To assess if the associations found between three previously identified dietary patterns with breast, prostate and gastric cancer are also observed for colorectal cancer (CRC).

MCC-Spain is a multicase-control study that collected information of 1629 incident cases of CRC and 3509 population-based controls from 11 Spanish provinces. Western, Prudent and Mediterranean data-driven dietary patterns—derived in another Spanish case-control study—were reconstructed in MCC-Spain. Their association with CRC was assessed using mixed multivariable logistic regression models considering a possible interaction with sex. Risk by tumor site (proximal colon, distal colon, and rectum) was evaluated using multinomial regression models.

While no effect of the Prudent pattern on CRC risk was observed, a high adherence to the Western dietary pattern was associated with increased CRC risk for both males [OR_{fourth(Q4) vs. first(Q1)quartile} (95% CI): 1.45 (1.11;1.91)] and females [OR_{Q4 vs. Q1} (95% CI): 1.50 (1.07;2.09)] but seem to be confined to distal colon [OR_{fourth(Q4) vs. first(Q1)quartile} (95% CI): 2.02 (1.44;2.84)] and rectal [OR_{Q4 vs. Q1} (95% CI): 1.46 (1.05;2.01)] tumors. The protective effect of the Mediterranean dietary pattern against CRC was observed for both sexes [males: OR_{Q4 vs. Q1} (95% CI): 0.71 (0.55;0.92); females: OR_{Q4 vs. Q1} (95% CI): 0.56 (0.40;0.77)] and for all cancer sites: proximal colon [OR_{Q4 vs. Q1} (95% CI): 0.70 (0.51;0.97)], distal colon [OR_{Q4 vs. Q1} (95% CI): 0.65 (0.48;0.89)], and rectum (OR_{Q4 vs. Q1} (95% CI): 0.60 (0.45;0.81)].

Our results are consistent with most of the associations previously found between these patterns and breast, prostate and gastric cancer risk and indicate that consuming whole fruits, vegetables, legumes, olive oil, nuts, and fish and avoiding red and processed meat, refined grains, sweets, caloric drinks, juices, convenience food, and sauces might reduce CRC risk.