Effect of the Mediterranean Diet on Cancer Reduction

Abstract

The Mediterranean diet is a plant-based dietary pattern characterized by high intake of olive oil, legumes, whole grains, fruit, vegetables, nuts, seeds, fish, and red wine. The diet has been linked to a decreased risk of developing many non-communicable diseases including several types of cancer. Although findings have been somewhat inconsistent, several large prospective cohort studies have shown an association between greater adherence to a traditional Mediterranean diet and lower overall cancer incidence. When specific forms of cancer are examined, current research suggests a stronger association with some types and a weaker or non-existent relationship with others. Existing literature is equivocal on the association between the Mediterranean diet and breast cancer, but studies are heterogeneous in menopausal status and tumor hormone receptor status. For colorectal cancer, data is reasonably consistent to suggest that adherence to the Mediterranean diet is associated with a reduced risk, although more studies are needed to confirm and refine the relationship. Evidence for a protective association of a Mediterranean dietary pattern on upper gastrointestinal cancers is quite consistent and suggests that the Mediterranean diet is associated with a reduction of risk. It should be noted that due to the small number of studies, more data, especially from non-European countries, is needed. Suggested mechanisms through which the Mediterranean diet may impact cancer initiation and proliferation include increased insulin sensitivity and reduction of excess insulin production, anti-inflammatory and antioxidant effects of the diet, high fiber content and an association with reduced risk of excess weight gain and obesity.