Among 304 patients who underwent procedures to clear a major artery in the neck, 58% were found to have microscopic and nanoscopic “jagged-edged” pieces of plastic in the plaque lining the blood vessel, including polyethylene and polyvinyl chloride containing chlorine, Dr. Raffaele Marfella at the University of Campania in Naples and colleagues reported.
Those with plastic particles in their carotid artery plaque had a 4.5 times higher risk of experiencing a heart attack or stroke or dying during the next three years, the researchers found after taking individuals’ other risk factors into account.
Patients with microplastics or nanoplastics in their plaque tissue also had high levels of inflammatory proteins in their blood that are known to play a role in atherosclerosis and heart failure, the researchers said.
“Polyethylene and polyvinyl chloride, in their various forms, are used in a wide range of applications, including the production of food and cosmetics containers and water pipes,” the authors wrote. In the report in The New England Journal of Medicine, they noted that such microplastics have been found in drinking water, a large range of foods, cosmetic products, and the air.
Earlier studies have detected various types of microplastics and nanoplastics in multiple tissues, including the colon, liver, spleen, lymph node tissues and placenta. Animal studies have shown these plastics can cause toxic effects.
While the new study cannot prove the plastic caused patients’ adverse events, it is the first to link the tiny particles with cardiovascular disease outcomes in humans, Dr. Philip Landrigan of Boston College, who was not involved in the study, wrote in an editorial that accompanied the report.
The finding of microplastics and nanoplastics in plaque is “a breakthrough discovery,” Landrigan wrote.
Among the questions it prompts, he said, are whether exposure should be considered a cardiovascular risk factor, and how exposure can be reduced.
In a 2022 report on dietary and inhalation exposure to tiny pieces of plastic, the World Health Organization noted overwhelming consensus that plastics do not belong in the environment, and that measures should be taken to mitigate exposure.
"The low cost and convenience of plastics are deceptive," Landrigan said. "In fact, they mask great harms, such as the potential contribution by plastics to outcomes associated with atherosclerotic plaque."
