Between Saturdays
This week: how meal timing shapes metabolism, why microplastics in the blood raise concern, what “social jetlag” means for mental health, and olive oil’s link to brain aging.
Every week, I spend some time digging into recent health research and share the studies that made me pause, reflect, and rethink. The goal isn’t just to highlight science for science’s sake, but to connect it to everyday health choices in a way that feels real and practical.
Caught My Eye…
• Intermittent fasting improves more than weight
A randomized clinical trial in Annals of Internal Medicine followed adults with obesity for 12 months. Participants were split into two groups: one group practiced time-restricted eating (eating all meals within an 8-hour window each day) while also reducing calories, and the other group followed a standard calorie-restricted diet spread across the day.
Both groups lost weight, but the time-restricted group showed greater improvements in insulin sensitivity, blood pressure, and liver fat reduction. The findings suggest that when we eat may be just as important as how much we eat—pointing to meal timing as a metabolic regulator, not just a lifestyle preference.
• Microplastics found in human bloodstream
Dutch researchers published one of the first large-scale studies detecting microplastics directly in human blood. Nearly 80% of participants had measurable levels, with the most common being polyethylene terephthalate (PET), often used in bottles and food packaging. Higher levels correlated with markers of low-grade inflammation. While the long-term health impact is still being studied, the finding underscores just how deeply plastics have entered our biology.
Click on the link to read full deep dive into microplastics
• Sleep irregularity raises mental health risks
A longitudinal study of over 30,000 U.S. college students found that inconsistent bedtimes—rather than just the total hours slept—were the strongest predictor of depressive symptoms. Students whose bedtimes varied by more than an hour from night to night showed significantly higher risks of mental distress.
Researchers describe this as social jetlag: the mismatch between our body’s natural circadian rhythm and the schedule we actually follow, often shaped by late-night studying, social life, or irregular routines. Just like crossing time zones, this misalignment disrupts hormones, mood regulation, and energy cycles.
The key takeaway is that the brain and body thrive on rhythm. Sleep regularity—going to bed and waking up around the same time—is as critical as sleep duration for mental health.
• Olive oil protects against cognitive decline
An observational analysis within the Harvard-led Nurses’ Health Study tracked over 90,000 adults for nearly three decades. Participants who consumed more than half a tablespoon of olive oil daily had a 28% lower risk of dementia-related death. The strongest benefit was seen when olive oil replaced butter or margarine, highlighting that substitution matters more than simply adding olive oil on top of an existing diet. Researchers suggest that olive oil’s polyphenols and anti-inflammatory properties help protect brain cells against age-related decline.
Until next Saturday,
Summaya