The Effects of Green Tea Amino Acid L-Theanine Consumption on the Ability to Manage Stress and Anxiety Levels: a Systematic Review

Jackson L. Williams, Julian M. Everett, Nathan M. D’Cunha, Domenico Sergi, Ekavi N. Georgousopoulou, Richard J. Keegan, Andrew J. McKune, Duane D. Mellor, Nicola Anstice, Nenad Naumovski*

*Corresponding author for this work

Research output: Contribution to journalReview articlepeer-review

Abstract

The green tea amino acid, L-theanine (L-THE) is associated with several health benefits, including improvements in mood, cognition and a reduction of stress and anxiety-like symptoms. This systematic review evaluated the effect of pure L-THE intake, in the form of orally administered nutritional supplements, on stress responses and anxiety levels in human randomised controlled trials. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist, 9 peer-reviewed journal articles were identified where L-THE as a supplement was compared to a control. Our findings suggest that supplementation of 200–400 mg/day of L-THE may assist in the reduction of stress and anxiety in people exposed to stressful conditions. Despite this finding, longer-term and larger cohort clinical studies, including those where L-THE is incorporated into the diet regularly, are needed to clinically justify the use of L-THE as a therapeutic agent to reduce stress and anxiety in people exposed to stressful conditions.

Original languageEnglish
Pages (from-to)12–23
Number of pages12
JournalPlant Foods for Human Nutrition
Volume75
Early online date22 Dec 2019
DOIs
Publication statusPublished - Mar 2020

Bibliographical note

© Springer Nature B.V. 2019. The final publication is available at Springer via http://dx.doi.org/10.1007/s11130-019-00771-5

Keywords

  • Anxiety
  • Green tea
  • Human trials
  • L-theanine
  • Mental health
  • Stress response

Fingerprint

Dive into the research topics of 'The Effects of Green Tea Amino Acid L-Theanine Consumption on the Ability to Manage Stress and Anxiety Levels: a Systematic Review'. Together they form a unique fingerprint.

Cite this