How many microplastic particles does chewing gum release?

A recent study has found that chewing gum – a daily habit for millions – could be an unexpected source of microplastic exposure. Researchers at the University of California, Los Angeles have discovered that natural and synthetic gums release microplastic particles into the mouth during regular chewing.

The investigation, carried out by a team of engineers, aimed to assess whether chewing gum contributes to the growing concern of microplastics entering the human body. 

Microplastics — tiny fragments less than five millimeters in size — are already known to be present in plastic containers, packaging, and various consumer products. However, gum had not been closely studied in this context until now.

To conduct the study, researchers analyzed ten different types of commercially available gum — half made with synthetic, petroleum-based materials and half made with natural, plant-derived polymers such as chicle. Each gum type was tested by having participants chew multiple pieces for four minutes, while saliva samples were collected every 30 seconds. A follow-up test tracked particle release over a 20-minute period.

The results showed both synthetic and natural gums released similar amounts of microplastics. On average, about 100 particles were released per gram of gum, though some types emitted as many as 600. With gum pieces typically weighing between two and six grams, this could translate to more than 3,000 microplastic particles being released from just one piece.

Researchers estimate someone who regularly chews gum — approximately 160 to 180 pieces per year — could potentially ingest around 30,000 microplastic particles annually. While the health effects of ingesting these particles are not yet fully understood, prior studies have linked microplastics to inflammation, tissue damage, and disruptions in cellular processes.

“Our goal is not to alarm anybody,” Sanjay Mohanty, principal investigator of the study, said. “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.”

The study also noted nearly all of the microplastics were released during the first eight minutes of chewing. To limit exposure, the researchers suggest chewing a single piece for a longer time rather than replacing it frequently.