SUN-LB028: Effect of bread containing high level of resistant starch on glucose and insulin responses

Abstract

Rationale: Resistant starch (RS) may modulate the postprandial glycaemic and insulinemic responses with health benefits. The aim of this study was to evaluate the effect of an ingestion of bread with high amount of RS on the postprandial increase in blood glucose and insulin levels and the glycaemic index (GI) of this bread. Methods: 37 nondiabetic adults were recruited (26 females and 11 males; 16 with BMI 24.9 and 21 with BMI >24.9 kg/m2; aged 22 59 years). This was a single-blind, single-ingestion crossover study. Two breads were tested: (A) conventional bread (white wheat flour) (RS = 1.18% dwb) and (B) original bread (80% white wheat flour and 20% maize flour) baked at long time/low temperature conditions (RS = 4.33% dwb). The test breads were given after an overnight fast on different days. Capillary-blood samples were taken immediately before (0) and 15, 30, 45, 60, 90 and 120 min. after the bread intake. The insulin level was determined in serum with an enzyme immunoassay kit. The GI was calculated according the ISO 26642:2010. All statistical analyses were carried out using SPSS 21.0. Significant differences (p < 0.05) were evaluated by paired Student’s t test. Incremental AUC was calculated using the trapezoid rule for 0 120 min. Results: Regarding to postprandial glucose response, the intake of B promoted an AUC increment (127.1) significantly lower (p < 0.05) when compared with A (153.8). Related to insulin response, these values did not differ significantly between A and B. We also determined the GI of this new bread (B), and we obtained a GI of 60, a healthier GI, when compared to A (GI = 82). Conclusion: Our original bread seems to promote a significantly lower glycaemic response when compared to traditionally bread. The decrease of the glycaemic response was clearly expressed by glucose response and the lower bread GI. This “functional food” can represent a healthier choice in many clinical situations.