Air pollution may be a risk factor for dementia that is difficult for many people, particularly those who live in big cities, to avoid. Several new studies recently presented during the Alzheimer’s Association International Conference highlight the link between dementia risk and pollution, presenting evidence that improving air quality may likewise result in a decrease in dementia cases.
Air pollution, which can be caused by things ranging from vehicle emissions to large industrial plants and wildfires, has been linked by previous studies to increased accumulation of plaques in the brain, an issue tightly linked to the development of dementia, including Alzheimer’s disease.
The new series of studies from the Alzheimer’s Association presents the first batch of evidence that improving air quality, particularly when it comes to pollution from burning fuels and fine particulate matter, is linked to a decrease in all-cause Alzheimer’s and dementia risk.
Reductions in fine particulate matter, often called PM2.5, were linked to benefits in both cognitive function and dementia risk. For example, older women in the US were found to have experienced a 14-percent drop in dementia risk and a 25-percent decrease in cognitive decline when the levels of PM2.5 and traffic fuel pollutants were reduced.
When looking at data on French individuals, the studies found that reducing PM2.5 pollutant concentrations over a decade correlated with a 15-percent drop in all-cause dementia risk and a 17-percent drop in all-cause Alzheimer’s risk.
On the flip side, individuals in the US who had long-term exposure to poor air quality were also found to have higher levels of the beta-amyloid plaques in their blood, possibly leading to the brain changes that are observed in people who have Alzheimer’s disease.
Air pollution is linked to other health problems, as well, including poorer lung function and an overall drop in life expectancy. In a statement about the findings reported in these new studies, the Alzheimer’s Association’s Claire Sexton said:
We’ve known for some time that air pollution is bad for our brains and overall health, including a connection to amyloid buildup in the brain. But what’s exciting is we’re now seeing data showing that improving air quality may actually 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.