Air pollution can cause fat accumulation and muscle mass loss even if diet and physical activity levels remain unchanged.
Medianews.az reports, citing Oxu.Az, that the results of researchers from the Balearic Islands Health Research Institute were published in the journal "Diabetes Care."
The scientists analyzed data from 1,454 individuals aged 55-75 living in Spain who were overweight and suffering from metabolic syndrome – a combination of high blood sugar, hypertension, and cholesterol metabolism disorders. The participants lived in five different cities, including Barcelona, where pollution levels are high.
The researchers evaluated the impact of three main air pollutants – PM2.5 fine particulate matter, nitrogen dioxide, and smog mainly produced by diesel engines.
Unlike most similar studies, in this new research, scientists did not limit themselves to measuring only weight. Participants underwent DXA densitometry three times – at the beginning of the study, one year later, and three years later. This method allows separate assessment of the amounts of fat and muscle tissue, as well as accurately determining which body regions the fat was accumulated in.
It was found that people living in more polluted areas had an increase in body fat percentage over time, while muscle mass decreased. Particularly, a strong link with smog was observed. Over the course of three years, residents of the most polluted regions lost about one kilogram of muscle tissue.
Additionally, for the first time, the study revealed a connection between air pollution and the accumulation of deep fat in the abdominal cavity surrounding the internal organs – visceral fat. This type of fat is considered especially dangerous because it is associated with chronic inflammation, diabetes, and cardiovascular disease risks.
According to the researchers, fine pollutant particles can enter the bloodstream, causing systemic inflammation. This, in turn, affects metabolism and the distribution of fat in the body.
However, the authors emphasize that this study only identified an association and does not yet fully prove a direct cause-and-effect relationship.