Initial studies link added sugar and IBD


Dear Doctor: I am 32 years old, and I just learned I have IBD. My doctor thinks the fact that in my family we eat a lot of sweets has something to do with it. I’m not the only one with stomach issues, but I figured since it runs in the family, it is genetic. Do you think it could really be from too much sugar?

Dear Reader: Inflammatory bowel disease, or IBD, is a general term used to describe a group of disorders that arise from chronic inflammation of the digestive tract. The most common of these are Crohn’s disease and ulcerative colitis. Although Crohn’s disease can affect any part of the digestive tract, most people experience problems in the area between the ileum, which is the end of the small intestine, and the start of the colon, or large intestine. In ulcerative colitis, the individual develops sores along the inner lining of the colon and rectum. Both ulcerative colitis and Crohn's disease can cause abdominal pain, diarrhea, rectal bleeding, urgency to defecate, unintended weight loss and fatigue.

It’s true there’s evidence that IBD, which affects upwards of 3 million people in the U.S., runs in families. Stress, diet and age also appear to play a role. Both ulcerative colitis and Crohn’s disease often develop in a person’s 20s and 30s. IBDs are also believed to arise from immune system impairment or malfunction.

This brings us to your doctor linking your IBD diagnosis to excessive sugar consumption. A study using mice, which was published last fall in the journal Science Translational Medicine, found evidence that added sugar in the diet can lead to IBD, and also make existing disease worse. Americans eat an estimated 65 to 70 pounds of added sugar per year, the highest rate in the world. Considering that the U.S. accounts for from one-third to one-half of all cases of IBD worldwide, it’s easy to see how the IBD-sugar connection became a subject of inquiry.

Elizabeth Ko, MD and Eve Glazier, MD

In that study, researchers looked at three groups of mice -- those with a healthy gut, a group genetically predisposed to develop colitis and a group fed a compound to induce colitis. The mice were then further divided into new groups. Some received simple sugars for seven days in concentrations equivalent to a soft drink. Others had no added sugars in their diet. At the end of the week, the mice on the sugary diets developed colitis that was far more severe than the sugar-free mice. The gut microbiomes of all the sugar-fed mice were significantly altered, with a marked increase in bacteria that degrade the layer of protective mucus that lines the gut.

Whether or not eating sugar erodes the protective mucus in the guts of humans remains to be seen, but these findings are intriguing. And considering we already know that too much added sugar has an adverse impact on heart health, blood sugar control, inflammation and even on mood, we think cutting back would be good not only for your gut, but also for your general health.

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