Mediterranean diet and colorectal cancer risk: a pooled analysis of three Italian case-control studies

Adherence to the Mediterranean diet (MD) is associated with a reduced risk of several cancers. However, studies conducted in Mediterranean regions are scanty.

To investigate the relation between MD and colorectal cancer risk in Italy, we pooled data from three case-control studies, including a total of 3745 colorectal cancer cases and 6804 hospital controls. Adherence to the MD was assessed using an a priori Mediterranean Diet Score (MDS), based on nine components.

Compared with the lowest adherence to the MD (0-2 MDS), the odds ratio (OR) was 0.52 (95% confidence interval (CI) 0.43-0.62) for the highest adherence (7-9 MDS), with a significant inverse trend in risk (P<0.0001). The OR for a 1-point increment in the MDS was 0.89 (95% CI 0.86-0.91). The inverse association was consistent across studies, cancer anatomical subsites and strata of selected covariates.

This Italian study confirms a favourable role of MD on colorectal cancer risk.