Ulcerative colitis, a common form of inflammatory bowel disease, is accompanied by an increased level of leukotriene B4 in the lining of the colon. Fish oils are known to inhibit the synthesis of leukotrienes and it has therefore been postulated that they might be beneficial in the treatment of ulcerative colitis. Researchers at the Veterans Affairs Medical Center have just released the results of a study aimed at testing this hypothesis.

The study involved 11 male patients aged 31 to 74 years who had been diagnosed with ulcerative colitis. The patients were randomized into two groups with one group receiving 15 fish oil capsules (providing 2.7 grams of eicosapentaenoic acid (EPA) and 1.8 grams of docosahexaenoic acid (DHA) daily); the other group received placebo capsules (olive oil). After 3 months on the supplements all participants underwent a 2-month wash-out period and were then assigned to the opposite treatment to what they had received during the first stage for another 3 months. Clinical evaluations of all patients were performed at the start of the study and every month thereafter.

Evaluation of the patients' clinical data at the end of the treatment periods showed a significant beneficial effect of fish oil supplementation. The mean disease severity score for the patients on fish oil declined by 56% as compared to 4% for the placebo group. Eight of the 11 patients (72%) were able to markedly reduce or totally eliminate their use of anti-inflammatory medication and steroids while taking the fish oils.

The researchers conclude that fish oil supplementation results in a marked clinical improvement of active mild to moderate ulcerative colitis.