Reduced viscosity Barley β-Glucan versus placebo: a randomized controlled trial of the effects on insulin sensitivity for individuals at risk for diabetes mellitus

Abstract

BackgroundPrior studies suggest soluble fibers may favorably affect glucose/insulin metabolism.MethodsThis prospective, randomized, placebo controlled, double blind, parallel group trial evaluated 50 generally healthy subjects without prior diagnosis of diabetes mellitus (44 completers), who were administered beverages containing placebo (control), lower dose (3 g/d), or higher dose (6 g/d) reduced viscosity barley β-glucan (BBG) extract. Subjects (68% women) mean age 56 years, Body Mass Index (BMI) 32 kg/m2 and baseline fasting plasma glucose 102 mg/dl were instructed to follow a weight-maintaining Therapeutic Lifestyle Changes (TLC) diet and consumed three 11 oz study beverages daily with meals for 12 weeks. The four primary study endpoint measures were plasma glucose and insulin [each fasting and post-Oral Glucose Tolerance Testing (OGTT)].ResultsCompared to placebo, administration of 3 g/d BBG over 12 weeks significantly reduced glucose incremental Area Under the Curve (iAUC) measures during OGTT and 6 g/d BBG over 12 weeks significantly reduced fasting insulin as well as the related homeostasis model assessment of insulin resistance (HOMA-IR). Beverages were generally well tolerated with no serious adverse experiences and no significant differences between groups for adverse experiences. Per protocol instruction, subjects maintained body weight.ConclusionsThese findings suggest 6 g/d BBG consumed in a beverage over 12 weeks may improve insulin sensitivity among hyperglycemic individuals with no prior diagnosis of diabetes mellitus, and who experience no change in body weight.Trial RegistrationClinicalTrials.gov Identifier: NCT01375803.

Developing Winter Food Barley for the Pacific Northwest of the US

“…In 2006, the U.S. Food and Drug Administration approved a health claim for barley based on varieties containing high levels of soluble b-glucan fiber, which has been shown to help reduce the postprandial glucose response, lower blood cholesterol levels, reduce insulin resistance, and reduce abdominal fat (AbuMweis et al, 2010;Bays et al, 2011;Behall et al, 2006;Casiraghi et al, 2006;Kim et al, 2009;Shimizu et al, 2008;Tiwari and Cummins, 2011 Barley (Hordeum vulgare L.) has been cultivated for human consumption for millennia. However, most North Americans do not consume barley as a foodstuff on a regular basis and the majority is grown for feed and malt.…”

Raisin Consumption by Humans: Effects on Glycemia and Insulinemia and Cardiovascular Risk Factors

“…Recently, we examined the effects of barley beta‐glucan, a soluble fiber, on glycemia and insulinemia. In overweight subjects with mean fasting glucose values in the prediabetic range, regular consumption of a soluble barley beta‐glucan with diets that were equivalent in energy and carbohydrate content was accompanied by a significant reduction in postprandial glucose values, decreases in fasting insulin values, and improvement in insulin sensitivity (Bays and others ).…”

Macronutrients and type 1 diabetes (revision number 6)

“…All of the trials identified in the systematic review report no significant effect of oat bran or β-glucan supplements on fasting insulin concentration. Of the trials identified in the update search, one reports no significant effect of β-glucan supplements on fasting insulin concentration and the other reports a dose of 6g/day refined β-glucans, but not 3g/day, to reduce fasting insulin concentration (Bays et al, 2011).…”

“…Four randomised controlled trials were identified that presented evidence on β-glucan in relation to fasting insulin concentration, all of which were included in a meta-analysis (Saltzman et al, 2001;Chen et al, 2006;Maki et al, 2007a;Smith et al, 2008). Two trials were subsequently identified in the update search (Bays et al, 2011;Charlton et al, 2012) (Cardio-metabolic review, diabetes and glycaemia chapter p 311-312; Update search table 161). Two trials compared oat bran containing diets to a refined wheat control (Saltzman et al, 2001;Chen et al, 2006).…”

“…Two trials compared oat bran containing diets to a refined wheat control (Saltzman et al, 2001;Chen et al, 2006). Four trials supplemented subjects with refined β-glucans, either from barley or oats (Maki et al, 2007a;Smith et al, 2008;Bays et al, 2011;Charlton et al, 2012). One of the trials was a weight-loss trial (Saltzman et al, 2001).…”