Microplastics and Heart Health: What a New Coronary Blood Study Found

August 3, 2026

Are microplastics putting you at a higher risk of heart attack?

Microplastics are now being studied in some of the most unexpected places—including the blood vessels that supply the heart.

In July 2026, researchers reported in the European Heart Journal that micro- and nanoplastics were found more often in coronary blood from patients experiencing an ST-segment elevation myocardial infarction, or STEMI, than in patients with stable coronary disease or normal-looking coronary arteries.

The headline number was striking: plastic polymers were detected in 16 of 19 people with STEMI, compared with 8 of 20 people with chronic coronary syndromes and 7 of 22 people whose coronary arteries appeared normal on angiography.

That is a result worth paying attention to. It is not, however, proof that microplastics caused the heart attacks.

This was a small, cross-sectional study—a carefully taken snapshot at one moment in time. It can show that several things occurred together, but it cannot tell us which came first or whether one directly caused another.

So, what did the study actually find? How reliable were the measurements? And should you change anything about the way you look after your heart?

What Are Microplastics and Nanoplastics?

Plastic does not simply disappear when it breaks down. Larger items can fragment into progressively smaller pieces through sunlight, heat, friction and weathering.

The terms are usually used as follows:

Microplastics are plastic particles smaller than 5 millimetres.
Nanoplastics are much smaller particles, often described as being below 1 micrometre.

For scale, one micrometre is one-thousandth of a millimetre. However, regulators note that there is not yet one universally accepted size definition for microplastics and nanoplastics.

People may encounter these particles through air, food, water and other environmental sources. Scientists have reported plastic-related particles in several types of human samples, but measuring them is technically difficult. Methods are still being refined, and the health meaning of a detected amount is not yet clear.

The US Food and Drug Administration currently states that more research is needed and that existing evidence does not demonstrate that the levels of micro- and nanoplastics found in food pose a human-health risk. The World Health Organization has also identified major gaps in knowledge about exposure, measurement and long-term health effects.

That uncertainty is important. Finding a substance and proving that it causes disease are two very different scientific steps.

What Did the New Study Investigate?

The study, published in the European Heart Journal, involved 61 adults undergoing coronary angiography at two hospitals in Italy between February and April 2025.

Their average age was 64, making the research particularly relevant to many adults in their 50s, 60s and 70s. Seventeen participants were women.

The researchers divided the participants into three groups:

STEMI group: 19 people experiencing an acute type of heart attack usually associated with a sudden coronary artery blockage.
Chronic coronary syndrome group: 20 people with established, more stable coronary artery disease who were undergoing a planned procedure.
Control group: 22 people whose coronary arteries appeared normal during angiography.

The word “control” needs context. These were not randomly selected healthy volunteers from the community. They had been referred for an invasive coronary investigation because coronary disease was suspected, even though their angiograms did not show obstructive disease.

Researchers collected blood from a peripheral artery and from within the coronary circulation. In the STEMI group, they also sampled blood around the artery involved in the heart attack.

They then measured:

The presence, concentration and type of selected plastic polymers
Two inflammatory markers, interleukin-6 and tumour necrosis factor-alpha
Estimated exposure to several air pollutants on the procedure day and over the previous two years
Smoking history and other cardiovascular factors

Air-pollution estimates came from the monitoring station nearest each participant’s home rather than from a personal pollution monitor.

How Did the Researchers Check for Plastic Contamination?

Contamination is one of the biggest challenges in microplastics research.

Plastic is common in laboratories, medical equipment, clothing and indoor air. Without careful controls, particles from the testing environment could be mistaken for particles that were already present in a biological sample.

The researchers took several steps to reduce this risk. They tested the sheaths, catheters, connectors, aspiration equipment and collection tubes used during the procedures. In the laboratory, they used glass tubes, worked under a fume hood, wore cotton coats and avoided plastic materials during processing.

