What Are Microplastics? Plus, How to Avoid Them at the Grocery Store

We’ve known about microplastics for decades. Previously, the focus was more geared toward animals that live in the sea and the impact on the environment. (It’s why you rarely see canned drinks in plastic six-pack rings on shelves anymore.) In more recent years the focus has shifted, and researchers have taken a deeper look at its potential impact on human health. 

As awareness (and concern) around the impact grows, let’s take a deeper look at microplastics — specifically what they are and potential ways to decrease your exposure to them.  

Microplastics are teeny-tiny plastic particles that are 5 millimeters (about the size of a small pea) or less, according to the Environmental Protection Agency (EPA). They come from a wide range of polymers like the ones used to make food and drink containers found on grocery shelves and are the by-products of plastic breakdown. These tiny plastics also can absorb environmental pollutants, including heavy metals. 

Marine animals ingest the microplastics, and for those of us that eat seafood, we ingest the animal that ingested the microplastics. This can also be the case for land animals, and some studies suggest that microplastics are even present in the fruits, vegetables, grains, and legumes that we eat. 

It’s so common across industries that the United Nations sponsored an exhibit called “Plastic is Forever.” More than 75% of plastic made is either trashed in landfills or released into the environment. That’s a startling statistic and a very sobering realization, especially when you realize it’s quite literally in every person’s body. According to a 2024 review, microplastics have been detected in more than eight human organs, including the heart, gut, lymph and lungs, as well as urine, stool, and breast milk.

So you may be in full panic mode at this point, thinking microplastics will be the end of us all. I invite you to take a deep breath. Listen, the truth is, it’s not great that plastics are everywhere and that these small particles enter our bodies through a variety of routes. There is very compelling evidence pointing to increased negative health outcomes. 

Currently, we know a lot more about how microplastics impact the health of animals that live in the sea. Research involving animals has seen changes in hormones and increased inflammation when microplastics are present. They have also noticed that there is a potential link between microplastics and an increase in the pathogenic bacteria (bad bugs) that live in the gut of the animals that were studied.

Some similarities were found in a review examining the potential connection between microplastics and chronic disease and gut dysfunction in humans, but more research is needed — especially the impact over time. 

Ultimately, it’s about personal preference, access, health literacy, and financial flexibility. Plastic is used widely across the food system (and every industry for that matter), so that’s hard to avoid. Still, there are some things you can do as an individual to reduce exposure.

If you are able to transition to glass storage containers, that’s a start. If you can purchase reusable cloth bags for produce, that’s also another win. Shopping at farmers markets, food co-ops, and CSA locations is another option for purchasing foods with less plastic packaging — and even better when you bring your own cloth bags! 

In the grocery store, seek out items packaged in glass or aluminum as an alternative to plastic. Do what you can and think about the areas that are realistic to change without overly stressing yourself out. Much of the changes that would result in a reduction of microplastics needs to be tackled at the global level across government and industry. 

Fad or Fact is a monthly column where Maya Feller, MS, RD, breaks down the most important — and, let’s be honest, sometimes confusing — products and trends taking over grocery aisles. Do you have a grocery question or topic you want Maya to cover? Tell us about it in the comments below.