Newsletter #124: Green Time & Aerobic Exercise for a Better Brain 🌳➕🏃♀️➡🧠
Hello Friends!
Welcome to the latest edition of the humanOS newsletter! We hope everyone is doing well and staying healthy in these strange times, particularly those of you who are affected by the wildfires on the west coast of the US. Our thoughts are with you all.
This week, we learned that just a single workout can make you smarter; spending more time in nature (green time) can help buffer the mental consequences of prolonged interaction with screen-based technologies; drinking beetroot juice every day can substantially lower blood pressure in people with hypertension (check out these past blogs to get a little more insight on that phenomenon), and a relatively small amount of weight loss can result in significant long-term benefits for people with overweight or obesity.
See below for more info, and please stay safe everyone. 👇
This Week’s Research Highlights
🧠 A single workout can acutely boost learning and memory in young adults.
Researchers performed a systematic review of the current literature to evaluate the acute effects of a single exercise session on learning and memory functions in young adults. Thirteen studies meet the inclusion criteria and were subsequently evaluated. These studies showed that aerobic exercise in a wide range of duration (from two minutes to up to an hour) at moderate to high intensity had a favorable impact on learning and memory. Specifically, the studies showed that a single aerobic workout, followed by a brief recovery before encoding, improved attention, concentration learning, and long-term memory, with effects enduring for 30-120 minutes. So if you want to take advantage of this phenomenon, you probably would want to exercise shortly before the learning activity.
🌳 More "green time" and less screen time are associated with more favorable psychological outcomes in kids.
Researchers reviewed a total of 186 eligible studies examining associations between screen time (time spent engaging with screen-based technologies), “green time” (time spent in contact with nature), and psychological outcomes in young people. They found that generally, high levels of screen time appeared to be associated with unfavorable psychological outcomes, while higher levels of green time was associated with more favorable outcomes, with disproportionate impact on youth from low socioeconomic backgrounds. But this doesn’t necessarily mean that we have to fully sacrifice technology (even if it were practical to do so). Preliminary evidence suggested that adding in green time could buffer some of the consequences of high screen time. Attention Restoration Theory postulates that when direct attention mechanisms are drained by constant fixation on screen-based technologies, they can be restored by time spent in natural environments because they call upon involuntary attention.
📉 People with obesity who lose a modest amount of weight can significantly lower their risk of chronic disease.
Researchers analyzed anonymized data from over 550000 adults with overweight (BMI 25 to 30 kg/m²) or obesity (BMI of 30 or above) between January 2001 and December 2010. Participants were divided into two groups based on their weight pattern during a 4-year period after the initial baseline measurements: One group of individuals whose weight remained stable, and then another group who lost weight (median BMI change of -13%). Importantly, the researchers also extracted information on weight loss interventions and dietary advice to confirm that these individuals intended to lose weight, to avoid the problem of reverse causation (weight loss in observational studies is sometimes associated with declining health due to preexisting disease, rather than leanness itself). They determined that people with obesity who intentionally lost 13% of their initial body weight reduced their relative risk of developing type 2 diabetes by 42%-44%, sleep apnea by 22%-27%, high blood pressure by 18%-25%, and dyslipidemia by 20-22%
🏥 Supplementation with beetroot juice significantly lowers blood pressure in hypertensive adults.
Forty-seven middle-aged and older participants with elevated blood pressure at baseline were randomly assigned to 3 conditions for a period of 60 days: 1) high-nitrate beetroot juice (∼400 mg nitrate) + folic acid (∼5 mg folic acid), 2) high-nitrate beetroot juice + placebo, or 3) nitrate-depleted beetroot juice and placebo. Compliance to the interventions was high and confirmed with significant increases in nitrate and folic acid levels in plasma and saliva. After sixty days, the groups given nitrates showed significant decreases in blood pressure, compared to the group given depleted beetroot juice. In the group given high-nitrate beetroot juice without folic acid, 24-hour systolic BP dropped by −10.8 ± 9.8 mm Hg, and diastolic BP dropped by −5.4 ± 5.0 mm Hg.
Podcasts We Loved This Week
- Alexis C. Madrigal: Is faster better? We want vaccines. We want rapid tests. But when is fast too fast? Via Social Distance.
- Russell Foster: The Suprachiasmatic Nucleus (SCN) and the Royal Society. Via Sleep4Performance.
- Glen Gibson: Human gut bacteriology, prebiotics, and probiotics. Via Sigma Nutrition.
Products We Are Enjoying
LEVOIT H13 True HEPA Filter Air Purifier
I have used this air purifier for my bedroom for a couple of years and I really like it. It is small, relatively quiet, energy efficient, and economical (both the unit and replacement filters are pretty cheap). Bear in mind that the area coverage for a little purifier like this is only 129 square feet, so I wouldn’t count on it to clean your entire home or a substantial portion of the house. It’s great for gobbling up allergens, dust, mold, etc in a small space though.
humanOS Catalog Feature of the Week
How-to Guide - Indoor Air Quality
There isn’t a whole lot that you can do individually about outdoor air pollution other than stay inside when levels of pollutants are high (or move somewhere with cleaner air I guess?).
But the indoor environment has its own perils. Indeed, the EPA has estimated that concentrations of certain recognized air pollutants can be 2-5 times higher in indoor environments than outdoors, due to compromised dilution capacity in enclosed spaces. And fortunately, indoor air is much more actionable.
In this How-to Guide, we identify the main types of indoor air pollutants and go over what you can do to mitigate or eliminate them, as well as some fact-checking on a very popular (but scientifically dubious) method for purifying indoor air.
This is obviously a relevant concern for those of us who work in offices most of the day, but it's also key if you're a member of the WFH brigade. One recent study that installed air monitors in the homes of people working remotely during the pandemic found that fine particulate matter levels in the homes of every single participant exceeded air quality standards established by the EPA for a healthy work environment.
That's why we created this guide. It will show you how to test indoor air quality, and support maintenance of better air quality in your indoor spaces, for a healthier body and sharper mind.