In a new study published in The New England Journal of Medicine, researchers say that microplastics and nanoplastics (MNPs) are emerging as a potential risk factor for cardiovascular disease.

Marfella R, Prattichizzo F, Sardu C, et al. Microplastics and nanoplastics in atheromas and cardiovascular events. New England Journal of Medicine. 2024;390(10):900-910.

 

The researchers conducted a preclinical trial evaluating carotid artery plaque samples from patients undergoing carotid endarterectomy for asymptomatic carotid artery disease.

The samples were analyzed for the presence of MNPs. Researchers followed up with patients 34 months later to evaluate them on different undesirable endpoints, including myocardial infarction, stroke, or death from any cause. The results showed that patients with detectable microplastics in carotid artery plaque were at higher risk for all three endpoints than those without microplastics. A total of 304 patients enrolled in the study, and 257 completed the desired follow-up. Polyethylene—a commonly produced plastic—was detected in carotid artery plaque of 150 patients.

Marfella R, Prattichizzo F, Sardu C, et al. Microplastics and nanoplastics in atheromas and cardiovascular events. New England Journal of Medicine. 2024;390(10):900-910.

 

These findings highlight the need for more research into how microplastics affect the body and what types of medical interventions are needed to prevent and treat unwanted outcomes.

“What this speaks to is a lot of unknowns about what microplastics do in the body,” says Yu-Ming Ni, MD, a board-certified cardiologist and lipidologist at MemorialCare Heart & Vascular Institute at Orange Coast Medical Center in Fountain Valley, CA. “I'm very concerned that there's such a high prevalence of microplastics in cholesterol plaque, and I'm concerned that we don't really know what it does to the body.”

Dr. Ni adds that while the connection is clear, there is not enough information to confirm that microplastics are solely responsible for the risks noted in the study.

“When plaque becomes unstable, it tends to rupture, and that can lead to a massive heart attack. That can lead to a stroke—and we don't know how microplastics play a role in that,” Dr. Ni says. “Seeing that they’re so prevalent, it's going to be really important for future research to look into the effects of microplastics on plaque stability.”

It will also be important to investigate how to remove microplastics embedded in the body—if this is possible. While plastic can at times escape the body through stool or vomit, the body does not have a process for eliminating this substance on its own, Dr. Ni says. Learning to remove microplastics from areas of the body like carotid artery plaque will likely be challenging and “very costly, time-intensive, and hard on the body,” Dr. Ni says.

Other researchers have also noted that microplastics can be harmful to the heart. A January 2023 article published in Environment International noted that MNPs could have cardiac effects like abnormal heart rate, pericardial edema, and myocardial fibrosis.

Zhu X, Wang C, Duan X, Liang B, Genbo Xu E, Huang Z. Micro- and nanoplastics: A new cardiovascular risk factor? Environment International. 2023;171:107662.

 

 

“A growing body of studies has advanced our understanding of the potential toxicity of MNPs, but knowledge gaps still exist regarding the adverse effects of MNPs on the cardiovascular system and underlying mechanisms, particularly in humans,” the researchers wrote. Per their review of 46 studies on toxicity of MNPs in the circulatory system, the researchers stated the results showed that “MNPs affected cardiac functions and caused toxicity on (micro)vascular sites.”

Zhu X, Wang C, Duan X, Liang B, Genbo Xu E, Huang Z. Micro- and nanoplastics: A new cardiovascular risk factor? Environment International. 2023;171:107662.

 

MNPs may enter the circulatory system through various methods, including by “penetrat[ing] intestinal or pulmonary barriers,” which allows them to accumulate in the heart, according to the 2023 article.

Zhu X, Wang C, Duan X, Liang B, Genbo Xu E, Huang Z. Micro- and nanoplastics: A new cardiovascular risk factor? Environment International. 2023;171:107662.

 

Before they can enter the circulatory system, however, microplastics need to enter the body. This may happen through many entry points, including eating, drinking, breathing, and through the skin. 

“Because microplastics are everywhere, there is no way to completely evade exposure,” says Rebecca Fuoco, MPH, Director of Science Communications at Green Science Policy Institute, an organization that supports research and advocacy work on safer uses of chemicals. However, there are ways to potentially reduce risk, including minimizing plastic use when possible, properly disposing of plastics and recycling items, and advocating for policies that support human and environmental health, she adds.

“This is not an individual problem; it's a policy problem,” Fuoco says. “We need action to curb the fast and furious proliferation of plastics and petrochemicals.”

Still, everyone can take some initiative to protect their own health. Fuoco recommends that doctors and patients start by taking steps like:

• Eliminating use of nonessential or replaceable plastics. 

• Avoiding plastic water bottles.

• Avoiding synthetic tea bags.

• Avoiding heating food in plastic containers.

• Regularly vacuuming and mopping to reduce risks of exposure to microplastics and other harmful chemicals.

A good place to start would be to eliminate nonessential and replaceable plastics. For all other types of plastic use, we need to speed up research into alternatives that aren’t produced from fossil fuels or laden with petrochemicals.