Each testing batch included multiple blank and quality-control samples. The researchers also subtracted background blank values and used recovery experiments to check analytical performance. They reported that the procedure materials did not release detectable micro- or nanoplastics into the samples.

Two laboratory techniques were used:

Pyrolysis–gas chromatography–mass spectrometry, which identifies and measures polymers by analysing their chemical breakdown products
Laser direct infrared spectroscopy, which helps characterise visible particles by polymer type, shape and size

These controls are a strength of the study, particularly because contamination concerns had been raised about earlier work in this field.

They do not make the wider science settled. Authorities still note that microplastics research lacks fully standardised definitions, reference materials, collection procedures and clinical thresholds.

What Were the Main Findings?

Micro- and Nanoplastics Were Detected Most Often in the STEMI Group

The researchers detected at least one of the tested polymers in:

84.2% of the STEMI group: 16 of 19 people
40% of the chronic coronary syndrome group: 8 of 20 people
31.8% of the normal-angiogram group: 7 of 22 people

The STEMI group also had higher measured concentrations and a greater variety of polymers. The median was three polymer types per person in this group, compared with a median of zero in the other groups.

Polyethylene was the most commonly detected material. It appeared in 97% of participants who had any detectable micro- or nanoplastics. Other detected polymers included polyethylene terephthalate, polyvinyl chloride, polypropylene, polystyrene and nylon 66.

A useful detail is that some participants in every group had no detectable particles, while some people with normal coronary angiograms did have them. Detection alone was therefore neither a diagnosis of coronary disease nor proof that a heart attack would occur.

Concentrations Were Higher in Coronary Blood

Within individual participants, the same polymer types were generally found in peripheral and coronary blood.

The highest concentrations were measured in coronary blood. Among people with STEMI, the highest values were found in blood collected upstream from the blocked area, followed by downstream coronary blood and then peripheral arterial blood.

This is an intriguing observation because it suggests that coronary sampling may reveal a different local picture from a standard blood draw.

It does not show why the concentration differed. The study cannot tell whether particles accumulated near an unstable plaque, were redistributed during the acute event, reflected another process or were simply associated with factors shared by the people in that group.

Inflammatory Markers Were Also Higher

The STEMI group had higher concentrations of interleukin-6 and tumour necrosis factor-alpha, particularly in coronary blood. These markers were also higher when micro- or nanoplastics were detected.

Inflammation is involved in atherosclerosis and acute heart attacks, so the overlap is biologically interesting.

However, a heart attack itself creates a powerful inflammatory response. Because samples were taken during the event, the study cannot establish that the plastic particles triggered the inflammation. The inflammation, the particles and the acute coronary event were captured in the same photograph; the study did not film which one moved first.

To understand the artery disease behind these events, read Understanding Atherosclerosis: Causes, Symptoms and Risk Factors.

What Did the Study Find About Air Pollution?

The researchers paid particular attention to PM2.5, or airborne particulate matter measuring 2.5 micrometres or less.

PM2.5 is much broader than plastic pollution. It can contain a mixture of soot, dust, metals, organic chemicals and other particles, depending on the source. Because it is so small, it can travel deep into the lungs and some components can enter the bloodstream. The World Health Organization reports that its links with cardiovascular and respiratory disease are well established.

Estimated PM2.5 exposure was higher in the STEMI group both on the procedure day and across the preceding two years.

The two-year median estimates were:

17 micrograms per cubic metre in the STEMI group
13 micrograms per cubic metre in the chronic coronary syndrome group
9 micrograms per cubic metre in the normal-angiogram group

More than 93% of all participants lived in areas with estimated long-term PM2.5 above the World Health Organization annual guideline of 5 micrograms per cubic metre.

Micro- and nanoplastic detection was also more frequent among people whose estimated long-term PM2.5 exposure exceeded 15 micrograms per cubic metre. Every participant who had both a smoking history and exposure above that level had detectable polymers.

That subgroup finding sounds dramatic, but the total study was small. It should not be read as a universal rule.

