Postdiagnostic Mediterranean and Healthy Nordic Dietary Patterns Are Inversely Associated with All-Cause Mortality in Long-Term Colorectal Cancer Survivors

Abstract

BackgroundDietary factors are known to affect the risk of new-onset colorectal cancer (CRC), but information on the extent to which postdiagnostic diet affects mortality in long-term CRC survivors is scarce. ObjectiveWe investigated the association of 2 a priori–defined postdiagnostic dietary patterns [Modified Mediterranean Diet Score (MMDS) and healthy Nordic Food Index (HNFI)] with all-cause mortality in long-term CRC survivors. MethodsDiet was assessed at a median time of 6 y after cancer diagnosis in 1404 CRC survivors (median age: 69 y; 56% men) in a prospective cohort study in Northern Germany by using a semiquantitative food-frequency questionnaire. Cox proportional hazard models, adjusting for clinical and sociodemographic characteristics, were used to assess associations of the MMDS and the HNFI with all-cause mortality. ResultsA total of 204 patients died during a median follow-up time of 7 y after diet assessment. In multivariable-adjusted models, higher adherence to the modified Mediterranean diet was significantly associated with lower all-cause mortality (HR: 0.48; 95% CI: 0.32, 0.74 for highest compared with lowest score quartile and HR: 0.88; 95% CI: 0.81, 0.96 per 1-point increment in pattern score). Similarly, the HNFI was inversely associated with all-cause mortality when the highest was compared with the lowest index quartile (HR: 0.63; 95% CI: 0.39, 1.04) and when modeled as a continuous trait (HR: 0.90; 95% CI: 0.82, 0.99 per 1-point increment in the score). ConclusionOur results suggest that higher adherences to the Mediterranean diet and to the healthy Nordic diet after CRC diagnosis are associated with better overall survival in long-term CRC survivors.