Plastic is everywhere, from our kitchen cupboards to our clothes—and, a new study shows, even in our arteries. Recent research has turned up evidence of tiny plastic debris called microplastics in samples of plaque, a fatty substance that builds up in arteries and increases risk of heart disease. What’s more, those plastic bits may be linked to an increased risk of heart attack, stroke and even death.
“Our use of plastics in everyday life has exploded exponentially over the years. And as the science progresses, we’re finding more evidence that plastic may affect our health,” says Henry Kim, M.D., M.P.H., a cardiologist at Henry Ford Health.
But the case is far from closed, and there’s no reason for panic yet, Dr. Kim adds. He explains what the science shows so far, and where we go from here.
What Are Microplastics and Nanoplastics?
Plastic is handy because it’s so durable. But over time, it breaks down into small pieces called microplastics that persist in the environment. Microplastics can wear down into even smaller particles, called nanoplastics, that are less than 0.001 millimeters wide.
Environments across the globe are contaminated with microplastics and nanoplastics. They’re in the soil, water and even the air we breathe. Previous research found microplastics in the human bloodstream. “We ingest them and inhale them, so it’s not surprising that they’ll be absorbed by the body,” Dr. Kim says.
Now a study published in the New England Journal of Medicine has found microplastics and nanoplastics in samples of plaque. Plaque buildup in the arteries leads to carotid artery disease and coronary artery disease—types of heart disease that can lead to serious cardiac events like heart attacks and strokes.
Microplastics and Heart Disease: What’s the Connection?
The researchers studied people who were having a procedure to remove plaque from the carotid artery in the neck to reduce their risk of stroke. After removing the plaque, it was studied under a microscope. In almost 60% of participants, the samples contained microplastics and nanoplastics.
The researchers followed the study participants for nearly three years after the procedure. They discovered those who had microplastics in their samples were 4.5 times more likely to have a heart attack or stroke—or to die—during that period.
“It’s a strong association, but it’s important to remember that this is just one small study,” Dr. Kim cautions. The study doesn’t prove microplastics increase the risk of cardiac events. There are also questions about why some people have microplastics in their arteries while others do not. “A lot of things still need to be sorted out,” he adds.
Inflammation Increases Risk
The study couldn’t say for sure why microplastics might increase the risk of heart attack and stroke. But it did turn up an important clue. The researchers found people with more microplastics in their plaque samples also had more markers of inflammation. Inflammation is a natural response to injury and illness. But chronic inflammation, which lasts long-term when no injury is present, is linked to a host of health concerns—including heart problems.
The buildup of plaque—a process known as atherosclerosis—is complicated, and has multiple causes, Dr. Kim says. But it’s clear that inflammation plays a part.
Chronic inflammation can contribute to plaque building up in the arteries in the first place, he explains. It can also make it more likely that a plaque ruptures, which can lead to blood clots that cause a stroke or heart attack. If microplastics lead to inflammation, its presence in arterial plaque could increase the risk.
Reduce the Risk of Microplastics Health Effects
Unfortunately, plastic is nearly impossible to avoid. We produce more that 400 million tons annually worldwide, and that number is expected to double by 2040.
As the case against microplastics builds, it points toward the need to reduce that number, Dr. Kim says. “At the global level, we as a society need to figure out ways to reduce plastic production and consumption,” he adds.
In the meantime, there are things you can do to reduce exposure to microplastics and protect your health:
- Switch containers: Use materials like glass or stainless steel to store food and drinks, and avoid plastic containers whenever you can.
- Shop smarter: Bring reusable cloth bags to the store and avoid single-use plastic bags.
- Turn down the heat: Don’t microwave plastic dishes or put them in the dishwasher. Heat can make chemicals leach from the container into the food or air around it.
- Reduce inflammation risk: Researchers are still exploring the link between microplastics and inflammation. But you can take steps to keep inflammation in check with a healthy diet and good oral hygiene.
- Quit smoking: Smoking—including cigarette alternatives—can affect the immune system and increase heart attack risk. With or without plastics, quitting tobacco is one of the best things you can do for your heart health.
Avoiding plastic can feel overwhelming. But you don’t need to live in fear, Dr. Kim says.
It’s a good thing that researchers are working to find out exactly how plastic might impact our health, and what we can do about it, he adds. In the meantime, the rest of us can focus on doing the best we can to reduce our exposure and make other heart-healthy choices.
Reviewed by Dr. Henry Kim, a cardiologist who sees patients at Henry Ford Hospital in Detroit and Henry Ford Medical Center - Livonia.
