Chew on This: Microplastics Found in Popular Gum Brands
- Mark Smith
- 5 days ago
- 5 min read
New Study Raises Health Concerns
For decades, chewing gum was the epitome of casual cool. But a new study has found that those who enjoy gum may be biting off more than they want to chew.
A pilot study on microplastics by experts at the University of California, Los Angeles (UCLA) found that a single piece of gum can release hundreds or even thousands of tiny plastic particles into the mouth as it is being chewed.
In their research, the team from UCLA’s Samueli School of Engineering tested 10 popular chewing gum brands, half of which were marked as synthetic and five as “natural.”
As volunteers chewed each piece of gum, the team collected saliva samples at set intervals, then measured the amount and rate of change of released microplastics.
The team discovered that, on average, 1 gram of gum released around 100 microplastic fragments, with some gums shedding more than 600 fragments per gram.
With a typical piece of gum weighing between 2 and 6 grams, it means a larger piece could release 3,000 particles.
The researchers also found that 92% of microplastic particles are released during the first eight minutes of chewing.
Chewing Remains Popular
Humans have been chewing on various saps and natural resins for millennia, but it was only in the post-World War I period that synthetic gum entered widespread use. With a global market totaling around $48 billion this year alone, chewing gum remains popular. Significant growth is due to sugar-free oral health gums, which help neutralize plaque acid and reduce cavities, plaque, and gingivitis. In fact, “The American Dental Association endorses chewing sugarfree gum for 20 minutes after meals as an effective way to maintain oral hygiene,” notes a recent Technavio market report.
In addition, there is increasing interest in gums that help people stop smoking as well as ones that have infused vitamins, teeth-whitening, or weight-loss properties—or new flavors that “shift” from fruity to minty tastes.
The biggest headaches of the chewing gun industry, according to market reports like Business Research (BR) Insights, have been consumer flight from the sugary gums and issues with gum disposal after use. The BR report noted that, according to the European Environmental Agency, “only 15% of consumers dispose of gum properly.”
Synthetic and Natural Gums
While natural gums use plant-based polymers such as chicle, synthetic alternatives use petroleum-derived plastic bases. Trends and tastes have spurred a partial return to some natural chewing ingredients, but both types remain popular.
Speaking exclusively to The Earth & I, Professor Sanjay Mohanty, who led the UCLA pilot study, said his team was surprised to find both shed similar levels of microplastics in their experiments.
“Surprisingly, we found that synthetic chewing gums released a similar number of microplastics as compared to natural or plant-based gums,” he said.
“Surprisingly, we found that synthetic chewing gums released a similar number of microplastics as compared to natural or plant-based gums.”
“The average concentration of microplastics per gram of gum that we studied was 104.0 for synthetics and 95.8 for natural or plant-based gum.”
The most abundant polymers for both types of gum were polyolefins, a group of plastics that includes polyethylene and polypropylene. Other polymers that appeared in both gum samples included polyethylene terephthalates (known as PET), polyacrylamides, and polystyrenes.
As well as being surprised at the findings, the professor said mystery still surrounds the origins of the plastics in the “natural” gums.
“As synthetic gums are made with petrochemical polymers, we went in expecting to see comparatively much less microplastics to the natural gums tested. We do not know what the potential source of those microplastics were, in either type of gum.”
One suggestion put forward by the team was that they may have been introduced during production or packaging processes.
Dr. Sherri “Sam” Mason from Gannon University in Erie, Pennsylvania, is one of the world’s leading experts on microplastic pollution, with her work being instrumental in raising global awareness and driving policy changes.
When she read about the UCLA team’s research, she said she was not shocked.
She told The Earth & I: “Sadly, I was not surprised at the findings. I was actually interviewed for a documentary called Dark Side of the Chew back in 2014 in which I was asked about chewing gum.
“Most chewing gums, especially those that dominate the market, use plastics as the base. It is not a surprise that the friction associated with chewing would cause the release of microplastics.”
Health Concerns
Microplastics—defined as plastics measuring less than 5mm in length—are literally everywhere, from oceans to the atmosphere. They do not biodegrade and are shed by everyday products such as food packaging and plastic bottles.
Much of the controversy and concern around them stems from uncertainty. And while scientists have not established any direct effect of microplastics on humans, some studies have begun to examine the correlation between microplastics in the human body and disease.
“Data is connecting various gastrointestinal issues, like IBS and changes in gut microbiomes, with microplastics, Mason said.
“Data is connecting various gastrointestinal issues, like IBS and changes in gut microbiomes, with microplastics.”
“Any particle of plastic that is smaller than 100 microns, which is basically the width of a human hair, can make their way across the gastrointestinal track into the blood and carried throughout the body.
“Micro-and nano-plastics have been found within organs, like the liver and kidney, as well as having crossed barriers into the brain and across the placenta,” she said.
“Their presence is being associated with various lung issues, like asthma and lung cancer, increases in blood plaques leading to heart disease, various neurological disorders, like Parkinson's and Alzheimer's, as well as fertility issues.”
Professor Mohanty’s team presented the results of their pilot study at the American Chemical Society in San Diego. But he said the gum industry had not been in touch about the findings.
The Earth & I reached out to the International Chewing Gum Association, the global trade body for the industry, to request a comment on the research but did not receive a response.
The professor added that he would like to look for even smaller particles.
“Our study could only resolve particles down to about 20 micrometers in diameter, due to limits with the spectroscopy technique we used. So, this study could have missed particles smaller than that.”
The study did not measure toxicity; it only evaluated ingestion risk and found that both types of gum presented similar risks. In general, though, the team said products containing natural or plant-based materials may introduce fewer dissolved chemicals into the human body.
Future Study
Mason said there was enough data generally to understand there was a “negative impact” of plastics on human health.
But she added, “We needn't catastrophize—this isn't the end of the world as we know it—but we need to make changes now before things get worse.
“We should have a reasonable amount of concern and be pushing for societal changes, like precautionary policies, to reduce our exposure, especially within the agricultural and consumables markets,” she said.
*Mark Smith is a journalist and author from the UK. He has written on subjects ranging from business and technology to world affairs, history, and popular culture for the Guardian, BBC, Telegraph, and magazines in the United States, Europe, and Southeast Asia.