Newsletter #019: The Impact of Sleep and Heart Health 💤
Welcome to the latest edition of the humanOS newsletter! Here, as always, is where we share our own work as well as the various cool studies that grabbed our attention and found their way onto our social media channels.
This week on the blog, Greg wrote up a very useful breakdown of how dietary nitrate works in the body. We have addressed nitrates previously in the context of brain function and aging. Nitrates act as precursors to nitric oxide (NO), which in turn relaxes the walls of blood vessels, reducing blood pressure and enhancing blood flow. This, as you can imagine, seems to have a favorable impact on certain types of exercise performance, plus just generally being good for your blood vessels. Best of all, Greg explains how you personally can take advantage of this phenomenon at home. Great stuff!
Finally, Dan is delivering a talk at TEDxMarin this evening! Super exciting for all of us. He will be discussing how modern patterns of light exposure affect our body and mind, and some possible solutions to this apparent evolutionary mismatch. Alas, the event appears to be sold out, so it is unlikely that you will be able to attend in person (which is kind of unsurprising - this slate of speakers looks pretty awesome). However, we will definitely share the video as soon as it becomes available.
This Week’s Research Highlights
Swedish researchers analyzed data from 759 50-year-old men living in Gothenburg. Participants underwent a physical exam and completed detailed questionnaires regarding their lifestyle, including sleep habits. The men were divided into four groups based on their average sleep duration at the start of the study, and were subsequently followed for 21 years. High blood pressure, obesity, type 2 diabetes, and cardiovascular disease were all more prevalent in men who slept five or fewer hours per night, compared to those who got at least seven hours of sleep. Compared to men with healthy sleep patterns, men who got five hours of sleep or less had twice the risk of having a major cardiovascular event by age 71, compared to those who sleep 7-8 hours per night. The risk remained doubled after adjusting for cardiovascular risk factors at the start of the study, like smoking, obesity, and diabetes.
Researchers analyzed cross-sectional data from 798 masters athletes (over the age of 35). Participants underwent a physical exam, and those with abnormal results underwent further testing. Cardiovascular disease was detected in 11.4% of participants, with ten athletes being diagnosed with significant coronary artery disease (meaning an arterial blockage of 70% or greater). The researchers conclude, "Masters athletes are not immune to elevated cardiovascular risk and cardiovascular disease.”
🧴 A novel facial cream containing carnosine inhibits the formation of advanced glycation end-products (AGEs) in human skin.
Researchers induced glycation in human skin samples via methylglyoxal in a petri dish. Then, they applied a facial cream containing carnosine topically to the skin. When they measured levels of AGEs in the skin sections, they found that the carnosine product dramatically inhibited the formation of glycation products.
Researchers recruited 120 participants and randomly assigned them to consume either placebo or a liquid nutraceutical containing hydrolyzed fish collagen (4 grams), as well as some vitamins and antioxidants. After 90 days of consuming the test product daily, the collagen group showed a significant increase in skin elasticity (+40%), compared to the placebo group. When the researchers analyzed skin biopsies, they saw improvements in collagen fiber organization in the experimental group. Furthermore, participants reported reduced joint pain (−43%) and improved joint mobility (+39%).
Podcasts We Loved This Week
- Simon Marshall: Why most people never learn from their mistakes - but some do. Via Nourish Balance Thrive.
- Sadaf Farooqi: What makes us fat? Via The Life Scientific.
New humanOS Content
- Blog: Dietary Nitrate and Exercise Performance: Benefits of Beetroot. By Greg Potter.
The humanOS Bookshelf
Internal Time. By Till Roenneberg.
Greg says: Till is a titan in chronobiology research and has done a huge amount to educate people about chronotypes and “social jetlag” (Till coined this term). This is a very accessible book in which he shares stories that illustrate simple principles to help you keep your biological clock on time.