A 2018 study found lesions, known to be characteristic of Alzheimer’s disease, in the brains of Mexico City residents, in their thirties and forties, decades before they could usually be signs of the disease, and linked it to exposure to poor air quality . Researchers working on this study found early forms of this damage in both newborns and young children. Other studies in England, Taiwan and Sweden have shown similar results. In the research of Alzheimer’s disease, genetics played a key role, and for years no one wanted to look beyond genes.
But in the past three or four years, a number of works linking air pollution and the disease have exploded. Jiu-Chiuan Chen, a physicist and epidemiologist specializing in the study of air pollutants in the brain, says that although the individual effects of substances are still debated, the overall effect is clearly linked to brain damage and cognitive problems. Chen co-authored a study that found a clear link between fine particle pollution, structural changes in the brain, and memory loss in older women. He stated that women who were exposed to high air pollution had an early decline in episodic memory.
What is encouraging is the fact that unlike genes, environmental factors are things we can control. Physical activity also reduces the risk of disease, because it increases blood flow to the brain, and thus increases the levels of brain neurotrophic factor, a protein that promotes the growth and maintenance of brain cells.