Plastic and The Cardiovascular system

What happens when microplastics and nanoplastics enter our bloodstream and encounter the arteries that supply the heart?

In this episode, Dr. Elie explores the emerging human evidence linking plastic particles with cardiovascular disease—from the landmark 2024 New England Journal of Medicine study that detected micro- and nanoplastics inside carotid artery plaques, to a 2026 European Heart Journal study finding them far more frequently in the coronary circulation of patients experiencing acute heart attacks.

We explore how a heart attack actually happens, why inflammation and the health of our arteries matter, and what scientists are beginning to investigate about the interaction between plastic particles and the cardiovascular system.

The evidence does not yet prove that microplastics cause heart attacks. But their presence in human blood, heart tissue, atherosclerotic plaque, and coronary circulation raises questions that are becoming increasingly difficult to ignore.

What happens when the environment we created becomes part of the biology we inherited?

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Hello friends, welcome to Beyond Plastic, where science meets consciousness. I'm your host, Dr. Ellie, and here we explore the ideas that shape our health, our lives, and ultimately our humanity. Our first series, The Plastic Age, is a journey through the remarkable story of how plastic transformed our world, entered our bodies, and became one of the defining challenges of our time. In our last episode, we crossed an important threshold. We followed microscopic pieces of plastic through the food we eat, the water we drink, and the air we breathe. We explored the evidence showing that some of the smallest particles can cross the barriers of the lungs, digestive system, and eventually enter our circulation. And once that happens, the story changes. Because the bloodstream is our body's transportation system. Every minute of every day, blood is carrying oxygen, nutrients, hormones, immune cells to virtually every organ in the body. And now we know it can carry something else. Plastic. For me, this part of the story is especially personal because I have spent more than 20 years working as a cardiologist. I have cared for people in the middle of heart attacks. I have looked at thousands of coronary angiograms and watched block arteries being opened in real time. And throughout my career, like every cardiologist, I have focused on the risk factors we know well: cholesterol, high blood pressure, diabetes, smoking, obesity, inflammation, and genetics. Those remain enormously important. But cardiovascular medicine is beginning to ask a broader question. What role might the environment around us play in the disease developing inside us? And specifically, what happens when tiny particles of plastic circulating in our blood encounter the arteries that supply our heart and brain? Until very recently, we simply did not know. Then in 2024, a study published in the New England Journal of Medicine changed the conversation. Researchers in Italy studied patients undergoing an operation called carotid endarterectomy. The carotid arteries are the large arteries in the neck that carry oxygenated blood from the heart to the brain. Over time, deposits known as atherosclerotic plaque can build within the walls of these arteries. When that buildup becomes severe enough, surgeons can open the artery and physically remove the plaque to reduce the risk of stroke. That operation gave the researchers something very valuable. Actual plaque removed directly from human arteries. So this is not cells growing in a lab. This is not an animal model, this is human arterial plaque. When researchers analyzed those samples for microplastics and nanoplastics, they found polyethylene in the plaques of 150 of the 257 patients who completed the study. That's 58% of the patients. Polyethylene is one of the most widely used plastics on Earth. It's found in packaging, in plastic bags, bottles, in containers, and countless products we encountered every day. Another plastic, PVC, was found in a smaller number of patients. And when researchers examined some of these plaques under powerful microscopes, they observed tiny foreign particles among the cells within the plaque, including within immune cells called the macrophages. Think about what that means. These particles were not simply passing through the digestive tract. They were not simply circulating temporarily in the blood. They had been detected within plaque removed from diseased human arteries. But the researchers wanted to know something even more important. Did their presence have any relationship to what happened to these patients afterward? So they followed those patients for almost three years. During that period, during that period, the patients whose plaques contained detectable microplastics or nanoplastics experienced a heart attack, stroke, or died. And that specific number was 20% of those patients. Now, among patients whose plaque did not contain detectable plastic, that number was 7.5%. So to compare, 20% of the patients whose plaques contained microplastics or nanoplastics experienced a heart attack stroke or death versus 7.5% for patients whose plaques did not contain detectable plastic. The difference would amount to something in the neighborhood of four and a half fold. So about 350% more risk in the patients that had detectable nanoplastics in their plaque. The finding that I just mentioned made headlines around the world. But it is important to understand exactly what the study showed and what it did not. So it showed a strong association, but not causation. It did not prove that the plastic caused those heart attacks, strokes, or deaths. There could be