Air pollution is associated with an increased risk of Lewy body dementia

Lewy body dementia is a progressive neurodegenerative disorder in which abnormal deposits of the protein alpha-synuclein, known as Lewy bodies, accumulate in brain cells. These deposits disrupt the transmission of nerve impulses, leading to severe impairments in cognitive functions, memory, attention, and motor control. Unlike other forms of dementia, this condition is often accompanied by characteristic fluctuations in consciousness, visual hallucinations, and motor impairments similar to those of Parkinson’s disease, which significantly complicates patients’ lives and requires a comprehensive medical approach.

The researchers analyzed the medical records of over two million individuals aged 65 to 95 living in Denmark over two decades. By comparing the patients’ residential addresses with ten-year air quality data, the scientists discovered a concerning pattern. It turned out that each increase in the concentration of microparticles in the air correlates with a nearly fourfold increase in the risk of developing dementia with Lewy bodies. The risk of developing dementia associated with Parkinson’s disease increases by more than twofold under the same conditions.

Experts attribute this phenomenon to the fact that the toxic particles produced by the combustion of fuel and the operation of vehicles are so small that they easily penetrate from the lungs into the bloodstream when inhaled. Then, bypassing the blood-brain barrier, they enter directly into the brain tissue.

In the body, these pollutants trigger chronic inflammation. Similar to how they damage the heart and lungs, the particles cause inflammation in the nervous tissue, which contributes to the accumulation of the abnormal protein alpha-synuclein. These protein clusters, known as Lewy bodies, disrupt brain function, gradually impairing a person’s ability to think, control movements, and manage emotions.

The authors of the study emphasize that their findings do not establish a definitive cause-and-effect relationship, but they clearly highlight the concerning association between urban environments and brain health. Doctors emphasize that air pollution affects not only the respiratory system, as previously believed, but also cognitive abilities, making air quality a priority for global healthcare.