Bread with a high level of resistant starch influenced the digestibility of the available starch fraction

Abstract

Eating foods in which available starch was replaced by resistant starch (RS) causes lower glucose and insulin responses. There is insufficient evidence for the effects of RS when the total available carbohydrates content remains constant. The present study aimed to evaluate the effects of bread with a high amount of RS3, compared to control bread. The effects of RS on glycaemia, insulin response, appetite visual analogue scale (VAS) scores were examined. It was also determined the glycaemic index (GI) of both loaves of bread. In a single-blind, crossover study, 37 nondiabetic adults consumed equivalent samples of a test bread with a high amount of RS (HRS - 2.4%) or a conventional bread (REF - 0.8%), with a washout period of at least one week. Postprandial glucose and VAS scores were measured at fasting, 15, 30, 45, 60, 90 and 120 min after the meal. Insulin response was measured at fasting and 30 min. HRS bread presented a significantly lower postprandial glucose response at 60, 90 and 120 min (P ≤ 0.05). Incremental AUC glycaemia response showed significantly lower values for HRS bread (127.15 ± 71.54 mmol*min/l) as well as higher satiety scores, compared to REF bread (153.77 ± 80.38 mmol*min/l); t(36) = 2.234; P = 0.016. HRS bread showed a GI = 60 much lower than the REF bread. The higher amount of RS causes a significantly lower postprandial glucose response. These results shows that RS3 influenced the digestibility of the available starch fraction. No differences were observed at insulin response. RS is related to higher satiety scores.