Air pollution can 'kill brain cells and drive dementia'

Fine-particulate air pollution can drive devastating forms of dementia by triggering the formation of toxic clumps of protein that destroy nerve cells as they spread through the brain, research suggests.

- Ian Sample

Exposure to the airborne particles causes proteins in the brain to misfold into the clumps that are hallmarks of Lewy body dementia, the second most common form of dementia after Alzheimer's disease.

The finding has "profound implications" for preventing the neurodegenerative disorder that affects millions of people worldwide, with scientists calling for a concerted effort to improve air quality by cutting emissions from industrial activity and vehicle exhausts, improving wildfire management and reducing wood burning in homes.

"Unlike age or genetics, this is something we can change," said Dr Xiaobo Mao, a neurologist at Johns Hopkins University in Maryland and the study's lead investigator. "The most direct implication is that clean air policies are brain health policies."

The researchers began by analyzing the hospital records of the 56.5 million US Medicare patients. They looked at those who were admitted for the first time between 2000 and 2014 with the protein damage.