Fischer Karina, Colombani Paolo C, Langhans Wolfgang, Wenk Caspar
INW Nutrition Biology, Department of Agriculture and Food Science, Swiss Federal Institute of Technology Zurich, ETH Zentrum-LFW A 58, CH-8092, Zurich, Switzerland.
Physiol Behav. 2002 Mar;75(3):411-23. doi: 10.1016/s0031-9384(01)00676-x.
The effect of different carbohydrate to protein ratios in food on cognitive functions and the relation between postprandial metabolic and cognitive changes were studied in 15 healthy male students. Subjects were tested in three sessions, separated by 1 week, for short-term changes in mood states, objective cognitive functions, blood parameters, and indirect calorimetry using a repeated-measures, counterbalanced cross-over design. Measurements were made after an overnight fast before and hourly during 3.5 h after test meal ingestion. The isoenergetic (1670 kJ) test meals consisted of three carbohydrate to protein ratios, i.e. a carbohydrate-rich (CHO[4:1]), balanced (BAL[1:1]), and protein-rich (PRO[1:4]) meal, respectively. Overall accuracy in short-term memory was best after the PRO[1:4] meal concomitant to the least variation in glucose metabolism and glucagon to insulin ratio (GIR). Related to changes in glucose metabolism and/or in the ratios of large neutral amino acids (LNAA), respectively, attention and decision times were transiently improved within the first hour after the CHO[4:1] meal, whereas after the first hour the BAL[1:1] and PRO[1:4] meal resulted in improved performance. Overall reaction times of a central task were fastest after the BAL[1:1] meal concomitant to the highest overall tyrosine (Tyr) to LNAA ratio. Our findings suggest that the carbohydrate to protein ratio in food specifically influences higher cognitive functions in the morning. Except for a transient positive effect of rising blood glucose after a carbohydrate-rich meal, a protein-rich or balanced meal seems to result in better overall cognitive performance presumably because of less variation in glucose metabolism and/or higher modulation in LNAA ratios indicated by the overall GIR.
在15名健康男学生中研究了食物中不同碳水化合物与蛋白质比例对认知功能的影响以及餐后代谢变化与认知变化之间的关系。受试者分三个阶段进行测试，每个阶段间隔1周，采用重复测量、平衡交叉设计，以检测情绪状态、客观认知功能、血液参数和间接热量测定的短期变化。在空腹过夜后以及摄入测试餐后3.5小时内每小时进行测量。等能量（1670千焦）的测试餐分别包含三种碳水化合物与蛋白质比例，即富含碳水化合物的餐食（CHO[4:1]）、均衡餐食（BAL[1:1]）和富含蛋白质的餐食（PRO[1:4]）。在摄入PRO[1:4]餐食后，短期记忆的总体准确性最佳，同时葡萄糖代谢和胰高血糖素与胰岛素比值（GIR）的变化最小。分别与葡萄糖代谢变化和/或大中性氨基酸（LNAA）比例变化相关，在摄入CHO[4:1]餐食后的第一小时内，注意力和决策时间短暂改善，而在第一小时后，BAL[1:1]餐食和PRO[1:4]餐食则使表现得到改善。在摄入BAL[1:1]餐食后，一项核心任务的总体反应时间最快，此时总体酪氨酸（Tyr）与LNAA的比例最高。我们的研究结果表明，食物中的碳水化合物与蛋白质比例特别影响早晨的高级认知功能。除了富含碳水化合物的餐食后血糖升高的短暂积极作用外，富含蛋白质或均衡的餐食似乎能带来更好的总体认知表现，这可能是因为葡萄糖代谢变化较小和/或由总体GIR表明的LNAA比例调节更高。
