Research from Dr. Walter Willett of Harvard University, Dr. Alice Lichtenstein of Tufts University, and the National Institute of Health and Nutrition in Japan confirms findings of the Food and Drug Administration (FDA) health claim for soy protein and heart disease.
Soy protein was shown to lower LDL (bad) cholesterol in the blood from 3-14 percent, depending on the starting point for blood cholesterol and the current diet and drug routine of individuals. Dr. Willett's study on women with metabolic syndrome appeared in the March edition of the "American Journal of Clinical Nutrition"; Dr. Lichtenstein's study on people with high blood cholesterol, and the meta-analysis conducted by the Japanese researchers, appear in the April issue of the same journal. These findings are consistent with results of many studies confirming that soy protein's cholesterol- lowering effects are modest, but important, for those concerned with heart health. Medical doctors and scientists contacted by the Soyfoods Association of North America (SANA) agree that for individuals who do not require cholesterol-lowering drugs, soy foods are among the smartest choices of foods that lower LDL cholesterol without any adverse effects.
"The cholesterol-lowering effect of soy is directly related to soy protein and other soy components, and not only to its low saturated fat content," notes Francene Steinberg, Ph.D., R.D. of University of California at Davis, regarding her editorial in the April issue of the "American Journal of Clinical Nutrition." "The science has not explained the exact mechanism by which soy improves cholesterol, but there is a clear benefit of including soy protein in a healthy diet."
David Jenkins MD, PhD, DSc. of the University of Toronto agrees, "Soy products are heart healthy for two reasons. First, they may make a significant reduction in cholesterol because of something in the soy itself, and second, they may displace saturated fat and cholesterol in the diet. It is the combined reduction due to soy itself and the reduction due to replacing other high-cholesterol foods that make soy food a heart healthy choice."