Newsletter #058: How Bad Sleep Affects Epigenetic Age Acceleration and Blueberries for Heart Health 🫐
Welcome to the newest edition of the humanOS newsletter! Here is where we share our work, plus the various studies and media that captured our attention this week. 🤓
This Week’s Research Highlights
Researchers analyzed self-reported data from ~44000 women (none of whom were shift workers, day sleepers, or pregnant). Women who slept with a light on (or with a television on in the background) were 17% more likely to gain 5 kilograms or more over five years. The findings remained when researchers adjusted for diet, physical activity, sleep duration, and sleep quality.
622 older adults had their sleep evaluated by polysomnography, and their blood DNA methylation measured. Researchers calculated epigenetic age and compared it to chronological age. The results revealed that each standard deviation increase in the apnea-hypopnea index - a measure of the severity of sleep-disordered breathing - was associated with the equivalent of 215 days of biological age acceleration. Similarly, each standard deviation increase in the arousal index, a measure of sleep disruption, was associated with the equivalent of 321 days of age acceleration.
Researchers followed 2003 participants in the Multi-Ethnic Study of Atherosclerosis (MESA). Subjects wore actigraph wristwatches to track sleep schedules for seven consecutive days and were followed for about six years. Individuals with greater variations in their bedtimes, as well as the hours that they slept, showed a higher prevalence of metabolic problems, including obesity, diabetes, and high cholesterol. For every hour of variability in time to bed and time asleep, there was up to 27% greater risk of metabolic abnormality. Importantly, variations in sleep duration and bedtimes preceded the development of metabolic dysfunction.
Researchers recruited 138 participants with an average BMI of 31 and had them consume either 150 grams of blueberries (freeze-dried) or a purple-colored placebo made from artificial colors and flavors. After six months, the blueberry group showed improved endothelial function, reduced systemic arterial stiffness, and higher HDL cholesterol levels. The observed effects predicted a 12-15% reduction in cardiovascular risk.
A prospective cohort of 172 women was evaluated at each trimester for depressive symptoms, as well as serum levels of omega-3 and omega-6 polyunsaturated fatty acids. Overall prevalence of depressive symptoms was quite high in this cohort. As women progress through pregnancy, higher levels of EPA, DHA, and total omega-3 were associated with lower odds of depressive symptoms, while higher total omega-6/omega-3 ratios were related to increased odds of depressive symptoms.
Podcasts We Loved This Week
- Christopher Barnes: Sleep, ethical behavior, and the workplace. Via Sleep Junkies.
- Roger Ekirch: The history of sleep. Via Sleep 4 Performance Podcast with Ian Dunican.
Products We Are Enjoying
Ginny says: This is currently our favorite non-dairy milk. Really delicious, great mouth-feel, and tastes good in coffee, tea, or just by itself. Way better than oat milk I’ve had in the past. It’s also a safe pick from a nutritional standpoint: free of added sugar, thickeners, or gums, and a good source of beta-glucans, calcium, and vitamins A and D. It’s gradually becoming easier to find in stores here in the US - I snagged it at Target - but you can also order online if it’s not available in your neck of the woods.