While we know that exposure to air pollution isn\u2019t healthy, many of the existing concerns about pollution have to do with the potential impact on your lungs and heart. But now, the latest research suggests living in a polluted area could impact your brain health, too.<\/p>\n
The study, published in the journal Stroke<\/a>, found a link between regular exposure to air pollution and lower cognitive performance. Over time, that can increase your risk of dementia, according to Russell Jude de Souza, ScD, RD<\/a>, senior study author and associate professor in the Mary Heersink School of Global Health and Social Medicine and the Department of Health Research Methods, Evidence, and Impact at McMaster University.<\/p>\n This doesn\u2019t mean you should panic if you live in a city where air quality isn\u2019t the best. But it does suggest that you should consider taking steps to clean up the air you breathe when you can. Here\u2019s why.<\/p>\n Meet the experts: Russell Jude de Souza, ScD, RD<\/a>, senior study author and associate professor in the Mary Heersink School of Global Health and Social Medicine and Department of Health Research Methods, Evidence, and Impact at McMaster University; Davide Cappon, PhD<\/a>, neuropsychologist at Tufts Medical Center; and Clifford Segil, DO<\/a>, a neurologist at Providence Saint John\u2019s Health Center in Santa Monica, California.<\/p>\n What did the study find?<\/p>\n For the cross-sectional study, researchers examined cognitive test performance and MRI data from nearly 7,000 middle-aged adults in Canada. They then cross-referenced that with air pollution data, looking specifically at average levels of exposure to common air pollutants, nitrogen dioxide, and fine particulate matter known as PM2.5.<\/p>\n After analyzing the data, researchers found that people living in areas with higher levels of air pollution scored lower on tests measuring memory, understanding, and mental speed. This effect was also observed among people living in areas with air pollution levels considered low by international standards.<\/p>\n People exposed to higher levels of pollution from traffic even had small signs of brain damage, based on MRI scans. This effect was seen more in women than in men.<\/p>\n \u201cWe wanted to understand whether the everyday exposures\u2026levels many people assume are \u2018safe,\u2019 might already be associated with subtle changes in cognition and brain health in midlife,\u201d de Souza says.<\/p>\n While the study was conducted in Canada, de Souza points out that air pollution levels in Canada and in many parts of the U.S. are considered relatively low. \u201cThis underscores a key point from our study: Even in countries and cities that perform relatively well by international standards, pollution levels that are considered \u2018low\u2019 or \u2018acceptable\u2019 may still have measurable implications for brain health.\u201d<\/p>\n Why might air pollution impact cognitive function?<\/p>\n Experts say it may be a few things. Tiny particles of air pollution can spark oxidative stress and inflammation in your body\u2014including the brain\u2014which can disrupt the blood-brain barrier that normally protects it, de Souza says. \u201cAir pollution can also worsen conditions such as high blood pressure, diabetes, and obesity, which are themselves linked to cognitive decline,\u201d he adds.<\/p>\n \u201cThe brain depends heavily on healthy blood flow and oxygen delivery, so over time, chronic exposure to pollution may subtly affect attention, processing speed, and memory,\u201d says Davide Cappon, PhD<\/a>, neuropsychologist at Tufts Medical Center.<\/p>\n Ultimately, \u201cwhat we breathe in can cause effects on more than our lungs,\u201d says Clifford Segil, DO<\/a>, a neurologist at Providence Saint John\u2019s Health Center in Santa Monica, California.<\/p>\n What\u2019s the takeaway?<\/p>\n While de Souza stresses that the exact way air pollution may affect dementia risk isn\u2019t entirely clear, experts agree that it\u2019s never a bad thing to do what you can to clean up your air.<\/p>\n