Dirty air may increase your chances for dementia

According to a new study in Sweden, Tuesday, March 31, 2020 (HealthDay News)-Smog increases the risk of dementia in older men and women, especially with heart disease.

For more than a decade, researchers have followed cases of air pollution exposure and dementia in approximately 3,000 residents of Stockholm over the age of 60.

Lead author Dr. Julia Grande stated that exposure to dirty air has long been associated with an increased risk of lung and heart disease.

“Recently, several research groups have begun to focus on damaging the air pollution to the brain-for example, it has an effect on cognitive functioning in the elderly,” she said.

Current research is based on that research. Participants averaged 74 years, and nearly two thirds were women. When the study began in 2001, all had no dementia. Tracked until 2013.

Due to strict air pollution regulations, Stockholm’s air quality is relatively good, says Grande of the Karolinska Institute and the Center for Aging Research at the University of Stockholm.

Her team fixed the city’s annual average pollution level to about 2.5 microns or less of particulate matter. This is the level that is considered “low” by international standards.

Nevertheless, the findings showed that more than 12% of the participants (364) developed dementia during the study period.

“And we found that those who were continuously exposed to higher levels of air pollution had a higher risk of dementia than those who were exposed to lower levels,” Grande said. Was. The association was particularly strong among participants with a history of heart failure, ischemic heart disease, or stroke.

According to Grande, almost half of the cases of pollution-related dementia are related to stroke.

The findings are consistent with other studies linking cardiovascular disease to faster rates of cognitive (“thinking”) decline.

But why does air pollution increase the risk of dementia in the first place?

“Unfortunately, the biological mechanisms by which air pollution affects the brain are not fully understood,” Grande said. “But several routes are possible.”

One possibility is that after inhaled contaminants have penetrated the brain, they accelerate the accumulation of plaque and increase the risk of dementia.

Poor air quality can also have indirect effects, Mr. Grande added. Air pollution is an established risk to heart health and is a “significant trigger” for heart attacks and strokes. Thus, she said, opening the way to dementia could be the development of heart disease.

The idea makes sense to Dr. Jesus Araujo, Head of Environmental Cardiology at David Geffen School of Medicine at UCLA. He said that the type of vascular damage caused by heart disease may be an essential prerequisite for dementia.

Araujo added that there is extensive evidence that air pollution causes inflammation and stiffening of the arteries (atherosclerosis) and dislodges the immune system (oxidative stress).

According to Araujo, who was not involved in the new study, these factors are all “important for the development of both cardiovascular disease and dementia.”

Grande said the findings were another reason to strengthen existing air quality laws.

“By 2050, 68% of the world’s population is expected to live in urban areas and be constantly exposed to air pollution,” she said. Her team predicts that the number of dementias worldwide will triple by 2050.

“Along with the global aging of the population, this raises global challenges for dementia prevention strategies,” Grande said. “Thus, establishing and characterizing the relationship between air pollution and dementia has a huge impact.”

Report published online on March 30 JAMA Neurology.

For more information

For more information on the impact of air pollution on health, World Health Organization.