Effect of the Molecular Weight of Oat β-glucan on Its Ability to Lower Serum Cholesterol - Full Text View

Purpose

The purposes of this study were:

To determine if a breakfast cereal containing 3g of high molecular weight oat beta-glucan fiber would lower low-density lipoprotein (LDL) - cholesterol (the "bad" cholesterol) compared to a control cereal containing wheat fiber.
To determine if the LDL-cholesterol-lowering effect of oat beta-glucan fiber was reduced when the molecular weight of the fiber was reduced.

Condition	Intervention	Phase
Hypercholesterolemia	Dietary Supplement: Wheat bran Dietary Supplement: 3g high MW Dietary Supplement: 4g medium MW Dietary Supplement: 3g medium MW Dietary Supplement: 4g low MW	Phase 2

Study Type:	Interventional
Study Design:	Allocation: Randomized Endpoint Classification: Efficacy Study Intervention Model: Parallel Assignment Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor) Primary Purpose: Treatment
Official Title:	Effect of Varying Dose and Molecular Weight on the Serum LDL-cholesterol-lowering Properties of Oat β-glucan

Resource links provided by NLM:

MedlinePlus related topics: Cholesterol Dietary Fiber

U.S. FDA Resources

Further study details as provided by Glycemic Index Laboratories, Inc:

Primary Outcome Measures:

Serum LDL-cholesterol lowering effect of 3g high MW beta-glucan [ Time Frame: 4 weeks ] [ Designated as safety issue: No ]
Correlation between serum LDL-cholesterol lowering and log(MW*C) [ Time Frame: 4 weeks ] [ Designated as safety issue: No ]

Secondary Outcome Measures:

Total cholesterol [ Time Frame: 4 weeks ] [ Designated as safety issue: No ]
Serum triglycerides [ Time Frame: 4 weeks ] [ Designated as safety issue: No ]
Serum HDL cholesterol [ Time Frame: 4 weeks ] [ Designated as safety issue: No ]
Fasting serum glucose [ Time Frame: 4 weeks ] [ Designated as safety issue: No ]
Serum aspartate transaminase [ Time Frame: 4 weeks ] [ Designated as safety issue: No ]
serum c-reactive protein [ Time Frame: 4 weeks ] [ Designated as safety issue: No ]
Serum urea [ Time Frame: 4 weeks ] [ Designated as safety issue: No ]
Serum creatinine [ Time Frame: 4 weeks ] [ Designated as safety issue: No ]
Time course of changes in blood lipids [ Time Frame: 4 weeks ] [ Designated as safety issue: No ]
Blood pressure [ Time Frame: 4 weeks ] [ Designated as safety issue: No ]
Macronutrient composition of diet [ Time Frame: 4 weeks ] [ Designated as safety issue: No ]
Symptoms questionnaire [ Time Frame: 4 weeks ] [ Designated as safety issue: Yes ]
apolipoprotein B [ Time Frame: 4 weeks ] [ Designated as safety issue: No ]
Serum markers of cholesterol absorption and synthesis [ Time Frame: 4 weeks ] [ Designated as safety issue: No ]

Enrollment:	367
Study Start Date:	November 2008
Study Completion Date:	August 2009
Primary Completion Date:	July 2009 (Final data collection date for primary outcome measure)

Arms	Assigned Interventions
Placebo Comparator: Control Wheat bran cereal	Dietary Supplement: Wheat bran 21g per day of ready to eat breakfast cereal containing wheat bran with 8g of total dietary fiber and 0.5g beta-glucan.
Active Comparator: 3g high MW Cereal containing 3g high molecular weight oat beta glucan	Dietary Supplement: 3g high MW 20.2 grams per day of ready to eat cereal containing 6g total dietary fiber and 3g oat beta glucan with high molecular weight
Active Comparator: 4g medium MW Cereal containing 4g oat beta glucan with medium molecular weight	Dietary Supplement: 4g medium MW 28.5g ready to eat cereal containing 8g total dietary fiber and 4g oat beta glucan with medium molecular weight
Active Comparator: 3g medium MW Cereal containing 3g oat beta glucan with medium molecular weight	Dietary Supplement: 3g medium MW 21.1g of ready to eat cereal containing 6g total fiber and 3g oat beta glucan with a medium molecular weight
Active Comparator: 4g low MW Cereal containing 4g oat beta glucan with low molecular weight	Dietary Supplement: 4g low MW 28.7g ready to eat cereal containing 8g total dietary fiber and 4g oat beta glucan with low molecular weight

Detailed Description:

The FDA allows a health claim that oat products may reduce the risk of heart disease, based on meta-analyses showing a cholesterol-lowering effect of oat beta-glucan, if the product delivers at least a 3g daily dose of oat beta-glucan. However, not all studies have demonstrated a lowering of oat products. This may be due to variable bioactivity of the beta-glucan in the oat products. The bioactivity of oat beta-glucan is believed to depend upon its viscosity in the gut. Factors influencing viscosity include the molecular weight (MW) of the beta-glucan molecule and the amount of soluble beta-glucan in the product, which, in turn determines its concentration (C) in solution. In finished food products both MW and C can be modified by beta-glucanase enzymes present in other ingredients in the food (eg. wheat flour), processing (eg. extrusion) and storage (eg. freezing of moist products such as muffins). The effect of altering the MW and solubility of beta-glucan in foods on glycemic responses has been shown, but a role for MW and C in cholesterol lowering has not been established.

