42 replies to this topic

[thenaturalstep]

I just think some needs to read this, since many here take green tea supplements, also "green tea + milk" neutralize the health effect so no milk while drinking green tea ....

http://www.newscient...line-news_rss20

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).

http://www.pubmedcen...i?artid=1964900

Case reports on the toxic effects of green tea extracts in humans are also beginning to emerge. “To date, there have been nine anecdotal case reports of liver toxicity in humans associated with consumption of high doses [700–2,000 mg/day] of green tea from dietary supplements,” s


And if you check the regimes (now i am not sure if it is only green tea extract in that) ....

http://www.imminst.o...ime-t11030.html
As soon as I wake: 60 minutes before breakfast
EGCG Green Tea Extract (NOW Foods) 400mg

Mid afternoon 60 minutes before meal or training:
EGCG Green Tea Extract (NOW Foods) 400mg

Edited by thenaturalstep, 13 December 2007 - 10:33 PM.

[Athanasios]

Here is a study that shows why the toxicity will occur:
http://clincancerres...t/full/9/9/3312

We conclude that p.o. administration of EGCG or Polyphenon E at a daily dose of 800 mg (based on the EGCG content) for 4 weeks is safe and well tolerated in healthy human subjects. Repeated green tea polyphenol administration at a high daily bolus dose (800 mg once daily) results in a >60% increase in the systemic exposure of EGCG, possibly because of inhibition of presystemic elimination of this catechin. Repeated administration of EGCG and Polyphenon E at a daily dose equivalent to the EGCG content in 16 Japanese-style cups of green tea for 4 weeks did not provide protection against UV-induced erythema.

also note:

The 400-mg twice daily regimen apparently did not result in tea catechin concentrations that would exert a significant inhibitory effect. The mechanism(s) responsible for the observed increase in the AUC of free EGCG after chronic treatment of EGCG/Polyphenon E at a high daily bolus dose remain(s) to be studied. Inhibitions in nonenzymatic degradation, intestinal flora metabolism, methylation, and/or intestinal efflux of EGCG are plausible contributing factors.

And here is the review in which the remarks from Chang are derived:
http://pubs.acs.org/.../tx7000515.html
Check out the mg/kg

Despite several human studies that showed no toxicity of tea polyphenol preparations and that the major adverse effects associated with consumption of high doses of tea preparations are due to gastrointestinal irritation, there have been a number of recent case reports of hepatotoxicity related to the consumption of high doses of tea-based dietary supplements (10-29 mg/kg/day po)

So the end result seems to be to take less than 800mg/day worth of EGCG (note: not just tea supplement). I would also consider splitting the dosage if taking 600mg worth or higher in a day.
This is what I take from it but I am not a doctor.

Edited by cnorwood, 13 December 2007 - 11:02 PM.

[Mind]

I usually brew 4 bags (each bag is meant to make 1 cup) and drink it during the morning over the course of 6 hours. I doubt this would be of much concern but I am not sure how much EGCG is in one brewed bag. Anyone have a quick answer? I'll go searching.

[Athanasios]

I usually brew 4 bags (each bag is meant to make 1 cup) and drink it during the morning over the course of 6 hours. I doubt this would be of much concern but I am not sure how much EGCG is in one brewed bag. Anyone have a quick answer? I'll go searching.

The papers here show concentrations of water extract and others:
http://www.imminst.o...showtopic=11475
You will be way under the 800mg mark. No worries

Edited by cnorwood, 13 December 2007 - 11:34 PM.

[Mind]

This website, not the most scientific, claims regular green tea to have up to 180mg of EGCG per cup. Would be close if true, but still under 800mg. Also claims decaf green tea has three times less EGCG.

[Athanasios]

This website, not the most scientific, claims regular green tea to have up to 180mg of EGCG per cup. Would be close if true, but still under 800mg. Also claims decaf green tea has three times less EGCG.

Yeah, that figure gets thrown around a lot but is false. You will even find it all over peer reviewed literature. You will not get near that amount unless it is an alcohol extract of sencha. To get an accurate number you have to read a full study in which they actually measure it themselves.

Edited by cnorwood, 13 December 2007 - 11:47 PM.

