SynthesisPlant foods for human nutrition (Dordrecht, Netherlands)2020
The Effects of Green Tea Amino Acid L-Theanine Consumption on the Ability to Manage Stress and Anxiety Levels: a Systematic Review.
Synthesis in Plant foods for human nutrition (Dordrecht, Netherlands), 2020. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to 3 registered trials, which are not on this map. Cited by 52 papers.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
A Randomized, Double-blinded, Placebo-controlled, Crossover Study, to Assess the Synergistic Effects of a Cranberry Beverage on Cognitive Function
A Double-blind, Randomized, Placebo-controlled Study to Evaluate the Effects of a Theanine Formulation on Stress, Burnout, Mood, and Sleep in Individuals Who Report Occasional Moderate or High Levels of Stress
A Double-blind, Randomized, Placebo-controlled Study to Evaluate the Effects of a Theanine for Stress Relief Formulation on Stress, Burnout Component, Mood, and Sleep in Individuals Who Report Occasional Moderate or High Levels of Stress
Who cites it
52 citing papers in PubMed, 122 citations in OpenAlex.
- Modulating stress and sleep through a multi-compound dietary supplement: a randomized, double-blind, placebo-controlled trial.Journal of the International Society of Sports Nutrition · 2026Trial
- Performance-enhancing effects of caffeine and L-Theanine among Iranian elite wrestlers: a focus on cognitive and specific physical performance.Journal of the International Society of Sports Nutrition · 2025Trial
- Effect of single or combined caffeine and L-Theanine supplementation on shooting and cognitive performance in elite curling athletes: a double-blind, placebo-controlled study.Journal of the International Society of Sports Nutrition · 2023Trial
- Soft Drinks and Symptoms of Depression and Anxiety in Overweight Subjects: A Longitudinal Analysis of an European Cohort.Nutrients · 2023Trial
- Matcha green tea beverage moderates fatigue and supports resistance training-induced adaptation.Nutrition journal · 2023Trial
- Use of Nutritional Supplements Based on L-Theanine and Vitamin B6 in Children with Tourette Syndrome, with Anxiety Disorders: A Pilot Study.Nutrients · 2022Trial
- Subjective Effects of Inhaling Kuromoji Tea Aroma.Molecules (Basel, Switzerland) · 2021Trial
- Metabolomic Signatures of Commercial Ready-to-Drink Beverages by Dual-Mode Untargeted LC-MS/MS.Metabolites · 2026Article
- Fecal virome transplantation alleviates weaning stress-induced behavioral alterations and intestinal health by reshaping the gut microbiome.Scientific reports · 2026Article
- Benefits of a Natural Dietary Supplement for Tinnitus: An Observational Prospective Exploratory Study.Audiology research · 2026Article
- Antidepressant Mechanisms of L-Theanine in Tea Based on Network Pharmacology, Molecular Docking, and Molecular Dynamics Simulations.Foods (Basel, Switzerland) · 2026Article
- Gut microbiota-derived L-theanine promotes host branched-chain amino acid catabolism.Nature microbiology · 2026Article
- The difference in light intensities during culture affects the production of health-beneficial metabolites in a diatom used in producing aquaculture feed.Scientific reports · 2026Article
- Guizhou Green Tea Metabolomics Analysis: Volatile Metabolites Based on HS-GC-IMS and UPLC-Q-TOF-MSMS and Quality Evaluation.International journal of food science · 2026Article
- L-Theanine ameliorates high-protein diet-associated hepatic glucose and lipid metabolic alterations by promoting fatty acid β-oxidation and suppressing lipid synthesis and gluconeogenesis in rats.Current research in food science · 2026Article
- Effects of L-theanine on cognition, mood and sleep: evidence from human trials.Frontiers in nutrition · 2026Review
- Effect ofIBRO neuroscience reports · 2025Article
- Promising, but Not Completely Conclusive-The Effect of l-Theanine on Cognitive Performance Based on the Systematic Review and Meta-Analysis of Randomized Placebo-Controlled Clinical Trials.Journal of clinical medicine · 2025Review
- Via entropy analysis (EA) and systematic cluster analysis (SCA), multi-index chemometric analysis of 20 amino acids, trace elements, etc., of five green teas from Guizhou, China.BMC chemistry · 2025Article
- Theanine modulation of monoamine metabolism visualized by derivatized imaging mass spectrometry.Scientific reports · 2025Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
10 authors at 4 institutions in 3 countries.
Funding
No grant is acknowledged in the PubMed record.
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.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.