Aim: to compare the blood glucose-lowering effect of a highly viscous fiber blend added to a starchy snack on postprandial glycemia between healthy participants and participants with diabetes mellitus.Study design: a randomized, single-blind, crossover, controlled clinical trial.
Subjects: two groups of experiments were conducted: in healthy participants and participants with type 2 diabetes mellitus.10healthy participants (4 men and 6 women, aged 18-75 years, body mass index 24,3 ± 0,8 kg/m2) and 9 participants with diabetes mellitus type 2 (3 men and 6 women, aged 18-75 years, BMI 28,8 ± 1,2 kg/m2) on four separate occasions took either 50 g available carbohydrates as control biscuits, biscuitswith 10 g of highly viscous fiber blend (approximately 70% glucomannan and 30% xanthan), white bread with 12 g of margarine, or white bread alone. Postprandial blood glucose response, glycemic index, and palatability were determined. Blood samples were obtained at 15, 30, 45, 60, and 90 minutes after the start of the meal in healthy volunteers and at 30-minute intervals for three hours in participants with diabetes.
Results: mean (95% confidence interval) glycemic index values of the viscous fiber blend biscuits were 26 (16-36) and 37 (27-47) glycemic index units for healthy participants and participants with diabetes mellitus, respectively. These values were significantly lower than those of whitebread, white bread with 12 g of margarine, and control biscuits (p < 0,001, paired t test) both in healthy participants (glycemic index 100, 108 [57-159], and 101 [44-158], respectively) and participants with diabetes mellitus (glycemic index 100, 103 [79-127], and 94 [78-110], respectively). Viscous fiber blendsignificantly reduced the glycemic index by 74% (7,4 glycemic index units/g of fiber) in healthy participants and by 63% (6.3GI units/g of fiber) in participants with diabetes. The GI did not differ between control meals in both healthy participants and participants with diabetes. There were no significant differences in pa glycemic index palatability among the types of meals, although participants with diabetes found the viscous fiber blend biscuits more palatable (p = 0,002, t test).
Authors’ conclusion: viscous fiber blend is a very potent and palatable soluble fiber addition to a starchy snack, which is able to reduce the glycemic response to a similar extent in both healthy participants and individuals with diabetes mellitus.