T Nation

Green Tea Toxicity

According to this article, up to 10 cups a day is ok, but any more than that and it may cause liver and kidney damage. How many people here drink at least that much? Any problems so far?

Green tea can be harmful in large quantities

Green tea is good for you, but only if drunk in moderation. While the polyphenols in green tea are credited with preventing heart disease and cancer, it seems they can cause liver and kidney damage if consumed in very large quantities, a review of studies into the toxicity of polyphenols has shown.

“People shouldn’t be too alarmed by this, but those taking supplements may experience problems,” says lead author Chung Yang of Rutgers, the State University of New Jersey.

He stresses that up to 10 small cups of green tea a day is fine. Problems are likely in people who take supplements, which can contain up to 50 times as much polyphenol as a single cup of tea.

Yang’s review cites experiments in which rodents and dogs died from liver poisoning when given very large doses of polyphenols. He also reports cases of people with liver toxicity after overdosing on green-tea-based supplements. Their symptoms disappeared when they stopped taking the pills, only to return when they started taking them again (Chemical Research in Toxicology, vol 20, p 583).

News Flash: Anything can be harmful in large quantities, moderation is key.

Any one who drinks more than 10 cups of caffeinated beverages a day is a dumb ass. I drink 2 maybe 3 cups of coffee or tea a day sometimes i mix em but the total is never more than 3 caffeinated beverages a day. CP says 3-5 cups a day depending on your body size is benefical and wont hurt you.

[quote]rsg wrote:
News Flash: Anything can be harmful in large quantities, moderation is key.[/quote]

FUCK! Now you tell me.

Stops drinking Spike by the gallon

[quote]Brutus_G wrote:
Any one who drinks more than 10 cups of caffeinated beverages a day is a dumb ass. I drink 2 maybe 3 cups of coffee or tea a day sometimes i mix em but the total is never more than 3 caffeinated beverages a day. CP says 3-5 cups a day depending on your body size is benefical and wont hurt you.[/quote]

Dumb ass? If you want to name call at least get your argument to make sense please. Coffee averages about 150mg. of caffeine a cup, green tea about 30mg. So if you drink 2-3 cups of coffee a day, you are consuming the equivalent caffeine of 10-15 cups of green tea. This article wasn’t about caffeine anyway.

Im not trying to make an argument i just think its foolish to drink that much tea.

[quote]duece wrote:
Brutus_G wrote:
Any one who drinks more than 10 cups of caffeinated beverages a day is a dumb ass. I drink 2 maybe 3 cups of coffee or tea a day sometimes i mix em but the total is never more than 3 caffeinated beverages a day. CP says 3-5 cups a day depending on your body size is benefical and wont hurt you.

Dumb ass? If you want to name call at least get your argument to make sense please. Coffee averages about 150mg. of caffeine a cup, green tea about 30mg. So if you drink 2-3 cups of coffee a day, you are consuming the equivalent caffeine of 10-15 cups of green tea. This article wasn’t about caffeine anyway.[/quote]

I’m not sure about that article, but I recently read that green tea can be harmful because of the flouride in it. I think I read that at Mercola’s site. Anybody care to comment on that?

Keep in mind this is a rat study, but just some food for thought:

Effect of green tea extracts on liver functions in Wistar rats.Bun SS, Bun H, Guedon D, Rosier C, Ollivier E.
Laboratory of Pharmacognosy, Faculty of Pharmacy, 27 Boulevard Jean Moulin, F-13385 Marseille Cedex 5, France. siya.bun@pharmacie.univ-mrs.fr

An herbal medicinal product (Exolise) containing as active ingredient an hydro-alcoholic extract of green tea named AR25 (standardized to 25% catechins) has been implicated in hepatic failures, leading to the withdrawal of the marketing authorization.

The active ingredient of Exolise being manufactured with 80% ethanol, the question to know whether the extraction solvent could introduce some toxic components was hypothesized.

Two investigations were conducted in Wistar rats to determine if repeated oral administration of different green tea extracts could corroborate the reported hepatotoxicity in humans.

In a preliminary 6 week-study, experimental groups (n=9/group) received either the vehicle or a methylene chloride extract (2500 mg/kg body weight) where potential non-polar hepatotoxin(s) could be concentrated.

In a second experiment (12 week-study), rats were divided in three groups (n=10/group) and treated with either the vehicle, or an aqueous extract (1400 mg/kg) or AR25 green tea extract (2000 mg/kg).

Rat liver functions were assessed by serum biochemistry of hepatotoxicity markers. No sign of evidence of characteristic hepatotoxicity was found in rats treated with very high amount of different green tea extracts in these two experiments (respectively a daily dosage, which was about 900 and 80 times higher to the therapeutic daily dosage of Exolise.

I hope its OK because I drink like 2 liters of the (non-caffienated) stuff a day. The water in Japan doesnt agree with me at all and I drink Green Tea instead

I wouldn’t worry about it. When was the last time you saw rats and dogs attack a tea plantation. Never? Well, that would be because they don’t consume tea. Never have, and prob never will.

No evolution = elevated rates of toxicity, because the organism has nothing in place to deal with the terpenes present in an overdose sample. I really wish we’d evolve away from animal studies. I drink 3 big 30oz mugs of tea, and even incidently consume some of the grounds, every day, and my liver works just fine.

DJ

[quote]greekdawg wrote:
I’m not sure about that article, but I recently read that green tea can be harmful because of the flouride in it. I think I read that at Mercola’s site. Anybody care to comment on that?[/quote]

I came across the same information on Weston A. Price’s website. I think it is a legitimate concern.

[quote]scorch wrote:
Keep in mind this is a rat study, but just some food for thought:

The active ingredient of Exolise being manufactured with 80% ethanol, the question to know whether the extraction solvent could introduce some toxic components was hypothesized.

[/quote]

So, let me get this straight, the green tea supplement mentioned in the article might have contained 80% Ethanol, like the corn-derived gasoline substitute? That’ll fuck you right up. The supplement I take is only supposed to be the equivalent of 2-3 cups of green tea in a 450 mg capsule. Two a day should be fine. I hope. Where are these wonder pills that contain 50x the amount, or is Exolise the only one?