Surgeons drew blood directly from the coronary arteries – the vessels feeding the heart – of patients in the middle of active cardiac procedures, and what they found inside that blood was plastic. Not traces. Not statistical noise. Plastic particles, circulating in the heart’s own blood supply, in more than eight out of ten patients who were actively suffering a severe heart attack.
The plastic type detected most often? Polyethylene. The same material used to make shopping bags, food packaging film, and the ubiquitous single-use bottles that line every supermarket shelf. A study published in the European Heart Journal detected microplastics and nanoplastics in the coronary blood of 84% of patients who had experienced a serious heart attack. Researchers weren’t looking in peripheral veins. They took samples directly from the blood vessels supplying the heart – a distinction that makes the location of these plastic particles particularly significant.
This isn’t the first study to connect microplastics and cardiovascular risk, but it’s among the most direct. Earlier research examined plastic particles trapped inside fatty plaque scraped from arteries after surgery. This study caught plastic in motion, in living coronary blood, sorted by cardiac diagnosis. The single factor that most strongly predicted whether a person’s coronary blood contained plastic at all wasn’t age, diet, or cholesterol. It was something far more specific.
Plastic Shows Up 3 Times More in Heart Attack Patients
Among those who had heart attacks, micro and nanoplastics were detected in 84% of patients, compared with 40% of patients with chronic ischemic heart disease and 32% of patients with normal coronary arteries. That three-way gradient drew immediate attention from the cardiology community when the findings were released in July 2026.
The study was authored by Dr. Pasquale Paolisso and colleagues, with senior authorship from Dr. Emanuele Barbato – both based at Sapienza University of Rome and Sant’Andrea University Hospital. Barbato is director of the Cardiology Unit of Sant’Andrea University Hospital, Rome, and senior author of the team’s published paper in the European Heart Journal. The study quoted Barbato saying the 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.”
For the study, the team sampled blood from 61 patients – some receiving emergency treatment for a heart attack with arterial blockage, some with chronic coronary syndromes, and some with normal coronary arteries. The highest concentrations were found in blood drawn from the blocked artery itself, at the site of the blockage. The study design also meant these measurements came from inside the heart’s circulation rather than from blood drawn at the arm.
Why Polyethylene Dominates
The most common type of plastic detected was polyethylene, which is commonly used in packaging and consumer products. According to data from the European Society of Cardiology, polyethylene was identified in 97% of cases where plastics were detected.
Polyethylene is produced in volumes exceeding 100 million metric tons per year globally – it’s in zip-lock bags, cling wrap, plastic bottles, and the linings of disposable coffee cups. It sheds particles during everyday use, and those particles enter the food chain through packaging contact, cooking heat, and drinking water. Heart attack patients had a greater variety of plastic types in their blood than patients with chronic disease or normal arteries – that wider diversity in the sickest patients suggests cumulative, multi-route exposure rather than a single source.
The finding that one specific plastic type dominates gives researchers a cleaner target. Polyethylene’s prevalence in cardiovascular blood points toward food and beverage packaging as a primary delivery route, which is one of the few exposure pathways individuals can meaningfully act on.
The Inflammation Connection
Patients exposed to higher long-term levels of air pollution were more likely to have microplastics in their blood, and smokers were six times more likely to have microplastics in their blood. Beyond the raw detection rates, the research found that microplastic presence correlated with elevated levels of two inflammatory markers: interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α). Both are proteins the immune system releases in response to injury or perceived threat, and both are independently linked to higher cardiovascular risk.
The presence of plastic particles in coronary blood alongside raised inflammatory markers fits a biological pattern researchers have been tracking for years. Foreign particles in the bloodstream can trigger immune responses, and chronic low-grade inflammation is one of the recognized drivers of arterial disease. The study cannot confirm that the plastics caused the inflammation – the relationship may run in multiple directions – but the co-occurrence in the most severely affected patients adds weight to the concern.
Elevated IL-6 correlates with plaque instability – the kind of arterial buildup that ruptures and causes a sudden blockage. The same biological environment where IL-6 is raised is also, according to this research, the environment where microplastic concentrations are highest.
The Research Wasn’t New
A landmark study published in The New England Journal of Medicine found that patients with carotid artery plaque in which microplastics were detected had a higher risk of myocardial infarction, stroke, or death from any cause at 34 months of follow-up than those in whom microplastics were not detected. Published in March 2024, this research studied patients undergoing surgery to remove plaque from their neck arteries.
Researchers enrolled 304 patients with asymptomatic carotid artery disease undergoing carotid endarterectomy, of whom 257 completed follow-up. Polyethylene was detected in the plaque of 58.4% of patients. People who had these plastic pieces in their plaques experienced a 4.5-fold greater risk of major complications, including heart attacks, strokes, or death, compared to those with plastic-free plaques.
