I. Evaluate whether a dietary flaxseed intervention among post-menopausal women influences circulating levels of sex steroid hormones and estrogen metabolites (including estradiol, estrone, 2-hydroxy(OH)-/16-OH-estrone ratio, SHBG, testosterone, 2-MeOH-E1&-E2, 4-MeOH-E1&-E2) thought to be involved in the development of breast cancer.