Inflammatory Bowel Disease Linked to Fatty Acids in Red Meats and Margarines

A study following more than 200,000 people in five countries suggests that one’s risk for developing ulcerative colitis, a type of inflammatory bowel disease, may be linked to a particular omega−6 fatty acid in the diet. The omega−3 fatty acids in fish and flaxseed oils, however, was associated with a greatly reduced risk for developing the disease.

The researchers, led by Andrew Hart at the University of East Anglia, Norwich, analyzed food diaries kept by the participants and assessed the quantity of a fatty acid called linoleic acid they consumed. This type of unsaturated fatty acid is found in some margarines, red meats, and in the oils of nuts and seeds, like safflower, walnut, sunflower, and grape seed oils, to name just a few.

On the other hand, participants who ate the most omega-3 fatty acids were at a 77% reduced risk of developing the disease.

By the end of the study, 126 people had developed ulcerative colitis. Those who consumed the most linoleic acid had about double the risk of developing the disease as those who consumed the least. On the other hand, participants who ate the most omega−3 fatty acids were at a 77% reduced risk of developing the disease. This study adds to the long list of health benefits linked to omega−3 fatty acids.

What is the mechanism behind the increased risk associated with linoleic acid? The body converts linoleic acid into arachidonic acid, which is used as a building block for cell membranes in the bowel. However, arachidonic acid can be converted into a variety of other molecules which cause inflammation in the bowel. Higher levels of these harmful chemicals are found in the bowel cells of individuals who suffer from ulcerative colitis.

Researchers have been unclear in the past as to specific environmental risk factors for ulcerative colitis. The disease is characterized by ulcers and inflammation in the colon, which can cause considerable pain and diarrhea. Though there is no cure for the ulcerative colitis, there are therapies that greatly reduce the symptoms and may actually put the patient into remission.

Hart sums up his findings by saying that "[t]here are no dietary modifications of benefit in patients with ulcerative colitis, although, based on this study's findings, a diet low in linoleic acid may merit investigation."