New research claims that exposure to outdoor light at night may increase the prevalence of Alzheimer’s disease, especially in people under the age of 65.
The researchers who conducted the study, funded by a National Institutes of Health grant and published in the journal Frontiers in Neuroscience on Friday, said they have found correlations between areas of the US with excessive exposure to artificial light at night and the prevalence of Alzheimer’s disease.
In the US, at least 19 states have legislation in place aimed at reducing light pollution, but the authors of the study say that despite this, the “levels of light at night remain high in many parts of the country”.
While “streetlights, roadway lighting, and illuminated signs can deter crime, make roads safer, and enhance landscaping”, undisrupted light, however, “comes with ecological, behavioral, and health consequences”, the authors said.
For this study, the researchers evaluated Alzheimer’s disease prevalence by looking at the average nighttime light intensity by state and county in the US from 2012 to 2018, using satellite-acquired light pollution data and Medicare data reports of Alzheimer’s prevalence. They also incorporated medical data about variables known or believed to be risk factors for Alzheimer’s disease into their analysis, they said.