A Month of Early Time-Restricted Eating Linked to Younger Estimated Brain Age - General science

In a small study of 23 men with metabolic syndrome, eating only between 8 a.m. and 4 p.m. for four weeks was associated with improved scores on some memory measures and a smaller MRI-estimated brain age gap. The researchers say the findings do not establish that meal timing caused the changes.

Men with metabolic syndrome who ate within an eight-hour daytime window for one month showed improved immediate and delayed recall scores, alongside a reduction in their estimated brain age, according to a study published in Frontiers in Aging. The results are preliminary: the study included 23 men and had no comparison group.

Participants were instructed to eat between 8 a.m. and 4 p.m. and drink only water during the remaining 16 hours. They were not told to restrict the types or amounts of food they ate. All 23 men completed the four-week program.

After the intervention, participants had lost an average of about 4.4 kilograms. Their fasting blood sugar and triglyceride levels also fell, while measures of insulin resistance improved. Changes in total, HDL and LDL cholesterol were not statistically significant.

On a word-list memory test, average immediate recall scores increased by about 19%, as did delayed recall. The change in a measure of interference recall was not statistically significant. MRI-based estimates put participants’ brains at an average of 2.8 years older than their actual ages at the start of the study; after a month, the gap was about 2.0 years, a reduction of roughly nine months.

The researchers also reported increases in gray matter volume in four left-side brain regions: the thalamus, hippocampus, substantia nigra and red nucleus. The hippocampus and thalamus are involved in memory processes. However, the study did not establish that these structural changes caused the improvements on the memory test.

The findings cannot show whether the changes resulted from the timing of meals, weight loss, reduced calorie intake or other factors. The researchers did not measure how much participants ate, and there was no control group to compare with men who continued their usual eating habits. The authors also noted that repeating the same memory test may have influenced scores.

The study’s findings apply only to a small group of men followed for four weeks, so it is not clear whether they would extend to women, older adults or people without metabolic syndrome. The researchers say larger, longer studies should track calorie intake and include comparison groups to help distinguish the effects of meal timing from those of eating less.

Sources: PsyPost.