Arabinoxylan fiber, a byproduct of wheat flour processing, reduces the postprandial glucose response in normoglycemic subjects

Background: Arabinoxylan (AX) is the major component of dietary fiber in the cereal grains that make up a large proportion of our diet. However, the physiologic effect of AX is unknown. Objective: The objective of this study was to determine whether AX improves postprandial glucose and insulin responses in healthy humans. Design: AX-rich fiber was extracted from the byproduct of wheat-flour processing. Three isoenergic breakfasts, comprising bread, margarine, and jam, had 75 g available carbohydrate, 10 g protein, and 14 g fat and contained 0, 6, and 12 g AX-rich fiber, respectively. Fourteen healthy subjects consumed the 3 breakfast meals in random order on 3 mornings ≥3 d apart after an overnight fast. Blood was taken from the subjects at regular intervals over 2 h and was analyzed for glucose and insulin. The palatability of bread containing AX-rich fiber was compared with that of a control bread. Results: Compared with the control meal containing 0 g AX-rich fiber, the peak postprandial glucose concentration after meals containing 6 and 12 g AX-rich fiber was significantly lower (6.3 ± 1.3 compared with 7.2 ±1.0 mmol/L, P < 0.01; 5.9 ± 0.9 compared with 7,2 ± 1.0 mmol/L, P < 0.001, respectively). The incremental area under the curve (IAUC) for glucose was 20,2% (95% CI: 5.8%, 34.7%; P < 0.01) and 41.4% (25,9%, 56.8%; P < 0,001) lower, whereas IAUC for insulin was 17.0% (2.0%, 32.1%; P < 0.05) and 32.7% (18.8%, 46,6%; P < 0.001) lower, respectively. Bread containing AX-rich fiber was as palatable as 50% whole-wheat bread when evaluated with sensory analysis by 30 volunteers. Conclusions: Postprandial glucose and insulin responses were improved by ingestion of AX-rich fiber. Further research is required to determine whether AX-rich fiber is of benefit to people with type 2 diabetes.