Mondelēz International R&D, Saclay, Francia
Introduction and objectives: Decreasing glycemic response is interesting in the prevention of metabolic diseases (Blaak et al. 2012). However, process and food composition influence dramatically the carbohydrate fate and then the metabolic consequences of carbohydrate rich foods. High slowly digestible starch (SDS) foods have been shown to provide low glycaemic response. A compilation of 5 intervention studies, including a meta-analysis model, has been done to evaluate the impact of cereal products high in SDS and eaten at breakfast on postprandial metabolism and to show particularly the strength between SDS and glycaemic response, and SDS and appearance rate of carbohydrates of cereal foods. Development: The five selected clinical trials included from 12 to 38 non diseased subjects. All studies were randomised clinical trials (Nazare et al. 2010, Vinoy et al. 2013, Péronnet et al. 2015). The breakfasts were designed to ensure that the main differences between the two meals resulted in the SDS content of the cereal products tested (0.1 to 0.9g and 10 to 21g SDS/portion for low SDS and high SDS products respectively). The other macronutrient contents were similar between the two conditions within each study. The CHO content of the breakfasts was derived mainly from the cereal product consumed. Taking all the studies together, the nutritional compositions of the breakfasts were comparable as to the energy (19-22% of average recommended daily calorie intake of 2,000 kcal), CHO (57 to 68 %), protein (10 to 12 %) and fat (20 to 32 %). In three from the 5 selected studies, in order to describe the difference in plasma glucose kinetics between the two types of breakfasts, the flour used in manufacturing the four cereal products was intrinsically labeled with 13C, and plasma glucose kinetics was measured using dual-tracer methodology with [6,6-2H2]glucose infusion. In addition, we synthesized the evidence via meta-analyses and meta-regression models. The odd ratios (OR) with 95% of confidence for the adjusted random-effects models investigate the association between SDS and postprandial metabolism as glycaemic response, insulin response and appearance rate of carbohydrates (Ra). The biscuits high in SDS led to a significantly lower glycemic response compared with breakfast cereals with almost no SDS when included in a breakfast meal. On average, the 2-hour incremental area under the curve (iAUC) of glycaemia was 30% lower with breakfasts high in SDS compared with those with low SDS content. In all five studies, postprandial insulin response was not exacerbated after the biscuits high in SDS within a breakfast. The effect observed on glycemia is actually induced by a lower and more stable rate of appearance of exogenous glucose (RaE) originating from the high-SDS products when compared with low-SDS products. Indeed, in the three studies evaluating plasma glucose turnover (Nazare et al., 2010; Vinoy et al., 2013; Péronnet et al., 2015), for both cereal products, RaE kinetics increased rapidly to reach a plateau and remained stable for the high SDS products, whereas it decreased in the late phase of the postprandial period for the low SDS products. Depending on the studies, the AUC of RaE was significantly reduced by ≈ 25 to 35% on the 0 - 270-minute postprandial period (p ≤ 0.05 in the three studies). From meta-analysis models, cereal products containing high SDS are 4,4 times more likely to generate low glycemic response and 2,6 times more likely to generate low insulin response than cereal products containing low SDS. The link between slow exogenous Ra and high SDS was even stronger with an OR of 14,6 while it was slightly lower with disappearance rate (OR=4,2). Strong link (69%) was obtained between exogenous Ra and glycemia. Conclusion: These observations show that substituting a cereal product high in SDS from low SDS at breakfast will slow glucose absorption, and reduce the challenge to plasma glucose which follows the meal. In fact, the ingestion of a high SDS cereal product reduces excursions in plasma glucose and insulin concentrations, and release the ingested glucose over a longer period. These phenomena might improve plasma glucose control and provide long term health interests. Key words: cereal foods, carbohydrates, glycaemic response, slowly digestible starch, isotope method. Referencias. Blaak EE, Antoine JM, Benton D, Bjorck I, Bozzetto L, Brouns F, et al. Impact of postprandial glycaemia on health and prevention of disease. Obesity reviews. 2012;13(10):923-84. Nazare JA, de Rougemont A, Normand S, Sauvinet V, Sothier M, Vinoy S, et al. Effect of postprandial modulation of glucose availability: short- and long-term analysis. Br J Nutr. 2010;103(10):1461-70. Péronnet F, Meynier A, Sauvinet V, Normand S, Bourdon E, Mignault D, St-Pierre DH, Laville M, Rabasa-Lhoret R, Vinoy S. Plasma glucose kinetics and response of insulin and GIP following a cereal breakfast in female subjects: effect of starch digestibility. Europ J Clin Nutr 2015. Apr 8. doi: 10.1038/ ejcn.2015.50 Vinoy S, Normand S, Meynier A, Sothier M, Louche-Pelissier C, Peyrat J, et al. Cereal processing influences postprandial glucose metabolism as well as the GI effect. J American College Nutrition. 2013;32(2):79-91.