A new large-scale study of nearly 28 million people has found that long-term exposure to fine particle air pollution and smog significantly increases the risk of Alzheimer’s disease. This means people in Lahore can be at a higher risk of Alzheimer’s disease.
The research, conducted at Emory University and published in PLOS Medicine, tracked health data over nearly two decades. Researchers examined whether air pollution harms the brain indirectly by causing cardiovascular conditions such as high blood pressure, stroke, and depression, which are linked to dementia.
The findings show that these conditions explained less than 5% of the connection between air pollution and Alzheimer’s disease. This means more than 95% of the increased risk appears to result directly from breathing polluted air.
The study also found a steady increase in Alzheimer’s risk as levels of PM2.5 rise. PM2.5 consists of fine particles from sources such as vehicle exhaust, power plants, wildfires, and burning fuels, which Lahore has plenty of.
Although PM2.5 is known to contribute to high blood pressure, stroke, and depression, managing these conditions does not eliminate the added dementia risk associated with air pollution. Reducing exposure to PM2.5 remains necessary to lower overall risk.
The increased risk applies broadly, but the study found that people who previously had a stroke were especially vulnerable. The reason for this greater susceptibility is not yet fully understood.
The study followed nearly 3 million Alzheimer’s cases, strengthening the evidence that improving air quality could play an important role in preventing dementia. The findings are particularly relevant for people living in lower-income communities, where exposure to PM2.5 is often higher.
Researchers said stricter air quality standards at the community or national level could lead to significant reductions in Alzheimer’s cases. However, they noted that no single measure can fully protect against the disease, as both genetic and environmental factors contribute to Alzheimer’s risk.
