Barley b-glucan reduces plasma glucose and insulin responses compared with resistant starch in men

Glucose and insulin responses have been reported to be lowered by acute consumption of soluble 0271-5317/$ – see fro doi:10.1016/j.nutres.2 4 Corresponding E-mail address: b oat fiber or high amylose cornstarch. This study sought to determine if barley b-glucan and preformed resistant starch reduced glucose and insulin responses in men independently or if a synergism exists between the two carbohydrate sources. A total of 20 men (10 control, 10 overweight; average body mass index, 23.8 vs 29.0) were fed a controlled diet for 2 days before each treatment containing 75 g available carbohydrate. Fasting subjects consumed 10 treatments consisting of glucose or 1 of 9 muffins containing 3 levels of resistant starch (0.1, 6.1, or 11.6 g/tolerance) and 3 levels of b-glucan (0.1, 3.1, or 5.8 g/tolerance) in a Latin square design. Plasma glucose and insulin responses were determined over 4 hours after each treatment. Compared with controls, overweight subjects had significantly higher mean glucose (5.5 vs 6.0 F 0.1 mmol/L) (P b .003) and insulin (153 vs 285 F 21 mmol/L) (P b .0001) concentrations. Glucose (P b .001) and insulin (P b .003) responses were lower and returned to fasting quicker in the controls than in overweight subjects. The highest b-glucan level was the most effective in lowering glucose (P b .001) and insulin responses (P b .0001). Average glucose (P b .025) and insulin (P b .0001) areas under the curve were lowest after the muffins containing the high b-glucan. Resistant starch content was less effective than b-glucan in reducing glucose or insulin response. Acute consumption of barley b-glucan, but not resistant starch, in muffins was effective in reducing glucose and insulin responses in men who were mildly insulin-resistant. D 2006 Published by Elsevier Inc.