# L-theanine Cognition Meta-analysis: What the Evidence Says
Canonical: https://www.migaku.app/guides/l-theanine-cognition-meta-analysis-evidence-review
Category: evidence-review
Summary: L-theanine Cognition Meta-analysis has 2 source documents in the current Migaku evidence database. The strongest available sources in this first pass are syst
Last reviewed: 2026-06-24
Reviewed by: Migaku Evidence Review
# L-theanine Cognition Meta-analysis: What the Evidence Says

## Quick Answer

L-theanine Cognition Meta-analysis has 2 source documents in the current Migaku evidence database. The strongest available sources in this first pass are systematic review, so conclusions should be framed as evidence-aware guidance rather than medical advice.

## Key Takeaways

- This page is generated only from sources stored in the Migaku evidence knowledge base.
- Current evidence mix: 2 systematic review.
- Claims should be interpreted with the source type, study design, population, and publication date in mind.
- This article is educational and does not replace care from a qualified clinician.

## Evidence Map

| Source | Evidence type | Level | Date | Identifier |
| --- | --- | ---: | --- | --- |
| 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 | systematic review | 1 | 2025-10-30 | 10.3390/jcm14217710 |
| Effects of Tea ( Camellia sinensis ) or its Bioactive Compounds l -Theanine or l -Theanine plus Caffeine on Cognition, Sleep, and Mood in Healthy Participants: A Systematic Review and Meta-Analysis of Randomized Controlled Trials | systematic review | 1 | 2025-10-01 | 10.1093/nutrit/nuaf054 |

## What The Sources Report

- Camellia sinensis Coffea arabica Camellia sinensis Paullinia cupana 1 2 3 3 3 4 3 5 l l Green tea is an evergreen plant found mainly in the tropical and temperate regions of Asia, especially in China, Srí Lanka, Japan and India, and it has been consumed for centuries as food and for its beneficial effects on human health. [Mátyus Rebeka Olga (2025); evidence level 1]
- Based on preclinical and clinical evidence, caffeine and-theanine are the two main constituents contributing to this effect. [Mátyus Rebeka Olga (2025); evidence level 1]
- ,,, Whilst current evidence points toward the beneficial effects of tea, or theanine plus caffeine, on cognition and mood, mostly being driven by caffeine, the presence and magnitude of positive effects observed appears to be inconsistent,possibly a result of variations in assessment methods and doses of caffeine and theanine. [Payne Edward R (2025); evidence level 1]
- Eligible studies were assessed for risk of bias using version 2 of the Cochrane risk-of-bias tool for randomized trials (RoB 2).Data extraction and quality assessment were performed by 1 author (E.P.). [Payne Edward R (2025); evidence level 1]

## How To Read This Evidence

Evidence level 1 generally reflects systematic reviews or meta-analyses. Level 2 includes randomized trials, guidelines, or public-health guidance. Level 3 usually reflects observational or narrative-review evidence. Level 4 is weaker or early-stage evidence. The level is a sorting aid, not a final quality grade.

## Practical Interpretation

There is at least one systematic-review style source in the current set, so it deserves more weight than single-study evidence. For l-theanine cognition meta-analysis, the next editorial step is to add more targeted sources and separate strong findings from early or indirect evidence.

## Limits Of This First Pass

This is a small-batch MVP article. It uses the first ingested sources for this topic and should be expanded with more targeted searches, license review, and human editorial checks before being treated as a definitive review.

## References

- Mátyus Rebeka Olga (2025). 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. DOI: 10.3390/jcm14217710. PMCID: PMC12609247. PMID: 41227106. License: CC BY 4.0. https://pmc.ncbi.nlm.nih.gov/articles/PMC12609247/
- Payne Edward R (2025). Effects of Tea ( Camellia sinensis ) or its Bioactive Compounds l -Theanine or l -Theanine plus Caffeine on Cognition, Sleep, and Mood in Healthy Participants: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. DOI: 10.1093/nutrit/nuaf054. PMCID: PMC12422004. PMID: 40314930. License: https://creativecommons.org/licenses/by-nc-nd/4.0/ https://creativecommons.org/licenses/by-nc-nd/4.0/ This is an Open.... https://pmc.ncbi.nlm.nih.gov/articles/PMC12422004/

## Safety Note

Health information can change, and individual risk depends on medical history, medications, pregnancy status, age, and diagnosis. Talk with a qualified clinician before changing treatment, supplement, or medication routines.