Acute post-ingestive and second-meal effects of almond form on diabetes risk factors
Nut consumption is inversely related to the risk of developing type 2 diabetes (Jiang et al., 2002). Little evidence exists regarding the manner in which nuts may positively influence diabetes risk outcomes. Of primary interest in this study was the effect of whole almonds and almond components included in a breakfast meal on immediate postprandial concentrations of blood glucose, insulin, non-esterified free fatty acids (NEFA), glucagon-like peptide-1 (GLP-1) and appetitive sensations. Additional alterations in insulin sensitivity past the immediate postprandial period, due to the residual effects of the previous meal (“second-meal effect”), was also determined after consumption of a subsequent standard lunch. Fourteen impaired glucose tolerant (IGT) adults participated in a randomized crossover design study with the following treatments incorporated into a breakfast meal: vehicle (V, no addition), whole almond (WA), almond butter (AB), defatted almond flour (AF), and almond oil (AO). Both the WA and AO treatments led to significantly attenuated daylong and second-meal blood glucose incremental area under the curve (AUCI) whereas AB only decreased blood glucose AUCI in the morning period. WA and AO elicited a greater second-meal insulin response, particularly in the early postprandial phase. GLP-1 concentrations did not vary significantly between treatments so the effect is not likely attributed to this incretin hormone. Daylong NEFA AUCI and feelings of fullness were the lowest after consumption of AF. WA and AO treatments led to a decreased second-meal NEFA response, likely due to increased insulin concentrations. WA led to the greatest daylong feeling of fullness. The lipid component of the almond appears to be largely responsible for the immediate post-ingestive response, although it cannot explain the increased blood glucose and NEFA response to a second-meal with consumption of AB compared to WA and AO. A separate chewing assessment found that the particle size distribution of the masticated almond did not determine the blood glucose response. Inclusion of almonds in the breakfast meal promoted decreased blood glucose concentrations and increased satiety both acutely and after a second-meal in adults with IGT.^
Richard D. Mattes, Purdue University.
Health Sciences, Nutrition