Hepatotoxicity with High-Dose Green Tea Extract: Effect of COMT and UGT1A4 Genes

Based on this paper [1] green tea can have up to about 130 mg per gram EGCG. In that case 6.5 grams of tea. Tea bags usually have about a gram and a half, but the extracion is less. In studies like this the tea is usually brewed for 5 minutes and in this study brewed 1g to 100ml.

My take is that it is not an unreasonable amount.

[1]https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6100455/#!po=31...

Drinking green tea doesn't seem to produce the same hepatoxicity as seen with green tea extract taken in pill form. The problem is the high catechin concentration of the extract and the large acute dose.

https://pubmed.ncbi.nlm.nih.gov/29580974/

"Average green tea consumption was reportedly three cups per day among tea drinkers (Hakim et al., 2003; Kaegi, 1998; Khokhar and Magnusdottir, 2002), while in some countries it could be as high as ten cups per day (Muramatsu, 1991)"

"Our review supports that consumption of GTE or EGCG in bolus dose, but not green tea consumed as a beverage or part of the diet, is causally associated with hepatotoxicity"

"Evidence from animal studies demonstrated that hepatotoxicity risk rose with increasing concentrations of catechins and EGCG"

"Hepatotoxicity was clearly absent in the animal studies in which GTE or EGCG was administered in the diet or drinking water despite that concentrations of catechins in the test materials were greater than that of a traditional green tea infusion (> 68% w/w)."