Now do K cups.
Chewing gum releases thousands of microplastic particles directly into your mouth with every piece you chew.
A pilot study from UCLA researchers, presented at the American Chemical Society’s Spring 2025 meeting, has identified chewing gum as a surprisingly significant and previously overlooked source of daily microplastic ingestion.
The researchers examined both traditional synthetic gums, which contain polymers such as polyethylene, polyvinyl acetate, and polystyrene, as well as brands marketed as “natural” that use chicle or other plant-based bases. By simulating realistic chewing conditions, they measured how many particles are released into saliva during typical use.
The results showed that a single piece of gum can shed anywhere from hundreds to more than 3,000 microplastic fragments over 10 to 30 minutes of chewing. The primary mechanism is mechanical abrasion from teeth combined with friction from saliva, which dislodges tiny particles directly from the gum base.
Surprisingly, “natural” gums performed no better than synthetic versions and, in some cases, released even higher numbers of fragments. Most of the particles fell within the microplastic size range of less than 5 millimeters, making them small enough to be easily swallowed.
Once ingested, these particles largely resist breakdown by digestive enzymes and pass through the gastrointestinal tract as persistent pollutants. Although the long-term health consequences of chronic low-level microplastic exposure are still under investigation—with emerging concerns about potential links to inflammation, gut microbiome changes, and leaching of chemicals—this represents a meaningful everyday contribution to personal plastic intake, especially for regular gum chewers.
Lead researcher Professor Sanjay Mohanty pointed out a practical way to reduce exposure: chewing a single piece for a longer time rather than frequently replacing it with a fresh one, since particle release tends to be highest in the early minutes and then decreases. The study underscores the need for greater transparency in labeling the materials used in everyday consumer products like chewing gum.
As microplastics continue to appear in unexpected places—from drinking water to seafood—this discovery adds chewing gum to the expanding list of common items quietly adding to our daily plastic burden.
[Lowe, L., Leonard, J., & Mohanty, S. K. (2025). Ingestion of microplastics during chewing gum consumption. Journal of Hazardous Materials Letters, 6, 100164. DOI: 10.1016/j.hazl.2025.100164]