How long does gum really stay in your stomach? Is it seven years? Here's the truth

Young woman Blowing Bubble Gum bubble - stock photo
For people who have had gastric surgery or issues with their gastrointestinal tract, swallowing gum could be problematic, according to experts. Photo credit: Getty Images

By Sadie Andrew of CNN

If you're one of many people who have swallowed a whole piece of chewing gum by accident, one question likely popped in your head right after that startling sensation.

How long will the gum stay there? There is a common notion that it will sit in your stomach for seven years after being swallowed.

Not true. 

"It's an old wives' tale," said Simon Travis, professor of clinical gastroenterology at the University of Oxford in the United Kingdom. "I've no idea where the myth came from - I can only imagine that it was suggested because someone wanted to stop their children from chewing gum."

Swallowing gum is only harmful to the body if done in excess, Travis said via email, which is very rare. He explained that swallowing three or more pieces of gum per day would be considered excessive.

"If you swallow chewing gum, it'll go through the stomach, and go through into the intestine, and pass out unchanged at the other end," Travis said. "There are cases of chewing gum lodging in the intestines of infants and even children if they've swallowed a lot, and then it causes an obstruction. But in over 30 years of specialist gastro practice, I've never seen a case."

Dr Aaron Carroll, a distinguished professor of paediatrics and chief health officer at Indiana University, has written several books debunking myths about the body. 

Carroll agreed that swallowing gum won't do you any harm, but he wouldn't actively encourage it.

"It has no nutritional value," he said. "Gum is made out of gum-based sweeteners, flavouring and scents. Gum base is a mixture of elastomers, resins, fats, emulsifiers and waxes. So, I wouldn't say it's healthy."

How long have people chewed gum?

Before gum became commercialized and sold in the packets we see today, it was used by ancient peoples to stave off thirst and hunger, according to Jennifer Mathews, professor of anthropology at Trinity University in San Antonio, Texas, and author of Chicle: The Chewing Gum of the Americas, From the Ancient Maya to William Wrigley

Mayans chewed on a substance called chicle, which comes from the sapodilla tree prevalent in southern Mexico and Central America, Mathews said.

"Chicle is a natural latex that comes from something called the Chico sapote tree, or sapodilla tree," Mathews explained. "If you cut into a chico sapote tree, the latex starts to ooze out as a form of protection. It forms a barrier to protect the tree. Well, you can just pull it off the tree, and start chewing on it."

Similarly, the Pima Indians in what is now the United States chewed on spruce tree sap for thousands of years before European settlers picked up on the habit and it became commercialised, Mathews said.

When to worry about swallowing gum 

Unless you are in pain or have swallowed a lot of gum, Travis and Carroll said you don't need to go to the doctor if you accidentally swallow a piece whole.

"It's a theoretical problem," Carroll said. "You theoretically could get something big enough in a small child to cause a blockage, but this is not something that regular people need to worry about."

However, for people with problems with their gastrointestinal tract, or GI tract, which is a series of organs joined together in a long, twisting tube from the mouth to the anus, swallowed gum could cause issues.

"If things are open, and there's no blockages, there's no narrowing, things are going to go through just fine," said academic gastroenterologist Dr Leila Kia, an associate professor of medicine at Northwestern University's Feinberg School of Medicine in Chicago. 

"If there's a narrowing or you have really severe inflammation for whatever reason, or you have a motility problem, where your stomach or your colon isn't emptying in the way that it should, then certainly eating something like gum or something that can't break down, it can hang around and that can actually cause problems," Kia said.

Crohn's disease is a common cause of inflammation in the GI tract and can cause it to narrow, according to Kia. She said doctors would usually recommend a low-residue diet for Crohn's patients, which avoids certain foods like raw fruit and vegetables, nuts and seeds, popcorn, and gum.

Some types of cancer and surgeries can cause that narrowing. "Certainly, if you were to swallow many pieces of gum, that could become a problem if you have only a tiny stomach or your anatomy's been rearranged, which is essentially what happens when you have gastric surgery," Kia said.

Still, Kia has never removed gum from anyone's body, although she has removed dentures that she thinks were swallowed inadvertently.