In a new study, researchers did not observe the benefits of physical activity on brain volume and health when the environment had higher levels of polluted air.

The study of more than 8,000 people also shows that air pollution is associated with a decrease in brain volume and health.

“This study shows that air pollution is associated with worse brain health, including white matter lesions, which are linked with increased risk of stroke and neurodegenerative disease,” says Melissa Furlong, an assistant professor in the University of Arizona Mel and Enid Zuckerman College of Public Health.

“We observed that the benefits of physical activity on white matter lesions in the brain significantly diminished as air pollution increased, so that there was no benefit of physical activity on these white matter lesions for people in areas with the highest levels of air pollution. This new analysis underscores the importance of re-evaluating emissions standards, since even low levels of air pollution can affect the brain.”

Previous studies have shown that physical activity is associated with a reduced risk of dementia and enhances cognition and structural brain volumes, while air pollution is associated with higher risk of dementia, poorer cognition, and adverse effects on brain volumes.

The new study, published in the journal Neurology, investigated how the negative brain health effects of air pollution affect the benefits of exercise on brain health.

“We are increasingly recognizing the importance of exercise as a modifiable lifestyle factor that can reduce the effects of brain aging and the risk for Alzheimer’s disease,” says coauthor Gene Alexander, professor of psychology. “These findings suggest that we may need to consider how and where we exercise to gain the most brain benefits.”

Read the full article about air pollution impacts exercise at Futurity.