Study Finds 50 Times More Microplastics in Fatty Neck Arteries

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People with more fatty tissue in their neck have 50 times more micronanoplastics, or tiny bits of plastic, than individuals whose carotid arteries are free of plaque buildup, according to a recent study published by the American Heart Association. Early research was presented at the American Heart Association’s Vascular Discovery 2025 Scientific Sessions: From Genes to Medicine, held April 22-25 in Baltimore.

Fatty tissue, otherwise known as plaque, can narrow the carotid artery situated in the neck and can lead to a stroke. People eat and drink micronanoplastics from plastic waste broken down and collected in the soil and water supply daily. Micronanoplastics can be visible, smaller than a pencil’s eraser (5 millimeters) or invisible to the naked eye (nanoplastic).

“Many people think that micro- and nanoplastics mainly come from using plastic utensils, cutting boards, packaging, water bottles and other plastic items. However, the main source is the food and water we eat and drink,” said lead study author Ross Clark, M.D., MBA, RPVI, a vascular surgeon-scientist at the University of New Mexico, in a statement.

Unfortunately, experts said there is no effective way to prevent exposure to micronanoplastics. However, EcoWatch recommends not microwaving food in plastic, drinking filtered water, avoiding takeaway cups, steering clear of products with recycling codes 3, 6 and 7, using a fiber-catching filter in your laundry machine or using laundry balls to prevent microfibers from breaking off clothes, and using plastic-free cosmetics such as avoiding products with acrylate copolymer and opting for ones that say “fragrance-free” or “phthalate-free.” Other preventive measures include limiting seafood consumption, replacing tea bags with loose leaf tea, and dusting and vacuuming regularly.

Some studies have discovered micronanoplastics in the artery plaques of people with carotid artery narrowing, even if they had no symptoms. In one 2024 study from Italy, people with these particles were more likely to die or have a heart attack or stroke within three years of surgery to remove the plaque.

Researchers wanted to test whether higher levels of micronanoplastics in the carotid artery are linked to symptoms such as stroke or ministroke, and how this may change how mesenchymal stem cells and immune cells communicate with each other. They evaluated micronanoplastics levels in 48 adults; one-third were 60 to 90 years old and had surgery to remove plaque from their carotid arteries.

The study compared the levels of micronanoplastics found in the carotid arteries of three groups: healthy arteries, plaque but no symptoms and symptoms due to plaque buildup. The team also compared plaques with low and high plastic levels to assess the effects of micronanoplastics on markers of inflammation, the gene activity of immune cells called macrophages and stem cells that help stabilize plaque.

Researchers found the concentration of micronanoplastics in carotid arteries with plaque buildup was 16 times greater in individuals without symptoms compared with levels found in artery walls of deceased tissue donors with no plaque (895 micrograms/gram versus 57 micrograms/gram) However, among people who experienced stroke, ministroke or temporary vision loss due to the blockage of blood flow to the retina, the concentration of micronanoplastics in the carotid artery plaque was 51 times greater than deceased tissue donors without plaque (2888 micrograms/gram versus 57 micrograms/gram).

This latest research did not identify a link between the amount of micronanoplastics and signs of sudden inflammation when comparing high-plastic and low-plastic levels. However, the study found that in the artery plaques, the cells that normally help keep plaques stable were acting differently than expected. It also found that macrophages were not turning on their anti-inflammatory genes as much, which could mean more inflammation and less stable plaques.

Although these findings suggest micronanoplastics could be a risk factor for stroke, the study did not prove this and warrants further studies.

“These findings indicate that the biological effects of micronanoplastics on fatty deposits are more complex and nuanced than simply causing sudden inflammation,” Clark said. “It's very important to study what these materials do to our bodies. However, we should be cautious about the early results of this study. We won’t fully understand the biological effects for many years to come.”