Microplastics in chewing gum and practical ways to reduce exposure

Chewing gum may be a harmless, even beneficial daily habit for many, but a recent “study” that has gone viral on social media and internet news sites suggests otherwise. This study (the study is not peer-reviewed and is a presentation being given at the American Chemical Society biannual meeting) revealed that every piece of gum you chew could introduce microplastics into your body.¹ Studies indicate that humans inadvertently consume tens of thousands of microplastic particles annually, leading to a growing awareness among the health-care community about the potential impacts of prolonged exposure. With concerns about microplastics pervasive across all aspects of our lives—food, water, packaging, and now chewing gum—it’s essential for dentists and health-care professionals to be able to speak to their patients about microplastics and what really poses a risk.

What are microplastics, and why are they a concern?

Microplastics are tiny plastic particles less than 5 mm in size, originating from degraded plastics or as by-products from manufacturing processes. These particles—composed predominantly of polymeric materials such as polyethylene, polypropylene, polystyrene, nylon, polyester, acrylic, polyoximethylene, polyvinyl alcohol, polyvinyl chloride, poly methylacrylate, polyethylene terephthalate, and polyurethane—are ubiquitous in the environment; they contaminate air, food, water, and, more importantly, the human body.² While definitive links to health outcomes are still under investigation, there is evidence suggesting microplastics may contribute to inflammation, endocrine disruption, and even cellular damage. Some studies have shown that these particles can be found in arterial plaque, increasing the risk of heart attack, stroke, and death.³ Other studies show that these particles can cross the blood-brain barrier, accumulating in the brain and possibly posing an increased risk for Alzheimer’s disease and cognitive impairment.⁴

Now, new research highlights an often-overlooked source of microplastic ingestion—chewing gum.

The study on microplastics in chewing gum

A recent pilot study by researchers at UCLA, presented at the American Chemical Society (ACS) conference, has shown that chewing gum may release 100 microplastic particles per gram of gum through the mechanical action of chewing.

Key findings of the pilot study

Synthetic and natural gums both contain microplastics: Researchers tested five commercially available synthetic gum products and five natural gum alternatives made with plant-based polymers. Surprisingly, both types released comparable levels of microplastics when chewed.
Volume of microplastics released: On average, approximately 100 microplastic particles were released per gram of gum. For larger pieces of gum (around 6 grams), this number could reach up to 3,000 particles per piece. The researchers highlight that the average person chews between 160 to 180 sticks of gum annually, which can result in the ingestion of approximately 30,000 additional microplastic particles per year.
Composition and mechanism: Most microplastics released during chewing consisted of polyolefins, polyethylene terephthalates (PET), and polystyrenes, materials common in both synthetic and natural gums. Notably, these particles were released due to the abrasiveness of chewing rather than enzymatic reactions, with 94% of plastic detachment occurring within the first eight minutes of chewing.

Should we stop chewing gum?

There are many limitations to this pilot study that the public and health-care professionals need to be aware of.

This is a pilot study that is not peer-reviewed, based on one subject, and being presented at a national meeting. It has not been replicated.
The researchers measured salivary concentrations of microplastics—not blood concentrations—so inference of these particles winding up in tissues and organs cannot be made.
This study couldn’t identify particles smaller than 20 micrometers, which are quickly detoxified by the liver. The smaller particles are more worrisome as they accumulate in tissue organs.⁵ This study assumes that there are also smaller microplastics released into the body by chewing gum.
There is no perspective given in this study. For example, chewing gum in this study released 100–3,000 plastic particles. The typical liter water bottle contains 240,000 plastic particle fragments.⁶

For those who want to chew gum: Ways to reduce exposure

Chew one piece of gum for longer periods of time. Since most microplastics in gum are released during the first two minutes of chewing, prolonged chewing of one piece instead of frequently renewing it may help minimize the total number of microplastics released.
Choose microplastic-free gum alternatives. Select gums specifically manufactured without synthetic polymers. Brands using natural chicle or sustainably sourced plant-based polymers are preferable; however, ensure these are marketed as genuinely free from plastic derivatives.
Explore natural freshening alternatives. Substitute chewing gum with more natural breath fresheners like mint leaves, clove, or green tea. These alternatives completely eliminate the risk of ingesting plastic particles.
Advocate for label transparency. One challenge faced by consumers is the lack of ingredient transparency in gum manufacturing. Health-care professionals can support efforts calling for better labeling of food-grade polymers and plastics by brands.
Reduce overall plastic use. Broader strategies to curb microplastic consumption—such as avoiding processed foods, investing in glass water bottles, avoiding heating foods in plastic containers, and encouraging sustainable packaging practices—will also indirectly limit exposure through other channels.

The findings of microplastics in chewing gum underscore the broader health challenges posed by plastic pollution in our modern world. While the direct health implications of chewing-gum-related microplastics remain under-researched and may prove to be negligible, cumulative exposure to microplastics is associated with chronic systemic disease. In the next article we will explore methods to reduce plastic exposure as well as methods to increase plastic detoxification by the body.

Editor’s note: This article originally appeared in Perio-Implant Advisory, a chairside resource for dentists and hygienists that focuses on periodontal- and implant-related issues. Read more articles and subscribe to the newsletter.

References

Chewing gum can shed microplastics into saliva, pilot study finds. American Chemical Society. News release. March 25, 2025. https://www.acs.org/pressroom/presspacs/2025/march/chewing-gum-can-shed-microplastics-into-saliva-pilot-study-finds.html
Ziani K, Ioniță-Mîndrican CB, Mititelu M, et al. Microplastics: a real global threat for environment and food safety: a state of the art review. Nutrients. 2023;15(3):617. doi:10.3390/nu15030617
Liu S, Wang C, Yang Y, et al. Microplastics in three types of human arteries detected by pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). J Hazard Mater. 2024;469:133855. doi:10.1016/j.jhazmat.2024.133855
Gaspar L, Bartman S, Coppotelli G, Ross JM. Acute exposure to microplastics induced changes in behavior and inflammation in young and old mice. Int J Mol Sci.2023;24(15):12308. doi:10.3390/ijms241512308
Yin J, Ju Y, Qian H, et al. Nanoplastics and microplastics may be damaging our livers. Toxics. 2022;10(10):586. doi:10.3390/toxics10100586
Plastic particles in bottled water. NIH Research Matters. National Institutes of Health. January 23, 2024. https://www.nih.gov/news-events/nih-research-matters/plastic-particles-bottled-water