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Green tea and its bioactive compounds (EGCG, L-theanine) may improve mood disorder symptomology, particularly symptoms of depression, but no evidence supports effects on BDNF.

A systematic review of 13 RCTs found that green tea, green tea extract, L-theanine, or EGCG improved depressive symptoms in 4 studies, anxiety in 6, stress in 5, and sleep in 1. No studies reported statistically significant effects on brain-derived neurotrophic factor (BDNF).

Last updated: Jul 7, 2026•1 RCTs•📖 Read as article →

Evidence Score

Evidence Score42/100
Human RCT★★☆☆☆
Meta-analysis☆☆☆☆☆
Mechanism★★★★★
Safety★★★★☆
Confidencelow

Study Evidence

Study 1. The Impact of Green Tea and Its Bioactive Compounds on Mood Disorder Symptomology and Brain Derived Neurotrophic Factor: A Systematic Review of Randomized Controlled Trials.

observational

Cavanah AM, Robinson LA, Mattingly ML, Frugé AD · Biomedicines (2025)

Participants: N/A
Duration: N/A
Intervention: Green tea, green tea extract, matcha, traditional green tea, or bioactive compounds (EGCG, L-theanine)
Outcome: Mood disorder symptomology (depression, anxiety, stress, sleep) and brain-derived neurotrophic factor (BDNF)
Effect Size: N/A
Population: Adults with mood disorder symptomology (depression, anxiety, stress) from published RCTs

Result:

PubMed: 40722728DOI: 10.3390/biomedicines13071656

Mechanism Graph

Green tea bioactive compounds (EGCG, L-theanine) are ingested
↓
Compounds exert neuroprotective properties via antioxidant and anti-inflammatory pathways
↓
Mood-related neurotransmitter systems (e.g., serotonin, dopamine) are modulated
↓
Improvements in depressive, anxiety, and stress symptoms are observed

Limitations

  • ⚠Only 13 RCTs met inclusion criteria, limiting generalizability
  • ⚠No studies found a statistically significant effect on BDNF, suggesting lack of evidence for this mechanism

Frequently Asked Questions

Does green tea improve depression symptoms?▼

Yes, the systematic review found that 4 out of 13 RCTs reported improvements in depressive symptoms with green tea or its bioactive compounds.

Does green tea affect BDNF levels?▼

No, none of the included studies found a statistically significant effect of green tea or its compounds on brain-derived neurotrophic factor (BDNF).

What specific compounds in green tea were studied?▼

The review focused on epigallocatechin gallate (EGCG) and L-theanine, as well as green tea extract, matcha, and traditional green tea.

How many studies were included in this review?▼

Thirteen randomized controlled trials met the inclusion criteria and were analyzed in the systematic review.

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References

  1. 1.Cavanah AM, Robinson LA, Mattingly ML, Frugé AD. "The Impact of Green Tea and Its Bioactive Compounds on Mood Disorder Symptomology and Brain Derived Neurotrophic Factor: A Systematic Review of Randomized Controlled Trials.." Biomedicines, 2025. PMID: 40722728 DOI: 10.3390/biomedicines13071656
Disclaimer: This content is 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.