Microplastics found in blood vessels linked to premature death, a study finds

Microplastics in arteries could contribute to heart attacks, stroke and even death at 34 months of the follow-up in the three-year long clinical trial.

People having microplastics lodged into their arteries are 4.5 times more likely to suffer a cardiac event, including heart attack, stroke or death from any cause at 34-months of the follow-up in the clinical trial, a study has found out.

Microplastics are found everywhere, in the soil, water bodies and in the surrounding air, finding a way into the human body through ingestion and inhalation. Multiple studies have found their presence in human tissues such as the placenta, liver, urine and even in blood.

Once released into the soil, the plastics are degraded by natural forces, leading to formation of microplastics (smaller than 5mm) and nanoplastics (smaller than 1000 nanometres), with these particles triggering a range of ill effects on human life.

The study found tiny particles of polyethylene in arteries, the world’s most commonly found plastic used in making bottles, pipes, and other daily products.

The study published in the New England Journal of Medicine had tested the plaque removed from the carotid artery (neck artery) for microplastics.

What did the study find?

A plaque is a sticky substance present on the walls of blood vessels which gets calcified and hardened over a period of time, restricting the blood flow.

The study involved patients who already had plaque deposits in their carotid artery, a blood vessel running down the neck (an oxygen rich artery) and were under treatment. 

The plaque extracted from their arteries was analysed for potential inflammatory markers which cause cardiovascular outcomes like heart attacks, stroke and even death at 34 months of the follow-up.

Out of 257 people who followed up the three-year-long clinical trial, about 150 patients had deposits of polyethylene and another 31 had small amounts of polyvinyl chloride, a polymer commonly used in construction, plumbing and medical industries.

Scientists found these particles to be scattered over with the fat deposits and debris of the blood cells in the lining of the arterial walls, forming a plaque.

The study found these microplastics alongside other inflammatory factors were observed to cause oxidative stress, inflammation and altered heart rate in the people. However, if microplastics alone could cause vascular lesions in the blood vessels is yet to be known.

Patients who had microplastics in the blood vessels were predominantly male and were more likely to smoke, and also had high creatine levels than those who didn’t have microplastics in their bloodstream.

Possibility of nanoplastics in blood

As per the World Health Organisation (WHO), microplastics larger than 150 micrometers are not likely to be absorbed into the bloodstream and do not penetrate the blood vessels.

The researchers suggest the presence of nanoplastics, rather than microplastics to contribute to plaque formation as seen in artery disease. The particles detected in the study were all below the 200 nm threshold which could have eased their entry into the lining of the blood vessels.

The study also found that the distribution of microplastics in the body increased with a decrease in their size.

In 2022, some studies had found traces of microplastics in the human milk.