Research conducted by neurologists at Johns Hopkins University (USA) has revealed that contaminated with various emissions can trigger the development of severe forms of . Such polluted air leads to the accumulation of toxic proteins in the brain that destroy nerve cells.
According to the university team, exposure to PM2.5 pollutants in the atmosphere causes proteins to misfold into clumps, a hallmark of a serious condition known as Lewy body dementia. This is the third most common neurodegenerative disease, following and vascular dementia, as reported by The Guardian.
It’s important to note that when microscopic PM2.5 particles penetrate deep into the lungs, they spread through the bloodstream to the brain and other organs.
What Did the Scientists Discover?
During the study, researchers analyzed hospital records of 56.5 million Medicare patients – a federal health insurance program in the U.S. The team examined data from patients who were first hospitalized between 2000 and 2014 due to protein damage. By knowing the zip codes of these individuals, the scientists assessed air pollution levels in their residential areas.
The researchers found that prolonged exposure to PM2.5 increases the risk of developing , but has a lesser impact on the onset of other neurodegenerative brain diseases not caused by toxic proteins.
Lewy bodies are formed from the protein alpha-synuclein, which is critical for healthy brain function but can become misfolded, leading to the formation of various harmful Lewy bodies. These can destroy nerve cells and result in severe diseases as they spread throughout the brain.
To determine whether air pollution could cause the formation of Lewy bodies, the researchers subjected mice to PM2.5 particles for 10 months in the second phase of the study. Some of these rodents were regular mice, while others were genetically modified to not produce alpha-synuclein. The results were striking: in the “normal” mice, nerve cells died, leading to a reduction in brain size and cognitive function, while the genetically modified mice avoided this issue.
Further studies on the mice showed that PM2.5 pollution leads to the formation of aggressive and toxic aggregates of alpha-synuclein, very similar to the Lewy bodies found in humans. The scientists believe that these findings also apply to humans.
According to the researchers, their work is extremely important for dementia prevention, a problem affecting millions of people worldwide. The authors of the study urged coordinated actions to improve air quality, including reducing emissions from industrial activities and vehicle exhaust, more effective management of wildfires, and decreasing wood burning in homes.
“Unlike age or genetics, this is something we can change. Clean air policy is a brain health policy,” said Dr. Xiaobo Mao, the study’s lead researcher.
The results of the study were published in the journal Science.
Photo: Unsplash
