Empirically-derived food patterns and the risk of total mortality and cardiovascular events in the PREDIMED study

Abstract

Background & aims: There is little evidence on post hoc-derived dietary patterns (DP) and all-cause mortality in Southern-European populations. Furthermore, the potential effect modification of a DP by a nutritional intervention has not been sufficiently assessed. We assessed the association between a posteriori defined baseline major DP and total mortality or cardiovascular events within each of the three arms of a large primary prevention trial (PREDIMED) where participants were randomized to two active interventions with Mediterranean-type diets or to a control group (allocated to a low-fat diet).Design: We followed-up 7216 participants for a median of 4.3 years. A validated 137-item food-frequency questionnaire was administered. Baseline DP were ascertained through factor analysis based on 34 predefined groups. Cox regression models were used to estimate multivariable-adjusted hazard ratios (HR) for cardiovascular disease (CVD) or mortality across quartiles of DP within each of the-three arms of the trial.Results: We identified two major baseline DP: the first DP was rich in red and processed meats, alcohol, refined grains and whole dairy products and was labeled Western dietary pattern (WDP). The second DP corresponded to a "Mediterranean-type" dietary pattern (MDP). During follow-up, 328 participants died.After controlling for potential confounders, higher baseline adherence to the MDP was associated with lower risk of CVD (adjusted HR for fourth vs. first quartile: 0.52; 95% Cl (Confidence Interval): 0.36, 0.74; p-trend <0.001) and all-cause mortality (adjusted HR: 0.53; 95% CI: 038, 0.75; p-trend <0.001), regardless of the allocated arm of the trial. An increasing mortality rate was found across increasing quartiles of the WDP in the control group (allocated to a low-fat diet), though the linear trend was not statistically significant (p = 0.098).Conclusions: Higher adherence to an empirically-derived MDP at baseline was associated with a reduced risk of CVD and mortality in the PREDIMED trial regardless of the allocated arm. The WDP was not associated with higher risk of mortality or cardiovascular events. (C) 2014 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.