Researchers in the United States (U.S.) said older adults exposed to air pollution might have a heightened risk of abnormal ‘plaque’ accumulation in the brain. Their findings were published online in ‘JAMA Neurology’.
Plaques refer to clumps of protein called betaamyloid that build up in the brains of people with Alzheimer’s disease. Alzheimer’s disease, the most common cause of dementia, is a progressive disorder that causes brain cells to waste away (degenerate) and die. It involves a continuous decline in thinking, behavioural and social skills that disrupts a person’s ability to function independently.
In the new study, researchers found that among older adults with memory and thinking problems, those exposed to higher levels of air pollution were more likely to show plaque buildup on brain scans.
A postdoctoral fellow at the University of California, San Francisco’s Memory and Ageing Center, Leonardo Iaccarino, who is lead researcher, said the findings did not prove air pollution causes plaques or dementia but the results added to a body of research suggesting that air pollution was a risk factor for dementia. The 18,000 study participants all had either dementia or mild cognitive impairment (problems with memory and thinking that can progress to dementia). Each underwent a PET scan to look for beta-amyloid deposits in the brain.
Iaccarino’s team used data from the U.S. Environmental Protection Agency (EPA) to estimate people’s exposure to air pollution — both around the time of the PET scan and 14 years earlier, based on their ZIP codes. Overall, 61 per cent showed beta-amyloid clumps on their brain scans, the ‘Newsmax’ reported and the odds inched up along with air pollution exposure.
People who lived in the most-polluted areas 14 years prior were 10 per cent more likely to have evidence of plaques than those in the least-polluted areas. In fact, Iaccarino noted that the Lancet Commission on Dementia recently added air pollution to its list of modifiable risk factors for the disease. Others include smoking, high blood pressure, physical inactivity and traumatic brain injury.