Not enough evidence for omega-3 bowel benefit, says study
effect on patients suffering from inflammatory bowel disease (IBD)
such as Crohn's disease and ulcerative colitis, but scientists from
California are disputing a firm link on the grounds that there is
not enough evidence.
Formulating with omega-3, from marine or vegetable sources, is one of the hottest trends in the food industry at the moment. ProductScan data indicates that this year foods fortified with omega-3 fatty acids are on track for 70 percent growth over 2004, with 109 new market entrants up until May 31 compared with 170 for the whole of last year. The main driving force behind the trend has been the thousands of studies into the fatty acid's role in warding off a number of health conditions, including heart disease and cognitive decline, and in aiding children's development. But in the case of inflammatory bowel disease, it seems there is a dearth of studies looking into the link. Those that have, have reported mixed results. In order to find out whether omega-3 fatty acids affect clinical outcomes in IBD, influence the need for other agents or modify their effects, researchers from the Southern California Evidence-Based Practice Center sought out studies published between 1966 and 2003 that investigated the clinical, sigmoidoscopic (visual inspection of the sigmoid colon) or histologic (microscopic structure of tissue) effects of omega-3; looked at rates of remission or relapse; or participants' needs for steroids and other immunosuppressive agents. Despite efforts to identify unpublished studies in the area, none were found. Although the researchers said that most of the clinical trials were good quality, less than six assessed the effects of omega-3 on any single clinical, endoscopic, or histologic outcome, or remission or relapse rates. What is more, while three of the studies found omega-3 to reduce the need to take corticosteroids, in only one of these was the effect statistically significant. The researchers concluded that: "The available data are insufficient to draw conclusions about the effects of omega-3 fatty acids on clinical, endoscopic, or histologic scores or remission or relapse rates." Earlier this year the publication of a new, large study shed light on the role of fish, the richest natural source of omega-3, in preventing colorectal cancer. In a study published in the Journal of the National Cancer Institute (vol 97, no 12), researchers reported that eating 100 grams of fish daily reduces the disease risk by half. People eating less than 14g of fish a day were 40 per cent more likely to develop the cancer than those eating more than 50g per day, the researchers report. These results were said to contradict other recent prospective studies on colorectal cancer, which failed to confirm earlier observations that fish might be protective. External links to companies or organisations mentioned in thisstory: ProductScan Online