Our parents invented some pretty wild stories to prevent us from swallowing things we weren't supposed to. Now that we're older (and wiser), we know watermelon seeds won’t actually sprout a tree in our stomach. But what about the tales of gum sticking around in our digestive tract for years?
The Sticky Situation
Gum has been around for a long time. Thousands of years ago, during the neolithic period, people chewed on birch bark tar (yum!), which actually kept their gums healthy. Fast-forward to the 1860s, when gum—made from chicle, a form of tree sap—first arrived in the U.S. When manufacturers realized the number of trees they could tap was limited, they started making gum out of rubber. Yes, the gum we chew today is completely synthetic, so it's no wonder our bodies have trouble digesting it.
“Your gut can handle all kinds of things like carbs and proteins because it has special enzymes to break them down into molecules,” says Mark Larson, M.D., a gastroenterologist at the Mayo Clinic. “But your stomach’s digestive enzymes can’t break down the rubbery substance found in chewing gum.” So your body breaks down the sugar and other flavoring in gum, but the actual rubbery substance goes straight through your system. In other words, it kindly exits your body via your poop.
And that gum doesn't spend years just chilling in your digestive tract, says Anish Sheth, M.D., a gastroenterologist and author of What’s Your Poo Telling You? Everyone’s transit time is different, but gum should pass through your system in three days, just like any other insoluble fiber (like a corn kernel).
So go ahead and swallow it—Larson says he's been doing so his entire life. “I just hate the idea of taking it out and putting it somewhere,” he says. “And I know it’s safe, so it’s just something I’ve always done.”
But there must be some reason parents tell their kids not to swallow gum, right? “The concern with kids is that they may develop a bezoar, which is essentially a large wad of gum that would block the digestive tract,” Sheth says. This is especially important since kids’ digestive tracts are smaller than adults. Kids would have to swallow a lot of gum (likely packs) for this to happen, but both doctors we spoke with said it's best for parents to play it safe, especially since gum can be a choking hazard for younger children.
Kids aside, there is also a risk associated with swallowing gum for people who have preexisting stomach problems. “If someone’s stomach isn’t working properly to begin with, they have stomach emptying problems, or they’ve had intestinal blockage in the past, swallowing multiple pieces a day could cause a problem,” Sheth says.
When it comes to swallowing gum, Sheth says there are two important things to consider: quantity and size. For most adults, downing a stick of gum per day shouldn't be an issue. You also need to think about the size of your digestive tract. If you have kids (or younger relatives), you should err on the side of caution and tell them swallowing gum is a no-no (at least for now).