Environmental regulations are now in danger of drastic changes under the Trump administration, but scientists have found powerful evidence that links air pollution and increased dementia risks.
A new study finds that older women who breathe air heavily polluted by exhaust from vehicles – and other sources – have nearly a 50% more chance of developing dementia, The Los Angeles Times reports. The effects on the brain are particularly more dangerous in women who carry the genetic variant called APOE-e4, increasing their risk of getting the degenerative disorder.
The nationwide research tracked the mental health of women between the ages of 65 and 79 for 10 years. Those who carried the APOE-e4 gene variant were close to three times more likely to develop dementia if exposed to high levels of air pollution, compared to those who did not have the gene.
In addition, among the genetic carriers, older women who breathed heavily polluted air were nearly four times likelier to develop “global cognitive decline.” This is a quantitative loss of memory and reasoning skills.
Researchers have long studied how air pollution affects asthma, lung and cardiovascular disease, but this is the first time brain health has been examined. This study gives insights as to how urban smog can negatively impact the brain.
The study looked at older American women, lab mice and brain tissue in petri dishes. They analyzed the link between very fine particles emitted by motor vehicles, power plants and burning biomass products like wood, and cognitive decline. They used air pollution standards set by the US Environmental Protection Agency.
Air pollution has been lowering since the EPA set new standards in 2012. But Dr. Jiu-Chiuan Chen, an environmental health specialist at the University of California’s Keck School of Medicine and senior author on the study, says it’s not clear that even today’s standards are safe for brains that are getting old.
Chen says, “If people in the current administration are trying to reduce the cost of treating diseases, including dementia, then they should know that relaxing the Clean Air Act regulations will do the opposite.”
The study was published in Translational Psychiatry.