Fatty Foods Bad for Bowel

Too Much Linoleic Acid From Red Meat, Fried Foods May Raise Risk of Ulcerative Colitis

Medically Reviewed by Louise Chang, MD on July 22, 2009
From the WebMD Archives

July 22, 2009 -- Too many burgers and fries may be bad for your bowel.

A new study shows that people who eat a diet high in linoleic acid, a type of omega-6 polyunsaturated fatty acid found in red meat and fried foods, may be more likely to develop a serious bowel condition known as ulcerative colitis.

Researchers found that people whose diets contained the most linoleic acid were nearly two and a half times more likely to develop ulcerative colitis than those who ate the least.

Ulcerative colitis is an inflammatory bowel disease in which the lining of the large intestine becomes inflamed and ulcerated, causing symptoms including abdominal pain, diarrhea, and bleeding. The cause of the condition is unknown, but researchers say diet may play a role.

In contrast, the same study also showed that people who ate diets rich in another type of polyunsaturated fat, omega-3 fatty acid (docosahexaenoic acid), had a 77% lower risk of developing ulcerative colitis. Omega-3 fatty acids are found naturally in oily fish like salmon and herring and are believed to have a number of beneficial health effects.

“Bad” Fat Hurts Bowel

Linoleic acid is an essential omega-6 fatty acid that is converted to arachidonic acid in the body. Arachidonic acid is found in the membranes of cells lining the large intestine and can be converted into various inflammation-causing chemicals. High levels of these inflammatory chemicals have been found in the bowel tissue of people with ulcerative colitis.

The study, published in the journal Gut, looked at the relationship between eating a diet high in linoleic acid and risk of ulcerative colitis in more than 200,000 adults 30-74 years old from the U.K., Germany, Italy, Sweden, and Denmark. The participants were part of a European cancer study and kept food diaries.

Over a four-year period, researchers found that 126 people developed ulcerative colitis. After adjusting for different variables, researchers found those whose diets had the most linoleic acid were almost 2.5 times more likely to develop ulcerative colitis than those who had the least.

Researcher Andrew Hart, MD, of the University of East Anglia in Norwich, England, and colleagues say if this association holds true as a cause, nearly a third of ulcerative colitis cases could be attributed to high consumption of linoleic acid and ulcerative colitis could be prevented by changing people’s diets.

Show Sources


Hart, A. Gut, July 2009, online first edition. 

News release, BMJ Specialist Journals.

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