The disguise
Gum is confectionery — it sits next to the mints, flavoured like fruit, endorsed by dentists. The label discloses everything except the main ingredient, which hides behind two words: “gum base”.
The plastic
Most modern gum base is a blend of petroleum-derived polymers from the same families as household plastics — polyethylene relatives, polyisobutylene, polyvinyl acetate. Chewing gum is a food-grade polymer engineered to stay rubbery in your mouth. That’s not an accusation; it’s the product spec.
The evidence
A UCLA pilot study had a volunteer chew ten brands — five synthetic, five “natural” — and counted what entered the saliva: on average ~100 microplastic particles per gram of gum, up to ~637/g for some brands; a typical piece can release 3,000+ particles, with 94% shed in the first eight minutes of chewing (UCLA, 2025; ACS press release) lab early.
The honest surprise from the same study: “natural” chicle-based gums released similar particle counts to synthetic ones — possibly contamination picked up in processing. And the caveats are real: one chewer, ten brands, particles ≥20 µm only (nanoplastics weren’t counted at all). A pilot, graded as one.
The tell — and the fix
The tell is the phrase “gum base” itself — manufacturers aren’t required to itemise it, and none volunteer “synthetic polymers” on the front of the pack. The fix: skip it, or work with the release curve — most particles come off in the first minutes, so one piece chewed long beats a fresh piece every ten minutes. And spit it in the bin: swallowed or spat on the footpath, it’s plastic either way.