Ulcerative colitis is a persistent condition that typically causes diarrhea, abdominal pain, decreased appetite and weight loss. Although the cause remains unknown, researchers suspect that the disease involves a complex interaction of factors, including heredity, the immune system and diet.
Researchers analyzed data from more than 200,000 adults who participated in the European Prospective Investigation into Cancer and Nutrition (EPIC). The participants completed food frequency questionnaires and were monitored for the development of ulcerative colitis.
During an average follow-up period of four years, 126 people developed ulcerative colitis.
A diet rich in a type of omega-6 polyunsaturated fatty acid called linoleic acid was associated with an increased risk of the disease. Linoleic acid is found in some margarines, red meat and cooking oils. The authors found that people who ate the most linoleic acid (13-38 grams daily) were 2.5 times more likely to develop ulcerative colitis than those who ate the least amount (2-8 grams daily).
The body converts linoleic acid into arachidonic acid, which may then be transformed into pro-inflammatory molecules. Elevated levels of these inflammatory molecules have been found in the colons of patients with ulcerative colitis.
In contrast, a high intake of the omega-3 fatty acid docosahexaenoic acid (DHA) was linked to a lower risk of ulcerative colitis. This fatty acid is found in fatty fish (such as mackerel and herring) and fish oil supplements. People who ate the most DHA were 77 percent less likely to develop ulcerative colitis than those who ate the least amount.
However, this study is limited by its design. Additional controlled trials are needed to fully understand the potential relationship between fatty acids and ulcerative colitis.
Although there is currently no cure for ulcerative colitis, several medications, including anti-inflammatories and immunosuppressants, are available to help alleviate symptoms. Various integrative therapies have also been studied as potential treatment options. For instance, good evidence suggests that various types of probiotics may help prevent relapses of ulcerative colitis.