Alzheimer's map shows US states where newly revealed risk factor is worst

Nearly 7 million Americans are currently living with Alzheimer’s disease , and that number is expected to double by 2060. New research has pointed to a risk factor many might not have considered – artificial light.

“Higher outdoor nighttime light was associated with higher prevalence of AD,” said a study published Thursday in the Frontiers in Neuroscience journal. Researchers from Rush University Medical Center in Chicago, Ill., conducted the study using satellite acquired outdoor nighttime light intensity and Medicare data.

What they found indicates that nighttime light intensity was more strongly associated with prevalence of Alzheimer’s than alcohol abuse, chronic kidney disease, depression, heart failure, and obesity. At the same time, atrial fibrillation, diabetes, hyperlipidemia, hypertension, and stroke were associated more strongly with AD prevalence than nighttime light intensity.

Age is a major risk factor for Alzheimer’s, and the number of people living with the disease doubles every five years after age 65, according to the U.S.
Centers for Disease Control and prevention . Nighttime light exposure more strongly associated with AD prevalence in those under the age of 65 than any other disease factor examined, based on the study findings.

“There are numerous factors that contribute to the development of Alzheimer's disease,” Robin Voigt-Zuwala, an associate professor at Illinois; Rush University Medical Center and lead author on this research, according to Newsweek . “It is the constellation of these factors in totality that determine the risk of Alzheimer’s disease.”

Newsweek created a light pollution map to show where the light risk factor might be highest in the U.S., where Alzheimer’s is the most common form of dementia. You can find the map here .

This map shows that Connecticut, Florida, Illinois, Maryland, Massachusetts, New Jersey, Ohio and Rhode Island had the highest light pollution in the country. It also showed that many states east of the Mississippi River had higher light intensity than those west of it, with the exception of Alabama, Maine, Mississippi, New Hampshire, Vermont and West Virginia.

According to the Chicago-based Alzheimer’s Association , the condition has no cure. Plaques and tangles in the brain are two features linked to the disease, and there are some Alzheimer’s treatments that work at targeting plaques (buildups of protein in the brain).

People with AD develop the condition gradually. It can begin with mild memory loss and get so severe that holding a conversation becomes difficult. Per the Alzheimer’s Association, “the discovery that Alzheimer’s disease begins 20 years or more before the onset of symptoms suggests that there is a substantial window of time in which we may be able to intervene in the progression of the disease.”

Family history and brain changes can be warning signs. Researchers are also looking into factors such as education, diet and environment. Already, some research indicates that “healthy behaviors, which have been shown to prevent cancer, diabetes, and heart disease,” may reduce cognitive decline risks.

According to the authors of the recent study, more research into the connection between nighttime light intensity and Alzheimer’s is needed.