This Nutrition and Cancer article summarizes the connection between a Mediterranean dietary pattern and cancer risk in observational epidemiological studies. All studies that met the following criteria were reviewed: human cohort and case-control studies, which examined the effect of the Mediterranean diet as an entire food pattern (the combined effect of individual components of the Mediterranean diet). Out of the 12 reviewed studies (7 cohort and 5 case-control), 10 studies (6 cohort and 4 case-control) provided some evidence that the Mediterranean diet was associated with a reduced risk of cancer incidence or mortality.
Although the reviewed studies varied according to certain study characteristics, such as being set in different populations and studying different cancer outcomes, the existing evidence from observational studies overall suggest that there is a "probable" protective role of the Mediterranean diet towards cancer in general. Results for specific outcomes, such as different cancer sites, still need additional evidence.
This favorable and overall positive effect of the Mediterranean diet on cancer reduction is relevant to the current state of public health, given the tendency of modern societies to shift toward a more U.S. and Northern European dietary pattern.