 The study was a double blind, parallel group, randomized clinical trial. A total of 160 healthy postmenopausal women 50 percent African-American with LDL cholesterol between 130 mgdL and 190 mgdL were enrolled. Following a pre-randomization run-in period on a NCEP Step I diet, women were randomized to receive soy containing isoflavones or casein dietary supplements for 3 months. Major outcome variables were assessed in both groups at baseline and again at 3 months. It was hypothesized that soy supplementation would result in significantly greater reduction in LDL cholesterol, LDL particle concentration, and prevalence of dense LDL particles and improvement in menopausal quality of life compared with placebo and that these effects would be comparable in African-Americans and whites. This was the first study to determine whether a natural plant product could ameliorate the unfavorable changes in known and novel lipid risk factors that are a consequence of menopause in both African-American and white women. The unique transitional outcomes explored in this study added substantially to the limited body of knowledge of the effects of soy. Evaluation of this nutritional alternative to hormone replacement therapy HRT that may provide a beneficial effect on lipid risk factors and menopausal symptoms but would be free of the adverse effects on triglycerides, the breast and uterus, and thrombotic events associated with HRT could have significant public health implications for postmenopausal women. 