A systematic review and meta-analysis of randomized controlled trials of the effect of barley β-glucan on LDL-C, non-HDL-C and apoB for cardiovascular disease risk reduction i-iv

Eur J Clin Nutr. 2016 Nov;70(11):1239-1245. doi: 10.1038/ejcn.2016.89. Epub 2016 Jun 8.

Abstract

Background/objectives: There has been recent interest in barley as a therapeutic food owing to its high content of beta-glucan (β-glucan), a viscous soluble fiber recognized for its cholesterol-lowering properties. The objective of this study was to conduct a systematic review and meta-analysis of randomized controlled trials (RCTs) investigating the cholesterol-lowering potential of barley β-glucan on low-density lipoprotein cholesterol (LDL-C), non-high-density lipoprotein cholesterol (non-HDL-C) and apolipoprotein B (apoB) for cardiovascular disease (CVD) risk reduction.

Methods: MEDLINE, Embase, CINAHL and the Cochrane CENTRAL were searched. We included RCTs of ⩾3-week duration assessing the effect of diets enriched with barley β-glucan compared with controlled diets on LDL-C, non-HDL-C or apoB. Two independent reviewers extracted relevant data and assessed study quality and risk of bias. Data were pooled using the generic inverse-variance method with random effects models and expressed as mean differences (MDs) with 95% confidence intervals (CIs). Heterogeneity was assessed by the Cochran Q-statistic and quantified by the I2 statistic.

Results: Fourteen trials (N=615) were included in the final analysis. A median dose of 6.5 and 6.9 g/day of barley β-glucan for a median duration of 4 weeks significantly reduced LDL-C (MD=-0.25 mmol/l (95% CI: -0.30, -0.20)) and non-HDL-C (MD=-0.31 mmol/l (95% CI: -0.39, -0.23)), respectively, with no significant changes to apoB levels, compared with control diets. There was evidence of considerable unexplained heterogeneity in the analysis of non-HDL-C (I2=98%).

Conclusions: Pooled analyses show that barley β-glucan has a lowering effect on LDL-C and non-HDL-C. Inclusion of barley-containing foods may be a strategy for achieving targets in CVD risk reduction.

Publication types

  • Meta-Analysis
  • Review
  • Systematic Review

MeSH terms

  • Apolipoproteins B / blood
  • Biomarkers / blood*
  • Cholesterol, HDL / blood
  • Cholesterol, LDL / blood
  • Coronary Artery Disease / blood
  • Coronary Artery Disease / prevention & control*
  • Dietary Supplements*
  • Hordeum*
  • Humans
  • Randomized Controlled Trials as Topic
  • beta-Glucans / administration & dosage*

Substances

  • Apolipoproteins B
  • Biomarkers
  • Cholesterol, HDL
  • Cholesterol, LDL
  • beta-Glucans