High molecular weight oat β-glucan enhances lipid-lowering effects of phytosterols. A randomised controlled trial

Clin Nutr. 2020 Jan;39(1):80-89. doi: 10.1016/j.clnu.2019.02.007. Epub 2019 Feb 10.

Abstract

Background & aims: Oat β-glucan (OBG) and phytosterols (PS) are known to lower blood cholesterol levels via different mechanisms. Combination of high molecular weight (MW) OBG and PS in a single functional food could have complementary and/or synergistic effects for optimising heart health. The aim of this study was to investigate the effects of dietary supplementation with high-MW OBG with or without PS on plasma lipids in hypercholesterolaemic individuals.

Methods: In a double-blinded, placebo-controlled, 2 × 2 factorial trial, participants were randomised to receive biscuits fortified with either no PS or OBG (PL, n = 18) or 2 g PS (PS, n = 18), 3 g OBG (OBG, n = 18), or combination of 2 g PS and 3 g OBG (PS-OBG, n = 18) per day for 6 weeks. Primary outcome was fasting plasma total cholesterol (TC) and secondary outcomes were LDL-cholesterol, LDL-C; HDL-cholesterol, HDL-C; triglycerides, TG and TC to HDL-cholesterol (TC:HDL) ratio.

Results: TC and LDL-C were significantly lowered following PS (-4.6% and -7.6% respectively; p < 0.05), OBG (-5.7% and -8.6%; p < 0.01) and PS-OBG (-11.5% and -13.9%; p < 0.0001) administration. The reduction in TC in the PS-OBG group was significantly greater compared to PL (p < 0.001) and PS (p < 0.05). PS-OBG group had a significantly greater reduction in LDL-C compared to PL (p < 0.01) but not in comparison to PS or OBG groups. TC:HDL ratio was significantly reduced following PS-OBG (-8.9%; p < 0.01) only, and there was no significant difference found between groups. Plasma TG reduced by 8.4% following PS-OBG, however, this was statistically non-significant. Plasma HDL-C remained unchanged across all groups.

Conclusions: Dietary supplementation with high-MW OBG and PS in a single functional food enhances their lipid-lowering potential. Blood cholesterol lowering by PS and OBG is additive. Delivery of these two bioactive nutrients in a single food allows optimisation of their lipid-lowering effects and may provide added heart health benefits with enhanced compliance. The trial was registered with the Australian New Zealand Clinical Trials Registry at http://www.anzctr.org.au/(ACTRN12618001455257).

Keywords: LDL cholesterol; Phytosterols; Total cholesterol; Triglyceride; β-glucan.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Anticholesteremic Agents / blood
  • Anticholesteremic Agents / pharmacology*
  • Dietary Supplements*
  • Double-Blind Method
  • Female
  • Humans
  • Lipids / blood
  • Male
  • Middle Aged
  • Phytosterols / blood
  • Phytosterols / pharmacology*
  • beta-Glucans / blood
  • beta-Glucans / pharmacology*

Substances

  • Anticholesteremic Agents
  • Lipids
  • Phytosterols
  • beta-Glucans
  • beta-glucan, (1-3)(1-4)-

Associated data

  • ANZCTR/ACTRN12618001455257