Tea L-theanine Cognition Sleep Mood Meta-analysis: What the Evidence Says

Quick Answer

Tea L-theanine Cognition Sleep Mood 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

• ,,, 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]
• Sleep is a complex biological process whose evolutionary purpose has remained equivocal for quite some time.More recently, however, compelling evidence has emerged, leading to recognition of the numerous metabolic and physiological functions sleep contributes to and actively supports. [Conti Federica (2026); evidence level 4]
• Epidemiological studies have revealed that sleep deprivation is associated with an increased risk of all-cause mortality,alongside numerous chronic conditions imposing a heavy burden on our healthcare and socioeconomic systems alike,including cardiovascular disease, stroke, obesity, type 2 diabetes, and various types of cancer and neurological disorders. [Conti Federica (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 tea l-theanine cognition sleep mood 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

• 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/
• Conti Federica (2026). Dietary Protocols to Promote and Improve Restful Sleep: A Narrative Review. DOI: 10.1093/nutrit/nuaf062. PMCID: PMC13075487. PMID: 40418260. 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/PMC13075487/

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.