[stephen_b]

Now I'm starting to get a little concerned about taking matcha green tea (PMID: 14518774):

Catechins in green tea are known to have many beneficial health properties. Recently, it has been suggested that matcha has greater potential health benefits than other green teas. Matcha is a special powdered green tea used in the Japanese tea ceremony. However, there has been no investigation to quantitate the catechin intake from matcha compared to common green teas. We have developed a rapid method of analysis of five catechins and caffeine in matcha using micellar electrokinetic chromatography. Results are presented for water and methanol extractions of matcha compared with water extraction of a popular green tea. Using a mg catechin/g of dry leaf comparison, results indicate that the concentration of epigallocatechin gallate (EGCG) available from drinking matcha is 137 times greater than the amount of EGCG available from China Green Tips green tea, and at least three times higher than the largest literature value for other green teas.

Stephen

[Athanasios]

Now I'm starting to get a little concerned about taking matcha green tea (PMID: 14518774):

No worries. That just shows how little there is in the off the shelf water extracted brew. Sencha's levels are not dangerously high either even though it has about 3 times as much EGCG as matcha! The levels for alcohol extract (approximates full leaf ingestion) was about 50mg/g of EGCG for matcha and 150 per gram for sencha.

Edited by cnorwood, 13 December 2007 - 11:59 PM.

[malbecman]

Nice find, thanks for all the postings. I got a little concerned at the beginning of the thread as I use the concentrated BAC green tea powder but am only usually making a tea with their powder that has ~250mgs EGCG (phew) so I should be under the threshold. Still, I guess polyphenols are just like everything else and we should follow Ben Franklin's advice, " All things in moderation and moderation in all things."

edit: On 2nd thought, maybe it was Aristotle who said something like that. anyways, you get the drift....

Edited by malbecman, 14 December 2007 - 01:00 AM.

[stephen_b]

That's a relief. I've really come to like the taste of matcha. I think I can hold myself to under 16 grams a day.

Stephen

[malbecman]

I recall Celestial Seasonings saying their green tea contained one of the highest levels of EGCG but I don't recall the exact #. I believe it was like ~110-150mgs?!? Anyone else remember the exact #? I've checked their website but they have completely changed it and it no longer has some of the pages about the potential health benefits of drinking tea (where I saw the original #). A couple of mugfuls of their stuff could mayb get you close to the limit, esp. since I know some people who brew it 2X.....

[Athanasios]

I recall Celestial Seasonings saying their green tea contained one of the highest levels of EGCG but I don't recall the exact #. I believe it was like ~110-150mgs?!? Anyone else remember the exact #? I've checked their website but they have completely changed it and it no longer has some of the pages about the potential health benefits of drinking tea (where I saw the original #). A couple of mugfuls of their stuff could mayb get you close to the limit, esp. since I know some people who brew it 2X.....

Unless they add additional EGCG themselves, no leaf has been recorded that has a water extract anywhere near that. Unless you are ingesting the leaf, drinking it powdered, or are taking extract it shouldnt even be a remote concern. Water extracts are VERY inefficient at extracting EGCG but they do get most of the caffeine out. Seriously, a water extract would be considered potent at 1mg of EGCG per gram of tea. Yep, that is a 1 and not a typo.

Edited by cnorwood, 14 December 2007 - 08:03 PM.

[malbecman]

You're right, sorry about that. I browsed around and could not find the Celestial Seasonings green tea ECGC content-it looks like most green teas are about 500-700 micrograms ECGC/ml of tea. I did find that Snapple's Green Tea does have 55mgs of ECGC:

Snapple's new Green Tea has the most EGCG, with 55mg per bottle, compared to leading ready-to-drink green teas, and is the second in a line of new products ...

www.snapple.com/newsletter/PressReleases.aspx?rid=23

I recall Celestial Seasonings saying their green tea contained one of the highest levels of EGCG but I don't recall the exact #. I believe it was like ~110-150mgs?!? Anyone else remember the exact #? I've checked their website but they have completely changed it and it no longer has some of the pages about the potential health benefits of drinking tea (where I saw the original #). A couple of mugfuls of their stuff could mayb get you close to the limit, esp. since I know some people who brew it 2X.....

Unless they add additional EGCG themselves, no leaf has been recorded that has a water extract anywhere near that. Unless you are ingesting the leaf, drinking it powdered, or are taking extract it shouldnt even be a remote concern. Water extracts are VERY inefficient at extracting EGCG but they do get most of the caffeine out. Seriously, a water extract would be considered potent at 1mg of EGCG per gram of tea. Yep, that is a 1 and not a typo.

