Cholesterol Lowering Effects Of Rice Bran Are Not Due To Fiber Content

Category: Conditions of the Circulatory System

Rice bran has recently gained interest as a cholesterol lowering food due to the popularity and efficacy of oat bran as a cholesterol-lowering agent. The beta glucan content of oat bran is responsible for its cholesterol lowering ability. However, rice bran does not contain high amounts of beta glucan, but does contain high amounts of saturated fats. Saturated fats are known to contribute to increased cholesterol, and are not protective.

A study found that rice bran lowered cholesterol when added to the diet of individuals with mild to moderate hypercholesterolemia. However the mechanisms that were involved were poorly understood, except that it was believed to be different than that of oat bran.

A recent study published in the American Journal of Clinical Nutrition was aimed at determining the mechanism and compounds in rice bran that may be responsible for the cholesterol lowering effects.

The study was organized in a parallel fashion, testing rice bran, defatted rice bran, and rice bran oil. The control groups had similar intakes of fiber and fatty acids. The variables that were measured at outcome included total cholesterol, LDL, and HDL.

The study found that the rice bran oil, and not the fiber, was responsible for the cholesterol lowering effects. It also found that the fatty-acid composition of rice bran oil, which is high in oleic and linoleic acids, is not responsible. The responsible compounds seem to be the unsaponified molecules, including phytosterols, tocopherols, tocotrienols, and triterpene alcohols.

This study represents an important step in understanding the role that rice bran has in lowering cholesterol. Foods that contain rice bran oil may become important for cardiovascular health, as well as the development of functional foods that contain the active components in rice bran oil.

Posted by on November 25, 2008 10:00 AM