A recent medical study has shown that those who exercise in areas of higher air pollution are likely to show fewer benefits of their vigorous activity in certain brain markers. This research was published in the American Academy of Neurology‘s December 8, 2021 online issue of Neurology®.
One of the markers examined was white matter hyperintensities, which are indicators of increased risk of dementia, stroke, and ultimately, death. When the brain has larger volumes of gray matter than white matter hyperintensity, the brain is healthy.
“We did show that physical activity is associated with improved markers of brain health in areas with lower pollution,” says Melissa Furlong, Ph.D., one of the authors of the study. “However, some beneficial effects essentially disappeared for vigorous physical activity in areas with the highest levels of air pollution.”
So, should those that live in areas of higher pollution avoid exercise? No, says Furlong. “Overall, the effect of air pollution on brain health was modest—roughly equivalent to half the effect of one year of aging, while the effects of vigorous activity on brain health were much larger—approximately equivalent to being three years younger.”
The study looked at over 8,600 people with an average age of 56. Scientists used land-use regression, a study that models air pollution levels with data from air monitors and land use, to determine people’s level of exposure to pollution. This exposure was broken into 4 disparate groups, ranging from lowest to highest.
Participants wore accelerometers to measure their level of physical activity each week. People that exercised the most averaged 800 cm3 gray matter volume; more than the average 790 cm3 found in those that didn’t exercise.
While vigorous physical activity in more polluted air did not affect gray matter volume, researchers did find that those that exercised in lower levels of pollution reduced the volume of white matter hyperintensities in their brain, while those in higher levels of pollution did not.
