Current evidence on the protective effect of dietary polyphenols on breast cancer

Epidemiological studies suggest that regular consumption of polyphenols, commonly contained in fruits and vegetables, is associated with a reduced risk of breast cancer (BC). Many epidemiological evidences suggest that the beneficial effect of a dietary pattern is attributable, at least in part, to phytochemicals which have antioxidant and antiproliferative activities. Since polyphenols are known to possess these properties, they have been hypothesized to contribute to the lower incidence of breast cancer. In this review the findings of 12 studies, including six case-control and six cohort studies are summarized and discussed. The results suggest that it is not yet possible to assess with certainty the effect of the Mediterranean diet (MD) on breast cancer (BC) risk in relation also to the individual characteristics such as genetic susceptibility, menopausal status, lifestyle and epigenetic modifications. Given the current evidences, further epidemiological studies on the relationship between polyphenols intake and BC risk are required.