Newsletter #137: Why Good Sleep is a Matter of Life and Death 💤
Welcome to the latest edition of the humanOS newsletter!
This week, we got some insight into how sleep - or the lack thereof - influences injury risk in athletes and occupational performance in medical doctors, and how night-time exposure to bright light and noise influences chronic disease risk.
Scroll down to learn more 👇
This Week’s Research Highlights
🏀 Sleep duration is an independent predictor of in-season injury in male collegiate basketball players.
A total of 19 male NCAA Division I basketball athletes provided self-reported training load, sleep, and well-being data throughout two consecutive 6-month seasons. Each morning, before any basketball events, athletes were asked to provide ratings of fatigue, mood, soreness, stress, and sleep quality on a 0 (worst) to 5 (best) Likert scale, as well as sleep duration in hours. Throughout the study period, injuries that resulted in time loss were recorded by the team athletic trainer. After analyzing the data, the researchers found that injuries per 1000 hours decreased dramatically as the preceding night’s sleep duration increased. Specifically, a one-hour increase in sleep duration was associated with a 43% decrease in injury risk the following day. Mechanisms are not clear; it is possible that poor sleep may predispose athletes to injury by increasing fatigue and/or compromising reaction time.
💡 Greater exposure to outdoor light at night was found to be associated with higher odds of developing obesity over 10 years.
Researchers analyzed data from a sample of 239781 participants (aged 50-71) who were not obese at baseline (1995-1996). They estimated individual exposure to outdoor light at night from satellite imagery around the participants’ residential addresses and then examined whether the light at night was associated with odds of developing obesity at follow-up (2004-2006). Compared with the lowest quintile of light at night, the highest quintile was associated with 12% and 19% higher odds of developing obesity at follow-up in men and women respectively. It is thought that exposure to artificial light in the evening may increase risk of obesity through circadian rhythm disruption and altered patterns of sleeping and eating.
🩺 Sleep impairment is associated with greater risk of medical error in physicians.
Researchers analyzed data on sleep-related impairment, clinically significant medical errors, and indicators of occupational wellness in 11395 physicians practicing at academic-affiliated medical centers. They found, unsurprisingly, that sleep-related impairment was strongly correlated with burnout. Most alarmingly, they determined that moderate and high sleep-related impairment were associated with 53% and 96% greater odds of self-reported clinically significant medical error respectively, after adjusting for gender, training status, practice specialty, and burnout.
🛩️ Chronic night-time noise exposure is a risk factor for cardiovascular mortality.
Researchers selected 24886 cases of death from cardiovascular disease situated in the vicinity of the Zürich Airport between 2000 and 2015. They estimated individual exposure to aircraft noise for these subjects at home locations using a list of all aircraft movements at the airport within the study period and determined that acute noise from aircraft at night was linked to a greater risk of cardiovascular death within two hours of exposure. The researchers found that the risk of cardiovascular death increases by 33% for night-time noise levels between 40 and 50 decibels and 44% for levels above 55 decibels. Exposure to such noise appears to be particularly deleterious at night, through sleep disruption and escalation of physiological stress response.
Question of the Week
🤔 How long is the memory of a goldfish - according to science?
Podcasts We Loved This Week
- Marcas Bamman: The many benefits of exercise and strength training. Via STEM-Talk.
- David Robert Grimes: Conspiracy theories and bad information - why are we susceptible? Via Sigma Nutrition.
Products We Are Enjoying
GEZEE 10W Edison Style Vintage LED Filament Light Bulb
Exposure to bright light (especially short wavelengths) during the day promotes alertness and cognition, and may even improve sleep at night. One study, for instance, found that people who were exposed to more sunlight during their workday were more physically active and got an additional 46 minutes of sleep per night.
But intense full-spectrum light is pretty hard to come by this time of year, when days are short, chilly, and often overcast. That is what makes these perfect for installing in your office. They are super bright (1000 lumens), emit a white light rather akin to sunlight (6000K), and the bulbs themselves even have a fun retro design. Just make sure not to use them in the evening, or for taking selfies (that cool bluish-white is not exactly flattering).
New humanOS Feature: Favorites ♥
We recently upgraded the search functionality on the site. This week, we are announcing that we have upgraded this even more by adding a “Favorites ” functionality. Here is how it works.
- You’ll notice now that we have added Favorites to the left navigation menu. Clicking on favorites from here will take you to the search page, now titled Search & Favorites.
- Here, you will see any recipe that you’ve added to your favorites. You favorite a recipe by clicking on the heart icon of any recipe to turn the heart red.
- At the top right, there is a Favorite toggle button. When you arrive at the search page from the Favorites link in the left nav, the favorites toggle will already be activated. If you arrive at the search page via other routes, you will need to manually activate the favorites toggle to filter for just your favorite items.
This function is only available if you are logged in. Also, we will be adding more items, like workouts, to the favorite function in the future. Enjoy!
humanOS Catalog Feature of the Week
How-to Guide - Chrononutrition (Eating Timing)
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.)