What's So Bad About High Fructose Corn Syrup?

Does HFCS irritate the stomach or cause irritable bowel syndrome (IBS)?

It’s true that, compared to other types of sugars, large doses of fructose can cause stomach upset, even in healthy people. That’s even truer in patients with IBS, a condition whose hallmark symptom is recurring gastrointestinal (GI) distress. “Fructose empties from the stomach more rapidly than other sugars, and it’s more slowly absorbed [from the GI tract into the blood] than glucose,” explains Peter Beyer, R.D., an associate professor of dietetics and nutrition at the University of Kansas Medical Center in Kansas City. A big hit of fructose—such as what you’d get in a giant serving of apple juice—can overwhelm your body’s capacity for absorbing it. Thus, it lingers undigested in your GI tract where it can cause gas, bloating and general GI distress.

But this generally isn’t an issue when fructose is combined with glucose, as you’d see with high-fructose corn syrup, and with sucrose, says Beyer. In fact, a recent study showed that when scientists gave healthy people and IBS patients a large dose of fructose and, on a separate occasion, a large dose of HFCS, both tolerated the HFCS solution better.

That said, with any sugar, “the poison is in the dose,” says Beyer. And, while there’s no evidence that IBS is caused by sweeteners, “people with IBS are more likely to be sensitive to any sugar than other individuals,” he notes. “HFCS is no worse in that regard.”