Brown Rice Protein Heart Healthy

ANAHEIM, Calif.Brown rice may protect against high blood pressure and atherosclerosis (hardening of the arteries), according to researchers at the Cardiovascular Research Center and Department of Physiology at Temple University School of Medicine in Philadelphia.

New research by Satoru Eguchi, associate professor of physiology, suggests 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, which is 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 nutrients. The subaleurone layer can be preserved in half-milled (Haigamai) rice or incompletely-milled (Kinmemai) rice.

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 investigated whether the subaleurone layer could somehow inhibit angiotensin II before causes cardiovascular disease (CVD).

First, the team removed the subaleurone tissue from Kinmemai rice. Then they separated the tissue's components by exposing the tissue to extractions of various chemicals such as ethanol, methanol and ethyl acetate. The team then observed how the tissue affected cultures of vascular smooth muscle cells. Vascular smooth muscle cells are an integral part of blood vessel walls and are direct victims of high blood pressure and atherosclerosis.

During their analysis, the team found 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.

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, said Dr. Eguchi. 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.