Microplastics Found in Human Arteries: A Major Risk Factor for Heart Attack and Stroke

For years, environmental scientists have tracked the accumulation of plastic pollution in our oceans, soil, and food supply. However, a groundbreaking study has moved the conversation from the environment directly into the human body. Researchers have identified microplastics and nanoplastics within the fatty plaque of human arteries. The implications are severe: the presence of these particles is now clinically linked to a significantly higher risk of stroke, heart attack, and death.

The Landmark Study: Evidence from the New England Journal of Medicine

In March 2024, the New England Journal of Medicine published findings that provide the first concrete evidence connecting microplastics to cardiovascular disease in humans. Led by Dr. Raffaele Marfella at the University of Campania Luigi Vanvitelli in Italy, the research team analyzed 257 patients who underwent a carotid endarterectomy. This is a surgical procedure used to remove built-up plaque from the carotid arteries, which supply blood to the brain, to prevent strokes.

The researchers analyzed the excised plaque using pyrolysis-gas chromatography-mass spectrometry and stable isotope analysis. These advanced techniques allowed them to identify the chemical composition of any foreign particles found within the tissue.

Key Findings

The results were stark. The study found detectable levels of microplastics and nanoplastics (MNPs) in the arterial plaque of 150 out of 257 patients, representing nearly 60% of the study group.

• Polyethylene: Found in the plaque of 58.4% of patients. This is the most common plastic used globally, found in plastic bags, bottles, and films.
• Polyvinyl Chloride (PVC): Found in 12.1% of patients. This material is often used in water pipes, flooring, and medical devices.

Using electron microscopy, the researchers observed that these plastic particles had jagged edges and were embedded deep within the plaque macrophages, which are immune cells responsible for clearing debris.

The Health Impact: A 4.5 Times Higher Risk

The most alarming aspect of the study was not just the presence of plastic, but the correlation with health outcomes. The researchers followed the patients for an average of 34 months after their surgery.

They compared the health outcomes of the 150 patients with plastics in their plaque against the 107 patients who had no detectable plastics. The difference was statistically massive. Patients with microplastics in their arterial plaque were 4.5 times more likely to suffer a heart attack, stroke, or death from any cause during the follow-up period compared to those without plastics.

This risk remained consistent even when researchers adjusted for other cardiovascular risk factors, such as smoking, diabetes, hypertension, and high cholesterol. This suggests that the plastic itself is an independent risk factor for severe cardiovascular events.

Mechanism of Harm: Inflammation and Instability

Why does plastic in the arteries cause such severe problems? The study suggests the answer lies in inflammation.

When plaque builds up in arteries, the body views it as an injury. However, when that plaque is contaminated with foreign bodies like microplastics, the immune system launches a more aggressive response. The study found that patients with plastics in their plaque had significantly higher levels of inflammatory biomarkers, specifically Interleukin-18 and Interleukin-6.

The leading theory is that these jagged plastic particles irritate the tissue and destabilize the plaque. Stable plaque can restrict blood flow, but unstable plaque is far more dangerous. If unstable plaque ruptures, it can break off and block blood flow entirely, causing an immediate heart attack or stroke.

Some experts have compared this mechanism to asbestos. Just as asbestos fibers irritate lung tissue and lead to chronic inflammation and disease, microplastics appear to irritate cardiovascular tissue, accelerating atherosclerosis (hardening of the arteries).

Sources of Exposure: How Plastics Enter the Bloodstream

Microplastics are defined as fragments smaller than 5 millimeters, while nanoplastics are even smaller, measuring less than 1 micrometer. Nanoplastics are small enough to pass through the body’s biological barriers, including the gut lining and the lungs, allowing them to enter the bloodstream.

Humans ingest and inhale these particles daily through several common sources:

• Bottled Water: A 2024 study using laser imaging found that a standard liter of bottled water could contain up to 240,000 plastic fragments.
• Food Packaging: Heating food in plastic containers can release millions of microplastics and nanoplastics into the food.
• Synthetic Clothing: Fabrics like polyester and nylon shed millions of microfibers during washing. These fibers enter the water supply and eventually the food chain, or become airborne dust that is inhaled.
• Tires: Rubber tires wear down on roads, creating microscopic dust that is easily inhaled by pedestrians and drivers.

Reducing Your Risk

While it is impossible to completely avoid microplastics in the modern world, medical experts suggest specific steps to lower your daily exposure load. Reducing the total amount of plastic entering your body may help lower the accumulation in tissues over time.

1. Switch to Glass or Stainless Steel: Avoid drinking from single-use plastic water bottles. Use glass or stainless steel vessels instead.
2. Filter Your Water: Use high-quality water filters capable of trapping micro-contaminants.
3. Avoid Heating Plastic: Never microwave food in plastic containers, even if they are labeled “microwave safe.” Heat accelerates the shedding of polymers. Transfer food to ceramic or glass before heating.
4. Dust Regularly: Microplastics accumulate in household dust. Vacuuming with a HEPA filter and damp-dusting surfaces can reduce inhalation risks.

Frequently Asked Questions

Can doctors test me for microplastics in my arteries? Currently, there is no non-invasive test available to detect microplastics in a living patient’s arteries. The study identified them by analyzing tissue surgically removed during an operation.

Does the body naturally remove microplastics? The body attempts to remove foreign particles using immune cells called macrophages. However, plastics are durable and resistant to degradation. The study showed these particles persisting within the immune cells, suggesting the body struggles to break them down or eliminate them effectively.

Are certain types of plastic worse than others? The study specifically identified polyethylene and PVC. These are concerning because of their prevalence and chemical additives. PVC, for example, often contains chlorine and other stabilizers that can be toxic. However, researchers believe the physical presence of any foreign particle in the plaque contributes to the inflammation risk.

Did the study prove that plastics cause the strokes? The study proved a strong association, meaning the link is undeniable, but it is technically observational. However, combined with the biological evidence of increased inflammation in those patients, the case for causation is very strong. Further research is underway to understand the exact biological pathways.