The pollution data also came from the nearest outdoor monitoring station. It could not capture each person’s workplace, travel, indoor air, daily routine or exact inhaled dose. Nor did it prove that the PM2.5 itself contained the polymers later found in blood.

What Did the Study Find About Smoking?

Smoking history was the only independent predictor of micro- or nanoplastic detection in the study’s main adjusted statistical model.

Participants with a current or former smoking history had 5.69 times the odds of detectable polymers compared with never-smokers. The confidence interval was wide, from 1.33 to 26.63, reflecting considerable uncertainty in a small sample.

An important distinction is often lost in headlines:

This does not mean smokers had 5.69 times the heart attack risk because of microplastics.

The statistical result concerned the odds of detecting the tested polymers, not the odds of having a heart attack. It also combined current and former smokers, and the researchers did not have enough information to examine how detection changed with years since quitting.

Smoking is already an established cause of cardiovascular disease, regardless of its possible relationship with microplastics. The World Health Organization identifies tobacco as a major risk factor for heart disease and stroke.

Does This Study Prove That Microplastics Cause Heart Attacks?

No.

The study found an association: detectable micro- and nanoplastics, higher inflammatory markers, smoking, greater estimated PM2.5 exposure and acute coronary presentation often appeared together.

It did not establish a cause-and-effect chain.

Several explanations remain possible:

Micro- or nanoplastics could contribute to biological processes involved in artery disease.
Smoking and polluted air could increase both cardiovascular risk and plastic-particle exposure.
The physiological changes surrounding an acute heart attack could affect how particles are distributed or measured.
Other unmeasured exposures or health differences could influence both findings.
Some results could be affected by chance in a small study.

The researchers also ran exploratory models in which detectable micro- or nanoplastics were associated with obstructive coronary disease. Those estimates had wide confidence intervals and were described as hypothesis-generating, not as a clinical risk calculation.

The responsible conclusion is not “microplastics cause heart attacks”. It is: the observed pattern is concerning enough to justify larger, better-controlled studies.

What Were the Study’s Main Limitations?

Every study has boundaries. These are especially important when the subject is new and likely to attract alarming headlines.

It Was Small

Only 61 people took part, including 19 with STEMI. Small samples can identify signals, but they produce less precise estimates and make it harder to account fully for differences between groups.

It Was Cross-Sectional

The researchers measured particles, inflammation and clinical status around the same time. There was no before-and-after sequence and no follow-up showing whether particle levels predicted later events.

The Groups Were Not Perfectly Matched

The control group included more women, while other medical conditions were more common in the chronic coronary syndrome group. These differences can complicate comparisons.

The Controls Were Not a General Healthy Population

People in the control group had normal coronary angiograms, but they were undergoing testing because coronary disease was suspected. The results cannot be assumed to represent all healthy adults.

The Research Was Geographically Narrow

Participants came from two Italian hospitals during a three-month period. Exposure patterns, air quality, smoking habits and population characteristics may differ elsewhere.

One Common Type of Heart Attack Was Excluded

The study excluded non-ST-segment elevation myocardial infarction, or NSTEMI. Its findings therefore do not cover the full range of acute coronary syndromes.

Several Exposure Routes Were Not Measured

The researchers considered smoking and outdoor pollution but did not directly assess food, drinking water, packaging, medicines, medical devices or occupational exposure as possible particle sources.

Pollution Exposure Was Estimated

The nearest monitoring station provides useful area-level information, not a personal exposure measurement.

The Field Still Lacks Clinical Standards

There is no agreed blood reference range that separates a “safe” from a “dangerous” microplastic level. Detection methods are not yet standardised for routine clinical use.

The authors themselves described the adjusted estimates as exploratory and hypothesis-generating rather than definitive.

How Does This Fit With Earlier Heart Research?

The new study did not appear in isolation.

