Substituting peas for potatoes significantly reduces post-prandial glycaemic response and glycemic index
Heather Blewett, Jay Petkau, Sora Ludwig, Dan Ramdath. (2018). Substituting peas for potatoes significantly reduces post-prandial glycaemic response and glycemic index. Appl. Physiol. Nutr. Metab. 43: S1–S42 (2018) dx.doi.org/10.1139/apnm-2018-0119 (S4).
Diabetes is a common chronic disease affecting Canadians and choosing foods that produce a low post-prandial glycaemic response may lower the risk of developing type 2 diabetes. Peas are high in fibre and protein, and replacing a portion of a high starch food like potato with peas may limit the rise in blood sugar after a meal. The objective of this study was to compare the post-prandial glucose response following consumption of instant potatoes with and without 3 common market classes of peas. Twenty-four healthy adults (9 men/15 women, age 26 ± 4.9; BMI 23.2 ± 3.0 kg/m2, % body fat (men) 18.8 ± 9.9, % body fat (women) 28.2 ± 6.8) completed the randomized controlled crossover clinical trial at the I.H. Asper Research Institute in Winnipeg, MB. Each participant attended six 2.5-hour study visits separated by washout periods of 3-17 days (average= 7 days). At the first and sixth visits, participants received 50g available carbohydrate (AC) from white bread. At visits 2-5, participants received in random order 50g AC from instant potatoes or 20g AC from instant potatoes + 30g AC from peas (yellow whole, yellow split, green split). Fasting and 15, 30, 45, 60, 90 and 120 minute post-prandial capillary blood samples were collected for analysis of blood glucose and plasma insulin. Repeated measures
ANOVA and differences in LSMeans were used to determine statistical differences in incremental area under the curve (iAUC) for glucose and insulin, as well as Glycemic Index (GI) among treatments. Compared to instant potatoes alone, glucose iAUC was significantly decreased (p=0.0005) by 29-36% and insulin iAUC was significantly decreased (p=0.036) by 32-43% when peas were combined with instant potato. The GI of instant potato (84±4.7) was significantly decreased (p<0.0001) by addition of each pea: (yellow whole (53±4.7), yellow split (56±4.8) and green split (58±4.7). These results show that replacing 60% of the AC from instant potato (a high-GI, starch-rich food) with peas supports a Function health claim related to the reduction in post-prandial glycaemic response.
(Funded by AAFC Growing Forward 2 and Pulse Canada Cluster.)