We go behind the headlines and fact-check articles that claim tiny pieces of plastic in your blood vessels can increase your chances of having a heart attack or stroke.

The idea that plastic particles so small that they are almost invisible to the human eye can enter the human body from air, food, and water is not new, and numerous studies on microplastics and human health have shown this fact. I am.

Previous research on human cells and animals in the lab also suggests that these plastic particles can harm the heart and circulatory system.

But until now, scientists didn’t know how they actually affect blood vessels.

So when new research on the subject was published, many media outlets quickly published articles about the finding that these tiny plastic particles can increase the risk of heart attack and stroke.

The study, published in the New England Journal of Medicine, found that patients undergoing a surgery called carotid endarterectomy to remove fatty material that has built up in the main blood vessels of the neck (atherosclerosis). This tracked the groups that

After the procedure, the researchers examined fatty material called plaque that was removed from the blood vessels in the necks of 257 people.

More than half of them (58%) found small plastic particles in their plaque.

Using a special high-powered microscope, researchers were able to see the jagged edges of particles known as microplastics and nanoplastics (the smallest particles).

They searched for 11 different plastics and found two: polyethylene and polyvinyl chloride.

They could have entered the body by eating or drinking contaminated products, breathing in the particles or absorbing them through the skin, the researchers said.

They also found that participants who had plastic in their plaques also had higher levels of certain inflammatory markers in their plaques.

These markers are known to be involved in the buildup of fatty plaques in blood vessels, which increases the risk of developing blood clots that can lead to heart attacks and strokes.

Researchers found that people with more plastic had higher blood levels of inflammatory markers. The research team followed study participants for nearly three years after the plaque was removed.

Over that three-year period, they found that people who had plastic in their blood vessels were 4.5 times more likely to have a heart attack, stroke, or die than those who didn’t have plastic in their plaques.

However, participants who had plastic in their plaques had lower rates of smoking, high cholesterol, diabetes, heart and circulatory disease (all known risk factors for heart attack and stroke) compared to participants who did not have plastic in their plaques. were more likely to be infected.

The researchers stressed that their findings do not prove that small plastic particles in the environment cause heart attacks or strokes.

But it showed that there was a connection between the two.

What do researchers say?

Researchers looked at the incidence of heart attacks and strokes in people with few known risk factors.

Researchers said the results of the study do not prove that microplastics and nanoplastics cause heart attacks or strokes, but they do suggest that they may be a previously unknown risk factor. ing.

Previous studies conducted in the lab using mouse and human cells also suggest that these plastics may have negative effects on the heart and circulatory system.

An analysis of this early research published in the journal Environment International found that certain microplastics and nanoplastics can damage cells in the heart and blood vessels, causing abnormal heart rate and damage to the heart muscle, causing the heart to stop functioning normally. It has been shown that it may interfere with functionality.

This new study furthers this knowledge by showing for the first time that microplastics and nanoplastics are present in fatty plaques in some people with atherosclerosis.

Interestingly, the particles the researchers found were primarily nanoplastics, which are the smallest particles.

Researchers say this supports the idea that nanoplastics are the most dangerous to human health because they can spread more easily into the body than larger particles.

However, it is not clear why only two plastics (polyethylene and polyvinyl chloride) were detected in the study participants.

Further research is needed to find out whether these two plastics are more likely to lodge in fatty plaques in blood vessels, and whether this means they are more harmful to the heart than other plastics, they say. states.

BHF judgment

Professor Brian Williams, chief scientific and medical officer at the British Heart Foundation, said the findings were “alarming”.

Finding tiny plastic particles stuck in fatty plaques in human arteries is important, he says, because it suggests that plastic pollution in the environment may be harming our hearts.

“This is the first study to show that microplastic and nanoplastic particles are present in fatty plaques in human arteries and that they may pose a potential risk to our heart health.

“This is concerning and should be taken into account when talking about the impact of the environment on our health.”

It may be impossible to avoid all invisible plastics in the environment.

However, there are many things you can do to reduce your risk of heart attack and stroke.

These include:

How successful was the research?

The study was an observational study of 257 people whose blood vessels had narrowed by more than 70% due to fatty plaques, but who were asymptomatic and underwent a procedure to remove the fatty plaques.

The size of the study is small. However, the researchers checked this before starting the study to ensure that the results were statistically significant.

To ensure accurate information about whether small plastic particles were present, the researchers used three different tests to analyze the removed plaque material.

They searched for 11 types of plastic, and found polyethylene in 150 participants and polyvinyl chloride in 31 participants.

They also tested participants’ plaques for four proteins that can indicate signs of inflammation in the body.

They did this based on a review of 46 studies by researchers in China and Denmark that suggested microplastics and nanoplastics cause inflammation, which is known to increase the risk of heart attack and stroke. Ta.

They found that participants whose plaques had plastic had higher levels of inflammatory proteins, and that the amount of proteins increased with the amount of polyethylene detected.

Researchers monitored participants’ electronic records to see which participants had a heart attack, stroke, or died during the 34-month follow-up period.

To avoid bias, those conducting the monitoring did not know who had plastic on their plaques and who did not.

Researchers also determined each participant’s baseline risk of heart attack, stroke, and death by looking at other risk factors such as age, gender, body mass index, diabetes, high cholesterol, high blood pressure, and the presence of previous cardiac events. was evaluated.

This meant that a link between the presence of small plastic particles in plaque and heart attack, stroke, or death could be clearly identified.

However, like all research, this study has limitations.

Importantly, the results cannot be generalized to other people, as only people with highly narrowed neck arteries and no symptoms were studied.

Also, although researchers account for many risk factors for heart attack and stroke, they did not focus on some social risk factors, such as an individual’s income and education.

The researchers also acknowledged that they cannot rule out the possibility that the fatty plaques were contaminated with plastic particles in the lab after they were removed.

They recommend using a clean room free of plastic materials to ensure that future studies take this into account.

How good was the media coverage?

The study was covered by a number of UK media outlets including the Daily Mail, Guardian, Sky News and The Independent.

Overall, they accurately reported their findings and did not prove that microplastics and nanoplastics cause heart attacks or strokes, only that there was a link between them.

However, the Sky News headline “Microplastics in the blood is linked to stroke, heart attack and early death, study finds” is misleading, as plastic particles are not found in the blood but in the neck. This is because it was detected in fatty plaques on blood vessel walls. .

The Independent took the most balanced approach to reporting, detailing the study’s limitations and concluding that it raised more questions than it answered.

The newspaper quoted Dr. Steve Nissen, a heart expert at the Cleveland Clinic in the US, as saying: However, there are major practical limitations.

“Maybe this is a wake-up call that we need to take the issue of microplastics more seriously. As a cause of heart disease? Not proven. As a potential cause? Yeah, maybe.”

What to read next…

Published March 19, 2024