Study links air pollution to increased Alzheimer's risk


They may be real health benefits to living in the country

If you live in Alabama, Georgia, California, Pennsylvania, Missouri, Texas, Indiana, or Illinois, stop what you’re doing and recite the names of 12 types of animals, as the Final Jeopardy theme plays quietly in the background.

Where in the heck are we going with this? We're just testing your memory.

A new study published in Neurology, a journal of the American Academy of Neurology, suggests that there’s a link between traffic-related air pollution -- the kind that's in Alabama, Indiana, etc. and the development of Alzheimer's disease.

According to the research, individuals exposed to fine particulate (PM 2.5) amyloid plaques – one of the chief indicators of Alzheimer's – in their brains were more likely to develop the cognitive illness. While the study doesn't definitively prove that it’s the actual cause, it adds to the growing body of evidence suggesting a potential environmental connection to this devastating disease.

And that would mean the people in the Top 10 most polluted areas of the U.S. – Birmingham, Atlanta, central Pennsylvania, Los Angeles, Houston, St. Louis, Indianapolis, the Chicago area, Northwest Indiana, and Bakersfield– could be most at risk.

Age is also important

Especially if they’re anywhere in the neighborhood of being in their mid-70s, because the average age of the people whose brains were donated for this study was 76.

“These results add to the evidence that fine particulate matter from traffic-related air pollution affects the amount of amyloid plaque in the brain,” said study author Anke Huels, of Emory University in Atlanta. “More research is needed to investigate the mechanisms behind this link.”

Researchers also dove into the question of whether having the main gene variant associated with Alzheimer’s disease – APOE e4 – had any impact on the relationship between air pollution and signs of Alzheimer’s. They found that the strongest relationship between air pollution and signs of Alzheimer’s was among those without the gene variant.

“This suggests that environmental factors such as air pollution could be a contributing factor to Alzheimer’s in patients in which the disease cannot be explained by genetics,” Huels said.

Wildfires, gas stations, and agriculture, too

Short of moving to Maine or Vermont or never going outside again, a second study from the University of Michigan School of Public Health indicates that it’s not just taking in the exhaust fumes as they roll on down the highway, but Alzheimers/dementia might also be tied to environmental factors, such as pollutants from agriculture applications, wildfires, and even gas stations.

Wildfires – because they can travel over a large area – are considered to be the root cause of up to 25% of fine particulate matter exposures over a year’s time across the US as a whole, and as much as 50% in some western regions of the country.

You can learn more about dementia at, home of the American Academy of Neurology’s free patient and caregiver magazine focused on the intersection of neurologic disease and brain health.

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