Phytosterol-enriched yogurt increases LDL affinity and reduces CD36 expression in polygenic hypercholesterolemia

Dietary enrichment with phytosterols (plant sterols similar to cholesterol) is able to reduce plasma cholesterol levels due to reduced intestinal absorption. The aim of this study was to investigate the effect of phytosterol-enriched yogurt consumption on the major serum lipid parameters, low density lipoprotein (LDL) receptor activity, LDL-receptor affinity, and CD36 expression in hypercholesterolemic subjects. Fifteen patients affected by polygenic hypercholesterolemia were evaluated in a single-blind randomized crossover study after a 4 weeks treatment with a phytosterol-enriched yogurt containing 1.6 g esterefied phytosterols (equivalent to 1.0 g free phytosterol). Lipid parameters were compared with a phytosterol-free placebo-controlled diet. The effect of the two treatments on each variable, measured as percentage change, was compared by paired samples t test and covariance analysis. The treatment induced a modest but significant decrease in LDL-cholesterol levels (4.3%, P = 0.03) and a significant increase in high density lipoprotein (HDL) 3-cholesterol (17.1%, P = 0.01). Phytosterol consumption had no effect on LDL-receptor activity whereas patient LDL-receptor affinity significantly increased (9.7%, P = 0.01) and CD36 expression showed a marked significant decrease (18.2%, P = 0.01) in the phytosterol-enriched yoghurt patients. Our data show that the oral administration of a phytosterol-enriched yogurt has modest but significant effects on commonly measured lipid parameters. The improvement of LDL-receptor affinity and the reduction in CD36 expression may reflect an important antiatherogenic effect.