Lay Summary

Proposal No. IBD-0249R
Principal Investigator:  Joanne K. Tobacman, M.D.
Applicant Organization:  The Board of Trustees of the University of Illinois (Chicago, U.S.A.)
Project Title:  Effects of carrageenan-free diet on activity of ulcerative colitis
Period of Award:  August 1, 2009 – July 31, 2012

The commonly used food additive carrageenan (CGN) can cause ulcerative colitis-like lesions in animals exposed to CGN. We have found that markers of inflammation are increased in human colonic cells exposed to small quantities of CGN. Since CGN is consumed in quantities of over 100 mg/day in the average Western diet, and intake by some individuals may be as much as 2-4 grams/day, it is possible that consumption of CGN may be an etiological factor in the development or on the activity of ulcerative colitis (UC). To test this hypothesis, we will study the duration of remission in patients with ulcerative colitis between patients who follow a diet in which CGN-containing foods are eliminated, and study participants who will be randomized to receive either a carrageenan supplement or a placebo. We will test how this difference in consumption of CGN affects the duration of remission and disease activity of UC. CGN is contained in a wide variety of food products, such as ice cream, processed meats, soymilk, yogurt, and whipped cream, but has no nutritional value. Study participants will complete questionnaires about their disease activity and medication use. Relapse will be defined as an increase in the SCCI score that quantifies ulcerative colitis disease activity in association with an increase in medications for UC. Patients will participate in the study for one year, during which time they will meet regularly with study investigators. In the laboratory, we have shown that CGN exposure activates inflammatory reactions, and laboratory tests will be performed to determine if there are differences between the two groups of patients. Since CGN is consumed in sufficient quantity in the Western diet to induce inflammation, it is relevant to test how CGN intake influences the clinical course of ulcerative colitis in patients and to consider if withdrawal of CGN from the diet may have a therapeutic role in inflammatory bowel diseases.