The research paper, published European Journal of Clinical Nutrition, suggests that as little as 7.5 grams of PGX – a novel fiber supplement – can reduce blood glucose responses over a two hour period by 50 percent, and can reduce post prandial responses by up to 28 percent.
The researchers, led by Prof. Jennie Brand-Miller from the University of Sydney, stated that PGX has “biologically important, dose-related effects on acute and delayed (second meal) postprandial glycemia.”
The study was performed in partnership with researchers from Factors Group R & D, and InovoBiologic Inc. The study was also supported by InovoBiologic Inc, who also supplied the study with PGX.
There is increasing evidence from long term studies to suggest that diets containing high quantities of whole grains and dietary fiber are associated with reduced risk of type 2 diabetes.
Controlled trials, have found that higher intake of cereal fiber leads to improvements in insulin sensitivity, whereas soluble fiber reduces postprandial glycemia, as well as serum lipids.
But despite awareness of the health benefits associated with dietary fiber, intakes have remained at about half the recommended level of 14 g per 1000 kcal.
Researchers noted supplementation of the diet with purified ‘functional’ dietary fibers “may be an option to increase fiber intake.”
“Although both insoluble and soluble fibers can be used this way, soluble fibers that develop viscosity in solution appear to provide greater benefits for metabolism,” added the authors.
Previous research has mainly focused on the ability of fiber preparations to improve lipid metabolism, however reductions in postprandial glycemia (often known as glycemic ‘spikes’) have increasingly been seen as an important part of the management and prevention of pre-diabetic glucose intolerance and type-2 diabetes.
PolyGlycopleX (PGX) is a newly developed highly viscous polysaccharide complex that is reported to demonstrate a delayed onset of peak viscosity, “allowing for a more palatable and easy-to-use functional fiber,” state the authors.
The new study investigated the effectiveness of two different forms of PGX (granules or capsules), in reducing postprandial glycemia.
Results from the study showed that the highest dose of the granular PGX (7.5 grams) dissolved in water and consumed with a carbohydrate meal at breakfast time, reduced the blood glucose responses by 50 percent.
The effectiveness of PGX granules was also related to timing, with researchers observing consumption within 15 minutes of the start of the meal reduced glycemia as effectively as when taken with the meal (up to 28 percent improvement) – however such effects were not found when taken at 45 or 60 minutes before the meal.
In contrast, PGX consumed as capsules did not produce immediate lowering of glycemia, but had important ‘second meal’ effects – improving glucose tolerance at breakfast time by up to 28 percent when consumed with the previous evening meal.
“These findings indicate that the effectiveness of PGX is dependent on dose, timing of consumption and physical form,” stated the researchers.
They stated that the precise timing of ingestion for the PGX was not critical, because consumption between 15 minutes before and after the start of the meal was seen to be effective.
The authors noted that the beneficial effects of functional fibers are highly dependent on the food matrix, adding that unpublished data has suggested PGX to be “just as effective when sprinkled on food as dissolved in water.”
They stated that further research was needed “to evaluate the long-term health benefits of this promising viscous polysaccharide.”
Source: European Journal of Clinical Nutrition
Published online ahead of print, doi: 10.1038/ejcn.2010.199
"Effects of PGX, a novel functional fibre, on acute and delayed postprandial glycaemia"
Authors: J.C. Brand-Miller, F.S. Atkinson, R.J. Gahler, V. Kacinik, M.R. Lyon, S. Wood