To address this issue, this study was designed with 2 primary objectives:

An extruded oat cereal containing 3g high-molecular weight oat β-glucan daily will reduce LDL cholesterol compared to a control wheat bran cereal.
A significant correlation exists between LDL cholesterol and log(C×MW), where C is the amount of soluble β-glucan in the daily dose of cereal and MW is the molecular weight of the β-glucan in the cereal.

Eligibility

Ages Eligible for Study:	35 Years to 70 Years
Genders Eligible for Study:	Both
Accepts Healthy Volunteers:	Yes

Criteria

Inclusion Criteria:

body mass index 18.5 to 40.0 kg/m^2
no intention to lose or gain weight
fasting total cholesterol 5.0 to 8.0 mmol/L
fasting LDL cholesterol 3.0 to 5.0 mmol/L
consuming diet containing <15% energy from saturated fat

Exclusion Criteria:

use of any cholesterol-lowering drug, herbal or nutritional supplement
regular consumption of oatmeal, oat bran or psyllium - containing cereals
fasting serum triglycerides >4.0mmol/L
serum aspartate transaminase >1.5 times upper limit of normal
serum urea or creatinine >1.8 times upper limit of normal
presence of diabetes or fasting glucose >6.9mmol/L
presence or recent major surgical or medical event
allergy to wheat or oats
presence of condition or drug which alters digestion or absorption of foods

Contacts and Locations

Please refer to this study by its ClinicalTrials.gov identifier: NCT00981981

Locations

Australia, New South Wales
SUGiRS Human Nutrition Unit, School of Molecular & Microbial Biosciences, Unviersity of Sydney
Sydney, New South Wales, Australia, 2006
Canada, Ontario
Human Nutraceutical Research Unit, Department of Human Health and Nutritional Sciences, University of Guelph
Guelph, Ontario, Canada, N1G 2W1
Glycemic Index Laboratories, Inc.
Toronto, Ontario, Canada, M5C 2X3
Canada, Quebec
Nutraceuticals and Functional Foods Institute, Faculte des science de l'agriculture et de l'alimentation, Universite Laval
Laval, Quebec, Canada
United Kingdom
Reading Scientific Services, Ltd (RSSL)
Reading, Berkshire, United Kingdom, RG6 6LA

Sponsors and Collaborators

Glycemic Index Laboratories, Inc

CreaNutrition, AG

University of Guelph

University of Sydney

Laval University

Reading Scientific Services Ltd.

University of Toronto

Agriculture and Agri-Food Canada

Investigators

Principal Investigator:	Thomas MS Wolever, MD, PhD	Glycemic Index Laboratories, Inc
Study Director:	Peter J Wood, PhD	Agriculture and Agri-Food Canada
Study Director:	Susan M Tosh, PhD	Agriculture and Agri-Food Canada
Study Director:	Alison L Gibbs, PhD	Department of Statistics, University of Toronto

More Information

Publications:

Wolever TM, Tosh SM, Gibbs AL, Brand-Miller J, Duncan AM, Hart V, Lamarche B, Thomson BA, Duss R, Wood PJ. Physicochemical properties of oat ?-glucan influence its ability to reduce serum LDL cholesterol in humans: a randomized clinical trial. Am J Clin Nutr. 2010 Oct;92(4):723-32. Epub 2010 Jul 21.

Tosh SM, Brummer Y, Miller SS, Regand A, Defelice C, Duss R, Wolever TM, Wood PJ. Processing affects the physicochemical properties of beta-glucan in oat bran cereal. J Agric Food Chem. 2010 Jul 14;58(13):7723-30.

Additional publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):

Wolever TM, Gibbs AL, Brand-Miller J, Duncan AM, Hart V, Lamarche B, Tosh SM, Duss R. Bioactive oat ?-glucan reduces LDL cholesterol in Caucasians and non-Caucasians. Nutr J. 2011 Nov 25;10:130.

Responsible Party:	Thomas MS Wolever, President, Glycemic Index Laboratories, Inc.
ClinicalTrials.gov Identifier:	NCT00981981 History of Changes
Other Study ID Numbers:	GIL8034
Study First Received:	September 18, 2009
Last Updated:	June 20, 2011
Health Authority:	Canada: Health Canada

Keywords provided by Glycemic Index Laboratories, Inc:

humans
randomized clinical trial
dietary fiber
nutrition

beta-glucan
oats
LDL cholesterol
coronary heart disease

Additional relevant MeSH terms:

Hypercholesterolemia
Hyperlipidemias
Dyslipidemias
Lipid Metabolism Disorders
Metabolic Diseases

ClinicalTrials.gov processed this record on May 23, 2013

Effect of the Molecular Weight of Oat β-glucan on Its Ability to Lower Serum Cholesterol (Bluebird)