In 2024, a prospective observational study published in The New England Journal of Medicine examined carotid plaques removed during surgery. Among 257 people who completed follow-up, polyethylene was detected in the plaques of 150 participants. People with detected micro- or nanoplastics had a higher rate of a combined outcome of heart attack, stroke or death over an average of almost three years.

That study was important, but it did not prove causation. It was also followed by scientific correspondence questioning whether external plastic contamination could have influenced the measurements.

The 2026 coronary-blood study explicitly strengthened its contamination controls by testing procedural materials, using multiple blanks, processing samples in glass and avoiding plastic in the laboratory workflow.

Taken together, the studies create a signal worth investigating. They do not yet provide a settled answer.

Stronger evidence would require:

Larger and more diverse populations
Standardised collection and measurement methods
Samples taken before cardiovascular events occur
Better personal assessment of air, food, water and occupational exposure
Repeated measurements over time
Follow-up for clinical outcomes
Trials showing that reducing exposure changes particle levels and improves health

Until those steps are completed, micro- and nanoplastics should be considered an emerging research concern rather than an established personal risk score.

What Does This Mean for Adults Over 50?

The study’s average participant was 64, so its questions are highly relevant to older adults.

However, the study did not find that age independently predicted micro- or nanoplastic detection. Nor does it provide a new test or treatment specifically for people over 50.

For someone in their 50s, 60s or 70s, the sensible response is review, not panic.

Environmental exposures may eventually become a more formal part of cardiovascular risk assessment. At present, the factors with the clearest evidence and most actionable treatments remain:

Smoking and second-hand smoke
Blood pressure
LDL cholesterol and other blood lipids
Diabetes and blood sugar
Physical activity
Eating pattern
Body weight and waist measurement where relevant
Sleep and sleep apnoea
Family history
Taking prescribed medicines as directed

A new environmental study is a reason to widen the lens, not to throw away the map.

For a practical overview of cholesterol-related testing, read Cholesterol Isn’t Just About What’s on Your Plate.

Should You Ask for a Microplastics Blood Test?

There is currently no standardised, guideline-recommended clinical blood test for micro- or nanoplastics with an agreed reference range and proven role in heart-care decisions.

The study used specialist research equipment, extensive contamination controls and methods that are not part of a routine blood panel.

A commercial result would be difficult to interpret if there is no accepted answer to questions such as:

What level is typical for someone of your age and location?
How much variation occurs from day to day?
Which collection method prevents contamination?
Does the result predict future disease independently of known risk factors?
Would a different result change evidence-based treatment?

There is also no established “microplastic detox” treatment shown to remove these particles in a way that reduces heart attacks or improves cardiovascular outcomes.

Be cautious with products, tests or programmes that promise to cleanse plastic from the blood, reverse exposure or protect the heart without robust clinical evidence.

What Practical Steps Make Sense Now?

Do Not Smoke

Smoking was the strongest predictor of polymer detection in this study, and its cardiovascular harms are already firmly established.

Avoid tobacco and second-hand smoke. If you currently smoke, seek evidence-based cessation support through a doctor, pharmacist or recognised quit service in your country. It is never too late to benefit from stopping.

Pay Attention to Air Quality

Use a trusted local air-quality service where one is available.

On days with poor air quality, you may be able to reduce exposure by changing the time or location of outdoor activity, choosing routes away from heavy traffic or exercising indoors. These options are consistent with World Health Organization guidance on personal actions to reduce air-pollution exposure. People with heart or lung conditions should ask a healthcare professional how to adapt activity safely.

Air pollution should not become a reason to remain inactive. The aim is to preserve regular movement while reducing exposure during the worst periods.

Make Low-Burden Plastic Choices Without Expecting a Medical Cure

Reducing unnecessary single-use plastic may be worthwhile for environmental reasons. You may also choose durable glass or stainless-steel containers when practical and use food-storage products according to their manufacturer’s instructions.

These are reasonable personal choices, but this study did not test whether changing containers lowers microplastic levels in blood or prevents cardiovascular events. Current evidence does not support turning ordinary household decisions into a source of fear.

