Study details and key findings

Microplastics are small pieces of plastic, less than five millimeters in size, that are either manufactured or come off plastic objects. Over the last decade, the concentration of microplastics in the human body has grown significantly, increasing by around 50% from 2016 to 2024.

For the study, researchers analyzed blood samples from the coronary arteries of 61 patients who were undergoing angiograms at two Italian health centers. The patients were divided into three groups: ST-segment elevation myocardial infarction (STEMI) with 19 patients, chronic coronary syndromes (CCS) with 20 patients, and 22 controls with normal coronary arteries.

The mean age of the patients was 64 years, and 27.9% were women. A majority of the patients were smokers, with a high of 73.7% in the STEMI group.

Overall, the researchers found that patients in the STEMI group had the highest frequency of any detection of microplastics in their blood at 84.2% compared to 40% for the CCS group and 31.8% for the control group. The STEMI group also had the highest concentration of microplastics in both coronary and peripheral blood with a median of ~1.2 to 1.4 µg/ml compared to 0.3 µg/ml for the other groups.

"These findings do not prove that microplastics cause heart attacks, but they reveal a strong association between environmental exposures, microplastics in the blood and cardiovascular disease," Barbato added.

Commentary

Because of the study's observational design and challenges with accurately measuring microplastics within the body, health experts said people should be cautious about its findings.

"This confirms what we already know about heart attacks being linked to smoking, but it makes it harder to work out if there is a link between microplastics and heart attacks, microplastics and smoking, or if microplastic exposure is from something else," said Ria Devereux, from the University of East London.

Kevin Thomas, from the University of Queensland in Australia, noted that it's not clear whether the lab methods used in the study actually detected microplastics in patients at all. "Microplastics are notoriously challenging to measure in human blood, and based on recently published confidence levels, the results presented are presumptive of the presence of plastics at best," he said.

How to reduce your exposure to microplastics

Although it's not possible to completely eliminate microplastics from your life, there are steps you can take to at least reduce your exposure.

"I say to people, 'Listen, there are some plastics that you can't escape. You're not going to get a cell phone or a computer that doesn't contain plastic,'" said Philip Landrigan, director of the Program for Global Public Health and the Common Good and the Global Observatory on Planetary Health at Boston College. "But do try to minimize your exposure to the plastic that you can avoid, such as plastic bags and bottles."

Michelle Routhenstein, a preventive cardiology dietitian at EntirelyNourished.com, recommends "[taking] inventory of your regular sources of microplastic exposure and see where you can reduce or swap them for better alternatives," such as using glass storage containers instead of plastic ones.

"Don't use plastic bags when you go shopping," Landrigan said. "Use a cloth bag or a paper bag or a recycle bag. Try to avoid plastic water bottles, if you can possibly do so."

Overall, people should "think of reducing plastic exposure as one piece of an overall heart-healthy lifestyle," Routhenstein said.