Air pollution can drive devastating forms of dementia, research suggests

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.

Exposure to the airborne particles causes proteins in the brain to misfold into the clumps, which 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, which affects millions 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 the US and the study’s lead investigator. “The most direct implication is that clean air policies are brain health policies.”

The researchers began by analysing 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. Armed with the patients’ zip codes, the scientists estimated their long-term exposure to PM2.5 pollution, airborne particles that are smaller than 2.5 thousandths of a millimetre. These can be inhaled deep into the lungs and are found in the bloodstream, brain and other organs.

They found that long-term exposure to PM2.5 raised the risk of Lewy body dementia, but had less of an impact on rates of another neurodegenerative brain disease that is not driven by the toxic proteins.

Air pollution can drive devastating forms of dementia, research suggests

Airborne particles cause toxic clumps of proteins in brain that are hallmarks of Lewy body dementia, study indicates

^{Ian Sample (The Guardian)}