Effect of [beta]-glucan on cholesterol and glucose levels.
Article Type: Report
Subject: Dietary supplements (Reports)
Blood cholesterol (Measurement)
Blood cholesterol (Reports)
Blood sugar (Measurement)
Blood sugar (Reports)
Author: Murphy, Kathleen
Pub Date: 12/22/2011
Publication: Name: Australian Journal of Medical Herbalism Publisher: National Herbalists Association of Australia Audience: Academic Format: Magazine/Journal Subject: Health Copyright: COPYRIGHT 2011 National Herbalists Association of Australia ISSN: 1033-8330
Issue: Date: Winter, 2011 Source Volume: 23 Source Issue: 4
Product: Product Code: 2834730 Nutrient Preparations NAICS Code: 325412 Pharmaceutical Preparation Manufacturing SIC Code: 2833 Medicinals and botanicals; 2834 Pharmaceutical preparations
Accession Number: 275312603
Full Text: Tiwari U, Cummins E. 2011. Meta-analysis of the effect of B-glucan intake on blood cholesterol and glucose levels. Nutrition 27:10;1008-16.

Cereals such as oats and barley are rich in soluble fibres such as [beta]-glucan, a non starch polysaccharide composed of linear chains of glucose with [beta]-(1-3) and [beta]-(1-4) linkages. Oat and barley [beta]-glucans are ascribed many health benefits and there is an increasing focus on enhancing soluble fibre consumption. Epidemiologic studies have reported that the intake of soluble fibre lowers lipid absorption and in turn decreases the risk of cardiovascular disease.

This meta analysis aimed to assess the relationship between [beta]-glucan consumption from oats and barley on cholesterol and blood glucose levels (BGLs). The analysis included 126 studies based on [beta]-glucan levels; of these, 82 studies were related to oats and the other 44 studies to barley. Consumption levels ranged from 2 to 14 g of [beta]-glucan per day.

The mean net change among individual studies for total cholesterol (TC) was -2.08 to -0.03 mmol/L. The mean net change among individual studies for LDL cholesterol was -2.46 to -0.04 mmol/L with overall pooled estimates of -0.65 mmol/L (95% CI -0.77 to -0.53, P < 0.0001) for the fixed effect model and -0.66 mmol/L (95% CI -0.96 to -0.36, P < 0.0001) for the random effect model.

The mean net change for BGL showed a wide variation within individual studies compared with blood cholesterol levels ranging from -10.33 to 0.21 mmol/L, with an overall pooled estimate for the fixed effect model at -2.48 mmol/L (95% CI -2.59 to -2.37, P < 0.0001).

A [beta]-glucan dose of 1 g/d produced changes in TC and BGL of -0.079 mmol/L (range -0.236 to -0.006 mmol/L) and -0.084 mmol/L (range -0.61 to 0.011 mmol/L) respectively. The predicted dose response models for TC and BGL were found to be significant (P < 0.0001).

Intake of oat or barley [beta]-glucan separately showed significant (P < 0.0001) decreases in TC, LDL cholesterol and TGL/TAG for oat or barley [beta]-glucan. HDL cholesterol increased significantly (P < 0.0001) with oat [beta]-glucan whereas no significant change was observed with barley [beta]-glucan intake when investigated separately.

This meta analysis demonstrated the potential for oat and barley [beta]-glucan consumption on TC, LDL, HDL, TGL/TAG and BGL. The study also showed a continuous dose response relation of [beta]-glucan dose (grams per day) on TC and BGL.

This study concludes that consumption of 3 g/d of oat or barley [beta]-glucan is sufficient to decrease blood cholesterol levels. Further analysis of the [beta]-glucan effect on BGL requires longer intervention periods.

Kathleen Murphy MNHAA

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