Newsletter #112: The Power of Nature, Activity, and Sunshine 🌞
Hello Friends!
Welcome to the latest edition of the humanOS newsletter! Below, as usual, is our own work, plus a roundup of the various studies and other media that we came across this week. This week, we found lots of research on the impact of exposure to sunlight and natural environments on various measures of health and human performance.
Check it out. 👇
This Week’s Research Highlights
🏃♀️ Sedentary time is independently associated with risk of cancer mortality - but physical activity can help.
Researchers analyzed data from 8002 participants in the REGARDS study, a prospective cohort based in the contiguous United States. Sedentary time, light-intensity physical activity, and moderate- to vigorous-intensity physical activity were measured using a hip-mounted accelerometer worn for 7 consecutive days. In multivariable-adjusted models, greater sedentary time was associated with greater risk of cancer mortality. However, replacing 30 minutes of sedentary time with light-intensity activity was associated with an 8% reduction in cancer mortality. Substituting sedentary time with moderate-to-vigorous physical activity was better — it was linked to a 31% lower risk of cancer mortality.
🌞 Natural daylight improves sleep and cognition in office workers.
Thirty knowledge workers spent one week working in each of two office environments with identical layouts, furnishings, and orientations. The only difference was the lighting conditions. One office was outfitted with electrochromic glass, resulting in 40.6 equivalent melanopic lux (a metric for measuring the biological effects of light). The other was equipped with traditional blinds, letting in much more sunlight and resulting in a much brighter, “optimized” 316 equivalent melanopic lux. Participants in the optimized daylight condition slept 37 minutes longer, as measured by wrist-worn actigraphs, and scored 42% higher on cognitive simulations designed to test their higher-order decision-making performance. Both sleep and cognitive function were measurably affected after one day in the space, and the impact became more significant over the course of the week.
🍃 Loss of green space in India is associated with higher cardiometabolic risk.
Researchers analyzed data on cardiometabolic risk factors from 6039 adults from the Andhra Pradesh Children and Parent Study (APCAPS) cohort (2010–2012) and trajectories of change in residential surrounding built-up land use from the preceding decade. They found that subjects whose neighborhoods had experienced greater built-up land use (and consequently reduced green space) had higher blood pressure, greater waist circumference measurements, and higher fasting blood glucose.
🌲 Exposure to nature lowers blood pressure and heart rate in healthy young adults.
120 university students were randomly assigned to four different sites, including two bamboo forests, a bamboo forest park, and an urban environment. During the 3-day testing period, participants were asked to view the landscape for 15 minutes in the morning, and then walk in the testing area for 15 minutes in the afternoon. Subjects who visited the natural environments showed reduced blood pressure and heart rate, compared to those in the urban setting. Female participants showed the greatest response, with a systolic blood pressure decrease of ~4.7 mmHG, and a heart rate decrease of 4-7 bpm.
👓 More time spent outdoors reduces risk of near-sightedness in children.
Children who had been born prematurely between January 2010 and December 2011 were enrolled in this cross-sectional study when they reached school age (between April 2017 and June 2018) in a referral center. Researchers analyzed refractive error, time spent outdoors, and serum vitamin D levels. After adjustment for age, sex, myopic parents, near-work time, and serum 25(OH)D concentration, more time spent outdoors was correlated with a lower odds of myopia (odd ratio of 0.13 per additional hour per day). Vitamin D insufficiency was highly prevalent in these participants, but was not associated with myopia.
Podcasts We Loved This Week
- David Watkins: A masterclass in immunology, monoclonal antibodies, and vaccine strategies for COVID-19. Via The Drive with Peter Attia.
- Noah Baker, Amy Maxmen, & Benjamin Thompson: Coronapod - The state of the pandemic, six months in. Via Nature Podcast.
- Christopher Hendon: Using chemistry to get the perfect cup of coffee. Via Science Friday.
Products We Are Enjoying
Year of Plenty Complete Fermenting Set.
This kit has pretty much everything you need to make sauerkraut and other fermented foods - including airlock lids, fermentation weights (to keep the veggies under water), and even a bamboo tamper to push everything down into the jars. All you need are some wide-mouth mason jars to begin making safe and healthy fermented vegetables. For those of you who are still under lockdown and feeling bored, this might be a nice (and healthy) project! If you want some expert guidance on how to do it successfully, the friendly folks over at r/fermentation can show you the way.
