All products are independently selected by our editors. If you buy something, we may earn an affiliate commission.
Plastics pervade all aspects of the food chain. They’re used to wrap our vegetables at the supermarket. They house tea leaves we dunk into cups of hot water with abandon. They’re even fed to animals. A suite of TikTok videos posted by a farmworker last year showed old grocery store food, including plastic-wrapped bread loaves, being ground up and mixed into food for pigs, who eventually became food for humans.
Since its invention in the early 1900s, synthetic plastic production has grown exponentially. We made 1.7 million tons in 1950 and now manufacture more than 400 million tons annually. In shipments alone, the plastics industry generated over $600 billion in 2021. And shoppers around the world buy a million plastic bottles every minute and use 5 trillion plastic grocery bags every year. What makes the material so commercially attractive is also what makes it so concerning for human and environmental health.
Plastics are light, pliable, and designed to last. Something like a single-use water bottle will break down into smaller and smaller fragments—what are known as microplastics—but likely won’t fully decompose for around 450 years, if ever. That means “the very first pieces of plastic ever manufactured are still somewhere on this planet,” says Sherri Mason, PhD, director of sustainability at Pennsylvania State University.
Microplastic waste is now so ubiquitous that snow in the Arctic and dust in remote deserts both carry substantial amounts. And even smaller nanoplastics are suspended in the air we breathe, floating in the oceans we fish, and found inside the fruits, vegetables, and packaged goods we eat. Research is still inconclusive about how these particles are impacting people and the planet, but experts aren’t optimistic.
Here’s what you need to know about dietary microplastics, including foodborne sources, the potential human health risks, and how to lessen your exposure.
What are microplastics?
The term refers to “any piece of plastic that is smaller than 5 millimeters,” says Mason. Nanoplastics, a subcategory of microplastics, are even smaller: less than a micron and invisible to the human eye. Primary microplastics are those intentionally manufactured in the small size range for commercial uses, like glitter or those tiny beads in an exfoliating face wash (which are now banned). Secondary microplastics are formed when larger pieces break down after being exposed to the elements—like waves, wind, or sunlight—for an extended period of time.
Which foods contain microplastics?
“They’re in everything you eat or drink,” says Mason. But the largest dietary source of microplastics can be found in drinking water. One 2018 study by Mason and her team discovered plastic particles in 93% of bottled water samples. Another from the year before found 83% of tap water samples from around the world contained microplastics. (The United States was the worst off, with a 94% rate of tap water contamination.)
Human plastic waste can also be found throughout the marine environment. It’s present on a macro level: in the form of huge, churning trash heaps in remote parts of the ocean and as particulate matter embedded into the ocean floor. But also more acutely: in the flesh of many species of fish, like mackerel and anchovies, and mollusks.
Other studies have found microplastics in beer, wines with polyethylene stoppers, rice, table salts, and honey. Microplastics can even be found in fruits and vegetables—like apples, broccoli, and carrots—with plants able to absorb nanoplastics through their root systems. And plastic tea bags are leaching billions of particles every time you make a cup of Earl Gray.
Likewise, “anything that has been packaged in plastic is going to have plastic in it,” says Mason. And it’s almost impossible to eat a meal without ingesting particulate matter. “There’s plastic in the air,” says Mason, which can potentially settle on everything it comes in contact with.
How much plastic are we ingesting?
Some scientists have estimated the average person might eat 5 grams of microplastics in a week—about the weight of a credit card. Another study breaks that down to up to 52,000 particles annually from various food sources. These figures, which only take into account microplastic particles, are likely underestimated, says Phoebe Stapleton, PhD, an assistant professor of pharmacology and toxicology at Rutgers University. “Nano-sized plastic particles are significantly harder to identify, and thereby quantify,” so they’re often unaccounted for, she says.
All this dietary plastic is showing up in our bodies. Research on human poop found 20 bits of microplastic in every 10 grams of “excreta” when testing eight international “samples.” In a study on pregnant rats, Stapleton and her team discovered that plastic nanoparticles inhaled by mothers were translocated to the fetus and placenta within 24 hours of exposure. And microplastics have also been discovered in human lung, liver, spleen, and kidney tissue. How does plastic accumulate in and travel through human and animal flesh? “We aren’t sure yet,” says Stapleton.
What risks does this pose to human health?
While it’s still not totally clear how these particles are affecting human health, Mason says this much plastic exposure is probably not good. “I think it’s fairly safe to say that your body doesn’t know what to do with it,” she says. “It’s going to treat it as a foreign substance in some way, shape, or form, and so that could lead to a whole suite of different outcomes.”
Various studies back this up. Inhaling airborne microplastic fibers has been shown to cause respiratory inflammation in some people. Research on fish who ingested microplastics found evidence of neurotoxicity (chemical- or substance-induced alterations to the nervous system) and oxidative damage (cell and tissue damage caused by an imbalance of free radicals and antioxidants in the body). A 2020 study on male mice also discovered that ingesting microplastics can affect reproduction. And microplastics are known to contain endocrine-disrupting chemicals, which can interfere with the body’s hormones and potentially lead to brain, immune, and other health problems.
Microplastics have also been identified as toxicological vectors. This means the particles “can adsorb additional chemicals on their surfaces before coming in contact with a human cell,” says Stapleton. Various organic materials and heavy metals collected in the life of a microplastic can “increase its toxicity” to the humans and animals which might ingest it.
How can I eat less plastic?
Though microplastic is now omnipresent in our food system, Mason says there are still some ways we can limit exposure. Start by trying to avoid foods packaged in plastic, she says. Reusable totes and produce bags can replace plastic options at the supermarket. Grocery staples like peanut butter and yogurt typically have plastic-free alternatives, albeit pricier ones. Go loose leaf instead of using tea bags. Also, ditch bottled water, our largest source of dietary microplastic, and bring your own water bottle whenever possible. (This advice depends on access to safe drinking water, something millions of Americans aren’t guaranteed.)
Then, bit by bit, try to eliminate household plastics, like shampoo bottles and bubble wrap. Every piece of microplastic that settles on our meals, contaminates our water, or lodges itself inside our apples “ultimately came from people,” Mason says. “And so if we’re cutting down our general usage of it, that impacts everything.”