Does gum really take 7 years to digest?

As kids, we were warned not to swallow chewing gum, because it supposedly takes seven years to digest. But is there any truth to this old wives' tale, or is it simply a myth?

Luckily for those who have accidentally downed a stick or two, it doesn't take anywhere close to seven years for swallowed gum to exit our bodies, according to Julia Zumpano, a registered dietician at the Cleveland Clinic's Center for Human Nutrition in Ohio. "It takes 40 hours, just as food does, to make its way through your digestive system and out through stool," she told Live Science.

That said, we don't actually digest chewing gum. "Our bodies don't have enzymes to digest some of the products in gum," said Dr. Nancy McGreal, a gastroenterologist at Duke University Medical Center. "So, if you swallow it, it does travel through your intestinal tract whole." 

This means that if you swallow gum, you poop it out whole, just like you would pieces of undigested corn (which may not be digested because they're high in fiber and have a cellulose coating, which we also lack enzymes to break down).

"I've had a few instances where I'm doing a procedure like a colonoscopy, and I've found a little bit of gum that a patient had swallowed. But again, that was probably something they swallowed within the last 24 hours and not something from seven years ago," McGreal said.

Related: Why do our stomachs growl? 

Gum is made out of an artificial product called gum base — which contains non-food ingredients such as resins, emulsifiers and softeners — that can't be digested, according to the Cleveland Clinic. However, our bodies are able to digest some of the other ingredients added to gum, such as sweeteners.