Breast Cancer Risk and the Traditional Mediterranean Diet: New Findings
A recent study published in the American Journal of Clinical Nutrition is the first to report findings on the associations of the traditional Mediterranean diet with breast cancer risk within a Mediterranean country. Trichopoula et al note the historical emergence of previous research suggesting a number of relations between a Mediterranean dietary pattern and several health outcomes; including total mortality, cardiovascular disease risk, and overall cancer risk. In the United States, cohort studies have observed relations between Mediterranean dietary patterns and reduction in breast cancer risk. Here, Trichopoula et al evaluated breast cancer risk in the context of cohort in Greece; where in great part the traditional Mediterranean diet is still followed.
Researchers followed 14,807 women participating in the European Prospective Investigation into Cancer and nutrition (EPIC) cohort in Greece over an average period of 9.8 years. In that time they identified 240 breast cancer incidence cases. In the validated food frequency questionnaires participant conformity to the traditional Mediterranean diet was based on a scale ranging from 0-9 points, based on 9 typical dietary components. Those with maximal adherence scored 9 while minimal to zero adherence scored 0.
Notably, no significant associations were observed between conformity to this dietary pattern and breast cancer risk in premenopausal women. Among postmenopausal women, however, a Trichopoula found evidence that conformity to the traditional Mediterranean diet is associated with a lower risk of breast cancer. This, they note, may explain the lower incidence of breast cancer in Mediterranean women relative to populations in the United States and other countries. They acknowledge previously proposed physiologic mechanisms to explain the protective effects of this dietary pattern rich in whole foods, including, among others, the role of various flavonoids and antioxidants, the reduction of endogenous estrogens and the increased level of sex hormone binding globulin.
Study: Trichopoula, A., Am J Clin Nutr, 92: 620-625 (2010)