The Effects Of L-theanine, Caffeine And Their Combination On Cognition And Mood
Notes for this study:
|Number of Subjects
In this randomized, placebo-controlled crossover trial, 24 healthy participants took 250 mg of theanine, 150 mg of caffeine, the combination, or placebo on different days 7 days apart, prior to cognitive and mood testing.
Funding issues for this study:
Simple reaction time was greatest in the combination group, but not statistically significant compared with caffeine, and theanine wasn't statistically significant compared with placebo. Digit vigilance reaction time didn't suggest a difference of theanine compared with placebo, nor did RVIP accuracy, numeric memory, sentence verification accuracy, though the combination was higher than caffeine, but not significant. Word recognition was nonsignificantly faster in the combination group. The theanine group performed worse on serial 7s after 90 minutes but not 30 minutes.
The combination increased alertness more than any other intervention, whereas l-theanine alone nonsignificantly decreased it. Tiredness, mental fatigue were unaffected by theanine, and theanine increased headaches.
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