A randomized, double-blind study of the effect of olestra on disease activity in patients with quiescent inflammatory bowel disease. Olestra in IBD Study Group.

PURPOSE: To determine the effects of olestra, a zero-calorie fat substitute that is neither digested nor absorbed, on the well-being and disease state of persons with chronic inflammatory bowel disease (IBD) in remission. PATIENTS AND METHODS: Eighty-nine patients with mild to moderate ulcerative colitis (n = 43) or Crohn's disease (n = 46) in remission, with a history of disease of 2 years or longer, were enrolled in this prospective study from nine private practices, three university-based medical centers, and one Veterans Administration medical center in the United States. Forty-four patients were randomly assigned to receive olestra and 45 to receive triglycerides in chips or cookies daily for 4 weeks. At Week 4, patients were classified as in remission, worsened, or relapsed according to an investigator's global assessment based on sigmoidoscopy (for ulcerative colitis) or the Crohn's disease activity index, laboratory findings, and clinical course. RESULTS: At Week 4, the olestra and triglyceride groups did not differ significantly with respect to the percentages of patients who relapsed (P = 0.494; difference = 2.4%; upper 95% CL = 8.8%) or with respect to the percentages of patients who experienced any worsening of their symptoms (P = 0.630; difference = 0.2%; upper 95% CL = 13.3%). Of evaluable patients, 90% (37 of 41) given olestra remained in remission with no worsening, compared with 90% (38 of 42) given triglycerides. Gastrointestinal symptoms were comparable between the treatment groups, and there were no treatment-related laboratory abnormalities. Six patients were excluded from analysis for reasons unrelated to treatment. CONCLUSION: Olestra did not affect the activity of quiescent mild to moderate IBD.

Randomized, double-blind, placebo-controlled, food allergy challenge to olestra snacks.

Following approval of the fat replacer olestra for use in preparing savory snacks, Procter & Gamble implemented a postmarketing surveillance program to monitor marketplace introduction. Three and one-half percent of all health effects reported by consumers to the surveillance toll-free number were allergy-type symptoms (e.g., rash, itching, edema, hives, dyspnea). Because of these reports, we investigated whether olestra or some component of olestra snacks was a likely allergen in some subset of the population. A single center, randomized, double-blind, placebo-controlled, within-subject crossover food challenge study was conducted to confirm or refute the allergenicity of olestra snacks. Of the 65 subjects who reported symptoms consistent with immediate hypersensitivity to olestra's postmarketing surveillance program, 14 men and women traveled to the Arkansas Children's Hospital Research Institute to participate in this study. Each subject underwent a standard skin prick test at the beginning of the study, to help determine what component, if any, of the olestra product was allergenic. Following the skin prick test, subjects ate in random order, olestra-containing potato chips and regular fat-containing potato chips. The dose of potato chips consumed at each challenge was at least the amount alleged to have caused the symptoms that prompted the consumer to phone the postmarketing surveillance toll-free number. No subject experienced an allergic reaction after consuming the olestra-containing chips. Nor did any subject elicit a positive response to olestra following the skin prick testing. Two subjects had positive reactions consistent with immediate hypersensitivity after consuming the regular-fat, placebo potato chips. The results of this study confirm that olestra is unlikely to have an allergenic potential.

Olestra's effect on vitamins D and E in humans can be offset by increasing dietary levels of these vitamins.

One hundred two normal healthy males and females were given 0, 8, 20 or 32 g/d olestra to which had been added graded amounts of vitamins A, D and E for 8 wk in a parallel, double-blind study. The primary purpose of the study was to determine the amounts of vitamins D and E needed to offset the effect of olestra on the availability of these vitamins. Serum concentrations of retinol, carotenoids, 25-hydroxyvitamin D metabolites, alpha-tocopherol, phylloquinone, lipids, ferritin and total iron, iron-binding capacity and hematology parameters, plasma concentrations of des-gamma-carboxyprothrombin and prothrombin, and urinary gamma-carboxyglutamic acid (Gla) excretion were measured biweekly. Clinical chemistry and urinalysis parameters, vitamin B12 absorption, and serum 1,25-dihydroxyvitamin D concentration were measured at wk 0 and 8. Serum concentrations of alpha-tocopherol and 25-hydroxyergocalciferol were restored to control concentration by adding 2.1 mg d-alpha-tocopheryl acetate and 0.06 microg ergocalciferol per gram of olestra, respectively, to the diet. Olestra reduced serum concentrations of 25-hydroxyergocalciferol, carotenoids and phylloquinone in a dose-responsive manner but did not affect Gla excretion, plasma des-gamma-carboxyprothrombin and prothrombin concentrations, overall vitamin D status, vitamin B12 absorption or iron status. Laboratory evaluations showed no olestra-related effects. Subjects in all groups reported mild to moderately severe transient gastrointestinal symptoms. These symptoms did not affect study compliance or the integrity of the data.