The question of whether the “plastic” in chewing gum is harmful is a common concern. The foundation of all chewing gum is the “gum base,” a non-nutritive, water-insoluble component responsible for the product’s chewiness and elastic texture. This base remains after the flavors and sweeteners are dissolved during chewing. Understanding the safety of chewing gum requires clarifying the composition and regulatory status of this gum base.
Decoding the Gum Base
The gum base used in most modern commercial chewing gum is not a single plastic, but a complex, proprietary mixture of synthetic and natural components. The primary components that provide the distinctive chew are synthetic food-grade polymers and elastomers, which are petroleum-derived substances.
Common examples of these synthetic materials include polyisobutylene (a type of rubber), polyvinyl acetate (a resin), polyethylene, and styrene-butadiene rubber. These polymers are combined with plasticizing materials, such as paraffin waxes and softeners like vegetable oils, to create a moldable and cohesive texture. The synthetic polymers act as the insoluble matrix that holds the entire gum together, allowing it to withstand prolonged chewing.
Health and Safety Assessment of Gum Base Components
The safety of these synthetic polymers is addressed by regulatory oversight from bodies like the U.S. Food and Drug Administration (FDA). The components used in the gum base are classified as “food-grade” additives, meaning they have been evaluated for safety under their intended conditions of use. The FDA’s regulations specifically list the permitted substances that can be used to manufacture chewing gum base.
The safety assessment for these materials rests on their chemical inertness and non-reactivity within the body. The polymers are designed to be stable, non-toxic, and non-absorbable by the digestive system. Concerns about the leaching of microplastics are mitigated because the polymers are high molecular weight molecules. This means they are chemically stable and do not easily break down into smaller, absorbable units during chewing. The trace amounts of these materials that may be incidentally ingested are considered safe because they are passed through the body without being absorbed.
The Truth About Swallowing Chewing Gum
The long-standing myth that swallowed gum remains in the stomach for seven years is scientifically inaccurate and stems from the gum base’s indigestible nature. The human digestive system is highly efficient at moving materials through the gastrointestinal tract, even those it cannot break down chemically. This indigestibility means the gum passes through the stomach and intestines intact, similar to how the body handles dietary fiber. Swallowed gum typically clears the body and is excreted normally in the stool within a few days. Accidental swallowing of a single piece of gum is generally harmless, though frequent swallowing of large masses can rarely cause a blockage, known as a bezoar, most often in children.
Options for Gum Without Synthetic Polymers
For consumers looking to avoid synthetic polymers, there are alternatives available that utilize natural, plant-based ingredients for their gum base. The original form of chewing gum base was chicle, a natural rubber derived from the milky sap of the sapodilla tree, native to Central America. This natural base is biodegradable and does not contain the petroleum-derived synthetic polymers found in most commercial gums. Other plant-based alternatives include natural waxes, resins, and gum Arabic, a substance extracted from the acacia tree. Consumers can identify these alternatives by looking for specific ingredients on the label, such as “chicle” or “natural chicle base.”