A Recent Study Unveils the Unexpected Truth
For years, most people assumed that only conventional, petroleum-based chewing gum contained plastic. However, a groundbreaking 2025 pilot study from UCLA's Samueli School of Engineering revealed a surprising finding: both synthetic and so-called “natural” gums release microplastics. The research, led by associate professor Sanjay Mohanty and graduate student Lisa Lowe, sought to quantify the extent of this overlooked source of microplastic exposure.
The Study’s Findings on Synthetic vs. Natural Gums
Researchers tested 10 different commercially available chewing gums, consisting of five synthetic brands and five natural alternatives. Their initial hypothesis was that the synthetic gums would release significantly more microplastics, but the results were more complex. The average release was comparable between the two groups, with synthetic gums shedding about 104 particles per gram and natural gums releasing around 96 particles per gram.
However, the study also found a wide range in particle release, with some synthetic brands shedding up to 637 microplastics per gram, a far higher rate than any of the natural gums. This means that while the average is similar, there's a greater potential for higher microplastic intake from certain synthetic formulations. The researchers also noted that they were perplexed by the source of microplastics in the natural gums, suggesting possible contamination during manufacturing or from other unknown sources.
The Mechanism of Release
Another key discovery was the mechanism and speed of microplastic release. The study found that 94% of the microplastic particles were released within the first eight minutes of chewing. This happens not because saliva is breaking down the gum, but rather due to the mechanical, abrasive action of chewing itself. The repetitive stress physically separates tiny fragments from the gum base, which are then swallowed with saliva.
How to Tell What's in Your Gum
The biggest challenge for consumers is the lack of transparency in ingredient labeling. Most conventional gum lists "gum base" as a generic ingredient, which can be a proprietary blend of dozens of approved substances. This often includes synthetic polymers like:
- Polyethylene (the same plastic used in plastic bags)
- Polyvinyl acetate (used in white wood glue)
- Styrene-butadiene rubber (a component of car tires)
This deliberate obfuscation means that short of a brand explicitly marketing itself as plastic-free, there is no way for a consumer to know exactly what is in the gum base. This makes it difficult to pinpoint which brand has the most microplastics, as the specific formulation and its particle shedding rate are not publicly known.
Comparison of Gum Types
To help navigate the market, here is a comparison of different types of gum based on available research and ingredient information.
| Feature | Conventional Synthetic Gum | “Natural” (Hybrid) Gum | Plastic-Free Gum |
|---|---|---|---|
| Gum Base | Primarily synthetic polymers, often petroleum-based. | Can use a plant-based base (like chicle) but may still contain synthetic additives or contaminants. | Uses traditional, naturally-derived chicle or other plant resins. |
| Microplastic Release | Average 104 particles/gram; some brands release significantly more (>600 particles/gram). | Average 96 particles/gram; source of microplastics is less clear (contamination?). | Designed to be plastic-free and biodegradable; minimal to no microplastic release expected. |
| Label Transparency | Often opaque, with ingredients hidden under "gum base". | Variable; some are more transparent about ingredients than conventional brands. | High transparency; brands often highlight their plastic-free ingredients. |
| Examples | Many mainstream brands. | Some brands marketed as healthier or plant-based. | Glee Gum, Simply Gum. |
What This Means for Consumers
Since the ingredients of most commercial gums are a secret, a precise ranking of which chewing gum has the most microplastics is not possible. However, the UCLA study provides valuable guidance for reducing potential microplastic exposure:
- Prioritize Certified Plastic-Free Gums: Choosing brands that explicitly state they are plastic-free and use natural chicle is the most reliable way to avoid microplastics from gum.
- Chew One Piece Longer: The study found most particles are released early in the chewing process. Instead of frequently refreshing your gum, chewing a single piece for a longer duration could reduce overall microplastic intake.
- Consider Alternatives: Natural breath fresheners like mint leaves or cloves offer a zero-plastic alternative.
Conclusion
While no single brand can be definitively named as containing the most microplastics without specific test data, research indicates that conventional, synthetic gums are a major source, and even some "natural" alternatives are not entirely free of contamination. The best course of action for health-conscious and environmentally aware consumers is to choose transparent, certified plastic-free brands. The findings underscore the broader issue of ubiquitous microplastics and the need for greater transparency in the food industry.
For more information on the UCLA study, you can review their press release.
