Less Than 42 Minutes of Bright Daylight Linked to Higher Dementia Risk

A new study of more than 87,000 adults found that spending less than 42 minutes each day in bright daylight is a stronger predictor of dementia than six established risk factors. Researchers measured daytime light exposure and followed participants for several years, discovering that higher levels of bright light were associated with a 16 % lower risk of developing dementia. The protective effect grew with longer exposure, suggesting a dose‑response relationship. The analysis controlled for age, genetics, education, and other lifestyle variables, reinforcing the robustness of the association. These results imply that brief, regular periods of natural light could be a simple, non‑pharmacologic strategy to reduce dementia risk. Public health guidelines may need to consider daylight exposure as a modifiable factor in cognitive health promotion.