Effect of mulberry fruit extract on post-prandial glycaemic and insulinemic responses to different rice types: a randomised trial in healthy adults

Abstract

We previously reported that the addition of a specified mulberry fruit extract (MFE) to rice consistently reduces post-prandial glycaemic (PPG) and post-prandial insulinemic (PPI) responses. This research tested whether this effect generalises to a broad range of rice types, reflecting the wide variation in rice characteristics known to influence glycaemic responses. In a randomised, balanced, partial factorial crossover design, Sona Masoori (SM), Bora Saul (BS), Gobindobogh (Gb) and Banskati (Bn) rices were tested with and without 0·37 g MFE. Healthy, normal-weight Indian adults (N 120) each consumed four of the eight possible boiled rice meals, all containing about 50 g available carbohydrate. The primary outcome was the effect of MFE on PPG, expressed as the percentage change in the positive, incremental AUC over 2 h. The mean effect of MFE on PPG for all rice types combined was -11·4 % (P < 0·003). The reduction in PPG was in a qualitatively similar range for all rice types (-9·8 to -15·1 %), and this was statistically significant for Bn. MFE also reduced the corresponding PPI response to all rice types combined by a mean of 10·1 % (P < 0·001; range -6·1 to -13·4 %), and the reduction in PPI was statistically significant for SM, Gb and BS. In conclusion, addition of 0·37 g MFE modestly reduced PPG and PPI responses to rices in general, and the effects were statistically significant for specific rice types.