Plasma lipid changes after supplementation with β-glucan fiber from yeast

Abstract

Background: Dietary fiber has been shown to improve blood lipids. Objective: The purpose of this study was to evaluate the effect on serum lipids of a yeast-derived β-glucan fiber in 15 free-living, obese, hypercholesterolemic men. Design: After a 3-wk period in which subjects ate their usual diet, 15 g fiber/d was added to the diet for 8 wk and then stopped for 4 wk. Plasma lipids were measured weekly during baseline and at week 7 and 8 of fiber consumption, and again at week 12. Results: Compared with baseline, fiber consumption significantly reduced plasma total cholesterol (by 8% at week 7 and 6% at week 8; P < 0.05 using Bonferroni correction); week 12 values did not differ from baseline. No significant differences were noted between baseline LDL cholesterol and values at weeks 7, 8, or 12 when comparing individual groups by using Bonferroni correction, even though the overall one-way analysis of variance with repeated measures was highly significant (P < 0.001). LDL-cholesterol concentrations did decline by 8% at week 8 compared with baseline. There was a significant effect of diet on plasma HDL-cholesterol concentrations (P < 0.005 by one-way ANOVA with repeated measures). However, a group difference was observed only between baseline and week 12 (16% increase; P < 0.05 by Bonferroni correction). Triacylglycerol concentrations did not change. Conclusions: The yeast-derived β-glucan fiber significantly lowered total cholesterol concentrations and was well tolerated; HDL-cholesterol concentrations rose, but only 4 wk after the fiber was stopped.