The possible link between air pollution and dementia has been a focus of several studies and at the recent US Alzheimer’s Association International Conference (AAIC), the topic came to the fore again. 

New findings

Whilst previous reports have linked long-term air pollution exposure with accumulation of Alzheimer’s disease-related brain plaques, a series of new reports released by the US Alzheimer’s Association suggest that reduced pollution is associated with lower risk of dementia and Alzheimer’s disease.

Some of the key findings are:

– A reduction of fine particulate matter (PM2.5) over 10 years was associated with reductions in dementia risk, and slower cognitive decline, in older U.S. women. These benefits occurred in women regardless of their age, level of education, the geographic region where they lived and whether they had cardiovascular disease.

– Long-term exposure to air pollutants was associated with higher beta amyloid levels in the blood in a large U.S. cohort, showing a possible biological connection between air quality and physical brain changes that define Alzheimer’s disease.


The NIHR’s Director for Dementia Research, Professor Martin Rossor comments on these new findings:

“There has been a steady increase in studies that show an association between high pollution and poor general health including cognitive health. Although association cannot prove causation, data showing changes with pollution and cognition and subsequent risk of later life dementia add to the weight of evidence. 

“Moreover the association with concentrations of amyloid – the protein found in senile plaques in the brain of those living with Alzheimer’s disease – provides a plausible causative link. 

“Many factors that contribute towards dementia are not changeable, but pollution is a factor that we can control. If nations were to act on the basis of this new evidence, it would help address not only the global challenge of dementia but also the issue of global warming.”