Researchers from Qingdao University have identified a link between long durations of sun exposure and changes in brain health. The study was reported in a peer‑reviewed scientific journal and examined how daily sun exposure might relate to brain structure and aging.
In this analysis, data from about 27,400 participants were reviewed, with an average age of 55. Each participant underwent brain imaging and provided information about the typical amount of time they spent outdoors in direct sunlight each day.
The participants were split into three groups based on daily sun exposure: less than 1.5 hours, between 1.5 and 3 hours, and more than 3 hours. This stratification allowed researchers to compare brain health markers across a spectrum of sun exposure while controlling for other factors.
Using statistical models, the researchers evaluated differences in structural brain markers among the groups, accounting for age, sex, physical activity, average sleep duration, skin tone, and medical history. The goal was to understand whether sun exposure itself is associated with measurable changes in the brain, independent of these other influences.
The findings indicated a concerning pattern. Participants who reported longer daily sun exposure tended to have smaller overall brain volume and greater white matter hyperintensity, both of which are linked to aging of the brain and potential cognitive changes.
Compared with those in the lower exposure category, participants in the highest exposure group showed notable reductions in total brain volume, white matter, and gray matter. The differences were more evident among men and among individuals under the age of 60.
Based on the data, researchers noted that sun exposure could be considered at up to about two hours per day without apparent adverse effects on brain structure, though the context of daily activities and individual risk factors matters.
The study underscores the importance of balancing sun exposure with protective measures and highlights how observational findings can prompt further investigation into the mechanisms connecting sunlight, brain aging, and cognitive health.
Earlier guidance from medical sources has addressed balancing vitamin D needs with skin cancer risk and the value of protective sun practices, such as using sunscreen and wearing protective clothing. These considerations remain part of a broader discussion about healthy sun habits and long‑term brain well‑being.