Amino Acids · L-Theanine

Walnut peptide and theanine combination (WPT) improves chronic stress-induced sleep disorders by restoring slow-wave sleep duration and quality in adults with poor sleep quality.

In an 8-week randomized, placebo-controlled human trial, WPT restored sleep duration and improved subjective sleep quality scores (PSQI ≥ 7). Mechanistically, WPT reduced serum corticosterone levels and increased GABA and tryptophan in CUMS mice, indicating HPA axis regulation and neurotransmitter modulation.

1 min readUpdated Jul 7, 20261 RCTsView structured evidence →
Evidence Score44/100
Human RCT★★☆☆☆
Meta-analysis☆☆☆☆☆
Mechanism★★★★★
Safety★★★★
Confidencelow

This article is automatically generated from the structured evidence profile behind the claim above. Scores reflect the quality and quantity of available research, not clinical advice.

Walnut peptide and theanine combination (WPT) improves chronic stress-induced sleep disorders by restoring slow-wave sleep duration and quality in adults with poor sleep quality. The current body of evidence comprises 1 study, including 1 randomized controlled trial. EvidenceHub rates the overall confidence at 44/100 (low).

The Claim

Walnut peptide and theanine combination (WPT) improves chronic stress-induced sleep disorders by restoring slow-wave sleep duration and quality in adults with poor sleep quality.

This conclusion is most relevant to: Adults with poor sleep quality (PSQI ≥ 7) in human trial; additionally, zebrafish and CUMS mice in preclinical models.

What the Research Shows

The conclusion draws on 1 linked study. Highlights from the cited literature:

  • Walnut peptide and theanine combination ameliorates sleep disorders: a multi-species study including a human trial. (Food & function, 2026) —

How It Works

The proposed biological pathway:

  • Reduces HPA axis hyperactivity by lowering elevated serum corticosterone
  • Increases inhibitory neurotransmitter GABA
  • Increases tryptophan, a precursor for serotonin and melatonin
  • Restores slow-wave sleep duration and delta wave power density, improving sleep architecture

Who Might Benefit

Evidence fit by population:

  • Adults with poor sleep quality (PSQI ≥ 7) in human trial; additionally, zebrafish and CUMS mice in preclinical models

Limitations & Caveats

Important context when interpreting this evidence:

  • Abstract does not report specific effect sizes or confidence intervals for human outcomes
  • Human trial sample size and detailed demographics not provided in abstract
  • Long-term efficacy and safety beyond 8 weeks are not addressed

Frequently Asked Questions

What is WPT?

WPT is a combination of walnut peptide and theanine, tested as a nutritional intervention for sleep disorders.

How does WPT improve sleep?

It reduces HPA axis hyperactivity by lowering corticosterone levels and increases inhibitory neurotransmitter GABA and tryptophan, a precursor for serotonin and melatonin.

Who was studied in the human trial?

Adults with poor sleep quality, defined as a Pittsburgh Sleep Quality Index (PSQI) score of 7 or higher.

What were the main outcomes in humans?

Restored sleep duration and improved subjective sleep quality as measured by the PSQI.

References

  1. 1.Gong J, Jia X, Wang L, Lu Y, Guo R, Gong R, Hao J, Zhao Z, Duan S, Liu X, He J, Li H, Liu Z. “Walnut peptide and theanine combination ameliorates sleep disorders: a multi-species study including a human trial..” Food & function, 2026. PMID: 41531275 DOI: 10.1039/d5fo03867g
Disclaimer: This article is auto-generated from structured research data for educational purposes only and is not medical advice. Evidence scores reflect the quality and quantity of available research, not clinical recommendations. Always consult a healthcare professional before starting any supplement or intervention.