For the first time, a direct link has been found between pollution and the risk of developing Alzheimer's disease.
People who have suffered a stroke are more vulnerable to the impact of pollution on the brain.
BarcelonaExposure to high levels of air pollution increases the risk of developing Alzheimer's disease, according to a study from Emory University in the United States. After analyzing the medical records of nearly 30 million people over the age of 65 from 2000 to 2018, researchers concluded that exposure to high levels of environmental pollution is directly associated with a greater likelihood of developing this dementia. The link established by this study holds true regardless of whether people suffer from other chronic illnesses—such as hypertension—although they observed that having had a stroke also makes one more vulnerable to the impact of pollution. The results, which They are published in the open access journal PLOS Medicine, They highlight that interventions to improve air quality in municipalities could contribute to the prevention of dementia and protect the overall health of the population.
"This is a very relevant study that provides very robust data," he says. Sandra Acosta, principal investigator at the Barcelona Beta Brain Research Center of the Pasqual Maragall Foundation and a professor at the University of Barcelona. For the first time, this neuroscientist emphasizes, "they have found a direct association between Alzheimer's and environmental pollution," which "is very relevant, because until now it was unknown whether there was a direct or indirect relationship."
PM2.5, toxic to the brain
It had been demonstrated years ago that environmental pollution, especially fine particles or PM2.5, are a major risk factor for dementia. In fact, the European Union is attributed with more than 500,000 cases of this neurodegenerative disease. The reason is that these extremely small particles, 2.5 microns in size and originating mainly from traffic, industry, and construction, can impact the heart and circulatory system, altering blood flow to the brain, which could contribute to mental decline and dementia.
This is not the only one health impact associated with exposure to environmental pollution: It is also linked to a higher probability of suffering from hypertension, stroke, or depression; illnesses that, incidentally, are also associated with Alzheimer's. Until now, it was unknown whether the impact of environmental pollution on dementia was direct or indirect; that is, whether it caused these chronic conditions that eventually led to dementia, or whether, on the contrary, these conditions amplified the direct impact of pollution on the brain.
And this is precisely what this study has determined. The researchers analyzed three elements: individual exposure levels to PM2.5, whether or not people developed Alzheimer's, and whether they suffered from other underlying illnesses. They found that greater exposure to pollution is associated with a higher risk of developing this dementia. And the association is somewhat stronger in the case of people who have previously suffered a stroke. That is why Acosta is calling for more "institutional governance" to control and reduce air pollution.
"Improving air quality is an important way to prevent dementia and protect older people," the study's authors also point out. a recommendation aligned with the latest from the Lancet commission Regarding the prevention, intervention and care of dementia, they also point out that reducing the prevalence of dementia in Europe – which is expected to affect 19 million citizens by 2050 – inevitably implies improving air quality.
