White David J, de Klerk Suzanne, Woods William, Gondalia Shakuntla, Noonan Chris, Scholey Andrew B
Centre for Human Psychopharmacology, Swinburne University of Technology, Hawthorn VIC 3122, Australia.
Division of Pharmacology, Utrecht University, 3508 TC Utrecht, The Netherlands.
Nutrients. 2016 Jan 19;8(1):53. doi: 10.3390/nu8010053.
L-theanine (γ-glutamylethylamide) is an amino acid found primarily in the green tea plant. This study explored the effects of an L-theanine-based nutrient drink on mood responses to a cognitive stressor. Additional measures included an assessment of cognitive performance and resting state alpha oscillatory activity using magnetoencephalography (MEG). Thirty-four healthy adults aged 18-40 participated in this double-blind, placebo-controlled, balanced crossover study. The primary outcome measure, subjective stress response to a multitasking cognitive stressor, was significantly reduced one hour after administration of the L-theanine drink when compared to placebo. The salivary cortisol response to the stressor was reduced three hours post-dose following active treatment. No treatment-related cognitive performance changes were observed. Resting state alpha oscillatory activity was significantly greater in posterior MEG sensors after active treatment compared to placebo two hours post-dose; however, this effect was only apparent for those higher in trait anxiety. This change in resting state alpha oscillatory activity was not correlated with the change in subjective stress response or the cortisol response, suggesting further research is required to assess the functional relevance of these treatment-related changes in resting alpha activity. These findings further support the anti-stress effects of L-theanine.
L-茶氨酸（γ-谷氨酰乙酰胺）是一种主要存在于绿茶植物中的氨基酸。本研究探讨了一种基于L-茶氨酸的营养饮料对认知应激源情绪反应的影响。其他测量方法包括使用脑磁图（MEG）评估认知表现和静息状态下的α振荡活动。34名年龄在18至40岁之间的健康成年人参与了这项双盲、安慰剂对照、平衡交叉研究。与安慰剂相比，服用L-茶氨酸饮料1小时后，对多任务认知应激源的主观应激反应这一主要结局指标显著降低。主动治疗后3小时，对应激源的唾液皮质醇反应降低。未观察到与治疗相关的认知表现变化。与安慰剂相比，主动治疗后2小时，静息状态下后MEG传感器中的α振荡活动显著增强；然而，这种效应仅在特质焦虑较高的人群中明显。静息状态下α振荡活动的这种变化与主观应激反应或皮质醇反应的变化无关，这表明需要进一步研究来评估这些与治疗相关的静息α活动变化的功能相关性。这些发现进一步支持了L-茶氨酸的抗应激作用。
