Acute Effects of Pea Fractions in Extruded Cereals on Glycemic and Insulin Responses in Adults
Authors: Johnston Alie J , Omer Dianna , Mollard Rebecca C , MacKay Dylan S , Ames Nancy , Curran Julianne , Bouchard Danielle R , Jones Peter J 
Published: November 2023

The beneficial effects of consuming pulses on glycemic control are well established; however, research examining the effects of pulse fractions incorporated into extruded products is limited. The objectives of this study were to assess the effects of replacing oat flour with pea fractions in extruded cereals on post‐prandial glycaemia and insulin before and after a meal consumed at 120 min. In a randomized, repeated‐measures crossover trial, adults (n = 26) consumed cereals (35g) made with: 1) oat flour (control), 2) oat flour and pea starch (starch), 3) oat flour and pea protein (protein), 4) oat flour, pea starch and pea protein (starch+protein), 5) oat flour, pea fibre and pea protein (fibre+protein), and 6) pea fibre, pea starch and pea protein (fibre+starch+protein). Blood glucose (BG) and insulin incremental area under the curve (iAUC) was calculated pre‐meal (0– 120 min) and post‐meal (120–200 min). For pre‐meal overall mean BG, there was a time (p<0.0001), treatment (p<0.0001) and time‐by‐treatment effect (p<0.0001). During the pre‐meal period, the protein, fibre+protein and fibre+starch+protein cereals resulted in a lower (p<0.05) overall mean BG response compared to starch and control cereals. The starch+protein cereal also resulted in a lower (p<0.05) overall mean BG response compared to control. There was also a treatment effect on pre‐meal BG iAUC (p<0.0001); protein, fibre+protein and fibre+starch+protein cereals resulted in a lower (p<0.05) BG iAUC compared to control and starch cereals. Starch+protein also had a lower (p<0.05) pre‐meal BG iAUC compared to starch cereal. For post‐meal BG, there was a time (p<0.0001), treatment (p<0.05), but no time‐by‐treatment effect. There was also an effect of treatment on post‐meal iAUC (p<0.05). However, for both post‐meal BG overall mean and iAUC, posthoc testing did not identify differences between treatments. For pre‐meal overall mean insulin, there was a time (p<0.0001), treatment (p<0.0005), and time‐by‐treatment effect (p=0.001). During the pre‐meal period, fibre+protein led to a lower insulin response compared to control (p<0.05), starch+protein (p<0.05), and protein (p=0.001) cereals. Fibre+starch+protein also led to lower pre‐meal insulin compared to protein cereal (p<0.05). There was also a treatment effect on pre‐meal insulin iAUC (p<0.05); fibre+protein resulted in lower (p<0.05) insulin compared to control cereal. For post‐meal overall insulin (120–200 min), there was a time (p<0.0001), but no treatment (p=0.47) or time‐by‐treatment effect (p=0.52). There were no effects on post‐meal insulin iAUC. These findings indicate that benefits of replacing oat with pulse fractions in extruded cereals on BG and insulin are dependent on fraction type. The protein+fibre and fibre+starch+protein resulted in both decreased BG and insulin levels. Data support the use of pea fractions in extruded products designed to improve post‐prandial glycemic control.

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