African starchy foods, gastric emptying, and starch digestion in Malian stunted children

Starch serves as the main energy source in cereal and tuber-rich diets, and its glycemic response profile has been associated with health-related conditions. Sorghum and millet are known to have relatively low starch digestibility, a potentially desirable property for controlling blood glucose response and providing sustained energy. Gastric emptying rates of traditional sorghum and millet-based African foods of the Sahelian region (couscous, thick and thin porridges made from millet and/or sorghum) were compared to those of non-traditional modern foods that are mostly consumed in urban areas using a non-invasive 13C-labelled octanoic acid breath test in healthy volunteers. The obtained results showed that traditional sorghum and millet-based solid African foods had markedly slower in gastric emptying rate compared to rice, potatoes, and pasta as measured by lag phase and half-emptying time ( P \u3c 0.0001). Factors that regulate gastric emptying of an ingested food are of interest since their understanding may help in controlling overall energy intake. In a second study, Polycose® solution (rapidly absorbed glucose) and slow digesting, cooked and washed alginate-based waxy starch-entrapped microspheres (of variable digestion rates) were consumed as a preload, followed 20 minutes later by a 13C-labeled non-nutritive paste mixture. A comparatively fast emptying rate was observed when the paste was consumed alone whereas the slowest digesting starch-entrapped microspheres preload presented the slowest paste emptying rate as measured by the lag phase and the half emptying time parameters of the gastric emptying test (P \u3c 0.05). Starch is also a dominant source of dietary energy in complimentary feeding of growing toddlers. After weaning, dietary glucose is generated mostly from starch which is the main component of most complementary foods. A new, non-invasive modified 13C-breath test was used to assess pancreatic &agr;-amylase activity, and the ability to digest sorghum porridge starch in healthy and moderately stunted toddlers from 18 – 30 months of age in Bamako, Mali. &agr;-amylase insufficiency was present in both Malian healthy and stunted toddlers. However, children with &agr;-amylase insufficiency digested, absorbed, and oxidized the released glucose from normal sorghum porridge starch at least as well as, and in some cases even better, than the healthy group, indicating that the &agr;-glucosidases compensate for the &agr;-amylase insufficiency, and particularly well in the stunted group. A thicker porridge and its &agr;-amylase thinned counterpart were also digested well by the stunted group. Overall, this work shows value of traditional African sorghum and millet foods and could lead to increased demand for local foods and, thus, provide better markets for smallholder farmers. The clinical study conducted on toddlers suggests that thick energy dense porridges supply digestible carbohydrates to stunted children, and that pending further study could be considered for supplemental feeding programs