Effects of diets enriched with two different plant stanol ester mixtures on plasma ubiquinol-10 and fat-soluble antioxidant concentrations

Plant stanols lower intestinal cholesterol absorption. This causes a decrease in serum low-density lipoprotein (LDL)-cholesterol, despite a compensatory increase in cholesterol synthesis. We therefore hypothesized that plant stanols also change LDL-cholesterol-standardized concentrations of ubiquinol-10 (a side product of the cholesterol synthesis cascade) and of those fat-soluble antioxidants that are mainly carried by LDL. To examine this, 112 nonhypercholesterolemic subjects consumed low erucic acid rapeseed oil (LEAR)-based margarine and shortening for 4 weeks. For the next 8 weeks, 42 subjects consumed the same products, while the other subjects received products with vegetable oil-based stanols (2.6 g sitostanol plus 1.2 g campestanol daily, n = 36) or wood-based stanols (3.7 g sitostanol plus 0.3 g campestanol daily, n = 34). Consumption of both plant stanol ester mixtures increased cholesterol synthesis and lowered cholesterol absorption, as indicated by increased serum cholesterol-standardized lathosterol and decreased plant sterol concentrations, respectively. Compared with the control group, absolute plasma ubiquinol-10 concentrations were lowered by 12.3% +/- 18.9% (-0.14 mug/mL v the control group; P = .004; 95% confidence interval [CI] for the difference in changes, -0.05 to -0.22 mug/mL) in the vegetable oil-based group and by 15.4% +/- 13.0% (-0.17 mug/mL v the control group; P < .001; 95% CI for the difference, -0.08 to -0.27 <mu>g/mL) in the wood-based group. Changes in LDL-cholesterol-standardized ubiquinol-10 concentrations were not significantly changed. The most lipophylic antioxidants. the hydrocarbon carotenoids (beta -carotene, alpha -carotene, and lycopene), decreased most, followed by the less lipophylic oxygenated carotenoids (lutein/zeaxanthin and beta -cryptoxanthin) and the tocopherols. These reductions were related to the reduction in LDL, which carry most of these antioxidants. The decrease in the hydrocarbon carotenoids, however, was also significantly associated with a decrease in cholesterol absorption. LDL-cholesterol-standardized antioxidant concentrations were not changed, except for beta -carotene, which was still, although not significantly, lowered by about 10%. We conclude that the increase in endogenous cholesterol synthesis during plant stanol ester consumption does not result in increased LDL-cholesterol-standardized concentrations of ubiquinol-10, a side product of the cholesterol synthesis cascade. Furthermore, decreases in absolute fat-soluble antioxidant concentrations are related to decreases in LDL-cholesterol. However, for the most lipophylic carotenoids, some of the reduction was also related to the decrease in cholesterol absorption. Copyright (C) 2001 by W.B. Saunders Company.