Alzheimer’s disease (AD) is characterized by the pathological formation of beta-amyloid plaques and tau tangles in the brain tissues, years before the actual symptoms of memory loss and behavioral deficits occur.
‘Reducing air pollution especially from the burning of fuel, traffic-related pollutants (NO2), and fine particulates (PM2.5) in the air is associated lower risk of dementia and Alzheimer’s disease in people. Thus improving air quality may aid in enhanced cognition.’
Air pollution and Cognitive Risk
The study team analyzed a group of older women (aged 74-92) in the U.S. from the National Institutes of Health-funded Women’s Health Initiative Memory Study-Epidemiology of Cognitive Health Outcomes (WHIMS-ECHO) with no pre-existing dementia. The participants underwent cognitive function tests and were followed from 2008-2018.
The study for the first time demonstrates that reducing pollution especially from burning of fuel, traffic-related pollutants (NO2) and fine particulates (PM2.5) per 10% of the Environmental Protection Agency’s (EPA) current standard over 10 years in the air is associated with 14% lower risk of dementia and Alzheimer’s disease in older U.S. women.
There was also 26% slower cognitive decline among them. The study adds that these positive effects were regardless of the age, level of education, geographic region, and presence of cardiovascular disease.
The other findings from the study were:
- Cutting down the PM2.5 concentration over 10 years reduced the risk of all-cause dementia in French individuals by 15% and of Alzheimer’s disease by 17% for every microgram of gaseous pollutant per cubic meter of air (μg/m3) decrease in PM2.5.
- Higher beta-amyloid levels in the blood were related to long-term exposure to air pollutants in a large U.S. cohort.
“We’ve known for some time that air pollution is bad for our brains and overall health, including a connection to amyloid build-up in the brain. But what’s exciting is we’re now seeing data showing that improving air quality may reduce the risk of dementia. These data demonstrate the importance of policies and action by federal and local governments, and businesses, that address reducing air pollutants,” says Claire Sexton, DPhil, Alzheimer’s Association director of scientific programs and outreach.