 A total of 222 healthy postmenopausal women 46 to 80 years old without CVD symptoms will be randomized to receive either micronized 17B-estradiol Estrace 1mgday, or a matching placebo tablet daily. All women will be on a low fatlow cholesterol diet, and will receive pravastatin if their LDL cholesterol level exceeds 160 mgdL. Participants will undergo ultrasonography at baseline and every 6 months throughout the 2 years of randomized treatment. Measurements of lipid and non-lipid biochemical markers will also be done at baseline and every 6 months. 