The effect of β-glucan on the glycemic and insulin index

Objective: To determine the effects of oat products with increasing beta-glucan content on the glycemic (GI) and insulin indexes (II) of oat products, and to establish the effect of physical properties of beta-glucan on these physiological responses. Design: Test group (n = 10) randomly attended to three glucose tolerance tests and glycemic response tests for four oat bran products. Settings: Functional Foods Forum and the Department of Food Chemistry, University of Turku, and the Department of Food Technology, University of Helsinki. Subjects: One male and nine female volunteers were recruited from university students and staff, and all completed the study. Interventions: GI and II of different products were calculated for each subject using the average of parallel glucose tolerance tests and the subsequent glycemic/ insulinemic responses for each product. Average indexes for products were calculated according to the individual data. Results: The glycemic responses to oat products with increasing amounts of beta-glucan had lower peak values than the reference glucose load. The amount of extractable beta-glucan had a high correlation between the glycemic and insulinemic response. Conclusion: In addition to the total amount of beta-glucan in oat products, the amount of extractable beta-glucan in oat products explains the magnitude of the decrease in glycemic responses to carbohydrate products.