Pick Brown Rice to Protect Your Heart

Reported April 30, 2010

(Ivanhoe Newswire) – Brown is better when it comes to rice, according to researchers. Brown rice may have the added advantage over white rice of offering protection from high blood pressure and atherosclerosis ("hardening of the arteries").

New research by Satoru Eguchi, Associate Professor of Physiology at the Cardiovascular Research Center and Department of Physiology at Temple University School of Medicine, Philadelphia, suggests that a component in a layer of tissue surrounding grains of brown rice may work against angiotensin II. Angiotensin II is an endocrine protein and a known culprit in the development of high blood pressure and atherosclerosis.

The subaleurone layer of Japanese rice, located between the white center of the grain and the brown fibrous outer layer, is rich in oligosaccharides and dietary fibers, making it particularly nutritious. However, when brown rice is polished to make white rice, the subaleurone layer is stripped away and the rice loses some of its nutrient value.

The Temple team and their colleagues at the Wakayama Medical University Department of Pathology and the Nagaoka National College of Technology Department of Materials Engineering in Japan sought to delve into the mysteries of the subaleurone layer to make a case for leaving it intact when rice is processed. Because angiotensin II is a perpetrator in such lethal cardiovascular diseases, the team chose to focus on learning whether the subaleurone layer could somehow inhibit angiotensin II before it wreaks havoc.

During their analysis, the team found that subaleurone components that were selected by an ethyl acetate extraction inhibited angiotensin II activity in the cultured vascular smooth muscle cells. This suggests that the subaleurone layer of rice offers protection against high blood pressure and atherosclerosis. It could also help explain why fewer people die of cardiovascular disease in Japan, where most people eat at least one rice-based dish per day, than in the U.S., where rice is not a primary component of daily nutrition.

"Our research suggests that there is a potential ingredient in rice that may be a good starting point for looking into preventive medicine for cardiovascular diseases," Dr. Eguchi was quoted as saying. "We hope to present an additional health benefit of consuming half-milled or brown rice [as opposed to white rice] as part of a regular diet."

Source: Presented at the annual Experimental Biology conference, Anaheim, CA, April 24-28, 2010.