Co-ingestion of whole almonds and almond oil with carbohydratesuppresses postprandial glycaemia in mice in an insulin-dependent andinsulin-independent manner

Abstract

Co-ingestion of almonds with carbohydrate prevents excessive increase in plasma glucose level (PGL), but information about the functional fractionislimited. Identifying the functional fraction is necessary to use almonds more efficiently in terms of controlling postprandial glycaemia after a high-carbo-hydrate meal. In the present study, we evaluated the effects of almond skin, oil, water-soluble fraction and water-insoluble fraction on both postprandialglycaemia and insulinaemia. The effect of almond skin was tested by comparing the effect of whole almonds with the effect of skinless almonds. Male ICRmice were administered dextrin and 4 g/kg body weight test samples. After the administration, 2-h postprandial changes in glycaemia and insulinaemia weremeasured. Oil was the only fraction being able to blunt postprandial glycaemia. Interestingly, when co-ingesting with dextrin, almond oil did not change theinsulin level compared with the control but whole almonds or skinless almonds triggered a 4-fold increase in insulin level. The co-ingestion of wholealmonds or skinless almonds similarly suppressed the PGL at 15 and 30 min (P<0·05), which means almond skin has no effect on postprandial glycaemia.Neither soluble nor insoluble fractions lead to any significant changes in postprandial glycaemia and insulinaemia. In conclusion, oil is the main functionalcomponent accounting for the glycaemia-lowering effect without altering insulin level.