Several mechanistic studies in cell culture and mouse models suggest possible estrogen receptor-mediated and non-estrogen receptor-mediated benefits of pomegranate juice with respect to breast cancer risk. These studies demonstrate that various constituents of pomegranates can inhibit aromatase and 17beta-hydroxysteroid dehydrogenase enzymes or have antiestrogenic activity. Additional large, well-controlled human studies are warranted to elucidate the effects of pomegranate juice intake on serum hormone levels. Clarifying the effects of pomegranate constituents on key hormones known to be involved in breast cancer could result in important information for consumers and shed further light on the impact of diet on breast cancer risk.