Microplastics have been found in the air, water, and everyday items, from tea bags to produce. Now, new research suggests that tiny plastic particles lurk in yet another product: chewing gum.

The study, presented at the spring meeting of the American Chemical Society (ACS) last week and not yet peer-reviewed, found that chewing gum may release hundreds, even thousands, of microplastics into saliva. And while you might think synthetic gums would contain more microplastics than natural varieties, the researchers found that both types release similar amounts.

Microplastics are minuscule bits of polymers—chemical compounds known for flexibility—that don’t break down and can accumulate in our bloodstream and organs when inhaled or ingested. Scientists don’t fully understand how they affect human health, but the evidence so far paints a bleak picture.

So, what do the latest findings mean for your favorite pack of spearmint gum? “Reducing gum consumption would be a good idea,” Lisa Patel, MD, a clinical associate professor of pediatrics at Stanford Medicine, told Health.

Here’s what else to know about the study, as well as what indulging in gum chewing could mean for your body.

In light of the many papers coming out about how microplastics seep out of consumer products, Lisa Lowe, a study author and PhD student at the University of California, Los Angeles, told Health that she and her team wanted to identify other potential sources of microplastics—like chewing gum. 

The researchers decided to test 10 popular chewing gums—five natural and five synthetic—sold in the United States (the study doesn’t mention the brands).

They instructed a group of participants to rinse their mouths three to five times with deionized water to determine the number of microplastics in their mouths at the start of the experiment.

The participants then chewed each type of gum for four minutes—and some for an extra 20 minutes—while researchers collected saliva samples at various points. Some samples then underwent multiple steps—including shaking, centrifugation, filtration, and digestion—to isolate the microplastic particles.

After examining the samples under a microscope, researchers found that one gram of gum could release up to 637 microplastics (a typical piece of gum weighs between two and six grams). Interestingly, synthetic and natural gums released a similar amount of microplastics—an average of 104 and 96 per piece, respectively.

The average size of microplastics was 82 micrometers, and about 56% of the particles were smaller than 50 micrometers. That said, it was difficult to identify smaller particles, and those tinier than 20 micrometers may have been missed.

If a person chewed 160 to 180 pieces of gum a year, they would theoretically ingest around 30,000 microplastics annually, according to the researchers.

The team also found that 94% of microplastics were released during the first eight minutes of chewing. After that point, the amount of microplastics released lessened and eventually plateaued over the course of 20 minutes. As such, chewing gum for a longer period of time doesn’t necessarily mean a person will ingest more microplastics, the authors noted.

Polymers give gum its elasticity, cohesiveness, and chewability. 

In natural gums, which are mainly made of plant materials, a type of polymer called polyolefins—typically used in food packaging—accounted for up to 50% of the identified particles. 

Synthetic gums contained high levels of the polymers PET and polystyrenes along with petrochemical substances, like synthetic rubber and polyvinyl acetate. 

Sanjay Mohanty, PhD, the project’s principal investigator and an engineering professor at the University of California, Los Angeles, told Health that while most research on microplastics in food focuses on whether an item’s packaging contains microplastics (think the bags that hold tea and the bottles that hold water) or how the manufacturing process contaminates products with microplastics, gum is different. “With gum, the food is the plastic,” he said. 

Scientists have identified microplastics throughout the body—in people’s lungs, bloodstream, placenta, brain, and intestines.

While research into microplastics is still limited, “microplastics essentially set off inflammation and damage of healthy cells in our bodies,” Patel said.

Studies show microplastics may damage DNA and cause oxidative stress, metabolic disorders, and organ dysfunction. When microplastics accumulate in the gut, the risk of inflammatory bowel disease increases. Similarly, microplastics in the bloodstream have been linked to a greater risk for cardiovascular disease. The tiny plastic particles may also lead to decreased fertility, neurotoxicity, and metabolic issues like insulin resistance, Patel added.

According to Lowe, we’re all regularly exposed to microplastics daily—and other products are likely far riskier than a stick of gum. “The amount of microplastics exposed by chewing gum is still very small compared to, say, tea bags,” Mohanty said.

That said, limiting how much gum you munch on is not a bad idea, Patel said. Because gums release the most particles within the first few minutes, it may be safer to keep chewing one piece rather than reaching for a new stick, she added.

Dispose of your gum properly—into a trash can and not onto the ground—so it doesn’t contaminate our soil and oceans. 

And try not to swallow it. Synthetic gum degrades in about three years, research suggests. Natural gum, on the other hand, breaks down much faster and could, in theory, release more microplastics more quickly if swallowed, according to the researchers.

Finally, in general, it’s a good idea to limit the amount of plastic you use, according to Patel. “The sooner we minimize our plastics use—keeping it only to the uses where we really don’t have good alternatives—the better off we’ll all be,” she said.