Randomized monkey trial study design. CL diet (n=37), Casein-Lactalbumin (CL) protein based atherogenic diet (0.28 mg cholesterol/Cal); Soy diet (n=34), soy protein based atherogenic diet (0.28 mg Cholesterol/Cal) (treatment diet). CL-CL (Control Group, n=20), animals fed CL diet pre and postmenopausally; Soy-Soy (n=17), animals fed Soy diet pre and postmenopausally; Soy-CL (n=17), animals fed Soy diet premenopausally and were switched to eat CL diet postmenopausally; CL-Soy (n=17), animals fed CL diet premenopausally and were switched to eat Soy diet postmenopausally.