High β-Glucan Whole Grain Barley Reduces Postprandial Glycemic Response in Healthy Adults-Part One of a Randomized Controlled Trial

Background/Objectives: The effects of sweetened and unsweetened high beta-glucan whole grain barley on postprandial blood glucose response in normoglycemic human subjects were evaluated in a randomized, controlled, crossover clinical trial. Methods: Sixteen healthy, over-night fasted participants were studied on four or eight separate occasions. Participants consumed an unsweetened preload condition (n = 16): white glutinous rice (WR; 0 g beta-glucan), low beta-glucan barley (LB; similar to 4 g), medium beta-glucan barley (MB; similar to 5 g), or high beta-glucan barley (HB; similar to 6 g); or a sweetened condition with high fructose corn syrup (HFCS; n = 8): WR + 50 g HFCS, LB + 50 g HFCS, MB + 50 g HFCS, or HB + 50 g HFCS. After consuming the preload as a breakfast food, participants self-administered blood glucose tests every 15 min for four hours. Results: In both sweetened and unsweetened conditions, higher beta-glucan content was associated with lower blood glucose peak response and incremental area under the curve estimates (iAUC). In comparison to the unsweetened conditions, the sweetened conditions resulted in less prominent decreases in mean blood glucose response and iAUC blood glucose as beta-glucan content increased. Conclusions: By attenuating postprandial glycemic response, high beta-glucan whole grain barley foods could play a role in helping to control blood glucose.