Enjoy chewing gum? It might have microplastics, says study

The researchers examined both synthetic gum and natural alternatives made with plant-based polymers such as tree sap. (Image: Canva)

Chewing gum may be quietly introducing tiny plastic fragments directly into consumers' mouths, a new study suggests, raising fresh concerns about microplastic contamination and its environmental impact. The research, unveiled on Tuesday, highlights yet another overlooked pathway through which these pervasive pollutants enter the human body.

Microplastics—minuscule plastic particles less than five millimetres in size—have been detected virtually everywhere, from the highest mountain peaks to the deepest ocean trenches. Scientists have even found them embedded in the air we inhale. More alarmingly, they have been discovered inside human organs, including the lungs, bloodstream, and even the brain, fueling concerns about their potential health effects.

"I don’t want to cause unnecessary panic," said Sanjay Mohanty, the study’s lead researcher from the University of California, Los Angeles (UCLA), in an interview with AFP. The study, which has yet to undergo peer review, does not confirm any direct harm from microplastics but seeks to highlight an underexplored route of exposure—chewing gum.

Gum as a microplastic source

To quantify how much plastic might be released during chewing, Lisa Lowe, a UCLA PhD student and co-author of the study, chewed seven pieces from 10 different brands of gum. Subsequent chemical analysis of her saliva revealed that each gram of gum released an average of 100 microplastic particles, with some brands shedding over 600. Given that a standard stick of gum weighs around 1.5 grams, the findings suggest that a frequent gum chewer consuming around 180 pieces annually could unknowingly ingest nearly 30,000 microplastics.

However, Mohanty emphasised that gum is far from the primary contributor to human microplastic intake. By comparison, research published last year estimated that a single liter of bottled water could contain approximately 240,000 microplastic particles.

Plastic ingredients hidden in plain sight

Most commercial chewing gum, commonly labeled as "synthetic gum," achieves its elasticity through petroleum-derived polymers—the same materials found in car tires, plastic bags, and disposable bottles. Yet, these ingredients are rarely disclosed on packaging, which typically lists only the vague term "gum base."

"Manufacturers don’t openly reveal the full list of ingredients," Mohanty noted. The researchers examined both synthetic gum and natural alternatives made with plant-based polymers such as tree sap. Surprisingly, microplastics were present in both varieties, suggesting potential contamination from external sources.

David Jones, a scientist at the University of Portsmouth who was not involved in the study, expressed skepticism about the presence of certain unexpected plastics, speculating that some may have come from the lab environment, according to AFP. However, he found the overall findings unsurprising, noting that people are often shocked to learn that chewing gum contains the same materials used in industrial plastics.

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Health and environmental implications

When improperly disposed of—such as being spat onto sidewalks—chewing gum contributes to persistent plastic pollution. (Image: Canva)

Despite the findings, Oliver Jones, a chemistry professor at RMIT University in Australia, reassured that swallowing small amounts of microplastics from gum is unlikely to pose an immediate health risk. "They would likely pass through the digestive system without significant impact," he said, adding, "I don’t think people need to stop chewing gum just yet."

Lowe, however, emphasised a broader concern: the environmental toll of discarded gum. When improperly disposed of—such as being spat onto sidewalks—chewing gum contributes to persistent plastic pollution.

The National Confectioners Association, representing U.S. gum manufacturers, downplayed the study's implications, pointing out that its authors themselves acknowledged there was "no cause for alarm." The association reaffirmed that gum has been safely consumed for over a century, with all ingredients approved by the U.S. Food and Drug Administration.

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While the study awaits peer review, its preliminary findings were presented at the American Chemical Society's annual meeting in San Diego, adding to the growing body of research on microplastic exposure and its potential consequences.