Adherence to Mediterranean Diet and Risk of Breast Cancer in Premenopausal and Postmenopausal Women

BACKGROUND: Mediterranean diet (MD) has long been suspected to impact on health promotion. Epidemiologic studies reveal the protective role of adherence to this dietary pattern on cancer incidence. However, its association with breast cancer risk remains unclear. Therefore, we aimed to investigate whether adherence to Mediterranean dietary pattern influence on breast cancer risk in postmenopausal and premenopausal women. METHODS: We performed an electronic search of published studies earlier than Apr 2015 using Pubmed, Google scholar, Cochrane and Scopus databases. The search terms included: breast neoplasm, breast tumors, mammary carcinoma, mammary neoplasm, breast cancer, and Mediterranean diet. Study inclusion criteria were: 1) written in English; 2) with a study arm of MD intervention or MD style assessment; 3) reported the BC risk in premenopausal and postmenopausal women. RESULTS: We summarized the findings of 8 studies in this review, including five cohorts and three case-control studies. Although, cohort studies reported controversial results in this field, case-control studies resulted inverse relation between this Mediterranean dietary pattern and breast cancer risk in pre or/and postmenopausal women. CONCLUSIONS: It seems that there is no sufficient data to reach a conclusion about the effect of MD on breast cancer risk in pre and postmenopausal, but there are some evidences suggesting the protective association. More cohort studies in different parts of the world are needed to confirm these results.