Newsletter #008: The Impacts of light exposure and vegetable intake on Health 🥦
Happy weekend friends, and welcome to the latest HumanOS newsletter! Dan and most of the team are away doing some exciting work overseas (we’ll reveal what they were doing next week), so Ginny held down the fort with Chelsea and Eric. This week on the blog, Greg interviewed Dr. Andrew Hill, founder of the Peak Brain Institute, on the subject of neurofeedback as a method to enhance mental performance and just generally make you a more effective human. Finally, we would like to congratulate Greg (or rather, Doctor Greg Potter!) on finishing his dissertation defense this week! We are so proud of his hard work and grateful to have him on the team.
Our Work
- Blog and podcast: Neurofeedback as a Way to Improve Your Mental Fitness (Interview with Dr. Andrew Hill of Peak Brain)
- Activity tracker update: We’re always working on improving our tools, and most recently we’ve added some new options to the activity tracker. You can now log kettlebell work, slackline, balance, and even sauna! (BTW: if you’re not yet sold on the benefits of using a sauna, definitely read this blog).
This Week’s Research Highlights
😴 Light exposure during sleep and metabolism
A new study shows that even a single night of light exposure during sleep can affect metabolic function. The study examined 20 healthy adults, ages 18 to 40, with participants split into two groups, Dark-Dark and Dark-Light. The Dark-Light group slept in the dark on Night 1 and in overhead room light of 100 lux on Night 2, while the DD group slept in the dark on both Nights 1 and 2. Homeostatic model assessment of insulin resistance change values were significantly higher in the morning following sleep in the light (Dark-Light group) compared to sleep in the dark (Dark-Dark group). This effect was primarily due to increased insulin levels for the Dark-Light group compared to the Dark-Dark group. Results show that a single night of light exposure during sleep acutely impacts measures of insulin resistance, which is the diminished ability of cells to respond to insulin action transporting glucose out of the bloodstream and precedes the development of type 2 diabetes. Given the widespread use of artificial light exposure, particularly at night, more research is needed to determine if chronic overnight light exposure during sleep has long-term cumulative effects on metabolic function.
🍚 As carbon dioxide levels rise, major crops are losing nutrients.
Scientists are running experiments to understand the impact of higher carbon dioxide levels on plants, given the mounting evidence that suggests many key plants lose nutritional value at higher CO2 levels. Rows of controlled chambers at the US Department of Agriculture's Adaptive Cropping Systems Laboratory are testing how plants react to different levels of CO2. Lewis Ziska, a plant physiologist with the USDA, demonstrated an experiment with coffee, where a chamber with plants growing at CO2 levels projected for the end of this century showed that coffee plants grew faster and larger. However, scientists have seen that other crops have lost some of their nutritional value under higher CO2 conditions. One example is rice, a primary food source for more than 2 billion people. A recent study by international scientists found that higher CO2 reduced multiple key measures of rice's nutritional value, with average reductions of 10% in protein, 8% in iron, and 5% in zinc. Four important B vitamins decreased between 13 and 30%. Wheat showed declines in protein, iron, and zinc, and soybeans and field peas showed declines in iron and zinc. Maize and sorghum were less affected.
🥦 Cruciferous vegetable intake is associated with a lower risk of atherosclerotic vascular disease deaths
Higher amounts of cruciferous and allium vegetables may be associated with a lower risk of death due to atherosclerotic vascular disease in older women. Atherosclerotic vascular disease refers to a condition in which plaque builds up inside the arteries, which can lead to serious cardiovascular complications such as heart attacks and strokes. The study followed a group of older women over a 15-year period and found that those who consumed higher amounts of cruciferous and allium vegetables had a lower risk of death due to atherosclerotic vascular disease compared to those who consumed lower amounts of these vegetables. Cruciferous vegetables include broccoli, cauliflower, and kale, while allium vegetables include onions, garlic, and leeks. The text ends with a light-hearted comment urging people to eat broccoli and onions, which are good sources of these beneficial vegetables.
Podcasts We Loved This Week
- Garth Nicolson: How to Repair Mitochondria with Lipid Replacement. Via The Quantified Body Podcast.
- Tommy Wood: From Neonatal Neurobiology to Elite Performance Coaching. Via the Physicians for Ancestral Health Podcast.
- Lyle McDonald: Nutrient Partitioning and Fuel Utilization. Via Danny Lennon of Sigma Nutrition Radio.
Products We Are Enjoying
Beet It Nitrate Sports Shots.
Ginny says: Beetroot is a rich source of nitrate, which relaxes the walls of the arteries when it transforms to nitric oxide. Wider blood vessels = better blood flow, and that makes it easier for blood to get to your muscles without increasing the workload of the heart. This is obviously nice for physical performance...but like many humans, I find beetroot, um, less than appealing in large doses. That’s why I like to use these highly concentrated juices before/between soccer games, which efficiently deliver 400 mg of nitrate per serving in a portable 2.4-ounce shot. Incidentally, Beet It happens to be the product that many researchers, including Jonathan Burdette, have used to examine the effects of dietary nitrate (check out our interview with him from last year).
humanOS Catalog Feature of the Week
Sleep and Weight Control
This week, we’d like to highlight one of the courses from the Ideal Weight Program, developed by Stephan Guyenet. Much of the Ideal Weight Program is centered around nutrition, as you would expect, but research has shown that multiple aspects of our lifestyle play an important role in body weight. Sleep is one of the most important, and perhaps most underappreciated.
In this course, Stephan reviews the basics of sleep and circadian rhythms, then zooms in on how insufficient or misaligned sleep specifically influences body fatness. He looks at a few key studies that have examined the impact of altered sleep on food intake, which largely mirror the findings that we described above. But it actually gets even worse - sleep loss can also adversely affect nutrient partitioning, making it harder for you to hold onto muscle! Fortunately, this is for the most part a solvable problem. Stephan covers realistic ways for you to obtain restorative sleep, and hopefully achieve your body composition (and health) goals.