n-3 Fatty acids are purported to have health effects in patients with inflammatory bowel disease (IBD), but studies have reported mixed results.
We aimed to synthesize published and unpublished evidence to determine estimates of the effect of n-3 fatty acids on clinical outcomes in IBD and whether n-3 fatty acids modify the effects of or need for treatment with other agents.
Computerized databases were searched for studies of n-3 fatty acids in immune-mediated diseases from 1966 to 2003. We also contacted experts in the nutraceutical industry to identify unpublished studies; however, none were identified.
Reviewers identified 13 controlled trials that assessed the effects of n-3 fatty acids on clinical, sigmoidoscopic, or histologic scores; rates of induced remission or relapse; or requirements for steroids and other immunosuppressive agents in Crohn disease or ulcerative colitis. Most clinical trials were of good quality. Fewer than 6 were identified that assessed the effects of n-3 fatty acids on any single outcome of clinical, endoscopic, or histologic scores or remission or relapse rates. Consistent across 3 studies was the finding that n-3 fatty acids reduce corticosteroid requirements, although statistical significance was shown in only 1 of these studies.
The available data are insufficient to draw conclusions about the effects of n-3 fatty acids on clinical, endoscopic, or histologic scores or remission or relapse rates.