The study collaborators behind the 2026 coronary blood research were part of the team behind the 2024 study and wondered whether micro- and nanoplastic levels were also higher in the blood of people with active heart disease. The answer, drawn from coronary blood during live procedures, was a clear yes. Together, the two studies form a consecutive body of evidence: plastic in artery walls, then plastic in the blood flowing through those arteries, both associated with worse cardiac outcomes.
You can read more about how microplastics accumulate in the body and what researchers are finding in other tissues in this piece on microplastics in drinking water.
Microplastics Heart Attack Risk: Smoking Was the Single Strongest Predictor
Smokers were six times more likely to have microplastics in their blood supplying the heart than non-smokers. When researchers ran statistical analysis to identify which factors independently predicted microplastic presence – controlling for age, disease severity, and other variables – smoking history was the only one that held up. Every other factor, including the severity of cardiac disease itself, lost statistical significance once smoking was accounted for.
The mechanism isn’t fully established, but researchers have a working hypothesis. Smoking history was strongly linked to microplastics in the blood, and the findings suggest that smoking might make it easier for micro and nanoplastics to enter the bloodstream via the lungs. Cigarette smoke carries fine plastic-coated particles from filters, packaging, and combustion byproducts directly into lung tissue, where nanoplastics can cross biological membranes into circulation. All patients who were smokers and were exposed to higher air pollution levels had plastics in their blood, compared with only 12.5% of patients who did not smoke and were not exposed to higher levels of air pollution.
The Human Body Is Already Saturated With Plastic
Rising global concentrations of environmental microplastics and nanoplastics drive concerns for human exposure and health outcomes. Complementary detection methods confirm the presence of microplastics in human kidney, liver and brain. These particles primarily consist of polyethylene, and brain tissues harbor higher proportions of polyethylene compared to the liver or kidney. Researchers publishing those findings in Nature Medicine in 2025 found concentrations in brain tissue considerably higher than in any other organ examined.
Over time, plastics fragment into microplastics and nanoplastics, which are now detected in virtually all environmental compartments, including air, water and soil. Increasingly, these particles are also found within the human body, including blood, lung tissue, placenta and breast milk, indicating systemic exposure. Major sources include vehicle tires, synthetic fabrics, plastic bottles, and paint. Humans absorb them through multiple simultaneous routes: food, drinking water, and inhaled air – both indoor and outdoor. A 2023 study found that indoor microplastic exposure is more than eight times higher than outdoor exposure, a finding that reframes the problem. The dust settling on your furniture, shedding from your synthetic carpet, and circulating through your HVAC system carries far more plastic than the street outside.
In April 2026, the U.S. Environmental Protection Agency added microplastics to its draft Sixth Contaminant Candidate List under the Safe Drinking Water Act – the first time the agency has elevated microplastics to that status as a priority contaminant group. Contaminants on the list are not yet regulated, but their inclusion indicates that the chemical or group of chemicals warrants consideration for regulation. That step signals that the science has matured past the point of dismissal at the federal level.
Read More: 18-Year-Old Builds Filter That Removes 95% of Microplastics From Water
What to Do Now
The research doesn’t yet prove that reducing microplastic exposure will lower your heart attack risk – that causal chain hasn’t been established. What it does show is a consistent association between plastic burden in coronary blood and worse cardiac outcomes, alongside a clear set of known exposure pathways that are at least partially within personal control.
Switching from bottled water to filtered tap water is the single highest-yield individual change: a 2024 study found that a one-liter plastic bottle contained about 240,000 tiny pieces of plastic, 90% of which were nanoplastics. Storing food in glass or stainless steel, never microwaving in plastic containers, and washing synthetic fabrics in cold water with a microfiber-catching bag all reduce daily intake from its highest-volume sources. Frequent indoor cleaning matters more than most people expect – since indoor dust carries a significantly heavier plastic load than outdoor air.
Smoking cessation carries specific relevance here that goes well beyond its established cardiac risks. It emerged as the only independent predictor of coronary microplastic presence in the 2026 European Heart Journal research – outweighing age, disease severity, and every other variable tested. Quitting smoking reduces a person’s two most significant modifiable microplastics risks simultaneously: the direct cardiovascular harm of cigarette smoke and, based on this research, the primary route by which plastic particles appear to reach the heart’s own blood supply.
Disclaimer: This information is not intended to be a substitute for professional medical advice, diagnosis, or treatment and is for information only. Always seek the advice of your physician or another qualified health provider with any questions about your medical condition and/or current medication. Do not disregard professional medical advice or delay seeking advice or treatment because of something you have read here.
AI Disclaimer: This article was created with the assistance of AI tools and reviewed by a human editor.
Read More: 6 Steps You Can Take to Minimize Microplastics in Your Body