Effects of The Mediterranean diet on the lipid profile and lipoprotein-related markers

Abstract

Decreased values of the most relevant HDL function, cholesterol efflux capacity, have been shown to be related to a high incidence of sub-clinical atherosclerosis and coronary events. Similarly, a predictive value of oxidized LDL for cardiovascular events has been reported. With this regard, it is becoming increasingly more accepted that the functionality of HDL and atherogenicity of LDL can be more indicative of the cardiovascular role of these particles than the mere concentration of HDL- and LDL cholesterol. Objective: Our aim was to study the effects of a whole Mediterranean diet (MedDiet) pattern intervention on HDL biological functions and LDL pro-atherogenic traits, in high cardiovascular individuals in the frame of PREDIMED Study. Methods: The PREDIMED Study is a large-scale, multicenter, randomized, controlled, and parallel-group trial with MedDiet interventions (supplemented with virgin olive oil or nuts) versus a low-fat diet control group, on primary prevention of cardiovascular diseases conducted in Spain. The sub-studies about lipoprotein state and their properties were performed in subsamples of approximately 296 and 210 participants in HDL and LDL subsets, respectively. Biological samples were obtained for the HDL- and LDL-related biomarkers at the start of the study and 1-year after for the lipoprotein-related analysis. Results: Both MedDiets increased cholesterol efflux capacity relative to baseline. The MedDiet-VOO intervention increased HDL ability to esterify cholesterol, paraoxonase-1 arylesterase activity, and HDL vasodilatory capacity relative to control, and decreased cholesteryl ester transfer protein activity relative to baseline. Adherence to a MedDiet induced these beneficial changes by improving HDL oxidative status and composition. The 3 diets increased the percentage of large HDL particles relative to baseline. In addition, after the MedDiet-VOO intervention LDL resistance against oxidation increased, the degree of LDL oxidative modifications decreased, estimated LDL particle size augmented, and LDL particles became cholesterol-rich relative to the low-fat control diet. LDL lipoproteins became less cytotoxic for macrophages only relative to baseline. Conclusion: The MedDiet, especially when enriched with VOO, improved HDL atheroprotective funcions and decreased LDL atherogenicity, in high cardiovascular risk individuals. These traits promoted by a MedDiet could contribute to explaining some of the cardioprotective benefits of this dietary pattern