New research shows that long-term exposure to air pollution may worsen brain changes linked to Alzheimer’s disease.
Published In: JAMA Neurology
Date: September 2025
Authors: Kim, B., et al.
Link to Study: Read the study
Summary
This study analyzed over 600 brain autopsies and found that people exposed to higher levels of fine particle air pollution (PM2.5) had more severe Alzheimer’s-related brain changes and worse cognitive decline. It also revealed that about 63% of the impact of air pollution on memory and thinking was due to these Alzheimer’s changes in the brain.
Key Takeaways
✅ Higher air pollution exposure (PM2.5) is linked to more severe Alzheimer’s brain pathology.
✅ People exposed to more PM2.5 showed faster cognitive and functional decline before death.
✅ Alzheimer’s brain changes (like amyloid plaques and tau tangles) may explain most of this decline.
✅ The association was consistent regardless of genetic risk (APOE ε4 status).
✅ Reducing exposure to air pollution could be a public health strategy to protect brain health.
Why It Matters for You
This study adds to growing evidence that clean air is crucial for a healthy brain. While you can’t control your genetics, you can reduce your exposure to polluted air by using air purifiers, avoiding outdoor activity on high-pollution days, and supporting clean air policies in your community.
Citation
Kim, B., Blam, K., Elser, H., Xie, S.X., Van Deerlin, V.M., Penning, T.M., Weintraub, D., Irwin, D.J., Massimo, L.M., McMillan, C.T., Mechanic-Hamilton, D., Wolk, D.A., & Lee, E.B. (2025). Ambient air pollution and the severity of Alzheimer disease neuropathology. JAMA Neurology. https://doi.org/10.1001/jamaneurol.2025.3316