Air Pollution Raises Risk for Dementia, Even at ‘Safe’ Levels, Study Shows
The evidence continues to build that breathing dirty air is bad for your brain.
A study published in the Journal of the American Medical Association (JAMA) Neurology Monday found that residents in Stockholm, Sweden who were exposed to relatively low levels of air pollution were at greater risk for dementia, especially if they also suffered from heart disease.
"Our findings suggest air pollution does play a role in the development of dementia, and mainly through the intermediate step of cardiovascular disease and especially stroke," lead study author Giulia Grande, a researcher at the Department of Neurobiology, Care Sciences and Society at Karolinska Institutet, said in a press release.
Several studies have found associations between exposure to particulate matter pollution and brain disorders such as dementia, cancers and neurodegenerative disorders, and depression and suicide. There is evidence that particulate matter can enter the brain directly via the nose and the bloodstream; however, this study focused more on how air pollution exposure interacted with both heart and brain health.
While previous studies have suggested both cardiovascular disease and air pollution exposure are correlated with dementia risk, this is the first to consider the three together, CNN reported.
The researchers followed nearly 3,000 Stockholm adults with an average age of 74 for as many as 11 years. They found that long-term exposure to air pollution increased dementia risk, but that risk went up significantly if the individual suffered from stroke. Almost 50 percent of the dementia cases linked to air pollution exposure were explained by stroke.
Further, the researchers noted that the study participants were living in the Kungsholmen district in central Stockholm, where pollution levels are safely below the international limit.
Tracking their exposure over a 20 year period, the researchers found that a person's dementia risk increased by more than 50 percent with every 0.88 micrograms-per-cubic-meter particulate matter increase and by more than 10 percent with every 8.35 microgram-per-cubic meter increase in nitrogen oxide, UPI reported.
Grande told UPI that the results suggested a need for higher pollution standards.
"Our results derive from a central area of Stockholm, where the control of environmental air pollution has been increasingly strict in the last decades," Grande said. "Interestingly, the higher limit that we reported is not only below the current European limit for fine particulate matter but also below the U.S. standard. In other words, we were able to establish harmful effects at levels below current standards. Next time air quality standards are revised, this risk should also be considered."
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- New Study Links Air Pollution to Dementia - EcoWatch ›