Mulberry-Extract Reduces Total Blood Glucose Rises in Normoglycaemic Adults

Problem

High sugar and carbohydrate intake is associated with obesity and type 2 diabetes. Reducing poor quality carbohydrate intake is a public health priority. Reducose®, a proprietary mulberry leaf extract (ME) and functional food ingredient, may reduce blood glucose responses by reducing gastrointestinal glucose absorption.

Approach

The primary objective was to determine the effect of three doses of ME versus placebo on blood glucose and insulin responses when co-administered with 50g maltodextrin, a high GI starch, in normoglycaemic healthy adults. We also determined the gastrointestinal tolerability of ME. This was achieved using a Phase 2 double-blind, randomised, repeat measure, 4-arm, crossover trial.

Findings

The mean participant (SD) age and BMI were 29.4 (10.9) years and 23.0 (2.3) kg/m2, respectively. Mean (95%CIs) for the difference in the positive Incremental Area Under the Curve (pIAUC) (glucose) for half, normal and double dose ME compared with placebo were -10.36 (-30.60,9.88; p=0.316), -23.58 (-43.82,-3.35; p=0.022) and -37.01, (-57.25,-16.77; p<0.001). The difference in the pIAUC (insulin) for half, normal and double dose ME compared with placebo were -350.32 (-927.87,227.23; p=0.234), -856.09 (-1433.64,278.54; p=0.004) and -887.35 (-1464.90,309.80; p=0.003). There were no differences between the groups in experiencing or severity of one or more adverse gastrointestinal symptoms.

Consequences

ME significantly reduces total blood glucose and insulinaemic responses after ingestion of high GI starch. The pattern of effect demonstrates a classical dose response. This food supplement may help safely modulate glucose absorption and consequent hyperglycaemia from dietary carbohydrates.