Invisible threat: air pollution increases the risk of dementia

The new study found that long-term exposure to fine particulate matter — PM2.5 — may trigger the formation of toxic protein aggregates that damage neurons and disrupt brain function.

Researchers analyzed data from 56.5 million Medicare patients in the United States who were first hospitalized with Lewy body–related disorders between 2000 and 2014. Using postal codes, they estimated air pollution levels in the patients’ residential areas.

The results showed that long-term exposure to PM2.5 increased the risk of developing Parkinson’s disease dementia by 17%, and dementia with Lewy bodies by 12%.

To validate the findings, scientists conducted experiments on mice. For 10 months, animals were exposed to polluted air every other day. Normal mice developed neuron loss, reduced brain volume, and impaired cognitive function. In contrast, genetically modified mice incapable of producing alpha-synuclein did not develop these changes.

Additional evidence revealed that pollution promotes the formation of stable and aggressive alpha-synuclein aggregates similar to human Lewy bodies. Although part of the research was conducted on animals, the results are considered strong evidence of the role of polluted air in the development of neurodegenerative diseases.

“We often assume that brain diseases are driven only by genetics or aging. But these findings show that polluted air affects not only the lungs and cardiovascular system — it also harms the brain. Long-term exposure to fine particulate matter can trigger mechanisms leading to severe forms of dementia. This underscores the importance of improving air quality and considering environmental factors in the prevention and treatment of neurodegenerative diseases,” commented Sagat Altynbekov, narcologist, professor at Asfendiyarov KazNMU, president of the Association of Mental Health Specialists, and expert of the National Association Densaulyq.