Researchers: Chewing gum releases microplastics into mouth

Chewing gum releases hundreds of tiny plastic pieces straight into people’s mouths, researchers have said.

The researchers, on Tuesday, March 25, 2025, also warned of the pollution created by the rubber-based sweet.

The small study comes as researchers have increasingly been discovering small shards of plastic called microplastics throughout the world, from the tops of mountains to the bottom of the ocean – and even in the air we breathe.

They also discovered microplastics riddled throughout human bodies – including inside our lungs, blood and brains – sparking fears about the potential effect this could be having on health.

“I don’t want to alarm people,” the lead researcher behind the new study, Sanjay Mohanty, told AFP.

There is no evidence directly showing that microplastics are harmful to human health, said Mohanty of the University of California, Los Angeles (UCLA).

The new pilot study instead sought to illustrate yet another little-researched way that these mostly invisible plastic pieces enter our bodies – chewing gum.

A PhD student at UCLA, Lisa Lowe, chewed seven pieces each of 10 brands of gum. Then the researchers ran a chemical analysis on her saliva.

They found that a gramme of gum (0.04 ounces) released an average of 100 microplastic fragments, though some shed more than 600. The average weight of a stick of gum is around 1.5 grammes.

Samsung Electronics co-CEO Han Jong-hee dies of heart attack

People who chew around 180 pieces of gum a year could be ingesting roughly 30,000 microplastics, the researchers said.

This pales in comparison to the many other ways that humans ingest microplastics, Mohanty emphasised.

For example, other researchers estimated last year that a litre (34 fluid ounces) of water in a plastic bottle contained an average of 240,000 microplastics.

The most common chewing gum sold in supermarkets is called synthetic gum, which contains petroleum-based polymers to get that chewy effect, the researchers said.

However, packaging does not list any plastics in the ingredients, simply using the words “gum-based”.

“Nobody will tell you the ingredients,” Mohanty said.

The researchers tested five brands of synthetic gum and five of natural gum, which use plant-based polymers such as tree sap.

“It was surprising that we found microplastics were abundant in both,” Lowe disclosed.

The gum shed almost all of the microplastics during the first eight minutes of chewing, she added.

Lowe also warned about the plastic pollution from chewing gum – particularly when people “spit it out onto the sidewalk”.

The study, which has been submitted to a peer-reviewed journal but not yet published, was presented at a meeting of the American Chemical Society in San Diego.

The world’s biggest chewing gum manufacturer, Wrigley, did not respond to AFP‘s request for comment.

The Star