Oil in rice bran helps lower cholesterol, according to a study reported in the American Journal of Clinical Nutrition (January 2005). The researchers based their findings on the results of 2 studies.

The first study included 26 men and women randomly assigned to a low-fiber diet. The participants ate 22 g of fiber daily, or a high-fiber diet with defatted rice bran, in which they ate 2 times as much fiber as the other group. At the conclusion of the 5-week study, none of the participants showed significant changes in their overall blood cholesterol levels. The researchers were surprised to learn that the participants in the defatted rice bran group had elevated levels of low-density lipoprotein ("bad") cholesterol.

In the second 10-week study, which was broken into 5-week periods, 14 participants were followed on 2 diets. During the first 5-week period, the participants ate one third of their total dietary fat in the form of a blend of peanut oil, olive oil, corn oil, canola oil, palm oil, and butter. The second 5-week phase replaced the oil blend with rice bran oil. At the conclusion of the study, lead author, Marlene M. Most, PhD, said that the study participants'cholesterol levels were the lowest when their diets included rice bran oil.