This is a signal worth studying, not a verdict on your lunch container.

Keep Established Heart Risks in View

Know your blood pressure, cholesterol and blood sugar. Stay active at a level appropriate for your health, eat a varied diet, attend recommended reviews and take prescribed medicines as directed.

These actions have far stronger evidence than any unproven microplastic test, cleanse or supplement.

When Should You Seek Emergency Medical Help?

Microplastics cannot be diagnosed from symptoms. However, possible heart attack symptoms always require urgent attention, whatever the suspected cause.

Contact the emergency medical service for your location immediately if you or someone else develops warning signs such as:

New or persistent pressure, squeezing, tightness, heaviness or pain in the chest
Discomfort spreading to an arm, shoulder, back, neck or jaw
Shortness of breath
Cold sweating
Nausea or vomiting
Sudden weakness, light-headedness or fainting
An unexplained feeling of being severely unwell

Symptoms may be mild, may come and go and do not always include obvious chest pain. The World Health Organizationadvises that possible heart-attack symptoms require immediate medical care. Do not wait for them to become severe, and avoid driving yourself when emergency transport is available.

Read How to Spot a Heart Attack—and What to Do Next.

Questions to Ask Your Doctor

You may wish to ask:

Which established cardiovascular risk factors are most important for me?
Are my blood pressure, cholesterol and blood sugar being checked often enough?
How do smoking or second-hand smoke affect my current risk?
Should local air quality change when or where I exercise?
Are any symptoms I have described suggestive of coronary heart disease?
Is there any clinical reason for me to have a microplastics test?
How should I assess claims made by commercial “detox” products or environmental tests?
Which changes would offer the greatest evidence-based benefit for my heart?

AtheroCare’s heart health checklist of questions to ask your doctor can help you prepare for the conversation.

The Bottom Line

A 2026 study detected micro- and nanoplastics more often, at higher concentrations and in a greater variety of polymers in coronary blood from people experiencing STEMI than in people with stable coronary disease or normal coronary angiograms.

Detection also overlapped with higher inflammatory markers, smoking and greater estimated PM2.5 exposure.

The study used unusually careful contamination controls, which strengthens confidence that the measurements deserve further investigation. Its small size, cross-sectional design, selected hospital population and indirect exposure estimates mean it cannot show that plastic particles caused the heart attacks.

For adults over 50, the findings are a reminder that heart health is influenced by the environment as well as by familiar risk factors. They are not a reason to panic, purchase unvalidated testing or replace proven care with a plastic “detox”.

Avoid tobacco, reduce exposure to heavily polluted air where practical, make sensible environmental choices and keep your main focus on blood pressure, cholesterol, blood sugar, physical activity, symptoms and professional medical care.

References

European Heart Journal: Micro- and Nano-Plastics in the Coronary Circulation and Air Pollution Exposure in Ischaemic Heart Disease Presentation

European Heart Journal Editorial: Nano- and Microplastics in the Cardiovascular Exposome

New England Journal of Medicine: Microplastics and Nanoplastics in Atheromas and Cardiovascular Events

New England Journal of Medicine Correspondence: Microplastics and Nanoplastics in Atheromas

World Health Organization: Dietary and Inhalation Exposure to Nano- and Microplastic Particles and Potential Implications for Human Health

US Food and Drug Administration: Microplastics and Nanoplastics in Foods

World Health Organization: Health Impacts of Particulate Matter and Other Air Pollutants

World Health Organization: Personal-Level Actions to Reduce Air Pollution Exposure

World Health Organization: Tobacco and Nicotine

World Health Organization: Cardiovascular Diseases

Medical Disclaimer

This article is provided for general information and education only. It is not intended to provide medical advice, diagnosis or treatment.

Always speak with a qualified healthcare professional about symptoms, test results, medicines, environmental exposures and your personal cardiovascular risk. Do not begin, stop or change any treatment based only on information in this article.

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