Effects Of L-theanine Or Caffeine Intake On Changes In Blood Pressure Under Physical And Psychological Stresses
Notes for this study:
||POMS. Figure 4
|Number of Subjects
In this randomized, placebo-controlled crossover trial, 16 healthy participants took 200 mg of theanine, 100 mg of caffeine, or placebo on separate days 7 days apart prior to performing a stressful task, followed by a cold pressor test.
Theanine decreased the rise in blood pressure after mental tasks in participants with a high-stress response, but the difference fo those with low-stress responses wasn't statistically significant. There weren't statistically significant differences during the cold pressor or recovery period, suggesting a mental effect only. Tension-anxiety on the Profile Of Mood States was notably reduced by theanine,. There were also lower feelings of depression, anger-hostility, fatigue/inertia, and confusion, but the differences weren't statistically significant. Vigor-activity wasn't different.