Exercise Physiology Research Group, Department of Kinesiology, KU Leuven, Leuven, Belgium.
PhytoLab GmbH & Co. KG, Vestenbergsgreuth, Germany.
J Int Soc Sports Nutr. 2013 Oct 21;10(1):45. doi: 10.1186/1550-2783-10-45.
Oral intake of a specific extract of Opuntia ficus-indica cladode and fruit skin (OpunDia™) (OFI) has been shown to increase serum insulin concentration while reducing blood glucose level for a given amount of glucose ingestion after an endurance exercise bout in healthy young volunteers. However, it is unknown whether OFI-induced insulin stimulation after exercise is of the same magnitude than the stimulation by other insulinogenic agents like leucine as well as whether OFI can interact with those agents. Therefore, the aims of the present study were: 1) to compare the degree of insulin stimulation by OFI with the effect of leucine administration; 2) to determine whether OFI and leucine have an additive action on insulin stimulation post-exercise.
Eleven subjects participated in a randomized double-blind cross-over study involving four experimental sessions. In each session the subjects successively underwent a 2-h oral glucose tolerance test (OGTT) after a 30-min cycling bout at ~70% VO2max. At t0 and t60 during the OGTT, subjects ingested 75 g glucose and capsules containing either 1) a placebo; 2) 1000 mg OFI; 3) 3 g leucine; 4) 1000 mg OFI + 3 g leucine. Blood samples were collected before and at 30-min intervals during the OGTT for determination of blood glucose and serum insulin.
Whereas no effect of leucine was measured, OFI reduced blood glucose at t90 by ~7% and the area under the glucose curve by ~15% and increased serum insulin concentration at t90 by ~35% compared to placebo (P<0.05). From t60 to the end of the OGTT, serum insulin concentration was higher in OFI+leucine than in placebo which resulted in a higher area under the insulin curve (+40%, P<0.05).
Carbohydrate-induced insulin stimulation post-exercise can be further increased by the combination of OFI with leucine. OFI and leucine could be interesting ingredients to include together in recovery drinks to resynthesize muscle glycogen faster post-exercise. Still, it needs to be confirmed that such nutritional strategy effectively stimulates post-exercise muscle glycogen resynthesis.
在健康的年轻志愿者进行耐力运动后，摄入特定的仙人掌果和果皮提取物（OpunDia™）（OFI）可增加血清胰岛素浓度，同时降低葡萄糖摄入后一定时间内的血糖水平。然而，目前尚不清楚运动后 OFI 诱导的胰岛素刺激是否与其他胰岛素原激动剂（如亮氨酸）的刺激程度相同，以及 OFI 是否可以与这些激动剂相互作用。因此，本研究的目的是：1）比较 OFI 引起的胰岛素刺激程度与亮氨酸给药的效果；2）确定 OFI 和亮氨酸对运动后胰岛素刺激是否具有相加作用。
11 名受试者参加了一项随机、双盲交叉研究，涉及四个实验阶段。在每个阶段，受试者在进行约 70% VO2max 的 30 分钟自行车运动后，连续进行 2 小时口服葡萄糖耐量试验（OGTT）。在 OGTT 的 t0 和 t60 时，受试者分别摄入 75 g 葡萄糖和含有以下物质的胶囊：1）安慰剂；2）1000mg OFI；3）3g 亮氨酸；4）1000mg OFI+3g 亮氨酸。OGTT 前和每隔 30 分钟采集血样，用于测定血糖和血清胰岛素。
亮氨酸没有效果，而 OFI 可使 t90 时的血糖降低约 7%，曲线下面积降低约 15%，血清胰岛素浓度升高约 35%，与安慰剂相比（P<0.05）。从 t60 到 OGTT 结束，OFI+亮氨酸组的血清胰岛素浓度高于安慰剂组，导致胰岛素曲线下面积增加（增加 40%，P<0.05）。
运动后碳水化合物引起的胰岛素刺激可以通过 OFI 与亮氨酸的联合进一步增强。OFI 和亮氨酸可能是在运动后恢复饮料中一起添加的有趣成分，以更快地合成肌肉糖原。然而，仍需要确认这种营养策略是否能有效地刺激运动后肌肉糖原的合成。
