The PREDIMED trial showed that Mediterranean diets supplemented with either extra-virgin olive oil or nuts reduced incident cardiovascular events compared to a control diet. Consumption of both supplemental foods has been associated with reduced LDL-cholesterol, but it is unknown whether they can shift lipoprotein subfractions to a less atherogenic pattern. We investigated changes in adiposity and lipoprotein subfractions after consumption of the PREDIMED diets.
In a PREDIMED sub-cohort (n=169), lipoprotein subclasses (particle concentrations and size) were determined by nuclear magnetic resonance spectroscopy at baseline and after intervention for 1 year.
Participants allocated to the Mediterranean diet supplemented with nuts showed significant reductions from baseline of waist circumference (mean [95% CI]; -5 cm [-7; -3]) and concentrations of medium-small (-27 nM [-46; -8]) and very small LDL (-111 nM [-180; -42]); decreased LDL particle number (a nuclear magnetic resonance-specific measurement) (-98 nM [-184; -11]); and an increase of large LDL concentrations (54 nM [18; 90]), with a net increase (0.2 nm [0.1; 0.4]) of LDL size. The Mediterranean diets with olive oil and nuts increased large HDL concentrations (0.6 μM [0.0; 1.1] and 1.0 μM [0.4; 1.5], respectively). Compared to the other two intervention groups, participants in the nut-enriched diet showed significantly reduced waist circumference (p≤0.006, both) and increased LDL size (p<0.05, both).
Lipoprotein subfractions are shifted to a less atherogenic pattern by consumption of Mediterranean diets enriched with nuts. The results contribute mechanistic evidence for the reduction of cardiovascular events observed in the PREDIMED trial.