A mouthful of chewing gum might also be a mouthful of microplastics, according to the results of a small pilot study. The research, presented at the spring meeting of the American Chemical Society, suggests that a single piece of chewing gum could introduce as many as 3,000 microplastic particles into the saliva, positioning them for potential ingestion.
“Our goal is not to alarm anybody,” said Sanjay Mohanty, a study author and an engineering professor at the University of California, Los Angeles, according to a press release. “But we know we are exposed to plastics in everyday life, and that’s what we wanted to examine.”
Read More: Microplastics Are Everywhere. What Are They Doing to Our Health?
Some Chewing Gum Is Plastic
Most of us use products that expose us to microplastics each and every day. In fact, it’s thought that our food, our drinks, and our plastic packaging can cause us to ingest tens of thousands of microplastics each year, with every piece sitting at around 1 micrometer to 5 millimeters across. But chewing gum’s impact on our ingestion of microplastics isn’t well studied.
To fill this gap, Mohanty and Lisa Lowe, an engineering student also at the University of California, Los Angeles, set out to study the ingestion of microplastics from natural and synthetic gums. While natural gums are made from plant-based polymers, such as tree sap, synthetic gums are made of petroleum-based polymers and are essentially sticks of synthetic plastic.
“Our initial hypothesis was that the synthetic gums would have a lot more microplastics because the base is a type of plastic,” Lowe said, according to the release. “Surprisingly, both synthetic and natural gums had similar amounts of microplastics released when we chewed them.”
Ultimately, Mohanty and Lowe’s tests isolated an average of around 100 microplastic particles and a maximum of around 600 microplastic particles per gram of gum. That correlates to a maximum of around 3,000 microplastics in a larger piece of gum, all of which could be ingested through the saliva.
Read More: Our Brains Are Soaking Up Microplastics More Than Other Organs
Microplastic in Saliva
Assessing five brands of natural gum and five brands of synthetic gum, Mohanty and Lowe asked a single participant to chew gum from each brand, creating a steady sample with consistent patterns of chewing and saliva production.
In one test, the participant chewed gum from each brand for 4 minutes. In another, they chewed gum from each brand for 20 minutes. In both, they periodically provided saliva samples, which revealed the amount and rate of microplastic release over time.
The testing showed that the majority of the microplastics were shed into the saliva within 2 minutes of chewing, while 94 percent were shed within 8 minutes. Interestingly, the chewing released these microplastics, rather than the presence of saliva, as the act was abrasive enough to tear tiny plastic particles from the larger pieces of gum.
While capable of capturing plastics that measured as few as 20 micrometers across, Mohanty and Lowe’s method missed the smaller microplastics, meaning that more plastic particles were probably present in the participant’s saliva that they couldn’t catch.
“The plastic released into saliva is a small fraction of the plastic that’s in the gum,” Mohanty said, according to the release.
Is Gum Safe for Our Bodies?
Ultimately, while it is clear that chewing gum exposes us to microplastics, it isn’t clear what that exposure is doing to us.
“Scientists don’t know if microplastics are unsafe to us or not,” Mohanty said, according to the release. “There are no human trials.” However, studies on animals and on human cells have shown that microplastics can cause harm, so it makes sense to reduce our exposure to them when we can.
To limit your intake of microplastics, Lowe recommends chewing on a single piece of gum for a long period of time rather than several pieces of gum for a shorter period of time. (Mohanty also recommends being careful about where you toss your chewed gum, as it could contribute to environmental plastic pollution.)
Of course, removing gum from your everyday routine can also reduce your exposure to microplastics. By cutting down on gum, you could swap a satisfying chew for a mouth a little less full of tiny plastic particles.
This article is not offering medical advice and should be used for informational purposes only.
Read More: How Microplastics Sneak Into Our Bodies
Article Sources
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Sam Walters is a journalist covering archaeology, paleontology, ecology, and evolution for Discover, along with an assortment of other topics. Before joining the Discover team as an assistant editor in 2022, Sam studied journalism at Northwestern University in Evanston, Illinois.
