Department of Psychology, Fylde College, University of Lancaster, Lancaster, LA 1 4YW, UK.
Psychopharmacology (Berl). 2012 Jan;219(1):83-97. doi: 10.1007/s00213-011-2379-0. Epub 2011 Jun 28.
Acute stress has been associated with changes in cognitive performance and mood, and these have been in part associated with stress-related increased release of cortisol. Both glucose and caffeine consumed in isolation have been shown to moderate cortisol response and affect cognitive performance and affect mood; however, there has been very little research into their behavioural and physiological effects when taken in combination. The aim of this study was to assess the effect of the two substances in combination under stressful and physically demanding conditions (fire-fighting training) on cognition, mood and cortisol release.
Using a double-blind, mixed measures design, 81 participants were administered a 330-ml drink containing either (1) 50 g glucose and 40 mg caffeine, (2) 10.25 g of fructose/glucose and 80 mg caffeine or a placebo drink and tested across a range of cognitive tasks, mood and physiological measures.
The results showed an increase in grip strength and improved memory performance after ingestion of the drink containing 50 g glucose and 40 mg caffeine, and both active drinks resulted in improved performance on the information-processing task compared to the placebo. In terms of mood effects, the drink containing 50 g glucose and 40 mg caffeine led to a reduction in anxiety and significantly reduced self-reported levels of stress following the fire-fighter training.
Based on the results of this study, in situations of stress combined with physical performance, administration of an energy drink containing glucose and caffeine might be an easy to implement and cost effective way to maintain mental performance levels and to ameliorate the negative effects of stress on mood.
急性应激与认知表现和情绪的变化有关，而这些变化部分与应激相关的皮质醇释放增加有关。单独摄入葡萄糖和咖啡因已被证明可以调节皮质醇反应，影响认知表现和情绪；然而，当它们一起服用时，对它们的行为和生理影响的研究很少。本研究旨在评估在应激和身体要求高的条件下（消防训练）两种物质联合使用对认知、情绪和皮质醇释放的影响。
使用双盲、混合措施设计，81 名参与者被给予含有（1）50 克葡萄糖和 40 毫克咖啡因、（2）10.25 克果糖/葡萄糖和 80 毫克咖啡因或安慰剂的 330 毫升饮料，并在一系列认知任务、情绪和生理测量中进行测试。
结果显示，摄入含有 50 克葡萄糖和 40 毫克咖啡因的饮料后，握力增强，记忆表现提高，两种活性饮料在信息处理任务上的表现均优于安慰剂。在情绪影响方面，含有 50 克葡萄糖和 40 毫克咖啡因的饮料可减少焦虑，并且在消防训练后显著降低自我报告的压力水平。
基于这项研究的结果，在应激结合身体表现的情况下，给予含有葡萄糖和咖啡因的能量饮料可能是一种简单易行且具有成本效益的方法，可以维持心理表现水平，并改善应激对情绪的负面影响。
