New research published in General Psychiatry has found that adults exposed to higher levels of daytime light may have a lower risk of developing dementia, according to a Jun. 24 report.
The study involved 87,577 adults who wore accelerometers on their wrists to measure both daytime and nighttime light exposure. Over a median follow-up period of 8.1 years, 741 participants developed dementia.
Researchers reported that average daytime light exposure above 1,000 lux—a moderately bright level comparable to an overcast day outdoors—was associated with a 16% reduction in the risk of developing dementia. The study also found that longer periods spent in bright daylight (at least 5,000 lux) were linked with an even greater reduction in risk.
The findings indicated that receiving less than 0.7 hours per day of bright daytime light was a stronger predictor of dementia than six established risk factors for the disease. In contrast, nighttime light exposure did not show any significant association with the likelihood of developing dementia.
The authors suggest these results highlight the potential importance of increasing daily exposure to natural or artificial bright daylight as part of strategies aimed at reducing dementia risk.
