Can you digest gum? As a child, you may have heard that a piece of swallowed gum will stay in your stomach for seven years. That hopefully convinced you to wrap up your chewy treat after the flavor ran out and throw it neatly in the trash. Less considerate people might stick their gum where some poor soul will need to scrape off the slowly solidifying, disgusting mess. But is swallowing gum that bad? Let’s explore what really happens when you swallow gum.

History of Chewing Gum

Humans have been chewing gum derived from trees since the Stone Age. In Denmark, a 5,700-year-old piece of birch tar with human toothmarks was found filled with well-preserved DNA from the chewer and her recent meal, as described by Smithsonian magazine. The ancient Greeks chewed the sweet resin of mastic trees. Native Americans chewed resin from spruce trees, and European colonists picked up the habit. Farther south, ancient Mayans and Aztecs chewed sap from sapodilla trees.

The first patented chewing gum sticks hit US markets in 1871. According to Britannica, they were manufactured from sapodilla sap that was harvested much like natural rubber. During World War II, chewing gum was included in US military rations, and soldiers helped spread its popularity overseas. Soon, there weren’t enough sapodilla trees to keep up with demand.

After World War II, chemists learned to create artificial gum bases using synthetic polymers, which are essentially different types of synthetic rubber. Today, many gum manufacturers use butyl rubber, which is also used to make inner tubes, tires and basketballs. A few companies still use natural sap. The US Food and Drug Administration (FDA) regulates gum as a non-food item, so manufacturers need to use “food grade” materials but don’t need to disclose their ingredients.

The rubbery gum base is typically mixed with softeners such as paraffin wax or vegetable oil for elasticity. Additional ingredients include natural or artificial sweeteners, flavors such as mint or fruit, colors, preservatives, and perhaps a candy coat. Through clever marketing and applying the science of taste, the gum industry had an estimated $32 billion in global sales in 2019, according to Statista.

What Happens When You Swallow Gum?

Except for the gum base, the ingredients in gum can easily be broken down by the digestive system. It’s the gum base that sticks to sidewalks, school desks, human hair, and dental work. So what happens if you swallow a piece? Can you digest gum? No, but it doesn’t stick to your stomach for seven years either. It follows the same path as anything else you swallow, including indigestible items such as popcorn kernels, watermelon seeds, small pieces of bone and the fiber base of raw vegetables.

Food enters the gastrointestinal (GI) system through the mouth. Chewing mechanically breaks food into smaller pieces, and enzymes in saliva start the process of chemically breaking down molecules so they can be absorbed. Anything that is swallowed, including gum, then enters the esophagus and is carried into the stomach.

The stomach mixes food with acid and digestive enzymes until it becomes a slurry of juices and solids. This slurry then drains into the small intestine, where bacteria and more enzymes help break down the solid material. Nutrients are absorbed through the walls of the small intestine. Muscle contractions move the slurry through the small intestine, which is about 20 feet long in adults. Anything left is then transferred to the large intestine, which is also called the colon. Water is absorbed through the walls of the colon until the remaining material is the appropriate consistency to be expelled as waste. If you swallow a piece of gum, it will typically exit the gastrointestinal track within a few days and be largely unaffected by the process.

What’s the Worst That Could Happen?

While occasionally swallowing a piece of gum is typically no big deal, serious problems can arise. For small children — who may not understand that gum should not be swallowed — gum is a choking hazard like coins or small toys that can block the esophagus. If these items make it through the esophagus into the stomach, anything smaller than a quarter will usually pass through the GI tract and be expelled as waste. However, indigestible items can clump together to form a bezoar, which is too large to move normally through the GI tract. This can clog the system and lead to severe abdominal pain, constipation and vomiting. A bezoar may require surgical removal.

While rare, there are some documented medical horror stories that involve swallowing gum. A publication in the journal Pediatrics described three cases of children who suffered gastrointestinal blockages because they regularly swallowed gum. The youngest child was 1.5 years old and had a mass stuck in the esophagus containing four coins held together by a large wad of gum. Two other cases involved 4.5-year-olds with bowel obstructions. One child had been suffering from constipation for two years, and was offered gum five to seven times a day to encourage trying to go to the bathroom. This child always swallowed the gum. Doctors found and removed a “taffy-like” mass from this child’s rectum consisting mostly of gum. The other 4.5 year old also regularly swallowed gum and had a “multi-colored mass” of chewing gum removed.

This is not just a problem for small children. Consider the case of an 18-year-old Israeli female reported in the journal Gastrointestinal Endoscopy. She had been chewing and swallowing at least five pieces of gum per day for several years and was admitted to the hospital with stomach pain. Her stomach was filled with solid masses of gum and food material, which had to be removed in multiple stages.

So, feel free to enjoy your gum just like the ancient Greeks, Mayans and Native Americans — just put it in the trash when you’re done. There’s no good reason to test your GI tract with tire rubber.

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