People who have suffered a serious heart attack were found to have significantly higher levels of micro and nanoplastics (MNPs) in their blood compared to patients with chronic heart disease or those with healthy coronary arteries, according to a study published in the *European Heart Journal*.
The findings, presented by researchers from Italy, provide new data on the presence of these tiny plastic particles in the coronary circulation—the blood vessels that supply the heart. While the study does not prove that microplastics cause heart attacks, researchers emphasize that the results reveal a strong association between environmental exposure, blood-borne plastics, and cardiovascular disease.
Study Findings and Methodology
The research, a collaboration between Sapienza University of Rome, the University of Verona, and the University of Campania “Luigi Vanvitelli,” analyzed 61 patients undergoing coronary angiography. Participants were divided into three groups: those who had experienced a serious heart attack known as ST-elevation myocardial infarction (STEMI), those with chronic ischemic heart disease, and a control group with normal coronary arteries.
Testing revealed that 84% of STEMI patients had micro and nanoplastics in their blood. In contrast, these particles were detected in 40% of patients with chronic ischemic heart disease and 32% of patients with normal coronary arteries. Furthermore, heart attack patients exhibited a greater variety of plastic types. Polyethylene, a common material used in consumer packaging, was the most prevalent, accounting for 97% of all detected particles.
Environmental Links: Smoking and Air Pollution
The research team investigated whether environmental factors influence the presence of plastic in the bloodstream. The analysis showed a clear correlation between life habits and plastic levels. Smokers were found to be six times more likely to have microplastics in their blood than non-smokers. Additionally, patients exposed to higher long-term levels of air pollution, specifically PM2.5 particles, were more likely to harbor these contaminants.
Among all study participants, those who were both smokers and exposed to higher levels of air pollution were the most affected; 100% of this subgroup had plastics in their blood, compared to only 12.5% of patients who were neither smokers nor exposed to elevated pollution levels.
Professor Emanuele Barbato, who led the research, suggested that smoking and air pollution might facilitate the entry of these particles into the bloodstream via the lungs.
Contextualizing Cardiovascular Risk
The presence of MNPs in the blood was frequently accompanied by elevated levels of inflammatory biomarkers, such as interleukin-6, interleukin-18, and tumor necrosis factor-alpha. When such plaque ruptures, it can lead to the formation of a clot, which is the mechanical cause of a heart attack or stroke. Supporting this, a 2024 study published in the *New England Journal of Medicine* found that patients who had microplastics and nanoplastics lodged in their carotid artery plaque were 4.5 times more likely to suffer a heart attack, stroke, or death over a 34-month period compared to those whose plaque was free of plastic.
Scientific Caution and Future Directions
While the findings are significant, experts caution against assuming a definitive cause-and-effect relationship at this stage. The research team maintains that their work highlights the need to treat microplastic pollution as a broader environmental determinant of health. They suggest that policies aimed at reducing air pollution, tobacco use, and environmental plastic contamination could have health benefits that extend well beyond environmental protection.
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