Green Tea Extract (EGCG) for Neuroprotection
Observational data on tea drinking is encouraging, but supplement trials have not shown neurological benefit.
Overview
Verdict
How It Works
Dosing & Protocol
Typical dose
- Recommended dose
- Not established; no human trial has tested green tea extract for neurological outcomes, and animal work used doses without a human equivalent
- Expected timeframe
- Not established
Protocol
- form
- Not applicable
- duration
- Not applicable
- co factor
- Evidence is insufficient. EGCG is neuroprotective in a wide range of animal models - it chelates iron, reduces amyloid aggregation, inhibits neuroinflammation and crosses the blood-brain barrier to a limited degree - and observational studies associate habitual green tea drinking with lower dementia and Parkinson disease incidence in Japanese and Chinese cohorts. Neither establishes benefit: observational associations are heavily confounded by overall diet, activity and socioeconomic factors, and no randomised trial has tested green tea extract for cognitive decline, dementia prevention or any neurological outcome. EGCG bioavailability in humans is low, and brain concentrations achieved are far below those used in cell studies.
- titration
- Not applicable
- starting dose
- Not applicable as an established treatment
Evidence
What the studies say
No studies are yet linked to both Green Tea Extract (EGCG) and Neuroprotection.
Safety
Caveats
Progressive memory loss, difficulty with familiar tasks or personality change needs medical assessment for reversible causes including B12 deficiency, thyroid disease, depression, sleep apnoea and medication effects. What has evidence for brain health is blood pressure control, physical activity, hearing aids for hearing loss, treating diabetes, sleep and smoking cessation. Safety ceiling: EFSA identified 800 mg/day or more of EGCG from supplements as associated with hepatotoxicity, with cases of acute liver injury including transplantation, and risk is highest with concentrated extracts taken fasted. Stop for nausea, abdominal pain, dark urine, pale stools or jaundice; avoid with liver disease or other hepatotoxic drugs. Green tea reduces iron absorption - relevant since iron chelation is part of the proposed mechanism - so separate from iron by two hours. It reduces the efficacy of nadolol, atenolol and bortezomib, interacts with warfarin via vitamin K, and has antiplatelet activity. In pregnancy keep caffeine below 200 mg/day.
Less likely to help if
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Individual results may vary. The statements on this website have not been evaluated by the Food and Drug Administration. Products and information are not intended to diagnose, treat, cure, or prevent any disease.