Diet, obesity and breast cancer: an update.

Numerous studies indagated the relationship between dietary pattern or specific nutrients and breast cancer (BC) risk and survival. Different ethnic o social groups show differences in breast cancer incidence that could be explained by different dietary patterns. Furthermore, many nutrients could reasonably increase the risk of cancer because of their content of carcinogens or their precursors as well as of promoting substances. However, the only convincing evidences linking life style to increased BC risk are related to obesity and moderate intake of alcohol and limited to postmenopause. Saturated fat, red meat, high temperature cooking have been indicated as possible risk factors, but adjusted analyses have not confirmed this association or have limited the relationship to specific subgroups. Even the protective effect of fiber, fruit, vegetables and phytoestrogens has been suggested but not definitively demonstrated. Thus, healthy dietary patterns, with abstention from alcohol and weight control, reduce the risk of cancer or at least improve the survival of affected women by reducing the incidence of comorbidities.