06/10/2026
Daytime naps may slow brain aging by up to 6.5 years, according to a 2023 study published in the journal Sleep Health. Researchers from University College London and the University of the Republic in Uruguay analyzed data from 378,932 UK Biobank participants and found that people genetically predisposed to napping had larger total brain volume, a marker of brain health linked to lower dementia risk. The difference, about 15.8 cubic centimeters, equates to roughly 2.6 to 6.5 fewer years of brain aging.
The study's strength is its method. Rather than simply asking people how often they nap, which can be skewed by illness, researchers used a genetic technique called Mendelian randomization to isolate napping's actual effect, making the case for causation stronger than a typical observational study.
Several caveats matter. The benefit appeared in brain structure only, with no measurable improvement in memory, reaction time, or cognitive test scores. The authors caution against overinterpreting the results, noting that napping can disrupt nighttime sleep, and prior research suggests short naps under 30 minutes are best.
Sources: Sleep Health, UCL, Medical News Today.
