- Title
- L-theanine improves neurophysiological measures of attention in a dose-dependent manner: a double-blind, placebo-controlled, crossover study
- Creator
- Dassanayake, Tharaka L.; Kahathuduwa, Chanaka N.; Weerasinghe, Vajira S.
- Relation
- Nutritional Neuroscience Vol. 25, Issue 4, p. 698-708
- Publisher Link
- http://dx.doi.org/10.1080/1028415X.2020.1804098
- Publisher
- Taylor & Francis
- Resource Type
- journal article
- Date
- 2022
- Description
- Objective: L-theanine, a non-proteinic amino acid found in tea, is known to enhance attention particularly in high doses, with no reported adverse effects. We aimed to determine whether oral administration of L-theanine acutely enhances neurophysiological measures of selective attention in a dose-dependent manner. Methods: In a double-blind, placebo-controlled, counterbalanced, 4-way crossover study in a group of 27 healthy young adults, we compared the effects of 3 doses of L-theanine (100, 200 and 400 mg) with a placebo (distilled water) on latencies of amplitudes of attentive and pre-attentive cognitive event-related potentials (ERPs) recorded in an auditory stimulus discrimination task, before and 50 min after dosing. Results: Compared to the placebo, 400 mg of theanine showed a significant reduction in the latency of the parietal P3b ERP component (p < 0.05), whereas no significant changes were observed with lower doses. A subsequent exploratory regression showed that each 100-mg increase in dose reduces the P3b latency by 4 ms (p < 0.05). No dose–response effect was observed in P3b amplitude, pre-attentive ERP components or reaction time. Discussion: The findings indicate L-theanine can increase attentional processing of auditory information in a dose-dependent manner. The linear dose–response attentional effects we observed warrant further studies with higher doses of L-theanine.
- Subject
- theanine; attention; cognition; event-related potentials; P300; reaction time
- Identifier
- http://hdl.handle.net/1959.13/1452657
- Identifier
- uon:44475
- Identifier
- ISSN:1476-8305
- Rights
- This is an Accepted Manuscript of an article published by Taylor & Francis in Nutritional Neuroscience on 11/08/2020, available online: https://www.tandfonline.com/doi/full/10.1080/1028415X.2020.1804098
- Language
- eng
- Full Text
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