Study Links Nighttime Light Exposure to Increase Alzheimer's Risk in Adults Under 65 - Video

“We show that in the US there is a positive association between Alzheimer's disease prevalence and exposure to light at night, particularly in those under the age of 65,” said the first author of the Frontiers in Neuroscience study, Dr Robin Voigt-Zuwala, an associate professor at Rush University Medical Center. “Nightly light pollution – a modifiable environmental factor – may be an important risk factor for Alzheimer's disease.”

The researchers studied light pollution maps and incorporated medical data about variables known or believed to be risk factors for Alzheimer's disease in their analysis. They generated nighttime intensity data for every state and divided them into five groups, from lowest to highest nighttime light intensity.

Their results showed that for people aged 65 and older, Alzheimer's disease prevalence was more strongly correlated with nightly light pollution than some other disease factors, including alcohol abuse, chronic kidney disease, depression, and obesity. Other risk factors, like diabetes, high blood pressure, and stroke were more strongly associated with Alzheimer's disease than light pollution.

For people aged under 65, however, the researchers found that higher nighttime light intensity was associated with a greater Alzheimer's disease prevalence than any other risk factor examined in the study. This could suggest that younger people may be particularly sensitive to the effects of light exposure at night, the researchers said.

The researchers hope that their findings can help educate people about the potential risks of light at night. “Awareness of the association should empower people – particularly those with risk factors for Alzheimer's disease – to make easy lifestyle changes,” said Voigt-Zuwala. “Easy-to-implement changes include using blackout curtains or sleeping with eye masks. This is useful, especially for those living in areas with high light pollution.”

Reference: Voigt, R. M., Ouyang, B., & Keshavarzian, A. (2024). Outdoor nighttime light exposure (light pollution) is associated with Alzheimer’s disease. Frontiers in Neuroscience.https://doi.org/10.3389/fnins.2024.1378498