space indicators. After adjusting for various potential confounding variables (age, parental education, neighborhood income, etc), they determined that residential green space was beneficial for both intelligence and behavioral development. Specifically, a 3.3% increase in green space within a 3000-m radius of the home was associated with a ~2.6 point increase in IQ, as well as a two point reduction in behavioral problems.
🥬 Supplementation with macular xanthophylls increases brain growth factors and improves cognition.
Fifty-nine young healthy subjects were randomly assigned to take either placebo or two different doses of the dietary carotenoids lutein, zeaxanthin, and meso-zeaxanthin (collectively known as macular xanthophylls). After six months, serum levels of xanthophylls, brain-derived neurotrophic factor (BDNF), and antioxidant capacity had significantly risen compared to placebo, while levels of the pro-inflammatory cytokine IL-1β had fallen.
Furthermore, the macular xanthophylls resulted in improvements in multiple aspects of cognitive performance, including composite memory, verbal memory, sustained attention, psychomotor speed, and processing speed. The best dietary sources of these carotenoids are green leafy vegetables and egg yolks.
Podcasts We Loved This Week
- Matthew Walker: Sleep and immune function, chronotypes, hygiene tips, and addressing questions about his book. Via The Drive with Peter Attia.
- Hannah Ritchie: Environmental Impacts of our Diet: Climate, Carbon Footprint & Land Use. Via Sigma Nutrition.
- Umair Irfan: Air Pollution Costs More Than Switching To Clean Energy. Via Science Friday.
Products We Are Enjoying
Further Food Turmeric Tonic.
If you’re looking for a good way to get substantial amounts of turmeric into your diet without having to take a bunch of pills, this is a solid option. One tiny scoop of this powder blend contains 1.5 grams of turmeric (plus black pepper to boost absorption), and a mix of herbs and adaptogens. I like to add it to carrot and pumpkin smoothies - perfect for fall. You could also add it to soups, or just blend it up with some warm cashew milk to make a golden milk latte. Smells really good too.
New humanOS Product Updates
- How-to Guides: We have expanded access to the How-to Guides for Basic users. Now, Basic Users can click on any of the How-to Guides and see previews of them. So, for instance, if you were curious about our HTG to Smart Daily Light, anyone can check it out and get a sense for what’s in there.
- Achievements: We have redesigned the Achievements page on the humanOS dashboard. You’ll notice that there is a little green marker on the badges indicating whether or not the finished course has Talking Points, and if you click on that button, you will generate said Talking Points to review for your edification. Plus, it looks a bit prettier, which is always nice.
- And if you scroll a bit further down the page, you’ll see something else… 👀
- Belt Mastery Levels: We are developing a system through which you will be able to gauge your progress in humanOS through various mastery metrics, and advance to different belt levels, depending on course completion and your own health behaviors. We are pretty excited about this, so stay tuned 🤩
