According to a new study, patients found to have microplastics and nanoplastics in their carotid artery plaque had a higher risk for death or major cardiovascular events compared with patients who had plaques where particles were not found.
, study coauthor Antonio Ceriello, MD, IRCCS MultiMedica, Milan, told this news organization.
“I believe we have demonstrated that plastics are a new risk factor for cardiovascular disease,” he added. And while plastics may have made our lives easier in many respects, it appears that the price we are paying for that is a shortening of our lives. That is not a good balance.”
The trial involved 304 patients undergoing carotid endarterectomy for asymptomatic carotid artery disease, whose excised plaque specimens were analyzed for the presence of microplastics and nanoplastics, ultimately found in almost 60% of patients.
After a mean follow-up of 34 months, patients in whom microplastics and nanoplastics were detected within the atheroma had a 4.5 times higher risk for the composite endpoint of all cause death, myocardial infarction, or stroke than those in whom these substances were not detected (hazard ratio, 4.53; 95% CI, 2.00-10.27; P < .001).
The study, led by Raffaele Marfella, MD, University of Campania Luigi Vanvitelli, Naples, Italy, was published in The New England Journal of Medicine on March 7, 2024.
The researchers say the study does not prove causality, and many other unmeasured confounding factors could have contributed to the findings.
However, Dr. Ceriello noted that many important risk factors such as diabetes, hypertension, and dyslipidemia, were controlled for.
“In this study, all the patients involved were at high risk of cardiovascular events and they were well treated with statins and antithrombotics, so the relationship between the presence of plastic particles in plaque and cardiovascular events is seen on top of good preventive therapy,” he said.
“While we cannot say for sure that we have shown a causal relationship, we found a large effect and there is a great deal of literature than supports this. We know that plastic particles can penetrate cells and act at the mitochondrial level to increase free radical production and produce chronic inflammation which is the basis for atherosclerosis,” Dr. Ceriello added.
He believes there is only one approach to addressing this issue, and that is to reduce the amount of plastic in the environment.
“Plastic is everywhere — in water pipes, in the ocean. We are hoping that this study will increase the push for government to act on this. This is even more important for the long-term health of our children, who will be exposed to high levels of plastics for the whole of their lives,” he said.
‘Strongly Suggestive of a Causal Relationship’
Commenting for this news organization, Philip J. Landrigan, MD, author of an editorial accompanying publication of the study in the NEJM, described the link as “strongly suggestive.”
“Because this was just a single observational study, it doesn’t prove cause and effect, but I think this is strongly suggestive of a causal relationship,” he said. “While there may be some other confounding factors at play, it is hard for me to imagine that these could account for a hazard ratio of 4.5 — that is a large and alarming increase in just 3 years.”
Dr. Landrigan, who is director of the Program for Global Public Health and the Common Good, Boston College, points out that although it is not known what other exposures may have contributed to the adverse outcomes in patients in this study, the finding of microplastics and nanoplastics in plaque tissue is itself a breakthrough discovery that raises a series of urgent questions. These include: “Should exposure to microplastics and nanoplastics be considered a cardiovascular risk factor? What organs in addition to the heart may be at risk? How can we reduce exposure?”
Dr. Landrigan said he was not surprised that plastic particles had been found in carotid plaques. “Previous studies have found microplastics in other tissues including the lungs, colon and placenta. Now they have turned up in the vessel wall,” he said. “But what is really striking about this study is that it suggests the presence of these plastic particles is causing serious harm.”
He says this should be a wake-up call. “It is telling us that we need to worry about the amount of plastic in our environment. And it is not something that’s going to be a problem down the line — it is affecting us now.”
Dr. Landrigan explained that plastic particles are taken into the body predominantly by ingestion, which could include drinking from plastic bottles or eating food wrapped in plastic. He said it is particularly damaging to use plastic containers to heat food in the microwave, as heating plastic up drives particles into the food. “That will really increase exposure.”
He noted that plastics are often already in the food itself, especially seafood.
“Plastics are dumped in the ocean, they break down and get picked up by the fish. Especially if you eat fish at the top of the food chain like tuna, or if you eat oysters or mussels that are filter feeders, you are more likely to ingest microplastics.”
Dr. Landrigan said he would not advise against eating fish in general, however. “Maybe tuna or other predatory fish may be an issue, but fish in general are good for us, and fish like salmon which have a mainly vegetarian diet are probably safer in this regard.”
The other route is inhalation, with these small plastic particles being widely present in the air, from sources such as vehicle tires becoming abraded from running along the highway.
While it is impossible to avoid taking in plastic completely, Dr. Landrigan says individuals can make efforts to reduce their exposure.
“People can make intelligent choices in their homes about what they purchase for themselves and their families, and they can act in their local environments and workplace to try and reduce plastics.”
He noted that 40% of all plastic currently being made is single use plastic, and that percentage is growing, with global production of plastic on track to double by 2040 and triple by 2060, and most of this rapid growth being single use plastic.
“We are all members of the broader society, and we need to become educated about the plastic situation and lobby our elected officials to come up with a good strong legally binding treaty that will place a cap on plastic production,” Dr. Landrigan said.
A version of this article appeared on Medscape.com.