Legumes Helpful in Cutting Risk of Colorectal Rectal Cancer

Legumes, the food family that includes beans, lentils, and peas, digest more slowly than other foods, and thus produce a substance in the colon that helps reduce the risk of cancer, according to University of Illinois researchers.

Their report in the Journal of Nutrition notes that most food is digested earlier in the digestive tract, usually in the small intestine, so the process is nearly complete by the time it reaches the colon.But foods that resist digestion longer produce a compound, as they digest in the colon, called butyrate, a short-chained fatty acid.

The researchers said butyrate is "desirable for its cancer-preventing qualities."

Legumes top the list of foods with the highest percentage of starch that prolongs digestion in this way. Black beans are the best of the legumes in this regard, with 63 percent of their total starch being resistant starch. Other types of beans range down to 60 percent resistant starch, followed by cereal grains, which measure from 33 percent for barley to 15 percent for white rice. As other examples from the study, rolled oats are 15 percent resistant starch, and corn 13 percent.

"The nice thing about legumes is that they have a great deal of dietary fiber plus the resistant starch. You always think of legumes for their protein, as you should. With their protein, fiber and resistant starch, these foodstuffs offer good nutrition," said George C. Fahey, Jr., who led the study.

"Until now, we never knew legumes had so much of their starch in the form of resistant starch," he said.

Other sources: Journal of Nutrition