The fat substitute olestra is a mixture of hexa-, hepta- and octaesters of sucrose that are formed from any edible oil. It is not absorbed from the intestines and therefore contributes no calories to the diet. It has been shown to be safe for consumption in healthy volunteers. However, other food additives, such as sorbitol, have been found to be associated with gastrointestinal distress in patients with certain types of bowel disease. Zorich and colleagues prospectively evaluated changes caused by olestra in the disease state of patients who were undergoing remission of certain types of chronic inflammatory bowel disease.

Adult patients were included in the study if they had a history of mild to moderate Crohn's disease or ulcerative colitis for at least two years and if the disease was in remission at the beginning of the study period. Patients who had had more than three relapses in the past year were excluded. Patients in the study group were not currently receiving oral or topical (rectal) steroid therapy or mesalamine suppositories and were not taking more than 3.5 g of sulfasalazine treatment per day. Patients were randomized to eat either 20 g of olestra-containing snacks and cookies or conventional vegetable triglyceride-containing snacks and cookies daily for 28 to 31 days. Patients were evaluated weekly by telephone or at the study site and were also interviewed four weeks after they last consumed the study product or conventional product. Patients kept track of their consumption of the assigned product and their well-being and disease state.

Forty-three patients with ulcerative colitis and 46 patients with Crohn's disease were included in the study, and 83 of these patients were available for inclusion in the final analysis. Forty-four patients were assigned to the olestra group and 45 were assigned to the triglyceride group. There was no significant difference in the number of patients who relapsed or had worsening symptoms. Three patients in the olestra group (7 percent) versus four patients in the triglyceride group (10 percent) had worsening symptoms without relapse. One patient in the olestra group (2 percent) relapsed, compared with no relapses in the triglyceride group. A few patients experienced increases in stool frequency or other gastrointestinal symptoms several weeks after the consumption period, but none of these symptoms appeared to be related to the ingestion of olestra. A total of 27 patients in the olestra group (61 percent) had adverse events, compared with 64 percent of the triglyceride group.

The authors conclude that 20 g of olestra ingested daily for one month does not affect the disease activity of patients with quiescent inflammatory bowel disease.