Improving air quality is linked to a 20% reduced risk of dementia

Lowering air pollution reduces the risk of dementia in older women, according to a new study published in the Proceedings of the National Academy of Sciences. 

The researchers assessed the cognitive function of 2,239 women in the United States annually between 2008 and 2018.

Participants’ performance on the tests was cross-referenced against changes in yearly average concentrations of outdoor air pollution for the regions in which they lived over a 15-year period.

Of the participants, none of whom had dementia at the start of the study, 18% developed dementia over the course of the study period.

Participants who lived in areas that saw PM2.5 and nitrogen dioxide levels reduced by roughly 20% had a 20% lower risk for dementia, according to the researchers.

The decline in dementia risk for women in this group was equivalent to taking nearly 2.5 years off of their age.

Study co-author Diana Younan said: ‘Our findings strengthen the evidence that high levels of air pollution can harm our brain, and that reducing the exposure may promote healthier brain aging in older women.

‘These toxic pollutants cause inflammation in the lungs and blood that may be harmful to the aging brains, resulting in altered brain function.

‘The health benefits seen in our study were a result of decreasing levels of both PM2.5 and nitrogen dioxide across the U.S., which were likely due to national policies and strategies aimed at regulating pollution.

‘We think that continuing these regulatory efforts are important for improving brain health of older women.’