Study Finds Link Between Air Pollution and Alzheimer’s Disease in the Brain
A groundbreaking study published in the journal Neurology has revealed a concerning link between air pollution and Alzheimer’s disease. The research, conducted by a team of scientists at Emory University’s School of Public Health, examined the association between ambient air pollution and signs of Alzheimer’s disease in the human brain.
The study found that individuals who were exposed to higher concentrations of fine particulate matter air pollution, known as PM2.5, at least a year before their death were more likely to have higher levels of plaques in their brain tissue. These plaques, abnormal clusters of protein fragments built up between nerve cells, are a hallmark sign of Alzheimer’s disease. The researchers also discovered a strong association between air pollution and signs of the disease in individuals who did not have a genetic predisposition to Alzheimer’s.
“This suggests that environmental factors like air pollution could be a contributing factor to Alzheimer’s disease, especially in patients in which the disease cannot be explained by genetics,” explained Anke Huels, the lead author of the study. While the study does not prove that air pollution causes Alzheimer’s disease, it does establish a clear association between exposure to specific types of pollution and signs of the disease.
To conduct the study, researchers examined brain tissue from 224 donors in Atlanta’s metropolitan area who had volunteered to donate their brains for research before their deaths. The findings revealed that donors who lived in areas with high levels of traffic-related air pollution had more plaques related to Alzheimer’s disease at death compared to those living in areas with lower pollution concentrations. This indicates that being exposed to high levels of pollution increases the risk of developing Alzheimer’s disease.
The study also shed light on the disproportionate impact of air pollution on marginalized communities. Gaurab Basu, the director of education and policy at Harvard’s center for climate, health, and the environment, emphasized that poorer communities and communities of color are often more exposed to particulate matter and traffic-related pollution due to the intentional placement of highways and roadways in their neighborhoods. “Vehicular air pollution is fundamentally an issue of health equity,” Basu stated.
While the research primarily focused on the brains of White, college-educated men, experts believe that the findings are applicable to a broader population. Emerging research has consistently linked exposure to air pollution with cognitive decline, mood disorders, and diagnoses of Alzheimer’s disease. Studies have also shown that exposure to traffic-related fine particulate matter is associated with reduced cortical thickness and thinner gray matter in the brain, which can affect information processing, learning, and memory.
Heather Snyder, the Alzheimer’s Association vice president of medical and scientific relations, emphasized that more research is needed to fully understand the connection between traffic-related air pollution and the brain changes associated with Alzheimer’s disease. However, she acknowledged that avoiding exposure to air pollution is a risk factor that some individuals can change, while others may face more significant challenges in doing so.
In light of these findings, lead author Anke Huels recommends individual actions such as limiting time spent outdoors when air pollution levels are high and wearing masks when appropriate. Additionally, she suggests considering lifestyle changes like driving electric vehicles or using public transportation to contribute to reducing air pollution. However, Huels emphasizes that true progress in reducing air pollution requires political decisions and systemic changes. “There really isn’t a safe or healthy level of air pollution in general or traffic-related air pollution,” she concluded.
As the evidence linking air pollution to Alzheimer’s disease continues to mount, it becomes increasingly crucial for policymakers, communities, and individuals to prioritize efforts to reduce pollution levels. By taking collective action, we can strive towards a future where clean air is a fundamental right for all, protecting not only our respiratory health but also our cognitive well-being.
