Background : Essential fatty acid supplementation has been found to ameliorate certain chronic inflammatory diseases. This effect is thought to be mediated through the modulation of eicosanoid synthesis. Pro-inflammatory eicosanoids have been implicated in ulcerative colitis.

Aim : To investigate the possible therapeutic benefit of essential fatty acids in quiescent ulcerative colitis to reduce the frequency of disease relapse.

Methods : A randomized, double-blind, placebo-controlled study was performed with a treatment duration of 12 months. Patients with quiescent disease received either trial medication (gamma-linolenic acid, 1.6 g, eicosapentaenoic acid, 270 mg, and docosahexaenoic acid, 45 mg, per day) or placebo (sunflower oil, 500 mg/day). The primary end-point was disease activity, assessed by a previously validated clinical index, sigmoidoscopic appearance and histology.

Results : Sixty-three patients were randomized, 31 to receive essential fatty acid treatment and 32 to receive placebo. Disease relapse rates were similar at 12 months (placebo, 38%; essential fatty acids, 55%), as were changes in sigmoidoscopic grade from baseline.

Conclusions : The supplementation of the diet with this combination of essential fatty acids does not prolong the period of disease remission of ulcerative colitis.