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 glycemic (PPG) and insulinemic (PPI) responses. This research tested whether this effect generalizes to a broad range of rice types, reflecting the wide variation in rice characteristics known to influence glycemic responses. In a randomized, 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 4 of the 8 possible boiled rice meals, all containing ∼50 g available carbohydrate. The primary outcome was the effect of MFE on PPG, expressed as the percentage change in the positive, incremental area under the curve over 2 hours. 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.