The combination of L-theanine and caffeine improves cognitive performance and increases subjective alertness
| Autor: | E.A. De Bruin, Jane Rycroft, Timo Giesbrecht, Matthew Rowson |
|---|---|
| Rok vydání: | 2010 |
| Předmět: |
Adult
Male Elementary cognitive task Task switching Adolescent Medicine (miscellaneous) Blood Pressure Placebos chemistry.chemical_compound Cognition Double-Blind Method Glutamates Heart Rate Caffeine Heart rate Reaction Time Humans Attention Effects of sleep deprivation on cognitive performance Fatigue Nutrition and Dietetics Tea General Neuroscience General Medicine Theanine Alertness Affect Blood pressure chemistry Anesthesia Female Psychology |
| Zdroj: | Nutritional neuroscience. 13(6) |
| ISSN: | 1476-8305 |
| Popis: | The non-proteinic amino acid L-theanine and caffeine, a methylxanthine derivative, are naturally occurring ingredients in tea. The present study investigated the effect of a combination of 97 mg L-theanine and 40 mg caffeine as compared to placebo treatment on cognitive performance, alertness, blood pressure, and heart rate in a sample of young adults (n = 44). Cognitive performance, self-reported mood, blood pressure, and heart rate were measured before L-theanine and caffeine administration (i.e. at baseline) and 20 min and 70 min thereafter. The combination of moderate levels of L-theanine and caffeine significantly improved accuracy during task switching and self-reported alertness (both P < 0.01) and reduced self-reported tiredness (P < 0.05). There were no significant effects on other cognitive tasks, such as visual search, choice reaction times, or mental rotation. The present results suggest that 97 mg of L-theanine in combination with 40 mg of caffeine helps to focus attention during a demanding cognitive task. |
| Databáze: | OpenAIRE |
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