While plastic is something that you wouldn’t eat voluntarily, the truth is that microplastics (plastic particles less than five millimeters in size) and nanoplastics (which are as small or smaller than a speck of dust) are widespread in our food supply. But while they feel inescapable, are certain foods and diets riskier than others? Here’s what you can do to reduce your intake of microplastics, according to experts. 

What foods contain the most microplastics?

There’s a good chance you’re aware that plastic water bottles, as well as other types of plastic packaging and kitchen items, are among the biggest culprits for microplastic exposure. (Also on the list is the air we breathe, the clothes we wear, and the personal care products we use, to name just a few.) But what you may not know is that a growing body of research is uncovering that a variety of foods and beverages—some of which you probably consume daily—contain more plastic than you’d imagine.

To start, microplastics are abundant in seafood, which isn’t too surprising given the immense amount of plastic pollution in the world’s oceans. More broadly, a study published in February 2024 found that protein at large—marine, terrestrial (or, land-based), and plant-based sources, as well as those with various levels of processing—is a significant source of dietary microplastic exposure for adults in the United States. The authors note that adults can expect to ingest an average of 11,000 microplastic particles annually from protein sources alone, with maximum exposure from this macronutrient skyrocketing to as much as 3.8 million microplastics a year.

Another study published in November 2024 found that tea bags made from the synthetic materials nylon and polypropylene released more microplastics and nanoplastics than those composed of paper-based cellulose. Plastics are also used in the glue that sticks tea bags together and their attached strings, says Aidan Charron, associate director at Global Earth Day.

However, this list is far from comprehensive. Charron adds that microplastics in soil can work their way into fruits and root vegetables. To date, they’ve also been detected in salt, sugar, honey, milk, and beer.

What are the potential hazards of microplastic exposure?

Andrea De Vizcaya-Ruiz, PhD, professor of environmental and occupational health at the UC Irvine Joe C. Wen School of Population and Public Health, notes that tiny pieces of foreign material accumulate in human tissues and organs, which have the ability to interfere with physiological and cellular processes and induce oxidative stress and inflammation (i.e., some of the drivers of disease). “Evidence shows microplastics could potentially impact the brain, reproductive system, fetal development, and more,” says Trevor Craig, a food safety expert and corporate director of technical training and consulting at Microbac Laboratories. “Additionally, some chemicals used in plastics have been linked to cancer in certain circumstances.”

According to Sophia Ruan Gushee—a nontoxic lifestyle expert and author of A to Z of D-Toxing—when microplastics break down into smaller nanoplastics, they can penetrate biological membranes including the blood-brain barrier, placenta, and gut.

Speaking of placenta, microplastics can also pose risks for hopeful or expectant parents and their offspring, says Charron. A study published in May 2024 found that all 62 placentas examined contained microplastics. “A mother's chemical body burden gets passed onto her children through pregnancy and nursing, and chemicals can influence epigenetics,” Gushee warns. Men aren’t spared either, as microplastics have also been found in semen samples.

So, how alarming are microplastics in your food?

While none of these potential outcomes seem to spell out good news for your health and well-being, there are a few less daunting caveats. According to the Food and Drug Administration (FDA), the presence of microplastics in the human body doesn’t guarantee harm, at least based on findings to date. Plus, Craig notes that it’s difficult to have absolute proof since most studies are conducted on animals (often mice), and the results won’t necessarily translate to humans. 

“Context also matters in many of these studies when discussing toxicity and carcinogens because we forget to pull in dosage into the conversation,” explains Craig. “The chemical and the dosage are important when we talk about effects, as [many] things are likely to show some toxic or effects in high volumes.”

Charron, on the other hand, is more uneasy about microplastics in our food supply. “We have been led to believe for years that plastic is inert and doesn't shed, but now we know it does and we have all been part of an unwitting health experiment on an epic scale,” he warns. Simply put, he says that humans aren’t designed to ingest plastics, so they will likely take their toll in some shape or form. 

Vizcaya-Ruiz is “reasonably alarmed” about these microplastics in everyday foods, again since the particles accumulate in the body and can lead to inflammation and endocrine disruption, among other effects. “Up to now, their toxicity level has been established as low or moderate,” she explains, “but the wide exposure, lack of regulation, and unknown long-term consequences are reasons for concern.”

How can you avoid or limit microplastics in your food?

As far as your grocery haul goes, there isn’t a perfect science to avoiding foods and drinks that contain microplastics. (Plus, I’m not going to advocate for avoiding protein at all costs, underscore the countless health benefits of green tea, or tell you to start fearing fruits and veggies.) “Even items labeled as GMO-free, grass-fed, or sustainable may still be exposed to plastics during production or their environment which they could pass on to you,” Craig shares.

All things considered, your best bet is to take a precautionary (versus flat-out fearful) approach and do what’s within your reasonable ability to limit microplastic exposure, both in and outside of the kitchen. “It’s important to recognize that you’re not going to remove all microplastics from your world and you can’t change the past,” says Craig, “but we can focus on smarter, more sustainable ways to use and reduce them in our daily lives.”

This includes, but isn’t limited to, minimizing your consumption of foods and drinks that are sold in plastic, storing your own in glass containers instead, and avoiding plastic kitchenware whenever possible. “If all you do is prioritize this, then you can significantly reduce your exposure by choosing healthier options one item at a time,” Gushee shares.