Artificial Sweeteners Like Splenda May Make Crohn's Disease Gut Issues Worse, Study Shows

Artificial sweeteners, such as Splenda, have stirred controversy for years. Now a new study has more bad news for the sugar substitute: It may worsen Crohn’s disease symptoms. Mario Tama/Getty Images

There's no one-diet-fits-all to fight Crohn's disease, a condition that causes inflammation of the digestive tract. However, avoiding artificial sweeteners such as Splenda may help prevent uncomfortable symptoms, according to a new study.

In an effort to understand how the zero-calorie sugar substitute impacts the body's intestines, researchers from Case Western Reserve University conducted three experiments on mice models. For the first experiment, they mixed in a "low dose" of Splenda into the drinking water of mice belonging to a genetic line known to suffer from Crohn's. They then compared those mice to others that instead received plain water for six weeks.

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During the second experiment, the researchers slightly increased the sugar dose, and finally, during the third experiment, they increased it 10 times higher. For both of those trials, they also introduced healthy mice into the mix. The findings, which are published in the journal Inflammatory Bowel Diseases, showed that the mice with Crohn's-like disease had an overgrowth of E. coli in their intestines, but the healthy mice did not. Although all people have a small amount of E. coli in their gut, those with Crohn's and other bowel diseases are known to carry a bit too much, as illustrated in previous studies.

"Our findings suggest that patients with Crohn's disease should think carefully about consuming Splenda or similar products," Alex Rodriguez-Palacios, study author and assistant professor of medicine at Case Western Reserve University, said in a statement. "The sweetener induces changes in gut bacteria and gut wall immune cell reactivity, which could result in inflammation or disease flare-ups in susceptible people."

The study results also suggest that those without Crohn's disease, ulcerative colitis and other intestinal diseases may not need to worry about the potential side effects of Splenda, Rodriguez-Palacios explained.

But, Keren Gilbert, a registered dietitian and nutritionist and founder of the New York–based nutrition consulting firm Decision Nutrition, suggests otherwise.

"I'm not surprised [the study authors] were seeing these effects because Splenda is artificial," Gilbert, who was not involved in the research, told Newsweek. "I think anything that's made in a lab you should be very cautious of."

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While Splenda may indeed cause inflammation, it's important to note that the research was a small study conducted on animal models. Therefore, further work must be done in order to better understand sugar substitutes' impact on humans.

Despite the widespread controversy over the pros and cons of Splenda (and other artificial sweeteners), it's been deemed safe for consumption by the Food and Drug Administration for nearly two decades.