Time and time again, studies have found high levels of microplastics in a range of global seafood, from mussels to mackerel. The latest spotlight-grabber? A new study in the journal Frontiers in Toxicology of six species of fish and shellfish found off the Oregon coast—including herring, salmon, and shrimp—revealed microplastics in all but two of 182 samples. These microplastics work their way up the food chain and can compromise our health, damaging the digestive, respiratory, endocrine, reproductive, and immune systems. Scientists also just found that the amount of microplastic in our brains has shot up rapidly in the last few decades.
All this has fed into a common misconception that fish are microplastic magnets—or at least more so than other foods. But do they really put more tiny plastic fibers, filaments, and films on the menu? Here’s what the research shows, and what you can do to minimize how much plastic ends up in your belly.
Microplastics in seafood vs. meat vs. plant-based proteins
Fish don’t necessarily contain more microplastics than any other proteins that we wolf down. A study published last year in the journal Environmental Pollution found that 88% of protein-packed foods tested contained the particles, with no difference between the levels in grub from the sea compared to vittles that come from dry land. All 16 types of protein tested—including shrimp, fish sticks, chicken nuggets, top sirloin steaks, pork loin chops, and even plant-based offerings like tofu and plant-based meat alternatives—contained some concentrations of microplastics.
One bright(ish) spot: The levels in tofu were one of the lowest studied, coming in third in least microplastics per serving behind chicken breasts and pork loin chops. “There’s no escaping them no matter what you eat, it seems,” study co-author Britta Baechler, a marine biologist at the Ocean Conservancy, said in a release.
How microplastics get into seafood and farm animals
Microplastics wind up in food in two main ways. The first is ingestion. Fish may mistake plastic for phytoplankton and accidentally munch on it while searching for food; filter feeders like mussels and oysters inadvertently suck them up, and bottom feeders pull them from the sediment. Land animals may drink contaminated water, breathe contaminated air, or eat contaminated food (including, sometimes, garbage). The second avenue is through processing: Machinery and plastic packaging are big drivers of microplastics contamination. That’s not just saved for products that came from an animal: Ready-made and precooked meals tend to be the worst offenders.
How to avoid microplastics in your diet
It’s impossible to completely avoid the newest food group: microplastics. The average American eats 11,500 pieces per year. But there are ways to cut down on your consumption.
Avoid packaging. Avoid the stuff you put in your body coming in contact with plastic whenever you can, especially when it comes to beverages: Bottled water has a much, much higher concentration of microplastics than any protein. When it comes to proteins, go for whole, local fish and meat whenever possible—and give it a rinse to remove any surface contaminants.
Minimize highly processed foods. Highly processed proteins like fish sticks, chicken nuggets, and faux nuggets come in contact with a lot of plastic machinery during production, which leads to contamination. So, opt for less processed meats, or focus on plant-based proteins like whole soybeans.
Pick the right fish. Fish from higher trophic levels (i.e., fish that eat other fish) actually have a lower concentration of microplastics than those from lower trophic levels (like shellfish). So, opt for the big guys if you want to minimize exposure, but be aware that they may have higher concentrations of other toxins, like mercury and some pesticides.