Meat and Microplastics: Which of Your Favorite Foods Are Full of Tiny Trash?
Every time you unwrap a hamburger, microwave a fish stick, or fry up a slab of tofu, the meal you’re preparing isn’t just carbs, protein, and a bunch of micronutrients. It’s also got a hefty serving of tiny pieces of plastic—anywhere from a 10 or 20 up to 500 just in your main source of protein. (The average is about 75.)
That’s according to a new study from the University of Toronto, which gives us the most accurate picture to date of just how much microplastic is in protein-rich dietary staples. We know they’re a health risk—more on that later—but it’s been hard to know how much we should worry, or how to avoid them, without better research.
This study gives us just that, after decades of slow-growing concern. We’ve known about microplastics since the early 1980s, and scientists started to study them seriously around the turn of the century. The term doesn’t refer to any one environmental hazard, instead it serves as a catch-all category for minuscule pieces of all kinds of material, from styrofoam and synthetic rubber to hard-shell plastic products and bits of wet wipe.
Microplastics can be as big as almost half a millimeter across (up to 450 microns, or “µm”) or as small as a few thousandths of a millimeter (5-10 µm). They come in every possible color, texture, and chemical composition, and we usually categorize them by shape—fragment, fiber, film, rubber, sphere, foam, film, flake, pellet, and so on. They get into our bodies mostly from food, beverages, and the everyday inhalation of dust and traffic fumes.
They’re all bad for us. Just how bad is an open question, but thanks to the Canadians, we now have a much clearer picture about which foods pose the greatest risk.
Your Annual Dose of Plastic
The scientists behind this new study started at the supermarket (and at health food stores—although those turned out not to be any safer). They bought piles of 16 commonly consumed sources of protein, including pork chops, steak, tofu, chicken nuggets and chicken breast, fresh fish, fish sticks, multiple kinds of shrimp, and popular plant-based meat substitutes.
They dissolved fragments of each meal in hydrochloric acid, rinsed the resulting goop in purified water, and filtered it through unimaginably small sieves. We’re talking Ant-Man-draining-pasta small. Tiny enough to separate a 45 µm piece of water bottle from a 50 µm flake of your cell phone case. Then they counted out sample plastic pieces by hand, measured them, and double-checked their chemical makeup using laser spectroscopy.
Their goal was to figure out the average amount of microplastic in each type of protein, and then to estimate how much plastic a normal American adult is eating every year based on our typical annual consumption of each food item. The numbers range from just a few fragments of microplastic in a serving of chicken breast up to 370 fragments in a meal’s worth of breaded shrimp. Take our collective national eating habits into account and you get a total average of 11,000 plastic bits per adult, per year. It’s a huge spread, though—annual plastic intake for a serious breaded shrimp enthusiast is in the millions. And it does add up. Those 11,000 plastic bits per adult, even on the small side of 50 µm in size each, is just under 2 feet (a half-meter) of plastic consumed per year!
The study also gives us four rules of thumb for deciding which meals are likely to have high plastic content.
- Breaded products are usually worse than plain meat or meat-substitute.
- Seafood tends to have more plastic than land-food (which should absolutely be a word).
- Processed food is higher-risk, unless the processing is very simple. Tofu is pretty safe, probably because it’s basically just mashed-up beans.
- If it comes in plastic packaging, it will have more plastic. This is also why bottled water has more microplastics than tap water.
Those four patterns explain the study’s results: breaded shrimp has the most microplastics, followed by chicken nuggets, plant-based nuggets, fish sticks, and non-breaded supermarket shrimp. Steak is alone in the middle of the pack, and then there’s a cluster of low-plastic options at the bottom: chicken breast, pork loin, tofu, and fresh-caught, unprocessed seafood.
Here’s a simpler way to say all that: whenever you have the choice, pick fresh over preserved, local over shipped, and less-processed over more. Plus, avoid plastic packaging as much as you can.
Here’s Why That’s Bad
An alternative title for this section might be: “Filling your organs and bloodstream with tiny pieces of plastic is not, as it turns out, super healthy.”
A systematic review from a few years ago found that microplastics can increase our risk of everything from cancer to Alzheimer’s Disease, alongside a long list of generally negative health effects. The risks come from two sources: the plastics themselves and the chemicals they absorb and then carry with them into our bodies.
Here’s a quick list of the top health issues microplastics can pose:
- Overall health issues: microplastics cause oxidative stress and chronic inflammation, which basically make everything in your body work less well
- Brain health and mental function: risk of neurodegenerative diseases, “neurotoxicity” that can affect judgement, movement, and more
- Energy and eating: microplastics might disrupt our ability to digest food, our ability to use energy stored as fat, our body’s hunger signals and thus our appetites, and more
- Circulation and respiratory health: over time, microplastics can get out of our stomach and other organs and into our circulatory systems, causing inflammation, high blood pressure and blood vessel blockages, and killing blood cells
- Sexual health: microplastics build up in our testicles, slowly causing low-grade damage, and can probably reduce sperm quality
- Immune function: microplastics probably weaken our immune systems and put us at greater risk for autoimmune diseases
The jury is still out on a lot of this. Most of our evidence comes from limited animal studies, and there’s a huge amount we still don’t know about how they affect our bodies and overall well-being.
What we do know is that they definitely don’t have any health benefits, that more of them are definitely worse for us, and now, thankfully, we also know which of our high-protein food options carry the greatest risk.
