L-theanine Cognitive Performance Meta-analysis: What the Evidence Says

Quick Answer

L-theanine Cognitive Performance 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: 1 systematic review, 1 preclinical study.
• 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

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]
• Under normal conditions, it is sequestered in the cytoplasm by Kelch-like ECH-associated protein 1 (Keap1), which targets it for degradation. [Cipriano Giovanni Luca (2026); evidence level 4]
• The following subsections provide a detailed analysis of the molecular profiles and clinical evidence for these three primary bioactives. [Cipriano Giovanni Luca (2026); evidence level 4]

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 cognitive performance 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/
• Cipriano Giovanni Luca (2026). Phytochemical and Fungal Bioactive Compounds in the “Brain Health Triad”: A Narrative Review on Neurostimulating, Neurotrophic, and Neuroprotective Synergy. DOI: 10.3390/ijms27083607. PMCID: PMC13116414. PMID: 42074246. License: CC BY 4.0. https://pmc.ncbi.nlm.nih.gov/articles/PMC13116414/

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.