For the first time, research has connected light pollution with an increased risk of Alzheimer’s disease, particularly in individuals under the age of 65. The study, conducted by Rush University System for Health and published in Frontiers in Neuroscience, highlights a potential new environmental factor in Alzheimer’s risk.
Lead investigator Robin Voigt-Zuwala, PhD, an associate professor at Rush, stated, “Our research shows that there is an association in the U.S. between Alzheimer’s disease prevalence and exposure to light at night, particularly in those under the age of 65.” The study suggests that nightly light pollution—a modifiable environmental factor—could influence the risk of developing Alzheimer’s.
Researchers analyzed light pollution maps across the lower 48 U.S. states, comparing them with medical data related to Alzheimer’s risk factors. They found that higher night-time light intensity was correlated with increased prevalence of Alzheimer’s disease, even after accounting for other well-known risk factors.
NIGHTTIME LIGHT AND ALZHEIMER’S RISK
The study found that increased exposure to night-time light was associated with a greater prevalence of Alzheimer’s disease, surpassing other risk factors for individuals under 65. This suggests that younger people may be more sensitive to light exposure at night.
Voigt-Zuwala explained, “Certain genes can influence early-onset Alzheimer’s, and these same genes may cause increased vulnerability to the effects of night-time light exposure. Additionally, younger people are more likely to live in urban areas and have lifestyles that increase exposure to light at night.”
Exposure to light at night disrupts the body’s natural sleep-wake cycle, or circadian rhythm. This disruption can lead to increased inflammation and reduced resilience, potentially contributing to various health issues, including Alzheimer’s disease. The study did not examine the impact of indoor light exposure or its direct effects on health.
MITIGATING LIGHT POLLUTION
Voigt-Zuwala highlighted that there are simple measures individuals can take to reduce their exposure to night-time light. “The good news is that simple changes can be made with minimal effort, such as adding blackout curtains or using an eye mask while sleeping.”
While the study provides important insights, it is limited to a subset of the population. Further research is needed to better understand the relationship between evening outdoor light and Alzheimer’s disease. The findings suggest that reducing light pollution could be a potential strategy for mitigating Alzheimer’s risk, particularly in younger populations