other differences between people who accumulate more plastic and those who accumulate less. Their diets may differ, their occupations may differ, their exposure to air pollution or cigarette smoke may differ. And because plastic is now so widespread, even within medical environments, scientists have appropriately raised questions about contamination and how rigorously it must be controlled in this kind of research. So those are important limitations. But limitations do not mean we ignore a finding, they mean we test it. That's how science moves forward. After two years, like two years later, after that study, the investigation moved somewhere even closer to the heart. In July of this year, 2026, researchers published a remarkable study in the European Heart Journal. This time, instead of examining plaque removed from the arteries of the neck, researchers went directly into the coronary circulation. That's the arteries supplying the heart itself. What they did is this the following. So 19 of those 61 patients were having this acutely. 20 other patients had what we call chronic stable coronary artery disease. And 22 patients out of the 61 had normal coronary arteries. So this made the study very interesting because we had this beautiful distribution of patients with an acute, serious heart attack, patients who had coronary blockages but they were stable, and patients who had normal coronaries. And the other thing that was interesting was where the blood was collected by the researchers. So the investigators didn't simply draw blood from an arm. During the angiogram, they were able to collect blood directly from inside the coronary circulation itself. And in the patients experiencing a heart attack, they were able to sample blood directly from the coronary artery containing the blockage responsible for the heart attack. The results were striking. Microplastics and nanoplastics were detected in 84% of the patients experiencing an acute heart attack, a STEMI. And among patients with chronic stable coronary disease, microplastics and nonoplastics were detected in 40% of the patients. And among people or patients with normal coronary arteries, those plastics were detected in about 32% of the patients. Polyethylene was again the most commonly detected plastic. But there was another finding that, as a cardiologist, I find especially intriguing. Within the patients having a heart attack, the highest concentrations were found in coronary blood collected upstream from the obstruction. So that's very close to the area where the RV had become blocked. Now we have to resist the temptation to jump from that observation to causation. This again was a small study with only 19 heart attack patients and it captured one moment in time. But the finding raises an important question. Why might the presence of foreign particles near or so near a diseased coronary artery matter at all? To understand that, we need to understand what a heart attack really is. For years we described atherosclerosis almost like a plumbing problem. Cholesterol builds up inside an artery, the opening becomes narrower and narrower, and eventually the artery closes. But that picture is incomplete because an artery is not a pipe, it is living tissue. And an atherosclerotic plaque is not simply a lump of cholesterol, it is a complex biological environment containing not only cholesterol but also connective tissue, blood vessel cells, and immune cells. Some plaques can remain relatively quiet for years, others become inflamed and unstable. And sometimes the surface of a plaque suddenly ruptures or erodes. When that happens, the body reacts as though a wound has occurred. So platelets rush to the area, the clotting system activates, a blood clot begins to form, and within minutes, an artery that had been carrying blood can become completely blocked. That sudden biological event, not simply the gradual narrowing of a pipe, is responsible for many heart attacks. And that is why the emerging plastic research becomes so interesting. Because several of the biological processes scientists are investigating in relation to microplastics, which are inflammation, oxidative stress, injury to the lining of blood vessels, immune activation, and changes in coagulation. So all those processes are also involved in the biology of atherosclerosis and heart attacks. We do not yet know whether microplastics meaningfully influence those processes in humans, but there are clues worth following. In the 2026 European Heart Journal study, we mentioned patients experiencing heart attacks had higher levels of inflammatory signaling molecules, including interleukin 6 and tumor necrosis factor alpha, so IL6 and TNF alpha. You don't need to remember those names, but think of them simply as chemical messages used by the immune system during inflammation. And so in the same group of patients, researchers were seeing two things. They were seeing a greater burden of plastic particles and a greater inflammatory state. That doesn't tell us which came first or whether one caused the other, but it gives scientists a biological trail they can follow. Another small human study published in 2024 examined the blood of 36 healthy adults and detected microplastics in almost 89% of them. People with higher concentrations also tended to have higher levels of C-reactive protein, CRP, another marker of inflammation, as well as fibrinogen, which is a protein involved in blood clotting, along with changes in other measurements related to coagulation. It was a small study and cannot establish cause and effect, but again, it pointed towards some of the same biological pathways researchers were beginning to see elsewhere. Plastic in the circulation, inflammation, changes in pathways related to clotting, plastic within diseased arteries, and