Green tea interactions and adverse reactions:
Green tea has been quoted by multiple sources to contain a range of 120 to 160 mg of catechins per cup and an average of 23 mg of caffeine per cup (range of 11-48mg) but with high variability. Preventive Health Advisor recommends that liver function tests be obtained for green tea consumption of 4 cups per day or greater at baseline, after 3 months, at 6 months, and then at the physician’s discretion due to high a variability in green tea catechin content. Green tea extract is not recommended due to increased risk of hepatotoxicity with a higher concentration of catechins which it provides. Patients should be advised to avoid drugs metabolized by the liver such as acetaminophen.