Review | Published:

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

European Journal of Clinical Nutrition volume 70, pages 12391245 (2016) | Download Citation

  • A Corrigendum to this article was published on 02 November 2016

This article has been updated

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.

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Change history

  • 02 November 2016

    This article has been corrected since Advance Online Publication and a corrigendum is also printed in this issue

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Author information

Affiliations

  1. Clinical Nutrition and Risk Factor Modification Centre, St. Michael’s Hospital, Toronto, Ontario, Canada

    • H V T Ho
    • , J L Sievenpiper
    • , A Zurbau
    • , S Blanco Mejia
    • , E Jovanovski
    • , F Au-Yeung
    • , A L Jenkins
    •  & V Vuksan
  2. Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada

    • H V T Ho
    • , J L Sievenpiper
    • , A Zurbau
    • , S Blanco Mejia
    • , E Jovanovski
    • , F Au-Yeung
    •  & V Vuksan
  3. Li Ka Shing Knowledge Institute, St. Michael’s Hospital, Toronto, Ontario, Canada

    • J L Sievenpiper
    •  & V Vuksan
  4. Division of Endocrinology & Medicine, St. Michael’s Hospital, Toronto, Ontario, Canada

    • J L Sievenpiper
    •  & V Vuksan
  5. Toronto 3D Knowledge Synthesis and Clinical Trials Unit, St. Michael’s Hospital, Toronto, Ontario, Canada

    • J L Sievenpiper
    •  & S Blanco Mejia

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Competing interests

HVTH, AZ, SBM, EJ and FAY declare no conflicts of interest related to this manuscript. JLS has received research support from the Canadian Institutes of health Research (CIHR), Canadian Diabetes Association, PSI Foundation, Calorie Control Council, American Society of Nutrition (ASN), The Coca-Cola Company (investigator initiated, unrestricted), Dr Pepper Snapple Group (investigator initiated, unrestricted), Pulse Canada, and The International Tree Nut Council Nutrition Research & Education Foundation, and the INC International Nut and Dried Fruit Council. He has received reimbursement of travel expenses, speaker fees and/or honoraria from the American Heart Association (AHA), American College of Physicians (ACP), American Society for Nutrition (ASN), National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), Canadian Diabetes Association (CDA), Canadian Nutrition Society (CNS), University of South Carolina, University of Alabama at Birmingham, Oldways Preservation Trust, Nutrition Foundation of Italy (NFI), Calorie Control Council, Diabetes and Nutrition Study Group (DNSG) of the European Association for the Study of Diabetes (EASD), International Life Sciences Institute (ILSI) North America, International Life Sciences Institute (ILSI) Brazil, Abbott Laboratories, Pulse Canada, Canadian Sugar Institute, Dr Pepper Snapple Group, The Coca-Cola Company, Corn Refiners Association, World Sugar Research Organization, Dairy Farmers of Canada, Società Italiana di Nutrizione Umana (SINU), III World Congress of Public Health Nutrition, C3 Collaborating for Health, White Wave Foods, Rippe Lifestyle and mdBriefcase. He has ad hoc consulting arrangements with Winston & Strawn LLP, Perkins Coie LLP and Tate & Lyle. He is on the Clinical Practice Guidelines Expert Committee for Nutrition Therapy of both the Canadian Diabetes Association (CDA) European Association for the study of Diabetes (EASD), and Canadian Cardiovascular Society (CCS), as well as being on an American Society for Nutrition (ASN) writing panel for a scientific statement on sugars. He is a member of the International Carbohydrate Quality Consortium (ICQC) and Board Member of the Diabetes and Nutrition Study Group (DNSG) of the EASD. He serves an unpaid scientific advisor for the Food, Nutrition, and Safety Program (FNSP) and the Technical Committee on Carbohydrates of the International Life Science Institute (ILSI) North America. His wife is an employee of Unilever Canada. VV holds a research grant from CDA for study of dietary intervention including viscous soluble fiber and holds the Canadian (2,410,556) and American (7,326.404) patent on the medical use of viscous fiber blend for reducing blood glucose for treatment of diabetes, increasing insulin sensitivity, reduction in systolic blood pressure and blood lipids. ALJ is director of research and part owner of Glycemic Index Laboratories, a clinical research organization.

Corresponding author

Correspondence to V Vuksan.

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DOI

https://doi.org/10.1038/ejcn.2016.89

Supplementary Information accompanies this paper on European Journal of Clinical Nutrition website (http://www.nature.com/ejcn)