plastic within the coronary circulation during heart attacks. Then there's the heart itself. In 2023, researchers studied tissue taken from 15 patients undergoing heart surgery. What they did, they examined the sac surrounding the heart, the fat around the heart, and portions of the heart muscle and tissue from one of the upper chambers. Several types of microplastics were detected across those tissues, not in every sample. And the study was again far too small to tell us whether those particles caused any disease. But it established another important piece of the puzzle that plastic particles can reach tissues of the human cardiovascular system. So consider now how quickly this story has moved. Not long ago, we were talking about plastic in oceans, then we found it in seafood, then in our drinking water, in our foods, then in human blood, now in human organs and inside arterial plaque. And now we are finding it with that we within the coronary circulation of people in the middle of a heart attack. So the boundary keeps moving inward and inward. And perhaps this is where we need to expand the way we think about cardiovascular health itself. There is a concept I want to introduce, which is increasingly important in medicine, in my opinion, called the exposome. I've talked about that before in my other teaching platforms. The exposome is simply the sum of the environmental exposures we accumulate throughout our lives. They include the air we breathe, the water we drink, the food we eat, the chemicals we encounter, the particles we inhale, where we live, where we work, how we live. For much of modern medicine, we have understandably focused on what is inside the patient, their biology, their cholesterol, their glucose, what's their blood pressure, their genetic makeup. But no human being exists separately from the environment. I'll be stressing this throughout this course. Every day our biology is in constant conversation with the world around us. We breathe that world, we eat from it, we drink from it, we absorb parts of it, and eventually some of that world becomes part of us. The 2026 coronary study gives us a glimpse of how complicated that relationship may be. The investigators also examined exposure to PM2.5, the tiny particles found in polluted air that we already know can affect cardiovascular health. Patients experiencing heart attacks had greater exposure to this air pollution, and microplastics were also detected more often among smokers and people with greater pollution exposure. In fact, smoking was the strongest independent predictor of microplastic detection in their analysis. That is an important reminder. Plastic does not exist in isolation, and neither do we. Our arteries live within the combined influence of our genes, our metabolism, our diet, our behavior, and our environment. Sure, cholesterol matters, blood pressure matters, diabetes, smoking, they all matter, exercise matters, and increasingly we are learning that the environment surrounding all of those factors may matter as well. There is still a great deal we do not know. We do not know whether reducing microplastic exposure reduces cardiovascular risk. We do not know whether there is a safe concentration of plastic particles in human blood. We do not know whether certain plastics are more harmful than others. And we do not know yet how much of the potential biological effect comes from the particle itself, from chemicals associated with that particle plastic, or from the interaction between those particles and everything else to which we are exposed. Those questions will take years to answer. But perhaps the question facing us today is not whether every uncertainty has been resolved. Perhaps it is whether the evidence has become strong enough for us to pay attention, not to panic or live in fear, but to pay attention. Because something extraordinary has happened during our lifetime. We created the material that was remarkably durable, extraordinarily useful, and increasingly difficult to escape. We released it into almost every corner of our environment, and now we are discovering pieces of that material within us. And as a cardiologist, I cannot tell you today that microplastics cause heart attacks. The science today does not allow me to say that, but I can tell you that the question has moved far beyond speculation. We are now finding these particles in human blood, in heart tissue, inside atherosclerotic plaque, and in the coronary circulation. Our biology is encountering a material that until very recently in human history simply did not exist. Perhaps that is the deeper question emerging from this entire journey. Our bodies evolved over millions of years in intimate relationship with the natural world. Our immune system learned what belonged. Our barriers evolved around what needed to remain outside. Our arteries evolved to carry blood through an environment shaped by nature. And then, in little more than a century, we introduced an entirely new class of materials into that environment. Materials designed to resist degradation, materials our biology had never encountered before. And now those materials are no longer only around us. They are moving through us. So perhaps the question is no longer simply is plastic in our environment? We already know the answer. The more important question is what happens when the environment we created becomes part of the biology we inherited? Because the bloodstream does not stop at the heart, it carries what is within it everywhere to the liver, to the kidneys, to the reproductive organs, and to perhaps the most protected and mysterious organ of all, the human brain. And that is where our journey takes us next. This is beyond plastic, where science meet consciousness. Until next time, thank you for listening.