Supplementation with n‐3 fatty acids from fish oil in chronic inflammatory bowel disease—a randomized, placebo‐controlled, double‐blind cross‐over trial

Abstract

Thirty‐nine patients with chronic inflammatory bowel disease were studied in a 7‐month, double‐blind, placebo controlled cross‐over trial of dietary supplementation with fish oil, which provided about 3.2 g n‐3 fatty acids per day. At control, biopsies from inflamed mucosa contained higher levels of arachidonic acid than uninvolved mucosa. Dietary n‐3 fatty acids were well tolerated and incorporated into plasma and enteric mucosa phospholipids at the expense of n‐6 fatty acids. The arachidonic acid‐derived prostanoid generation was reduced by fish oil and the extension and severity of macroscopic bowel involvement was moderately improved. In patients with Crohn's disease, clinical activity was unchanged by fish‐oil supplementation. In patients with ulcerative colitis, clinical disease activity fell during fish oil supplementation and thereafter: this was not significant however. Despite a moderate reduction in inflammatory lipid mediators by dietary n‐3 fatty acids and limited morphological improvement in chronic inflammatory bowel disease, the clinical benefit seems to be confined to patients with ulcerative colitis.