Microplastics have moved from an ocean story to a human-body story. They have been detected in blood, placenta and arterial plaque, and one prominent study linked their presence to later cardiovascular events. That has produced a wave of advice, filters and supplements promising to “detox” you from plastic.
The evidence is genuinely concerning and genuinely incomplete, and the gap between those two things is where most of the internet’s microplastics content goes wrong. Here is what has actually been measured.
What microplastics are
Microplastics are plastic fragments under 5 mm; nanoplastics are smaller still, under 1000 nanometres. They come from the breakdown of larger plastics, from synthetic textiles, from tyre wear, and from packaging and containers. They are now detectable in food, water and air, which means everyone is exposed.
Detection is a technical problem as well as a health one, because plastic is everywhere in laboratories too, and distinguishing particles in a sample from particles picked up during collection is genuinely hard. That issue recurs below.
The study everyone is citing
In 2024, The New England Journal of Medicine published a prospective, multicentre, observational study of patients undergoing carotid endarterectomy, an operation to remove plaque from the neck arteries. Researchers analysed the removed plaque for plastics and then followed the patients.
A total of 304 patients were enrolled in the study, and 257 completed a mean follow-up of 33.7 months. Polyethylene was detected in carotid artery plaque of 150 patients (58.4%), and 31 patients (12.1%) also had measurable amounts of polyvinyl chloride.
The outcome was striking. Patients with plastics in their plaque were at higher risk of heart attack, stroke or death from any cause, with a hazard ratio, 4.53; 95% confidence interval, 2.00 to 10.27.
Why that number needs handling with care
Three caveats matter, and the first two come from the scientific literature rather than from sceptics online.
It is observational. Patients were not randomised to have plastic in their arteries. Crucially, the study did not track participants’ diet or drinking water, the main routes by which plastic enters the body, so an unmeasured behaviour behind higher plastic levels could also be driving the risk.
Contamination is a live question. Operating theatres and laboratory equipment contain the same plastics being measured, and critics have noted the study did not rule out plastic introduced during surgery or sample handling. If some of the detected plastic arrived that way rather than during life, the grouping is unreliable.
The population was not the general public. These were people already sick enough to need carotid surgery. Whether the same association exists in healthy adults is untested.
The authors were also careful about the bigger picture, noting that over a period of decades in which exposure to plastics has presumably been increasing, the rate of cardiovascular disease has been falling. That is not a reason to dismiss the finding; it is a reason to be cautious about assuming plastics are a major driver of heart disease.
What is established and what is not
Established: plastic particles are present in human tissue, including arterial plaque, in a majority of people tested in at least one study.
Suggestive: their presence in plaque was associated with a substantially higher rate of cardiovascular events in one cohort of surgical patients.
Not established: that microplastics cause any human disease; that reducing your exposure changes any health outcome; that any product removes them from your body. No trial has randomised anyone to lower plastic exposure and measured what happens.
What to do with that
The honest position is that exposure reduction is a reasonable precaution with unquantified benefit. The actions that plausibly reduce dietary exposure are cheap and low-risk: not heating food in plastic containers, using glass or stainless steel for hot liquids, filtering tap water, reducing reliance on single-use bottles.
What the evidence does not support is spending money on anything marketed as removing microplastics from your body, or treating this as an emergency that outranks the cardiovascular risks that are proven and modifiable. Blood pressure, smoking, activity and lipids have decades of trial evidence behind them. Microplastics have one observational study and a contamination debate.
This is not individual medical advice. Concerns about cardiovascular risk belong with a clinician, who can address the risk factors that are actually measurable in you.
Common questions
Do microplastics cause heart disease?
No study has shown cause. One observational study found patients with plastics in carotid plaque had a higher rate of heart attack, stroke or death, with a hazard ratio of 4.53, but the design cannot separate cause from association.
How do microplastics get into the body?
Through food, drinking water and air. The 2024 cardiovascular study did not examine diet and water as sources, so the main exposure routes for the plastic found in tissue remain unquantified.
Can you detox microplastics from your body?
There is no evidence that any supplement, cleanse or protocol removes microplastics from human tissue. Nothing marketed for this purpose has been tested in a trial.
What is the best way to reduce microplastic exposure?
Reducing plastic contact with hot food and drink, filtering tap water and using glass or steel containers are low-cost precautions. Whether they change any health outcome has not been tested.
The bottom line
Plastic particles are in human arteries, and in one study of surgical patients their presence tracked with later heart attacks and strokes. That is a serious signal and not yet a proven cause, with an unresolved contamination question attached. Reduce exposure where it is cheap to do so, ignore anyone selling a plastic detox, and keep your attention on the cardiovascular risks that have trials behind them.
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