News - Theanine may boost concentration when anxious
Daily supplements of theanine may help people with anxiety focus on their daily activities, suggests a new study from Japan.
Theanine is an amino acid found in tea leaves that has been shown to help reduce stress, promote relaxation and improve the quality of sleep. Unfortunately, theanine is only found in very low concentrations in tea (less than two per cent), which means that effective dosage levels (of 100 – 200mg/day) require supplementation.
In this new study, Japanese researchers recruited 18 healthy university students and assessed their anxiety levels using a specialist anxiety scale. Students with high anxiety were put in one group, while students with minimal anxiety were put in another group. Both groups received water or water plus 200mg of theanine. The test was performed repeatedly and assessments performed between 15 and 60 minutes after ingestion.
Results showed that highly anxious students receiving the theanine displayed a slowing of their heart rate, improved attention and better reaction times compared to members of the same group receiving just the water. EEG measurements carried out by the scientists also showed that the theanine increases the brain’s production of alpha brain waves, which are associated with a state of alert relaxation.
Commenting on their trial the authors wrote that the dose of 200mg of theanine “enhanced performance in visual attention task, and reaction time response, among the subjects with higher anxiety”, adding that “it is noteworthy to mention that unlike other conventional anti-anxiety treatments, L-theanine did not result in increased drowsiness, slowed reflexes, or impaired concentration”.
Ref: Higashiyama A et al. Effects of L-theanine on attention and reaction time response Journal of Functional Foods