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).
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.
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. The current body of evidence comprises 1 study, including 1 randomized controlled trial. EvidenceHub rates the overall confidence at 42/100 (low).
The Claim
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.
This conclusion is most relevant to: Adults from published randomized controlled trials.
What the Research Shows
The conclusion draws on 1 linked study. Highlights from the cited literature:
- ▸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) —
How It Works
The proposed biological pathway:
- ▸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
Who Might Benefit
Evidence fit by population:
- ▸Adults from published randomized controlled trials
Recommended Dose
N/A
Limitations & Caveats
Important context when interpreting this evidence:
- ▸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.
References
- 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