Tiny particles that pollute the air — the type that mainly comes from power plants and automobiles — may greatly increase the chance of dementia, including Alzheimer’s disease, according to new research.
Scientists and engineers have found that older women who live in places with fine particulate matter exceeding the U.S. Environmental Protection Agency's standard are 81 percent more at risk for global cognitive decline and 92 percent more likely to develop dementia, including Alzheimer's. If their findings hold up in the general population, air pollution could be responsible for about 21 percent of dementia cases.
The adverse effects were stronger in women who had the APOE4 gene, a genetic variation that increases the risk for Alzheimer's.
The study, published in Translational Psychiatry, adds to an emerging body of research from around the world that links air pollution to dementia. The offending pollutants — known as PM2.5 — are fine, inhalable particles with diameters 2.5 micrometers or smaller.
The researchers analyzed data of 3,647 65- to 79-year-old women. These women lived across 48 U.S. states and did not have dementia when they enrolled. The researchers adjusted for potential bias associated with geographic region, race or ethnic background, education, socioeconomic status, lifestyle and medical conditions.
The researchers said more research is needed to confirm a causal relationship and to understand how air pollution enters and harms the brain. Accurate pollution monitors are important for this task. In addition, future studies will need to include both sexes to evaluate generalizability to men as well as examine how PM2.5 interacts with cigarettes and other pollutants.
Paper: “Reduction of Abeta amyloid pathology in APPPS1 transgenic mice in the absence of gut microbiota”
Reprinted from materials provided by Lund University.