Tiny plastic particles, too small to see with the naked eye, have been found in the neck arteries of people who’ve suffered strokes or other problems caused by blocked blood flow to the brain or eyes.
A new study shows that these people have much higher levels of these particles—called micronanoplastics—compared to people with healthy blood vessels.
This research was presented at the American Heart Association’s Vascular Discovery 2025 meeting. The findings add to growing concern about how plastic pollution might affect human health—not just the environment.
Micronanoplastics are small plastic pieces that come from larger plastic items as they slowly break down.
These particles can come from everyday items like food containers, water bottles, and packaging.
Over time, these plastics end up in oceans, soil, and food. Eventually, they can enter our bodies through the food we eat and the water we drink.
Microplastics are less than 5 millimeters long—about the size of a grain of rice or smaller. Nanoplastics are even tinier—less than 1,000 nanometers wide.
Because they’re so small, they can travel easily through the body and even enter our cells. Scientists say that while people often use the term “microplastics,” the focus of new research is more on nanoplastics, since these are the ones that can do more damage by entering tissues.
Dr. Ross Clark, a vascular surgeon and lead author of the study, says many people think they get exposed to plastics only through using plastic items. But in reality, food and water are the biggest sources of exposure.
The study followed earlier research from Italy in 2024, which found micronanoplastics in the neck arteries of people who had surgery to remove plaque. Plaque is a fatty buildup inside the arteries that can block blood flow and lead to strokes, mini-strokes, or temporary vision loss.
In the new study, researchers looked at fewer than 50 people. They split them into three groups: those with healthy arteries, those with plaque but no symptoms, and those who had symptoms like stroke or vision problems. The scientists compared the levels of micronanoplastics in these groups.
They found that people with plaque but no symptoms had 16 times more micronanoplastics in their arteries than people of similar age who had no plaque. Those who had experienced stroke-like symptoms had 51 times more plastic particles in their plaque compared to the healthy group.
The researchers also looked at how the plastic levels affected the body. They didn’t find signs of sudden inflammation caused by these plastics.
However, they did find changes in how certain cells behaved—especially immune cells that are supposed to keep the plaque stable and reduce inflammation. In people with more plastic in their plaque, these cells showed less activity in genes linked to healing and protection.
This suggests the tiny plastic particles might be affecting our immune system in more subtle, long-term ways—not by triggering sudden damage, but by slowly changing how our bodies respond to threats.
Still, the study has limitations. It doesn’t prove that the plastic particles caused strokes or artery problems. It’s possible that the plastic is just a sign of other health issues.
Also, the method used to detect plastics—called pyrolysis gas chromatography-mass spectrometry—can sometimes confuse plastics with natural substances, like fats in the plaque. The researchers are working to improve their technique so that future results are clearer.
Experts say more research is needed. Dr. Karen Furie, a neurologist who wasn’t involved in the study, said this is a troubling but interesting finding. She pointed out that we’ve never considered plastic exposure as a risk factor for stroke before. If more studies confirm these results, it could open up a new way to prevent stroke by reducing plastic exposure in daily life.
In summary, this study raises an important question: could the tiny plastic particles we consume every day be quietly affecting our health, especially our risk of stroke? While it’s too early to say for sure, this early research suggests the answer might be yes.
The findings highlight the need for more research and possibly a closer look at how we handle plastic in our food, water, and environment.
If you care about stroke, please read studies about how to eat to prevent stroke, and diets high in flavonoids could help reduce stroke risk.
For more information about health, please see recent studies about how Mediterranean diet could protect your brain health, and wild blueberries can benefit your heart and brain.
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