Microplastics that enter the human body can accumulate inside the arteries and, if they do, they carry a greater risk of stroke, heart attack and death. This is demonstrated by research that analyzed the carotid arteries of 257 people with cardiovascular risk factors. The results indicate that the probability of dying or suffering a stroke or heart attack is multiplied almost fivefold if there are detectable plastic remains in the arteries.
A series of research presented in the last five years has shown that food and air can contain plastic debris so small that it is ingested and breathed without being aware of it. Plastic remains have been detected in various organs and fluids such as the lungs, liver, placenta, blood, urine or breast milk, among others. But the consequences that these microplastics can have for health in the medium and long term have not yet been studied in detail.
The new research, led by the University of Campania Luigi Vanvitelli (Italy), was based on 257 people who were well but who had large accumulations of cholesterol in their carotid arteries. These clumps, called atheromatous plaques, restrict blood flow to the brain and increase the risk of stroke. All of them underwent surgery to remove carotid atheroma plaques between August 2019 and July 2020. The patients, who had an average age of 72 years and included both men and women, were treated in hospitals. from the Naples region.
According to the results presented this week in The New England Journal of Medicine, 58% of the patients (150 of the 257) had detectable plastic residues in the atheroma plaques. All of them had traces of polyethylene (PE), the simplest and most common plastic. In addition, 12% (31 patients) had traces of polyvinyl chloride (PVC), another very common plastic.
The presence of plastics was detected with chemical analysis techniques and confirmed visually with electron microscopy. Most were nanoplastics, which are usually defined as microplastics that measure less than a micron (or one thousandth of a millimeter).
People who had plastic waste also had higher levels in their arteries of pro-inflammatory molecules involved in strokes and heart attacks, such as, among others, IL-18, TNF-alpha or CD68. Previous studies carried out with in vitro cell cultures had pointed out, along these same lines, that microplastics and nanoplastics promote oxidative stress, inflammation and self-destruction of arterial cells.
The researchers followed the patients for an average of 34 months, until July 2023. 20% of those who had plastic debris in their arteries suffered a stroke, heart attack or died during this period (specifically, 14 non-fatal strokes were recorded , 10 non-fatal heart attacks and 6 deaths from any cause). Among those who did not have plastics, the percentage was 7.5% (with 5 strokes, 2 heart attacks and 1 death).
The levels of blood pressure, cholesterol, body mass index and smoking were similar in both groups, so they cannot explain this difference.
According to the results of the statistical analysis, the presence of microplastics or nanoplastics in the carotid arteries is associated with a 4.53 times higher risk of suffering a heart attack, stroke or death in the following three years.
“Our findings suggest that nanoplastics can accumulate in anatomical locations of atherosclerosis. The vast majority of particles detected were below 200 nanometers [and] the absorption and distribution of nanoplastics increases as the size of the particles reduces,” the authors of the research point out.
“The low price and convenience of plastics are deceptive,” adds Paul Landrigan, from Boston College (USA), in an analysis article published in The New England Journal of Medicine. “We need to encourage our patients to reduce their use of plastics, especially single-use plastics [and] we need to support the United Nations Global Plastics Treaty.” According to Landrigan, this treaty, which has not yet been approved, should include “a mandatory limit on global plastic production, with targets and schedules, restrictions on single-use plastics, and comprehensive regulation of plastic chemicals.” .
