The science of Reducose®

Blood glucose basics

Dietary carbohydrates are classified as either sugars, starches or fibers and are defined by their ease of digestibility and the length of their saccharide chain (the number of basic carbohydrate units, such as glucose).  These chains can vary in length from short chains of two units, such as sucrose or table sugar, to chains containing hundreds of thousands of saccharide units such as starch and fiber.

Starches are further classified based on their speed of digestion: rapidly digestible starch (RDS), slowly digestible starch (SDS), or resistant starch (RS).  When we eat these different starches, they have markedly different effects on our blood glucose levels.  Rapidly-digestible starch is quickly broken-down and causes a rapid increase in our blood glucose levels.  In contrast, resistant starches and fiber escapes digestion in the small intestine and passes into the large intestine where it becomes food for the microbiome1.


Related to the rate of carbohydrate digestion is the glycemic index (GI), a relative ranking system for carbohydrate foods and their impact on our blood glucose levels.  Carbohydrates with a high GI value have a dramatic influence on our postprandial blood glucose levels and eating them releases a large amount of glucose rapidly into the blood stream.  Many people are unaware, but gram for gram, refined starches have twice the glycemic impact as sugar and that sugar is a medium GI carbohydrate. Conversely, a low GI diet leads to low and slow changes in postprandial blood glucose levels and have been clinically demonstrated to improve blood glucose profile, blood lipid profile, and insulin resistance2,3,4.

Testing and labelling complex foods and meals that have a low GI, or using supplements that can lower the GI of a meal regardless of the nutrient mix would be of great value to consumers who are looking to maintain healthy blood glucose levels.


Reducose® is clinically proven to lower blood glucose & the glycaemic index of foods

In a clinical trial conducted by Phynova, a single 250mg dose of Reducose® was incorporated directly into common dietary carbohydrates and given to healthy individuals.  Reducose® caused a significant reduction in the glycemic index of the test carbohydrates.  The greatest effect was seen with maltodextrin, a long chain carbohydrate made from corn starch, where Reducose® lowered the GI of the maltodextrin by 55%. These findings were replicated in a second clinical trial, the results of which have been published5 .  This reduction in glycemic index of foods results in significant lowering in postprandial blood glucose levels.


In two clinical studies (one published6), Reducose® was shown to lower postprandial blood glucose and postprandial blood insulin following a carbohydrate challenge (sucrose in one study, maltodextrin in the second).  These studies showed that Reducose® lowered the postprandial blood glucose levels by up to 42% (p<0.001).  Reducose® also lowered the postprandial insulin response by a corresponding amount (-41%, p<0.001).  The clinical study reported no adverse events and in a gastrointestinal symptom questionnaire, there was no difference between Reducose® and placebo in incidence or severity of GI side-effects.


"Reducose® demonstrates a classical dose response curve with significant effects over placebo. Importantly, we did not find any significant differences between the treatment groups in the odds of experiencing one or more gastrointestinal symptoms"

Lown et al. PLoS ONE. 2017

How does Reducose® work?

Reducose® lowers blood glucose and the glycemic index of foods by inhibiting the enzymes that are responsible for digesting carbohydrates.  Most carbohydrates are too large to be absorbed across the gut lumen and require hydrolysis into monosaccharides to allow absorption.  The body makes use of enzymes to achieve this, enzymes such as salivary amylase, pancreatic amylase, and α-glucosidases7.  Reducose® has been shown to be a competitive inhibitor of α-glucosidase in the brush border of the small intestine.

After inhibiting the digestive enzymes, Reducose® dissociates from the enzyme and unlike other ‘carb blockers’ is absorbed into the blood stream where it is rapidly excreted unmetabolized through the kidneys.  This is important from a side-effect perspective as the microbiome utilizes the same enzymes to break down undigested foods and inhibitors remaining with the food bolus would impact this activity.


1.  Campbell, GJ, et al. 2017. Metabolic effects of high glycaemic index diets: a systematic review and meta-analysis of feeding studies in mice and rats. Nutrients 646-665.

2.  Elliott, DE and Thomas DJ. 2010. The use of low-glycaemic index diets in diabetes control. Br J Nutr 797-802.

3.  Goff, LM et al. 2013. Low glycaemic index diets and blood lipids: a systemative review and meta-analysis of randomised controlled trials. Nutr Metab Cardiovasc Dis 1-10.

4.  Ojo, O et al. 2018. The effect of dietary glycaemic index on glycaemia in patients with type-2 diabetes: a systematic review and meta-analysis of randmised controlled trials. Nutrients.

5.  Wang, R et al. 2018. Mulberry leaf extract reduces the glycemic index of four common dietary carbohydrates. Medicines 1-8.

6.  Lown M et al, 2017. Mulberry extract improves glucose tolerance and decreases insulin concentrations in normoglycaemic adults: results of a randomized double-blind placebo controlled study. PLoS ONE; Feb 22.

7. Holmes R, 1971. Carbohydrate digestion and absorption. J. Clin. Path; 24 (5): 10-13.