Artificial nighttime light exposure linked to Alzheimer’s risk

By Faruk Zorlu

A new study revealed a significant association between outdoor nighttime light exposure, commonly known as light pollution, and the prevalence of Alzheimer's disease in the US.

The research was conducted by scientists at Rush University Medical Center, utilizing satellite-acquired light pollution data and Medicare records from 2012 to 2018.

The study, funded by the National Institutes of Health and published in Frontiers in Neuroscience, revealed a significant association between high levels of artificial outdoor light at night and increased Alzheimer's disease prevalence, particularly in individuals under the age of 65.

This group exhibited a stronger correlation between light pollution and Alzheimer’s disease compared to older populations.

The analysis categorized some states based on their average nighttime light intensity, revealing a statistically significant difference in Alzheimer's disease rates between the darkest and brightest states. For instance, states with the highest light pollution exhibited a markedly higher prevalence of Alzheimer's compared to those with minimal exposure.

Lead researcher Robin Voigt highlighted that light pollution could contribute to neuroinflammation, circadian rhythm disruptions, and sleep disturbances -- factors known to play roles in Alzheimer's disease development.

The findings suggest that those under 65 may be especially vulnerable to the effects of nighttime light exposure, Voigt said.

While conditions like hypertension and diabetes are more strongly linked to Alzheimer's disease, light pollution was found to be a more significant factor than other known risk contributors, including alcohol abuse, depression, and obesity.

The research built on previous studies that have explored the broader health implications of light pollution, which include sleep disruption and increased risk of various health conditions.

The findings suggested that public health interventions targeting light pollution could help mitigate Alzheimer's disease risks, particularly in urban areas where light levels remain high despite existing regulations.

As the global population continues to urbanize and light pollution rises, the researchers stressed the need to understand its broader implications for neurodegenerative diseases.