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

Hypercholesterolemia Clinical Trial

— Bluebird  

Official title:

Effect of Varying Dose and Molecular Weight on the Serum LDL-cholesterol-lowering Properties of Oat β-glucan

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT00981981
• Other study ID #: GIL8034
• Status: Completed
• Phase: Phase 2
• First received: September 18, 2009
• Last updated: June 20, 2011
• Start date: November 2008
• Est. completion date: August 2009

Study information

• Verified date: June 2011
• Source: Glycemic Index Laboratories, Inc
• Contact: n/a
• Is FDA regulated: No
• Health authority: Canada: Health Canada
• Study type: Interventional

Clinical Trial Summary

The purposes of this study were:

1. 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.

2. To determine if the LDL-cholesterol-lowering effect of oat beta-glucan fiber was reduced when the molecular weight of the fiber was reduced.

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:

1. An extruded oat cereal containing 3g high-molecular weight oat β-glucan daily will reduce LDL cholesterol compared to a control wheat bran cereal.

2. 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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 367
• Est. completion date: August 2009
• Est. primary completion date: July 2009
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Both
• Age group: 35 Years to 70 Years

Eligibility

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

Study Design

Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor), Primary Purpose: Treatment

Related Conditions & MeSH terms

• Hypercholesterolemia

Intervention

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.
• 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
• 4g medium MW
28.5g ready to eat cereal containing 8g total dietary fiber and 4g oat beta glucan with medium molecular weight
• 3g medium MW
21.1g of ready to eat cereal containing 6g total fiber and 3g oat beta glucan with a medium molecular weight
• 4g low MW
28.7g ready to eat cereal containing 8g total dietary fiber and 4g oat beta glucan with low molecular weight

Locations

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

Sponsors (8)

Lead Sponsor	Collaborator
Glycemic Index Laboratories, Inc	Agriculture and Agri-Food Canada, CreaNutrition, AG, Laval University, Reading Scientific Services Ltd., University of Guelph, University of Sydney, University of Toronto

Countries where clinical trial is conducted

Australia,  Canada,  United Kingdom, 

References & Publications (2)

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. doi: 10.1021/jf904553u. — View Citation

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 ß-glucan influence its ability to reduce serum LDL cholesterol in humans: a randomized clinical trial. Am J Clin N — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Serum LDL-cholesterol lowering effect of 3g high MW beta-glucan		4 weeks	No
Primary	Correlation between serum LDL-cholesterol lowering and log(MW*C)		4 weeks	No
Secondary	Total cholesterol		4 weeks	No
Secondary	Serum triglycerides		4 weeks	No
Secondary	Serum HDL cholesterol		4 weeks	No
Secondary	Fasting serum glucose		4 weeks	No
Secondary	Serum aspartate transaminase		4 weeks	No
Secondary	serum c-reactive protein		4 weeks	No
Secondary	Serum urea		4 weeks	No
Secondary	Serum creatinine		4 weeks	No
Secondary	Time course of changes in blood lipids		4 weeks	No
Secondary	Blood pressure		4 weeks	No
Secondary	Macronutrient composition of diet		4 weeks	No
Secondary	Symptoms questionnaire		4 weeks	Yes
Secondary	apolipoprotein B		4 weeks	No
Secondary	Serum markers of cholesterol absorption and synthesis		4 weeks	No