β‐glucan from oat and barley concentrates affect postprandial glycemia and insulinemia in relation to the level of viscosity

Abstract

Beta-glucan from oats and barley may lower blood glucose and insulin levels and reduce the risk of type 2 diabetes. There is, however, a lack of evidence correlating the dose of β-glucan to glycemic and insulinemic response. In a double-blind, randomized, crossover design, 12 healthy participants(gender:3M:9F;age:31±3yrs;BMI:25±0.8kg/m2)received 8 treatments: doses of 0,2,4 and 8g of β-glucan given in a 75g glucose drink. Intravenous blood samples were collected at 0,15,30,45,60,90 and 120min and analyzed for plasma glucose (PG) and plasma insulin (PI). Oat 8g β-glucan significantly reduced PG at 15min(p<0.01) and at the peak compared to the 0and2g; similarly, PG was significantly reduced by the barley 8g β-glucan at 15,30 and 90min(p<0.01) compared to 0and2g. Barley 4g β-glucan significantly lowered PG compared to barley 0and2g at 15min. The iAUC of oat 8g β-glucan was significantly lower than 0and2g. Similarly, the iAUC of barley 8g β-glucan was significantly lower than 0and2g. Oat 8g β-glucan significantly lowered PI at 15,30,45,60,90 and 120min compared to control (p<0.01). Barley 8g β-glucan decreased PI at 15,30,45 and 90min(p<0.01). The iAUC of PI was significantly lower after the oat 8g and barley 8g β-glucan compared to the 0,2 and 4g doses(p<0.01). This study demonstrates the glucose and insulin lowering potential of β-glucan from both oats and barley in a dose-dependent manner.