Spending time outdoors, even on cloudy days, may play a crucial role in preventing dementia, according to a study published in the journal General Psychiatry. Researchers from China found that individuals who spend less than an average of 42 minutes outside each day are at a significantly higher risk of developing the incurable brain disease. Conversely, the longer people spend outdoors daily, the lower their risk appears to be.
The study suggests that the benefits could be realized even in overcast conditions, with regular outdoor time potentially reducing dementia risk by up to 16 percent. While the exact reasons for this correlation remain unclear, some experts propose that people in poorer health, who are thus at a higher risk for dementia, may be less likely to leave their homes. Others hypothesize that sunlight is vital for regulating the body's circadian rhythm, which influences sleep and helps eliminate toxic cells.
Dementia currently affects nearly a million people in the UK, with numbers projected to rise due to an aging population. The condition, which has no cure, causes over 75,000 deaths annually. Growing evidence indicates that lifestyle changes, including regular exercise, social interaction, and maintaining healthy blood pressure, weight, and cholesterol levels, can reduce the likelihood of developing dementia. Research also suggests that using glasses or hearing aids when needed can lower risk.
The new findings could add sunlight exposure to the list of preventative lifestyle modifications for dementia. The research involved monitoring the day and night-time light exposure of 87,000 adults over eight years. During this period, 741 participants developed dementia. The scientists observed that those who developed the condition had markedly less daily sunlight exposure. Dr. Hongliang Feng of Guangzhou Medical University stated that "Daytime light exposure may serve as a [new] indicator of dementia risk."