WEBMD - A popular ingredient in the American diet has been linked to ulcerative colitis, a type of inflammatory bowel disease marked by a chronically inflamed large intestine. The ingredient is soybean oil, which is very common in processed foods. In fact, U.S. per capita consumption of soybean oil increased more than 1,000-fold during the 20th century.
In a study from the University of California Riverside and UC Davis, mice fed a diet high in soybean oil were more at risk of developing colitis.
The likely culprit? Linoleic acid, an omega-6 fatty acid that comprises up to 60% of soybean oil.