Spending time outdoors, even on cloudy days, may be crucial in preventing dementia, according to a study published in the journal General Psychiatry. Chinese researchers found that people who spend less than an average of 42 minutes outside each day are significantly more likely to develop the incurable brain disease.
The study, which monitored the day and night-time light exposure of 87,000 adults over eight years, observed that those who developed dementia had markedly less daily sunlight exposure. Scientists concluded that the longer individuals spend outdoors daily, the lower their risk of developing dementia.
Even in overcast conditions, regular time spent outdoors could potentially lower the risk of dementia by up to 16 percent. Experts are exploring the reasons behind this link, with some suggesting that individuals in poorer health may be less inclined to go outside, while others hypothesize that sunlight plays a role in regulating the body's circadian rhythm, which influences sleep and the removal of toxic cells.
Dementia affects nearly a million people in the UK, with numbers expected to rise due to an aging population. The condition is currently incurable and causes more than 75,000 deaths annually. Current research suggests that lifestyle changes such as regular exercise, social interaction, and managing blood pressure, weight, and cholesterol levels can reduce the likelihood of developing dementia. The findings of this new research could potentially add sunlight exposure to the list of preventative lifestyle factors.
"Daytime light exposure may serve as a [new] indicator of dementia risk," stated Dr. Hongliang Feng at Guangzhou Medical University.