A recently published study has found a link between air pollution and dementia and a tie is especially prevalent among people with cardiovascular diseases.
There have been recent studies that discovered a tie between cardiovascular disease (CVD) and air pollution to developing dementia. However, the results of the link to air pollution have been inconsistent, according to a press release from Sweden’s Karolinska Institutet.
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Conducted at the Swedish medical university, the study, which was published in the journal JAMA Neurology, analyzed the link between dementia and long-term exposure to air pollution and the role cardiovascular diseases play in it.
For 11 years, researchers followed nearly 3,000 adults who had an average age of 74 and were living in central Stockholm’s Kungsholmen district. Of the participants, 364 developed dementia. Compared to international standards, the average particulate matter of 2.5 microns or less in width (PM2.5) is considered low when it comes to pollution.
“Interestingly, we were able to establish harmful effects on human health at levels below current air pollution standards,” said lead author Giulia Grande, researcher at the Department of Neurobiology, Care Sciences and Society at Karolinska Institutet in a statement. “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.”
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The final five years of exposure in the study showed the risk of dementia grew by more than 50% per interquartile range (IQR) difference in average PM2.5 levels and by 14% per IQR in nitrogen oxide. These measurements pertain to the pollutants in the air. Exposure early on appeared less important. Researchers state heart failure and ischemic heart disease increased the risk of dementia. Additionally, stroke accounted for nearly 50% of dementia cases tied to air pollution.
“Air pollution is an established risk factor for cardiovascular health and because CVD accelerates cognitive decline, we believe exposure to air pollution might negatively affect cognition indirectly,” Grande said in a statement. “In our study, virtually all of the association of air pollution with dementia seemed to be through the presence or the development of CVD, adding more reason to reduce emissions and optimize treatment of concurrent CVD and related risk factors, particularly for people living in the most polluted areas of our cities.”
