People carry all kinds of misconceptions and myths they learned about food as a kid with them through their entire lives. These pieces of food folklore often come from a parent or grandparent as a warning or a piece of advice which then sticks with the child even into adulthood.
One warning that commonly sticks with people through the years is that gum will take an incredibly long time, usually seven years, to digest. Many VERIFY readers told us this tale was one of the food legends they grew up with.
Is there any truth to this warning, or is it just a tactic to scare children away from swallowing gum?
Does gum really take seven years to digest?
- Elizabeth Rajan, M.D., in a 2019 “expert answer” for the Mayo Clinic
- Duke Health blog post, including quotes from gastroenterologist Nancy McGreal, M.D.
- Bwalya Lungu, Ph.D., food science and food folklore professor at the University of California Davis
No, gum does not take seven years to digest.
WHAT WE FOUND
Your body can’t digest gum, but that doesn’t mean you have to worry about it sticking to the wall of your stomach for the better part of the next decade.
“If you swallow gum, it's true that your body can't digest it,” said Elizabeth Rajan, M.D., in a 2019 expert answer for the Mayo Clinic. “But the gum doesn't stay in your stomach. It moves relatively intact through your digestive system and is excreted in your stool.”
On average it takes two to five days from the time you swallow something to the time it leaves your body in feces, Rajan explained in a different Mayo Clinic expert answer. That would mean gum should leave your body in less than a week, not seven years.
Bwalya Lungu, Ph.D., a food science and food folklore professor at the University of California Davis, explained that gum is made up of a gum base, sweeteners, flavoring agents and coloring. It’s that gum base which can’t be digested.
“The gum base is insoluble, just like the fiber base of raw vegetables, corn, popcorn kernels, and seeds,” said gastroenterologist Nancy McGreal, M.D., in a Duke Health blog post. “Our bodies do not possess digestive enzymes to specifically break down gum base.”
Lungu said that when we chew food, we’re breaking it down into smaller particles because the body can more easily digest those smaller particles. Then the acids in our stomachs break down the food further into what’s called slurry. Enzymes act upon that slurry in the small intestine so we can digest and absorb its nutrients. Anything left in the small intestine when the slurry passes into the large intestine is then passed through our stool.
“Gum, on the other hand, is passing through all of that relatively untouched,” Lungu said. “Because one, it's not broken up by the chewing. Number two, the time it stays in [the stomach and the acids is] not long enough to really break that down. The body doesn't produce any enzymes to break down the gum.”
Even though it doesn’t get broken down, gum still travels the same path as food and is excreted in stool, Duke Health said. It doesn’t even stay in your stomach any longer than usual — Duke Health says your stomach empties its contents, including gum if it’s in there, into the intestines 30 to 120 minutes after eating.
But the Mayo Clinic, Duke Health and Lungu all agreed there are very rare scenarios where gum might cause a blockage.
The Mayo Clinic said if a child with constipation eats a very large amount of gum, it’s possible for the gum to contribute to or cause a blockage. Duke Health said gum might hang around in the stomach longer if the person who swallows it has gastroparesis, or paralyzed stomach, which can result in a buildup of food in the stomach. Lungu said you might have blockage issues if you have a “serious condition” with your stomach or intestines.
But even in the most extreme versions of these already rare cases, it’s incredibly unlikely that gum would stay in someone’s stomach for seven years.
“In all the upper endoscopies I have done in both children and adults, I have yet to see a wad of gum lying around in the stomach,” McGreal told Duke Health.
More from VERIFY: Yes, putting Mentos into any soda can make it explode