Newsletter #042: How bed rocking and magnesium affect sleep quality. 🛌🏻💤
Welcome to the latest edition of the humanOS newsletter! Here, we’ll share our work, plus some of the cool studies and media that we reviewed this week and that found their way onto our social media channels. 🤓
This Week’s Research Highlights
Researchers randomly assigned 250 subjects to receive either magnesium or placebo, then determined changes in plasma vitamin D. The researchers found that the relationship between magnesium intake and plasma concentration of vitamin D was different in participants depending upon their baseline concentrations of 25(OH)D. Magnesium supplementation elevated vitamin D concentration when baseline levels were close to 30 ng/mL, but decreased it when baseline 25(OH)D was higher (from ∼30 to 50 ng/mL) - suggesting that magnesium was playing a regulating role. Unfortunately, food records and large-scale dietary surveys suggest that around half of the US population (perhaps more) is falling short of meeting the recommended daily intake of magnesium.
Researchers had 18 young participants spend two nights in a lab — one on a rocking bed, one on an identical bed that stayed still. When sleeping on the rocking bed, subjects fell asleep faster, spent more time in NREM sleep, slept more deeply, and woke up less. They also performed better on memory tests the next morning. Another study, using mice, found similar benefits for sleep latency and duration. They found that mice who lack functional otolithic organs in their ears did not experience these effects - suggesting that the effects of rocking may be linked to rhythmic stimulation of the vestibular system.
🩸 Relatively modest elevations in blood pressure may have negative effects on the brain - even in young people.
Researchers analyzed the relationship between blood pressure and gray matter volume from magnetic resonance imaging in 423 healthy adults between the ages of 19 to 40. They found that blood pressure higher than 120/80 mm HG was correlated with lower gray matter volume in various regions in the brain, including the hippocampus, amygdala, thalamus, frontal, and parietal structures.
A group of 137 people with prediabetes were randomly assigned to various exercise regimens (resistance, aerobic, or aerobic + resistance), or to a control group. The groups performed supervised exercise for 60 minutes per day, 3 days per week. After 24 months, incidence of diabetes was decreased by 65-74% compared to controls, along with accompanying improvements in blood glucose and lipid profiles.
Podcasts We Loved This Week
- Michael Rose: Embracing the power of evolution to stop aging. Via the Live Long and Master Aging (LLAMA) Podcast.
- Jed Fahey: Moringa (FYI: green plant, super rich in nutrients and antioxidants, deserves more attention!). Via Smart Drug Smarts with Jesse Lawler.
- Katie Thomas & Eric Campbell: Doctors failed to disclose when drug companies were paying them. Via Science Friday.
- Brad Lister & Erica McAlister: How disappearing insects could trigger ecological calamity. Via Science Friday.
New humanOS Content
- Blog: Men Who Can Do More Push-ups Have Lower Risk of Cardiovascular Diseases. By Greg Potter.
This week on the blog, Greg talked about a unique new study from the good folks at the Harvard School of Public Health, which purports to have found a super easy (and free!) method to assess cardiovascular disease risk.
Cardiovascular disease accounts for 31% of deaths worldwide – more than anything else. The terribly frustrating thing about this is that most of these deaths are preventable by sticking to the fundamental tenets of a healthy lifestyle. Of course, to effectively prevent cardiovascular disease, we need reliable tests that identify people who are at high risk before clinical events occur. New research by Professor Stefanos Kales’ team from Harvard School of Public Health suggests that the humble push-up may actually be one such test. Here's what they did.
Researchers looked at the results of push-up tests completed by male firefighters from Indiana fire departments between 2000-2007. The scientists then split the firefighters into quintiles based on how many push-ups they were able to perform.
To assess whether push-up scores predicted risk of dying from cardiovascular disease in the following 10 years, the researchers referred to a registry of firefighter deaths. Sure enough, push-up capacity emerged as a remarkably good predictor - and you might be surprised by how much. To learn more, check out the blog!
The humanOS Bookshelf
Merchants of Doubt by Naomi Oreskes and Erik Conway.
Ginny says: Think back to the high-profile scientific issues that have dominated public policy debate over the past 60 or so years. The link between tobacco and lung cancer. Climate change. Second-hand smoke. DDT. Acid rain. These may not seem to be obviously connected to one another. But research has revealed that the same few contrarian scientists, driven by ideological and financial incentives, worked behind the scenes to challenge overwhelming scientific consensus and prevent public interventions against these problems. How did they do it? They engaged in a few common tactics, originally developed from their response to tobacco: "discredit the science, disseminate false information, spread confusion, and promote doubt."
If you’ve ever wondered why it took so long for the government to intervene against tobacco - despite the fact that there was already pretty convincing epidemiological and animal research suggesting it was harmful - this will open your eyes. It is fascinating (and disturbing) from a historical standpoint to consider how much the deliberate misuse of science may have cost us. But aside from that, I think it is also instructive for understanding current and future issues that face us in understanding and communicating scientific consensus.
If you study closely the tactics used by these “experts” to obfuscate and create false controversy, for instance, you might find some interesting parallels in the dialogue surrounding scientific issues today.
Finally, this book was also recently made into a documentary, which is no substitute for the book but totally worth watching (I rented it on YouTube for about four bucks).