Daylight to prevent dementia? How exposure may protect your brain

A large-scale new study found that exposure to less than 42 minutes of daylight per day is associated with a 17% increase in the risk of dementia. Researchers tracked about 87,500 participants over eight years. A neurologist explains the connection to the biological clock.

A large-scale new study published in the journal General Psychiatry found a link between lack of daylight exposure and an increased risk of dementia. According to the findings, people exposed to an average of less than 42 minutes of daylight had a 17% higher risk of developing dementia compared to those exposed to more time. Researchers tracked about 87,500 participants without dementia for about eight years, using light meters worn on the wrist. The association remained significant even after researchers accounted for other risk factors such as physical activity, diet, obesity, and cardiovascular health. Dr. David Perlmutter, a specialist neurologist, explains that light absorbed by the eyes helps synchronize sleep-wake cycles, hormone secretion, and metabolism, leading to quality restorative sleep. The main recommendation is to make daylight exposure part of the daily routine, especially in the morning hours. The article notes that the study is observational and indicates a correlation, not causation.