Microscopic plastics may increase risk of stroke and heart attack, study says
Doctors have warned of potentially life-threatening consequences of plastic pollution after finding a substantially increased risk of stroke, heart attack and earlier death in people whose blood vessels were contaminated with microscopic plastic.
Researchers in Naples examined fatty plaques removed from the blood vessels of patients with arterial disease and found that more than half had deposits contaminated with small particles of polyethylene or polyvinyl chloride (PVC).
Those whose plaques contained microplastics or nanoplastics were almost five times as likely to suffer a stroke, heart attack or death from any cause over the next 34 months, compared to those whose plaques were free of plastic pollution.
The findings don’t prove that plastic particles cause strokes and heart attacks – people who are more exposed to the pollution may be at greater risk for other reasons – but research on animals and human cells suggest the particles may be to blame.
“Our data will have a dramatic impact on cardiovascular health if confirmed, because we are defenseless against plastic pollution,” said Dr Raffaele Marfella, first author of the study from the University of Campania Luigi Vanvitelli in Naples. “The only defense we have available today is prevention by reducing plastic production.”
Because plastic pollution is ubiquitous and extends across the planet, Marfella says that even if society were to succeed in the monumental task of reducing plastic pollution, the health benefits of the cleanup would not be visible for years.
The doctors began the study after noticing an increase in strokes and heart attacks in patients who would normally be considered low risk. Marfella and his colleagues wondered whether plastic pollution might be involved in damaging people’s blood vessels by causing inflammation.
Writing in the New England Journal of Medicinethe doctors describe how they analyzed fatty plaques removed from 304 patients with atherosclerosis affecting the carotid arteries. The carotid arteries are the main blood vessels that supply blood to the neck, face and brain. The disease causes a buildup of plaque in the arteries, significantly increasing the risk of stroke. The plaques can be removed by a procedure called carotid endarterectomy.
Laboratory tests on the extracted plaques revealed polyethylene in 150 patients and polyvinyl chloride in 31 patients, in addition to signs of inflammation. When examined under an electron microscope, the researchers discovered jagged foreign particles in the fat deposits, most of which were less than a thousandth of a millimeter wide.
The doctors followed 257 patients for an average of 34 months after the carotid plaques were removed. Those who had plastic particles in their plaques were 4.5 times more likely to have a stroke or heart attack, or to die from any cause, than those whose plaques were free of plastic pollution.
Marfella said the discovery of plastic in the plaques was “surprising” and the likely effect on cardiovascular health was “concerning”. The findings may explain what doctors call “residual cardiovascular risk,” where 20%-30% of patients treated for common risk factors, such as high blood pressure and diabetes, still experience heart attacks and strokes. .
Further research is needed to confirm whether plastic pollution plays a role in strokes and heart attacks, but Marfella called for greater awareness of the potential threat.
“People need to become aware of the risks we take with our lifestyle,” he said. “I hope that the alarm message from our research will raise the awareness of citizens, especially governments, so that they finally become aware of the importance of the health of our planet. To put it in a slogan that can unite the need for health for people and the planet: plastic-free is healthy for the heart and the earth.”
Holly Shiels, professor of integrative physiology at the University of Manchester, said the impact of micro- and nanoplastics on plaque formation and coronary heart disease needs more attention. “It is conceivable that microplastics and nanoplastics, and the toxins they carry, could trigger events that lead to the development of atherosclerosis,” she said.