Microplastics in Arteries: New Study Links Pollution to Heart Risks

For years, scientists have known that microplastics permeate our oceans, soil, and food supply. A groundbreaking study published in the New England Journal of Medicine has now confirmed a direct link between these tiny particles and human cardiovascular health. Researchers discovered that patients with microplastics in their arterial plaque face a significantly higher risk of heart attack, stroke, and death compared to those without.

The Landmark Study on Carotid Arteries

This research marks a pivotal moment in medical science because it moves beyond simply finding plastics in the human body to correlating them with specific, deadly health outcomes. The study, led by Raffaele Marfella, M.D., Ph.D., at the University of Campania Luigi Vanvitelli in Italy, analyzed 304 patients who were already undergoing a procedure called a carotid endarterectomy.

A carotid endarterectomy involves surgery to remove fatty deposits, known as plaque, from the carotid arteries in the neck. These arteries are critical because they supply blood to the brain. If this plaque breaks loose, it can cause a stroke.

By examining the excised plaque from these patients, the researchers aimed to see if microplastics had accumulated within the fatty deposits and if that accumulation changed the patients’ long-term health trajectory.

Specific Findings Within the Plaque

The results of the analysis were stark. Of the 257 patients who completed the follow-up, researchers found measurable amounts of microplastics and nanoplastics in the plaque of 150 patients (58.4%).

Using advanced techniques like pyrolysis-gas chromatography-mass spectrometry and electron microscopy, the team identified two specific types of plastic:

• Polyethylene: Found in the plaque of 58.4% of patients. This is the most common plastic in the world, widely used in clear food wrap, shopping bags, and bottles.
• Polyvinyl Chloride (PVC): Found in 12.1% of patients. This material is commonly used in water pipes, plastic flooring, and synthetic leather.

The electron microscope images revealed that these were not smooth, passive spheres. The plastic particles were jagged shards embedded within the tissue, surrounded by immune cells and inflammation markers.

Quantifying the Health Risk

The most alarming aspect of the study was the follow-up data. The researchers tracked the patients for an average of 34 months (nearly three years) after their surgery. They looked for major adverse cardiovascular events, specifically heart attacks, strokes, or death from any cause.

The data showed a dramatic divergence between the two groups:

1. Patients with plastics: 20% experienced a heart attack, stroke, or death.
2. Patients without plastics: Only 7.5% experienced these events.

After adjusting for other risk factors like age, smoking, diabetes, and high cholesterol, the researchers concluded that patients with microplastics in their arterial plaque were 4.5 times more likely to suffer a heart attack, stroke, or death within those three years. This represents a massive increase in risk that cannot be explained by traditional cardiovascular factors alone.

Inflammation as the Driver

Why does the presence of plastic increase heart risks so drastically? The study suggests that inflammation is the key mechanism.

When foreign objects enter the body, the immune system attacks them. The study found that the plaque samples containing microplastics showed much higher levels of inflammatory biomarkers, such as interleukin-18 and interleukin-6.

In the context of heart disease, inflammation is dangerous. It makes arterial plaque unstable. Stable plaque might narrow an artery, but unstable plaque is prone to rupturing. When plaque ruptures, it forms a clot that can block blood flow entirely, causing a heart attack or stroke. The jagged plastic particles appear to irritate the arterial walls constantly, creating a chronic state of inflammation that makes the plaque more likely to break apart.

Sources of Microplastic Exposure

Understanding how these particles enter the bloodstream is essential for grasping the scope of the problem. Microplastics (particles less than 5 millimeters) and nanoplastics (particles less than 1 micrometer) are ubiquitous in the modern environment.

Ingestion

Humans consume plastics through food and water. A 2019 study by the University of Newcastle in Australia estimated that the average person consumes about 5 grams of plastic every week, roughly the weight of a credit card.

• Water: Both bottled and tap water contain microplastics, though bottled water generally has higher concentrations due to the packaging.
• Food: Seafood is a known source, as marine life ingests plastic. However, agricultural products can also be contaminated through soil and water usage.

Inhalation

We breathe in plastic fibers constantly. These come from the abrasion of car tires on asphalt, which releases dust into the air, and from synthetic clothing fibers (like polyester and nylon) in our homes. Once inhaled, nanoplastics are small enough to pass through the lungs and enter the bloodstream.

Skin Contact

While the skin is a strong barrier, there is emerging evidence that certain nanoplastics found in cosmetics and lotions may be able to penetrate the dermal layer, though ingestion and inhalation remain the primary routes of entry.

What This Means for Future Treatments

This study changes the conversation regarding cardiovascular disease prevention. Historically, doctors have focused on cholesterol (LDL), blood pressure, glucose levels, and smoking. While these remain critical, the “environmental risk factor” is now undeniable.

Cardiologists may eventually need to consider pollution exposure when assessing a patient’s risk profile. Currently, there is no standardized clinical test to measure a patient’s microplastic load, nor is there a medical procedure to “detox” these particles from the arteries. The focus, therefore, shifts to exposure reduction and systemic policy changes regarding plastic production and waste management.

Frequently Asked Questions

Can I test myself for microplastics? Currently, there are no commercially available medical tests for patients to check their microplastic levels. The testing used in the study required the surgical removal of arterial tissue and advanced laboratory equipment.

Do water filters remove microplastics? Yes, certain high-quality water filters can reduce microplastic intake. Reverse osmosis systems are generally considered the most effective at removing the smallest particles. Standard activated carbon pitchers may remove larger microplastics but might miss nanoplastics.

How can I reduce my exposure? While total avoidance is impossible, you can lower your intake by:

• Drinking from glass or stainless steel bottles instead of single-use plastic.
• Avoiding heating food in plastic containers, which accelerates the release of chemicals and particles.
• Choosing natural fibers (cotton, wool, linen) over synthetics for clothing and home textiles to reduce dust.
• Vacuuming regularly with a HEPA filter to remove plastic dust from your home.

Is this risk limited to people who already have heart disease? The study looked specifically at people who already had plaque buildup (atherosclerosis). However, the finding that plastics cause inflammation suggests they could contribute to the initial formation and progression of heart disease in otherwise healthy individuals, though more research is needed to confirm this specific timeline.