A recent study has uncovered that chewing gum releases hundreds of tiny microplastic particles into people’s mouths, raising concerns about both health and environmental impacts.
This discovery adds to the growing worries about microplastics, which have been found in environments ranging from the highest mountaintops to the deepest ocean trenches, and even in the air we breathe. Researchers from the University of California, Los Angeles (UCLA) conducted a pilot study that explored how chewing gum, often considered a harmless treat, may contribute to the widespread issue of plastic pollution.
“I don’t want to alarm people,” said Sanjay Mohanty, the lead researcher and a professor at UCLA, during an interview. “However, our findings highlight a previously overlooked source of microplastics.” While Mohanty clarified that there is no direct evidence connecting microplastics to health problems, the results are concerning.
The study involved Lisa Lowe, a UCLA PhD student, who chewed seven pieces of gum from ten different brands. Afterward, the researchers analyzed her saliva chemically. They found that a gram of gum (around 0.04 ounces) released an average of 100 microplastic particles, with some brands shedding more than 600 pieces. With an average stick of gum weighing around 1.5 grams, this suggests that someone chewing approximately 180 pieces of gum annually could ingest up to 30,000 microplastic fragments.
While this figure is small compared to other common microplastic sources, Mohanty emphasized that the study draws attention to another under-explored method of plastic ingestion. For instance, research has shown that a liter of water from a plastic bottle can contain as many as 240,000 microplastic pieces.
The majority of chewing gum sold in supermarkets is synthetic, made from petroleum-based polymers. However, the packaging often only lists the vague term “gum-based,” without specifically mentioning plastics. “Nobody will tell you the ingredients,” Mohanty remarked.
Both synthetic and natural gums—those made with plant-based polymers like tree sap—were tested in the study, and microplastics were found in both types. The researchers also discovered that most microplastics were released within the first eight minutes of chewing.
David Jones, a researcher at the University of Portsmouth in the UK, expressed surprise at the findings. Although he was not involved in the study, Jones suggested that the plastics might have come from other sources besides the gum itself. However, he noted that the discovery was “not at all surprising,” pointing out that chewing gum shares similar building blocks with materials found in car tires, plastic bags, and bottles.
Lowe also drew attention to the environmental impact of chewing gum, particularly when improperly discarded. “Plastic pollution from gum becomes a significant issue, especially when people spit it out onto the sidewalk,” she said.
The study has been submitted for publication in a peer-reviewed journal and was presented at a meeting of the American Chemical Society in San Diego. A request for comment from Wrigley, the world’s largest chewing gum manufacturer, went unanswered.
