Effects of Supplemented Mediterranean Diets on Plasma-Phospholipid Fatty Acid Profiles and Risk of Cardiovascular Disease after 1 Year of Intervention in the PREDIMED Trial

Background Plasma fatty acids (FAs) have been associated with cardiovascular disease (CVD) risk. Diet and endogenous metabolism influence the FA profile of the plasma phospholipid (PL) fraction. In the PREDIMED trial, we examined 1-year changes in the FA profile of plasma PL according to a nutritional intervention with Mediterranean diets, either supplemented with extra-virgin olive oil (MedDiet + EVOO) or mixed nuts (MedDiet + nuts), in a high cardiovascular risk population. We also analyzed if 1-year changes in PL FAs were associated with subsequent cardiovascular risk. Methods We included 779 participants in our case-cohort study: 185 incident cases and 594 participants in the subcohort (including 31 overlapping cases). The end point was the incidence of CVD. We measured the FAs of plasma PL at baseline and after 1 year of intervention. Results MedDiet + EVOO increased C17:0 and C20:3n9 in linear regression models [beta coefficient(perSD) : 0.215 (95% CI, 0.032-0.399) and 0.271 (0.107-0.434), respectively] and decreased 16:1n7 and C22:4n6 [beta(perSD): -0.239 (95% CI, -0.416 to -0.061) and -0.287 (95% CI, -0.460 to -0.113), respectively] vs the control group. MedDiet + nuts increased C18:3n3 [beta(perSD): 0.382 (95% CI, 0.225 - 0.539)], C18:2n6 [beta(per SD): 0.250 (95% CI, 0.073 - 0.428)], C18:0 [beta(perSD): 0.268 (95% CI, 0.085-0.452)], and C22:0 [beta(per SD): 0.216 (95% CI, 0.031-0.402)]; and decreased the sum of six n6 FAs [beta(per SD): -0.147 (95% CI, -0.268 to -0.027)] vs the control group. The 1-year increase in C18:2n6 was inversely associated with the subsequent CVD risk (HRperSD: 0.64 (95% CI, 0.44-0.92)). Conclusions MedDiet interventions changed n6 FAs and C16:1n7c; other changes were specific for each group: MedDiet + EVOO increased C17:0 and C20:3n9, and MedDiet + Nuts C18:3n3, C18:2n6, C18:0, and C22:0 FAs.