Moderate alcohol consumption and estrogen levels in postmenopausal women: a review

This report reviews the literature to evaluate association between moderate alcohol consumption and estrogen levels in healthy postmenopausal women. Of the eight studies available in literature on postmenopausal women who were not on estrogen therapy, two analyzed urine samples and six analyzed blood samples for estrogen levels. Of the two urine sample studies, only one reported positive association (p < 0.05) between alcohol consumption and estrogen (estrone and estradiol) levels that increased by 16 to 20%. Of the six blood sample studies, only two--one in American women and one in European women--reported significant increases (p < 0.05) in estradiol levels in response to alcohol consumption. In the American women study, estradiol levels increased only with wine and not with beer or whiskey. In the European women study, estradiol levels increased in Danish and Portuguese women, but not in Spanish women. Thus, further studies are required to establish correlation between moderate alcohol consumption and estrogen levels in postmenopausal women. Of the two studies on postmenopausal women who were on estrogen replacement therapy, one administered estradiol through transdermal patch (0.15 mg) and one orally (1 mg/day). In both studies, blood estradiol levels were measured after administering a single dose of ethanol orally (0.7-0.75 g/kg of body weight). Estradiol levels were increased by 22 and 300% in the transdermal patch and oral studies, respectively. These results suggest that alcohol consumption may increase blood estradiol levels in postmenopausal women who are on estrogen replacement therapy, and this may increase the risk of breast cancer.