We previously demonstrated that a functional polymorphism in alcohol dehydrogenase type 1C (ADH1C, also known as ADH3) modifies the association between moderate alcohol consumption and high-density lipoprotein (HDL) levels and risk of myocardial infarction among older men. In this study, we investigated the effect of the ADH1C gamma(1) and gamma(2) alleles on the relationship between alcohol consumption and HDL levels among four populations with varied exposure to endogenous and exogenous estrogens: premenopausal women, middle-to-older aged men, postmenopausal women currently using postmenopausal hormones (PMH) and postmenopausal women not currently using PMH. We observed an interaction between moderate alcohol consumption and ADH1C genotype on HDL level that was similar among middle-to-older aged men and postmenopausal women not using PMH. Among the moderate drinkers (approximately a half a drink per day for women and a full drink per day for men), there was a significant 5.3mg/dL (P=0.02) higher level of multivariate adjusted HDL level comparing the gamma(2) homozygotes (slow oxidizers) to the gamma(1) homozygotes (fast oxidizers). This interaction was not present among premenopausal women or postmenopausal women using PMH, who had higher overall HDL levels irrespective of alcohol consumption. Our results confirm that ADH1C genotype modifies the association between alcohol consumption and HDL levels among men and postmenopausal women not using PMH who drink moderately. However, this was not observed among individuals with estrogen-elevated HDL levels, specifically premenopausal women and postmenopausal women taking PMH, suggesting that these populations may benefit less from alcohol consumption with respect to coronary heart disease.