People with ulcerative colitis, a severe inflammation of the lower intestine, often go for stretches of time when their symptoms are absent or mild, before they relapse again and symptoms come rushing back. Though there are theories, no one is quite sure what causes relapses. Scientists from the United Kingdom analyzed the diet of colitis patients to see if food could be a factor.

What the researchers wanted to know: Does diet influence the relapse rate in people with ulcerative colitis?

What they did: The researchers followed 183 English colitis patients who were in remission for a year. At the beginning of that year, the researchers asked patients about how often they ate 107 different kinds of foods, and how much they ate of each one. To determine relapse rate, the participants were given prestamped postcards that asked questions about bowel frequency, urgency, amount of blood in the stool, and manifestations of the disease outside of the bowel, such as abdominal pain and general well-being. The patients mailed completed cards to the researchers every week.

What they found: During the year, 52 percent of the participants (96 people) relapsed. People who had a diet high in red and processed meat were more than six times as likely to relapse as people who did not consume much of that kind of food. Meat in general was also associated with a higher rate of relapse, and people who drank a lot of alcohol were four times as likely to relapse as those who drank only a small amount. No other types of foods, including carbohydrates, dairy products, or fiber increased the rate of relapse in this study.

What it means to you: The authors speculate that colitis relapses are caused by foods high in sulfur—which includes red meat, processed meat, and alcohol. Animal studies have shown that sulfuric compounds degrade the lining of the large intestine so that it no longer protects your intestines from bacteria or foreign substances. In addition, people with colitis have higher concentrations of sulfur in their intestines, which increases during spells when the disease is worse.

Caveats: The researchers only asked participants about their dietary habits once, at the beginning of the study. The patients' initial responses might have been specific to the season or might have reflected recent disruptions to their normal eating patterns (such as a vacation). Also, participants' eating habits may have changed over the course of the year.

Find out more: The National Digestive Diseases Information Clearinghouse has general information about ulcerative colitis, including its causes, symptoms, and treatment.

The Crohn's and Colitis Foundation of America website has information for people who suffer from colitis, including an explanation of how digestion is affected and what foods aggravate the condition.

Read the article: Jowett, S.L. "Influence of Dietary Factors on the Clinical Course of Ulcerative Colitis: A Prospective Cohort Study." Gut. October 2004, Vol. 53, No. 10, pp. 1479–1484.

Abstract online: http://gut.bmjjournals.com