Microplastics and our exposure to them is a growing concern these days. Not only do microplastics pollute our environment, including food, but they are also found in all of us. Thus there is interest in how to lower our exposure to them.
A recent small study found that chewing gum can be a source of microplastics. Researchers found that chewing gum releases hundreds to thousands of microplastics per piece (depending on the brand) into our saliva in the mouth - which we then swallow. The first two minutes of chewing on a fresh piece of gum is when the most microplastics are released into the mouth.
How could that be? Chewing gums are made from a rubbery base, sweetener, flavorings, and other ingredients. Natural gum products use a plant-based polymer, such as chicle or other tree sap, to achieve the right chewiness. But most gums sold in stores is synthetic gum, which contain petroleum-based polymers (plastic!) to get that chewy effect. In other words, with these gums a person is chewing on plastic!
Gum ingredient lists do not mention that plastics are in them, and may only say "gum based".
In the study, 5 brands of natural gums and 5 brands of synthetic gums were tested. Surprisingly, both natural and synthetic gums released microplastics (up to 3,000 plastic particles per synthetic gum piece). While the results are concerning, note that bottled water releases many more tiny particles of plastic - one study found an average of 240,000 plastic pieces in a liter of bottled water.
From Medical Xpress: Chewing gum releases microplastics into mouth: researchers
Gum gets some of its chewiness from polymers similar to those used in car tires. Chewing gum releases hundreds of tiny plastic pieces straight into people's mouths, researchers said on Tuesday, also warning of the pollution created by the rubber-based sweet.
The small study comes as researchers have increasingly been finding 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 have 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.
The pilot study instead sought to illustrate yet another little-researched way that these mostly invisible plastic pieces enter our bodies—chewing gum.
Lisa Lowe, a Ph.D. student at UCLA, chewed seven pieces each of 10 brands of gum, before the researchers then ran a chemical analysis on her saliva.
They found that a gram (0.04 ounces) of gum 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 grams.
People who chew around 180 pieces of gum a year could be ingesting roughly 30,000 microplastics, the researchers said.
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 told AFP.
David Jones, a researcher at the UK's University of Portsmouth not involved in the study, said he was surprised the researchers found certain plastics not known to be in gum, suggesting they could have come from another source in the lab. But the overall findings were "not at all surprising," he told AFP.
People tend to "freak out a little bit" when told that the building blocks of chewing gum were similar to what is found "in car tires, plastic bags and bottles," Jones said.