Counting Macros… and Microplastics?

A scientific study reveals which high-protein foods have the most microplastics

Protein With a Side of Plastic

If you are serious about your workouts, you probably keep a close eye on your protein intake. That might mean chicken breast for lean muscle, tofu for plant-based gains, or a post-workout shrimp stir fry. But while you are fueling your body, you might be getting more than just protein. Microplastics, tiny plastic particles less than five millimeters in size (smaller than the width of a human hair), have made their way into many of the most common protein-rich foods on the market. Keep reading to see which foods have the highest microplastic content.

Shopping for Science

A peer-reviewed study, “Exposure of U.S. adults to microplastics from commonly consumed proteins,” was published in the journal of Environmental Pollution (Volume 343). For the research, scientists went shopping like any regular person. They picked up chicken, beef, pork, seafood, tofu, and lentils from grocery stores near Portland, Oregon, choosing mostly natural and organic products labeled as made in the United States. They even took it a step further, heading to the docks to collect fresh fish right off the boats for comparison.

Every single type of protein they tested contained microplastics.

What Protein Had the Most?

All 16 protein products in the study contained microplastics, and 88 percent of the samples tested had particles. Per serving, the highest amounts were found in pollock fillets, plant-based shrimp, and fresh shrimp. While that might make seafood sound like the main culprit, processing level played a bigger role than whether the protein came from the ocean, the land, or plants. Highly processed foods carried more particles per gram than minimally and unprocessed products.

The team identified what kind of microplastics were found using Fourier transform infrared spectroscopy, or FTIR. This method shines infrared light on each particle and reads the unique pattern that bounces back, like a fingerprint, to reveal what type of plastic it is. Plastic fibers were the most common type of microplastic, making up almost half of all particles found. Plastic fragments came next, followed by bits of rubber.

The study’s chart groups products by processing level and colors them by protein type. Dots mark outliers, and asterisks show statistically significant differences. The top panel shows the full range of results, while the bottom panel zooms in on the 0 to 1.5 particles per gram range to make smaller differences easier to see.

Where are the Plastics Coming From?

The scientists theorize that highly processed foods tend to spend more time in contact with plastic equipment like conveyor belts or worker clothing, and they often go through many steps before they are packaged. That extra handling also means more exposure to fibers and dust. Interestingly, packaging did not seem to be a major source of contamination, and there was no real difference in microplastic levels between conventional grocery stores and those selling mostly natural or organic products. No matter the label, microplastics seem to make their way into our food long before it hits the shelf.

Figure 1: # of Microplastics per gram found on different types of protien (Milne et al. 2024). https://doi.org/10.1016/j.envpol.2023.123233

Should You Be Concerned?

Although we do not yet fully understand the health effects of consuming microplastics, research has already linked them to inflammation, hormone disruption, and the potential to carry toxic chemicals into the body. These concerns are especially relevant when microplastics break down into even smaller particles, called nanoplastics, which can enter organs and tissues more easily.

You can weigh your food, track your calories, and count every gram of protein, but some things slip in unnoticed. Microplastics are making their way into our meals, not because of our daily choices, but because plastic has become deeply embedded in the systems that produce, process, and package our food. While avoiding certain brands or types of protein is not a realistic solution, understanding how microplastics can end up in what we eat is an important first step in tackling a problem that affects us all.

How You Can Help

Research has shown that laundry machines are the leading source of microplastic pollution. CLEANR’s Premium Microplastic Filter for washing machines captures 90%+ of microplastics from the laundry, preventing them from entering our environment.

How do microplastics go from our clothing to our food?

About CLEANR

CLEANR builds best-in-class microplastic filters for washing machines that effortlessly remove the largest source of microplastics into the environment. Its technology, VORTX, represents a breakthrough in filtration, with a patented design that is inspired by nature and proven to outperform conventional filtration technologies by over 300%. The company is building a platform filter technology that enables product manufacturers and business customers to materially reduce their microplastic emissions from impacted in-bound and out-bound fluid streams, including residential and commercial washing machine wastewater, in-home water systems, wastewater treatment, textile manufacturing effluents, industrial wastewater, and other sources. www.cleanr.life

Sources:

Milne, M. H., De Frond, H., Rochman, C. M., Mallos, N. J., Leonard, G. H., & Baechler, B. R. (2024). Exposure of U.S. adults to microplastics from commonly-consumed proteins. Environmental Pollution, 343, 123233. https://doi.org/10.1016/j.envpol.2023.123233
Ullah, S., Ahmad, S., Guo, X., Ullah, S., Ullah, S., Nabi, G., & Wanghe, K. (2023, January 16). A review of the endocrine disrupting effects of micro and nano plastic and their associated chemicals in mammals. Frontiers in Endocrinology, 13, 1084236. https://doi.org/10.3389/fendo.2022.1084236

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