Newsletter #015: The lasting impact of sedentary behavior on metabolic health 🏥
Hello again everyone, and welcome to the latest HumanOS newsletter! Here we share our own work, as well as any studies and media that grabbed our attention.
This week on humanOS Radio, Greg interviewed Dr. Stuart McGill, professor emeritus of spine biomechanics at the University of Waterloo. Dr. McGill is one of the world’s leading experts in lumbar research, and has more than thirty years of experience in back pain prevention and rehabilitation. This show pretty much covers everything you ever wanted to know about back pain, an all-too-common problem - if you don’t have spinal issues, you probably know someone who does. This episode addresses, among other things, whether lifting belts are a good idea for people with back pain, appropriate bedding, training the back, whether back surgery is a good idea, and some key things that Dr. McGill has picked up from observing and treating elite athletes. Definitely worth a listen!
This Week’s Research Highlights
🏃 Taking a break from physical activity may have a lasting impact on metabolic health.
Researchers at McMaster University in Ontario recruited 22 overweight older adults with prediabetes and had them dramatically lower their physical activity levels for seven days, followed by 14 days of returning to normal activity patterns. The participants managed to reduce their daily step count from 7362 ± 3294 to 991 ± 97 during the inactive phase. During this time, they experienced lowered rates of muscle protein synthesis as well as worse glycemic control. And these effects lingered weeks later. Even after 14 days of restored normal physical activity, levels did not return to baseline.
🏋️ Relatively small doses of exercise can make a big difference in health and lifespan.
Researchers analyzed data from a large cohort of healthy French retirees, whose physical activity levels were assessed every four years. After 15 years of followup, they found that the risk of all-cause mortality was reduced by 22% for participants who achieved a low level of physical activity (equivalent to just 15 minutes of moderate activity daily), compared to those who were inactive. The researchers determined that this was mediated partially by up-regulation of the autonomic nervous system.
💊 Higher dietary omega-6 to omega-3 polyunsaturated fatty acid ratio is associated with higher body fatness and a worse metabolic profile.
Researchers examined cross-sectional data from 170 Mexican adults. Participants provided dietary information, blood samples, and their body compositions were measured. The researchers found that subjects whose diet contained a higher ratio of omega-6 to omega-3 had more body fat and a larger waist circumference on average. Furthermore, they had higher levels of triglycerides, glucose, insulin, and insulin resistance, compared to those with a lower ratio of omega-6 to omega-3.
Podcasts We Loved This Week
- David Sabatini: Rapamycin and the Discovery of mTOR — the Nexus of Aging and Longevity? Via The Peter Attia Drive.
- Ken Ford: Optimal Diet and Movement for Healthspan, Amplified Intelligence and More. Via Nourish Balance Thrive.
- Daniel Kahneman: On Misery, Memory, And Our Understanding Of The Mind. Via Hidden Brain.
New humanOS Content
Media Featuring humanOS
Poor mental health is underappreciated as a cause of reduced productivity.
In an analysis of economic and demographic data from 2008 to 2014, researchers found that just one extra day of poor mental health in a month was associated with a 1.84% drop in per capita real income growth rate, resulting in $53 billion less total income each year.
High intake of both EPA and DHA may reduce the risk of preterm birth.
Pregnant women who have low plasma levels of eicosapentaenoic acid (EPA) and docosapentaenoic acid (DHA) in their first and second trimesters were found to be at 10 times higher risk of early preterm birth when compared with women who had higher levels of these fatty acids.
People who believe that they are sensitive to gluten may actually be reacting to fructan, a fructooligosaccharide that is found in wheat, as well as other fruits and veggies.
When people on a self-instituted gluten-free diet were given either fructan, gluten, or placebo (cleverly hidden in muesli bars) they are more likely to react to fructan than gluten, and there is no difference in reactions between gluten and placebo groups…
The humanOS Bookshelf
Enlightenment Now by Steven Pinker.
Greg says: Does it ever seem that the world has been spiraling out of control in the last few years? Sometimes it’s instructive to pause, pan back, and assess your perspective. In this timely book, Pinker persuasively argues that our species actually generally continues to head in the right direction… and we’ll stay on track if we continue to use reason and science to guide our path. Bill Gates is a pretty smart guy, and he says Enlightenment Now is currently his favorite book. I can vouch that this is for good reasons!