7.2. Anti-hyperglycemic and hypercholesterolemia activities
The rheological properties of dietary fibre are proposed as an important mechanistic factor in reducing postprandial increases in plasma glucose and insulin concentrations in both normal and diabetic individuals. Vuksan et al. (2001) evaluated the use of KGM as an alternative therapy for type 2 diabetes mellitus by comparing the viscosity of KGM with other soluble fibres such as psyllium and xanthan at 1% (v/v) concentration. The flattening of postprandial glycemia following 20 g of glucose challenge and 3 g of each fibre added, closely mirrored the relative viscosity of the fibres (KGM:
12×10−1 cp; xanthan: 6.2×10−1 cp; psyllium: 2.1×10−1 cp) with KGM demonstrating the greatest effect followed by xanthan and psyllium. In addition, the effect on the glycemic response of incorporating KGM-polysaccharide mix in a group of seven type 2 diabetics has been studied. 3 g of KGM-polysaccharide mix were added to a 50 g available carbohydrate portion of a test biscuit compared to matched control biscuits consumed on two different occasions. Blood glucose was measured over two hours following consumption of the test meals, with postprandial glycemia calculated as the incremental area under a glucose response curve expressed as a percentage of the mean of the control biscuits. It was
demonstrated that the KGM-polysaccharide mix has a low glycemic index of 42±5 (Vuksan et al., 2001). In addition to the effect of KGM on the glycemic index of foods, considerable research effort has focussed on the potential benefits
of KGM as a cholesterol reducing agent in individuals with and without type 2 diabetes. Vuksan et al. (1999) studied the effect of adding KGM to conventional CHD treatment in 11 hyperlipidemic and hypertensive type 2 diabetic patients treated conventionally by a low-fat diet and drug therapy through a double-blind placebo-controlled crossover design with two successive three week treatment periods separated by a two week wash-out period. The results demonstrate that serum fructosamine was significantly reduced during both the KGM and control treatments by 6.1±2.4% and 0.5±1.4%, respectively. The TC:HDL-C ratio decreased significantly by 5.7±2.3% during KGM treatment compared with
an insignificant increase of 4.7±4.4% during the control treatment. The resultant between-treatment result had significantly decreased by 10±4.0% in those on the KGM treatment. Moreover, systolic blood pressure significantly declined in those on KGM supplementation by 5.5±1.4% compared with 1.4±2.7% in those on the control treatment, producing a significant between-treatment difference of 6.9±2.5% or 9.4±3mmHg.However, it is important to
note that both the sample number (11) and the treatment period (3 weeks) employed in this study are inadequate to allow meaningful conclusions to be drawn.