Effects of a phytosterol-enriched dairy product on lipids, sterols and 8-isoprostane in hypercholesterolemic patients: A multicenter Italian study

Abstract

Background and aims Plant sterols, added to several food sources, lower serum cholesterol concentrations. Plant sterol-induced cholesterol lowering is paralleled by a mild decrease in plasma levels of the antioxidant β-carotene, the amount of this decrease being considered clinically non-significant. Whether the effect on lipid profile of daily consumption of plant sterol-enriched low-fat fermented milk (FM) is paralleled by a concomitant variation in a reliable marker of the oxidative burden like plasma isoprostane levels is unresolved. Methods and results The effect of plant sterol consumption on plasma lipid and isoprostane levels of hypercholesterolemic patients was evaluated in a multicenter, randomized double blind study. Hypercholesterolemic patients consumed a FM daily for 6 weeks. Subjects were randomized to receive either 1.6 g of plant sterol-enriched FM ( n = 60) or control FM product ( n = 56). After 6 weeks of plant sterol-enriched FM consumption, LDL cholesterol was reduced from 166.2 ± 2.0 to 147.4 ± 2.8 mg/dL ( p = 0.01). A significant reduction was observed for total cholesterol (from 263.5 ± 2.6 to 231.0 ± 3.2 mg/dL, p = 0.01). There was greater LDL cholesterol lowering among hypercholesterolemic patients with higher LDL cholesterol at baseline. We found a reduction of plasma 8-isoprostane in patients taking plant sterol-enriched FM (from 43.07 ± 1.78 to 38.04 ± 1.14 pg/ml, p = 0.018) but not in patients taking the control product (from 42.56 ± 2.12 to 43.19 ± 2.0 pg/ml, p = NS). Campesterol and β-sitosterol levels were not influenced by phytosterol consumption. Conclusions Daily consumption of low-fat plant sterol dairy product favourably changes lipid profile by reducing LDL-cholesterol, and may also have an anti-oxidative effect through a reduction of plasma isoprostanes.