AIR POLLUTION, particularly fine particulate matter (PM2.5), has been linked to the formation of toxic protein clumps in the brain that drive Lewy body dementia, according to a new study. Exposure to PM2.5 increases the risk of this severe neurodegenerative disease by up to 17 per cent and triggers harmful alpha-synuclein protein aggregation similar to that seen in patients.
Lewy body dementia is characterised by abnormal accumulations of alpha-synuclein protein, known as Lewy bodies, affecting brain regions vital for motor control and cognition. Researchers combined data from over 56 million US patients with laboratory and animal studies, revealing a molecular connection between air pollution and dementia development. The study, published in Science, builds on years of research linking air pollution from industrial, vehicle, and wildfire sources to brain diseases.
The team used hospital admission records to estimate long-term PM2.5 exposure and found a 17 per cent higher risk of Parkinson’s disease dementia and a 12 per cent increased risk of dementia with Lewy bodies for people living in more polluted areas. Mice exposed nasally to PM2.5 over months developed brain atrophy, cognitive decline, and widespread alpha-synuclein clumps, while genetically modified mice lacking this protein did not suffer brain damage. Further analysis showed that PM2.5 creates a unique strain of toxic protein clumps that accelerates disease processes, mirroring those found in Lewy body dementia patients. Similar results were observed with PM2.5 samples collected from China, Europe, and the United States, indicating global relevance.
These findings highlight air pollution as a potential driver of Lewy body dementia and identify alpha-synuclein strains linked to pollution as new drug targets. Clinically, reducing exposure to fine particulate air pollution may help prevent or delay the onset of dementia, and research into therapies aimed at these specific toxic proteins could open innovative treatment avenues. Public health strategies focused on pollution control are increasingly vital to combat the growing burden of neurodegenerative diseases.
Reference
Zhang X et al. Lewy body dementia promotion by air pollutants. Science. 2025;389(6764):eadu4132.
