Microplastics Are in Our Bodies. Are They Playing a Role in Heart Attacks?

Microplastics, which have been found throughout the body, have been linked to a growing list of potential health concerns, including reproductive and digestive problems. Now, mounting evidence suggests they may also pose a threat to heart health.

A new study found that heart attack patients were significantly more likely than other people to have microplastics or the even-tinier nanoplastics (collectively referred to by the researchers as MNPs) in their blood. These fragments of degraded plastic are ubiquitous in the environment, where people can ingest or inhale them.

The findings, published earlier this month in the European Heart Journal, build on a landmark 2024 study linking MNPs in carotid artery plaque to a higher risk of adverse cardiovascular events and death.

“As each study emerges showing a potential link,” said Sean Mendez, MD, a cardiologist at Weill Cornell Medicine and NewYork-Presbyterian Hospital who wasn’t involved with the research, “the urgency for understanding the cardiovascular and overall health implications becomes larger.”

Testing Heart Patients For Microplastics

For the new study, researchers wanted to determine whether MNPs could be detected in blood collected from patients’ coronary arteries, whether they were associated with different heart conditions, and what role pollution and inflammation might play, said Emanuele Barbato, MD, a study author and interventional cardiologist at Sant’Andrea University Hospital in Italy.

The researchers analyzed samples collected from the peripheral and coronary arteries of 61 adults undergoing invasive coronary angiography—a test used to assess blood flow through the heart’s arteries—between February and April 2025 at three hospitals in Italy. They also analyzed participants’ air pollution exposure on the day of the procedure and over the previous two years.

Of the participants, 19 experienced a heart attack, 22 received a chronic ischemic coronary disease diagnosis, and 22 had normal coronary arteries.

More Microplastics in Smokers and Participants With Heart Attacks

After analyzing the data, researchers found a clear association: Participants who had experienced heart attacks were far more likely than those in the other groups to have detectable MNPs in their blood. Among patients who had heart attacks, 84% had detectable MNPs, compared with 40% of those with heart disease and 32% of those with normal coronary arteries.

The heart attack group also had a wider variety and higher concentrations of MNPs, particularly at sites of arterial blockage, than the other two groups.

Those findings add to a growing body of evidence suggesting that microplastics can enter the bloodstream and play a role in cardiovascular disease, Trisha Vaidyanathan, PhD, science director of Beyond Plastics, an organization dedicated to ending plastic pollution, told HEALTH.

Beyond the differences between groups, researchers also made what Barbato called a “remarkable” discovery. Every participant who smoked and had higher exposure to PM2.5, a type of fine air pollution particle, had detectable MNPs in their blood, compared with only one in eight of the remaining participants.

That suggests that MNPs, smoking, and air pollution are closely intertwined, Barbato explained. PM2.5 and cigarette smoke might act as “carriers” for MNPs, inflaming the lungs and making it easier for the smallest particles to cross the bloodstream, he added.

Barbato said the research is part of a broader effort to understand how environmental exposures—not just traditional risk factors—affect heart health.

“Heart disease has traditionally been framed around cholesterol, blood pressure, and diabetes,” he said. “This work is part of a shift toward also recognizing the environment—the air, and potentially the plastics in it—as part of the picture.”

How Could Microplastics Raise the Risk of Heart Attacks?

Mendez noted that the research shows only an association, not a causal relationship, between MNPs and heart attacks. And while he said the study was well done, he pointed to the small sample size as a major limitation.

Even so, research offers some clues about how microplastics might play a role in heart attack risk. According to lab and animal studies, MNPs may impair cardiac function by causing oxidative stress, blood vessel dysfunction, and inflammation. Notably, the new study found that participants with higher levels of microplastics also had more elevated levels of inflammatory markers in their coronary arteries.

One possible explanation, according to Barbato, is that chronic exposure to MNPs—as well as PM2.5 and cigarette smoke—may fuel low-grade inflammation in artery walls. That could destabilize plaque, which can then rupture and cause a heart attack.

How to Protect Your Heart From Microplastics

Microplastics can infiltrate the body when you inhale them or consume food and water contaminated with them.

While it’s hard to avoid them completely, it is possible to reduce exposure. To minimize ingestion, Vaidyanathan recommends avoiding heating food in plastic containers, storing food in glass or stainless steel when possible, and eating fewer packaged and processed foods. To reduce exposure through the air, she added, people can cut back on household dust through regular vacuuming and ventilation.

It’s also a good idea to pay attention to local air quality and limit time outdoors during high-pollution periods, Barbato said.

Beyond that, Mendez added, “the most proven ways to reduce your risk of a heart attack [are] having a healthy diet high in plants and low in processed and fried foods, exercising adequately for approximately 150 minutes per week, and avoiding smoking.”