New microplastics research shows the scary ways they’re harming your body

Scientists have long known that microplastics can infiltrate the human body. But they didn’t know what the presence of these tiny plastic particles might mean for human health. Until now. A new study published in the New England Journal of Medicine finds that people with microplastics in their heart are at higher risk for heart attack, stroke, and death.



For the study, the researchers in Italy took samples of carotid plaque—a buildup of fatty deposits that can block arteries—from 257 people undergoing surgery to have the plaque removed. They examined the plaque for microplastics and nanoplastics, and found them in nearly 60% of the patients.



They were even able to identify specific kinds of microplastics. Polyethylene, the most commonly used plastic in the world, was found in 58% of the samples. Polyvinyl chloride—or PVC—was found in about 12%. The researchers also found higher levels of inflammation markers in people whose plaque contained these particles, which is consistent with previous studies suggesting microplastics promote inflammation.



Those are all quite shocking findings, but the researchers wanted to know how the patients’ health would fare over time. So they followed up with them three years later and found that people whose plaque samples contained microplastics were two times as likely to suffer from a heart attack, stroke, or to die than other patients.



“This is pivotal,” says Philip Landrigan, an epidemiologist and professor of biology at Boston College, who was not involved in the study. “For so long, people have been saying these things are in our bodies, but we don’t know what they do.”



The findings lead to more questions. Why did some people have microplastics in their plaque while others did not? How did it get there in the first place? Are certain populations more at risk than others? And if microplastics can do this to hearts and the circulatory system, what might they do to other parts of the body where they’ve been found, like the lungs or the spleen or the placenta?



“If they can get into the heart, why not into the brain, the nervous system?” asks Landrigan. “What about the impacts on dementia or other chronic neurological diseases?”



Another big question is why microplastics might cause more heart attacks and strokes. The researchers don’t know for sure, and they emphasize that their study doesn’t show causality, only a connection. But they have a hunch. “We are reasonably sure that the problem comes from a frailty of the plaque itself,” says Giuseppe Paolisso, a professor of internal medicine and geriatrics at the University of Campania Luigi Vanvitelli in Naples, Italy, and one of the study’s authors. “We suppose due to the fact that the plaques with microplastics and nanoplastics have a higher degree of inflammation, this kind of plaque can be broken more easily; and once they are broken, they can go into the blood streams.”



Landrigan says the findings should get physicians thinking about whether exposure to microplastics should be considered a cardiovascular risk factor. But even if it were, it’s not clear how we would limit our exposure when plastic is so pervasive in our environment. Global plastic production is projected to double by 2040 and triple by 2060, and the majority of that rise is in single-use plastics.



“The first step is to recognize that the low cost and convenience of plastics are deceptive and that, in fact, they mask great harms,” Landrigan wrote in his commentary on the study, also in the New England Journal of Medicine. “We need to encourage our patients to reduce their use of plastics, especially unnecessary single-use items.” He urges physicians and medical institutions to throw their weight behind the United Nations Global Plastics Treaty and call for a global cap on plastic production. And he places the blame for the rise in plastics squarely on fossil fuel companies. “They realize that their market for burning fossil fuels is going down, yet they’re sitting on vast stocks of oil and gas and they’ve got to do something with it,” he says. “So they’re transitioning it to plastic.”



The new paper is one step toward a better understanding of what’s going on inside our bodies as we swim in a sea of plastic. “I anticipate that other groups of cardiology researchers are going to try to replicate these findings,” Landrigan says. “I suspect this paper will be a catalyst for more work.”