Too much exposure to natural sunlight has been linked to negative effects on brain health.
A study found that spending more than two hours in the sun each day could be linked to decreased brain volume and increases in brain structural markers associated with disease, particularly in individuals under 60 years old -- and men.
Study participants who reported longer sunlight exposure tended to have smaller brain volumes and increased white matter hyperintensities, which are considered markers of brain aging and can be linked to cognitive decline. Specifically, those in the highest exposure group (more than 3 hours) showed significant reductions in total brain volume, white matter, and gray matter compared to those with shorter exposure times.
The researchers noted that these effects were more significant during the summer months, indicating that seasonal variations may play a role in how sunlight impacts brain structure.