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 reductioni-iv.
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.



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 I2statistic.



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%).



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.
Clinical Nutrition and Risk Factor Modification Centre, St. Michael's Hospital, Toronto, Ontario, Canada.|Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.
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Clinical Nutrition and Risk Factor Modification Centre, St. Michael's Hospital, Toronto, Ontario, Canada.|Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.|Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Ontario, Canada.|Division of Endocrinology & Medicine, St. Michael's Hospital, Toronto, Ontario, Canada.|Toronto 3D Knowledge Synthesis and Clinical Trials Unit, St. Michael's Hospital, Toronto, Ontario, Canada.
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Sievenpiper
Clinical Nutrition and Risk Factor Modification Centre, St. Michael's Hospital, Toronto, Ontario, Canada.|Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.
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Zurbau
Clinical Nutrition and Risk Factor Modification Centre, St. Michael's Hospital, Toronto, Ontario, Canada.|Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.|Toronto 3D Knowledge Synthesis and Clinical Trials Unit, St. Michael's Hospital, Toronto, Ontario, Canada.
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Blanco Mejia
Clinical Nutrition and Risk Factor Modification Centre, St. Michael's Hospital, Toronto, Ontario, Canada.|Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.
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Jovanovski
Clinical Nutrition and Risk Factor Modification Centre, St. Michael's Hospital, Toronto, Ontario, Canada.|Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.
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Au-Yeung
Clinical Nutrition and Risk Factor Modification Centre, St. Michael's Hospital, Toronto, Ontario, Canada.
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Jenkins
Clinical Nutrition and Risk Factor Modification Centre, St. Michael's Hospital, Toronto, Ontario, Canada.|Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.|Li Ka Shing Knowledge Institute, St. Michael's Hospital, Toronto, Ontario, Canada.|Division of Endocrinology & Medicine, St. Michael's Hospital, Toronto, Ontario, Canada.
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Vuksan
D001055:Apolipoproteins B / Q000097:blood; D015415:Biomarkers / Q000097:blood*; D008076:Cholesterol, HDL / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D003324:Coronary Artery Disease / Q000097:blood / Q000517:prevention & control*; D019587:Dietary Supplements; D001467:Hordeum; D006801:Humans; D016032:Randomized Controlled Trials as Topic; D047071:beta-Glucans / Q000008:administration & dosage*
D001055:Apolipoproteins B; D015415:Biomarkers; D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D047071:beta-Glucans