Higher daytime light exposure linked to lower dementia risk

New research in General Psychiatry has uncovered a link between higher levels of daytime light exposure and a lower risk of dementia.

For the study, investigators measured daytime and nighttime light exposure in 87,577 adults who wore accelerometers on their wrists. Over a median follow-up of 8.1 years, 741 participants developed dementia. Average daytime light exposure above 1,000 lux (a moderately bright light level equivalent to an overcast day outdoors) was associated with a 16% reduced dementia risk. Longer exposure to bright daytime light (at least 5,000 lux) was associated with a further reduction in risk.

Less than 0.7 hours per day of bright daytime light was a stronger predictor of dementia than 6 established dementia risk factors. Nighttime light showed no significant association with dementia risk.

Daytime light exposure may serve as a novel indicator of dementia risk."

Hongliang Feng, PhD, corresponding author, Guangzhou Medical University, China