Background: Evidence from epidemiological studies investigating associations between adherence to the Mediterranean diet and colorectal cancer is inconsistent. The aim of this study is to assess in the UK Women's Cohort Study whether adherence to the Mediterranean dietary pattern is associated with reduced incidence of cancers of the colon and rectum.
Method: A total of 35 372 women were followed for a median of 17.4 years. A 10-component score indicating adherence to the Mediterranean diet was generated for each cohort participant, using a 217-item food frequency questionnaire. The Mediterranean diet score ranged from 0 for minimal adherence to 10 for maximal adherence. Cox proportional hazards regression was used to provide adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for colon and rectal cancer risk.
Results: A total of 465 incident colorectal cancer cases were documented. In the multivariable adjusted model, the test for trend was positive (HR = 0.88, 95% CI: 0.78 to 0.99; Ptrend = 0.03) for a 2-point increment in the Mediterranean diet score. For rectal cancer, a 2-point increment in the Mediterranean diet score resulted in an HR (95% CI) of 0.69 (0.56 to 0.86), whereas a 62% linear reduced risk (HR 0.38; 95% CI: 0.20 to 0.74; Ptrend < 0.001) was observed for women within the highest vs the lowest category of the MD score. Estimates for an association with colon cancer were weak (Ptrend = 0.41).
Conclusions: Findings suggest that women adhering to a Mediterranean dietary pattern may have a lower risk of colorectal cancer, especially rectal cancer.
Keywords: Mediterranean; colonic neoplasms; diet; epidemiology; rectal neoplasms.
© The Author 2017; all rights reserved. Published by Oxford University Press on behalf of the International Epidemiological Association