Omega-3 fatty acids are seemingly useless in preventing relapse of Crohn's disease, researchers from the Robarts Research Institute at The University of Western Ontario in London, Canada have suggested.
Found in fatty fish such as salmon, mackerel, herring and sardines, omega-3 fatty acids have an anti-inflammatory effect and are therefore used in the treatment of inflammatory disorders such as rheumatoid arthritis and IgA nephropathy (a kidney disease).
"A significant amount of time and money is spent annually on alternative therapies such as Omega-3 fatty acids, without strong evidence that they are beneficial to patients with inflammatory bowel disease," said lead author Dr. Brian Feagan of Robarts Research Institute at The University of Western Ontario in London, Canada.
"I encourage Crohn's patients to focus on prescription medications that we know are effective for preventing relapse of disease, such as azathioprine, methotrexate, and TNF blockers," he added.
Researchers said that there is a widespread belief among patients and health care providers that omega-3 fatty acids are effective treatment for inflammatory bowel disease.
They said that the belief might have stemmed from a relatively small Italian research study, published in 1996 in the New England Journal of Medicine, which found a benefit for preventing relapse of Crohn's disease.
"Small, single centre clinical trials often overestimate the true effects of treatment. That's why it is important to conduct large-scale, randomized, multi-centre studies in order to confirm preliminary results," Dr. Feagan said.
The new study included two large-scale trials involving 738 Crohn's patients at clinical centres in Europe, Israel, Canada, and the United States from January 2003 to February 2007.
Both trials showed that the omega-3 fatty acid formulation offered no benefit in preventing relapse in Crohn's disease.
Researchers however found that patients who took the omega-3 fatty acid preparation did have significantly lower concentrations of triglycerides, a high level of which is a risk factor for heart disease.
The study is published in the April 9 Journal of the American Medical Association.