Air pollution increases the risk of some types of dementia

"The study, published in Science on 4 September, suggests that there is a clear link between long-term exposure to PM 2.5 - airborne particles that are smaller than 2.5 micrometres in diameter - and the development of dementia in people with Lewy body dementia or Parkinson's disease. The study found that PM 2.5 exposure does not necessarily induce Lewy body dementia, but "accelerates the development," in people who are already genetically predisposed to it, says Hui Chen, a clinician-neuroscientist at the University of Technology Sydney in Australia."

"Lewy body dementia is an umbrella term for two different types of dementia: Parkinson's disease with dementia, and dementia with Lewy bodies. In both cases, dementia is caused by the build-up of α-synuclein (αSyn) proteins into clumps, called Lewy bodies, in the brain's nerve cells, which cause the cells to stop working and eventually die. Studies have suggested that long-term exposure to air pollution from car-exhaust, wildfires and factory fumes, is linked with increased risks of developing neurodegenerative illnesses, including Parkinson's disease with dementia."

Analysis of 56.5 million people linked long-term PM 2.5 exposure to higher rates of hospitalization for Lewy body dementia and Parkinson's disease with dementia. Long-term PM 2.5 exposure appears to accelerate the development of Lewy body dementia in people already genetically predisposed, rather than necessarily inducing it in those without predisposition. Lewy body dementia results from α-synuclein protein clumps (Lewy bodies) that cause nerve-cell dysfunction and death. Major PM 2.5 sources include car exhaust, wildfires and factory fumes. Hospital-admissions data from 2000–2014 identified severe neurological cases and showed increased hospitalization risk, including a 12% increase.

Read at Nature