SAN DIEGO (KSWB/KUSI) – A recent study found that chewing gum can release up to thousands of microplastics per piece and potentially be ingested, according to researchers.

Lisa Lowe and Jamie Leonard, both graduate students at the University of California, Los Angeles, and Sanjay Mohanty, an engineering professor at UCLA, shared the findings at the American Chemical Society’s 2025 Meeting and Expo in San Diego this week.

“Our goal is not to alarm anybody,” Mohanty said in an ACS statement. “Scientists don’t know if microplastics are unsafe to us or not. There are no human trials. But we know we are exposed to plastics in everyday life, and that’s what we wanted to examine here.”

In the study, researchers tested five different brands of synthetic gum and five brands of natural gum that are currently being sold commercially.

Chewing gums, according to the study, are usually composed of a rubbery base, sweetener, flavorings and more. Natural gum products, on the other hand, use a plant-based polymer.

“Our initial hypothesis was that the synthetic gums would have a lot more microplastics because the base is a type of plastic,” said Lowe.

However, both synthetic and natural gums used in the study had the same polymers: polyolefins, polyethylene terephthalates, polyacrylamides and polystyrenes.

For the study, one person in the lab chewed seven pieces from each brand separately. The person was asked to chew a piece of gum for four minutes, producing samples of saliva each time.

All of the saliva was then combined into a single sample, according to the study.

In a separate experiment, saliva samples were collected over 20 minutes so that researchers could look at the rate microplastics were released from each piece of gum.

“Our initial hypothesis was that the synthetic gums would have a lot more microplastics because the base is a type of plastic,” Lowe said in a news release.

She started the project as an undergraduate intern at UCLA.

The study found an average of 100 microplastics were released per gram of gum. However, some other pieces released as many as 600 microplastics per gram, according to the release.

With a typical piece of gum weighing between two to six grams, an individual piece could release up to 3,000 plastic particles, researchers said. If that sounds like a lot, a study published last year in the Proceedings of the National Academy of Sciences found that liter-sized plastic water bottles contained 240,000 particles, on average.

According to Mohanty, the study’s principal investigator, most of the microplastics detached from the gum within the first two minutes of chewing. Lowe said if people want to reduce their potential exposure to microplastics, they should chew one piece for a long time versus starting on a new one.

The researchers added that if gum is not properly thrown away, it can contribute to plastic pollution.

Microscopic particles of plastic, which get increasingly smaller but don’t biodegrade, have been found throughout our environment and in human brains, blood and testicles.

Nexstar has reached out to a major gum manufacturer and the National Confectioners Association for a statement on the study, but did not receive a reply as of publishing time.