In a recent study, researchers have found that the Mediterranean-type diet (MedDiet) reduces plasma LDL-cholesterol concentrations primarily by increasing LDL clearance and reducing cholesterol absorption. 19 men with metabolic syndrome had their diet first standardised to a baseline North American control diet for 5 weeks followed by 5 weeks of a MedDiet, both under weight-maintaining isoenergetic feeding conditions. The participants then underwent a 20-week free-living energy restriction period, followed by the consumption of the MedDiet for 5 weeks under controlled isoenergetic feeding conditions. The LDL-cholesterol-lowering effect of the MedDiet was accompanied by significant reductions in plasma PCSK9 concentrations (-11.7%) and in the phytosterol:cholesterol ratio (-9.7%) compared with the control diet.
Richard C, Couture P, Desroches S, Benjannet S, Seidah NG, Lichtenstein AH, Lamarche B. Effect of the Mediterranean diet with and without weight loss on surrogate markers of cholesterol homeostasis in men with the metabolic syndrome. Br J Nutr. 2012 Mar;107(5):705-11.