Thanks for bringing this to light, it does make sense that green tea extract would cause liver damage, as it is in a highly concentrated form, but I somewhat disagree on such risk for brewed green tea when taken with food, considering the extremely low prevalence of liver AE case reports for the brewed form.
As you can guess from my username, I am a big fan of matcha and green tea, but I always take them in brewed liquid form from tea bags after heavy meals and have been doing so for decades with no AE's of any kind whatsoever. I think the key is taking them with meals preferably heavy meals.
I conjecture that taking with meals help in 2 ways:
1. The catechins or EGCG interact with the food contents, especially non-haem iron, which reduces the bioavailability of active flavonoids reaching the liver.
2. Depending on the size of the meal, gastric emptying time is reduced to different extent. This will invariably reduce the rate in which the flavonoids reach the liver, thus reducing the likelihood of the liver being overwhelmed and resulting in AE.
It's hard for me to say anything definitive about this, as there is a paucity of research on the topic. Most of the case reports involve supplemental extracts, the three I came across involving liquid green tea involved matcha in one case and a Herbalife concentrate in another. Both of which, due to their powdered nature, may contain higher amounts of EGCG compared to regular leaf teas. The third case involved the teen drinking over three cups a day of "Chinese green tea", but the case report doesn't provide any further information on what form the tea presented in, ie powdered concentrate, tea bags, loose tea, etc.
So my stance at present is that everyone should avoid green tea extracts, exercise caution with liquid tea, and give them both a miss if one has a history of liver issues.
Thanks for bringing this to light, it does make sense that green tea extract would cause liver damage, as it is in a highly concentrated form, but I somewhat disagree on such risk for brewed green tea when taken with food, considering the extremely low prevalence of liver AE case reports for the brewed form.
As you can guess from my username, I am a big fan of matcha and green tea, but I always take them in brewed liquid form from tea bags after heavy meals and have been doing so for decades with no AE's of any kind whatsoever. I think the key is taking them with meals preferably heavy meals.
I conjecture that taking with meals help in 2 ways:
1. The catechins or EGCG interact with the food contents, especially non-haem iron, which reduces the bioavailability of active flavonoids reaching the liver.
2. Depending on the size of the meal, gastric emptying time is reduced to different extent. This will invariably reduce the rate in which the flavonoids reach the liver, thus reducing the likelihood of the liver being overwhelmed and resulting in AE.
It's hard for me to say anything definitive about this, as there is a paucity of research on the topic. Most of the case reports involve supplemental extracts, the three I came across involving liquid green tea involved matcha in one case and a Herbalife concentrate in another. Both of which, due to their powdered nature, may contain higher amounts of EGCG compared to regular leaf teas. The third case involved the teen drinking over three cups a day of "Chinese green tea", but the case report doesn't provide any further information on what form the tea presented in, ie powdered concentrate, tea bags, loose tea, etc.
So my stance at present is that everyone should avoid green tea extracts, exercise caution with liquid tea, and give them both a miss if one has a history of liver issues.