[bdelfin]

Is it possibly to avoid the binding of casein to polyphenols by taking one Now Foods' Gluten Digest at the beginning of a meal containing milk or cheese? It has one enzyme (DPP IV) that's supposed to be great at breaking up casein. The ingredients are:

Supplement Facts
Serving Size: 1 Vcap	Amount Per Serving
BioCore DPP IV	100 mg
Protease (from Aspergillus oryzae)	30,000 HUT
Protease (from Aspergillus oryzae)	500 DPP-IV
Protease (from Aspergillus melleus)	8.5 AP
Amylase (from Aspergillus oryzae)	12,000 DU
Protease (from Aspergillus oryzae)	30,000 HUT
Glucoamylase (from Aspergillus nigel)	20 AGU

And if not, how much absorption of polyphenols that are supposed to be taken with food can I expect to lose if I take them before breakfast instead of with breakfast?

[Dmitri]

I only drink 2 cups a day, 3 at the most which isn't a problem according to the article.

[VespeneGas]

I only drink 2 cups a day, 3 at the most which isn't a problem according to the article.

Thank goodness, I was growing concerned about you, Dmitri.

[aikikai]

In my country Sweden we have had some cases of people getting liver damage due to green tea extract supplements.

Personally I drink maybe 10 big cups of green, black and red roibos tea daily.

Edited by aikikai, 31 January 2009 - 08:15 PM.

[Mixter]

Probably most of the cases overdose on ECGC supplements (> 750 mg/day), cases are
probably bodybuilders etc. who want to boost their metabolic rate with it or other nonsense.

Which is long known to be harmful. Only time I would take 750 mg twice a day would
be to ward off an infection/cold. > 750mg for a few days puts a huge strain on your liver and
> 750 mg long term could be toxic. But all supplements I know of have an upper dose
of less than 800 mg. People overdose on everything. So let's just remember ECGC is orders
of magnitude less harmless than paracetamol and other OTC poisons, even when overdosed

Personally, the ECGC in a multi like LEF Mix or OrthoCore along with 5-6 cups of quality
organic green/white tea daily is enough for me, and should suffice for most people. I have
an high ECGC extract but only take that rather occasionally.

[Wellington]

Thanks alot for the warning. I used to take about 800mg per day for quite a long time, but have reverted to 400-600mg per day from now on.

[niner]

So let's just remember ECGC is orders of magnitude less harmless than paracetamol and other OTC poisons, even when overdosed

You mean less harmful, right?

[Mixter]

Umm, right. Well, ten times less harmful could at least be, given paracetamol's record.

[pycnogenol]

I take the Enzymatic Therapy brand of Green Tea a couple times per week with only 100 mg per capsule.

http://www.iherb.com...x?pid=2149&at=0

[Snoopy]

I been taking 1gram per day of decaffeinated green tea capsules - what is recommended on the bottle.

I also take green tea, white tea, red tea infusions with every meal. So far everything is firing on all cylinders.

My take is that it depends on the individual - if you are a young strapping 6'2" lad with a high metabolism or an inactive person who lets these compounds sit inside you for a long time.

@Mixter - I would rather be physically strong with excellent fitness levels and a high metabolism than thin and weak with low fitness levels and a low metabolism.

Often there are trade off's which need to be factored in before saying high metabolism is bad. High metabolism has a lot of positive benefits - you excrete toxins quicker, you burn more fat = lower ldl...

Edited by Snoopy, 24 May 2012 - 01:33 PM.

[Snoopy]

ps. vince giuliano who i would consider the best anti aging guru on the internet - is taking 1.5grams per day!

[tintinet]

I've really only tried Vitacost's brand, but it gave me massive anxiety, so I quit it some time ago.

[kingnut]

i currently take Now EGCg (2 x 400 mg) one after breakfast and one after lunch. so a total of 800mg a day. EGCg makes me feel great. i was wondering if anyone using EGCg has had a liver function blood test? i am currently in afghanistan, so i cant get one right now or else i would.

i just started back on EGCg because it does burn fat and gives me energy. im in pretty good physical shape. the reason i stopped is because it was constipating me. but now its fine because i intake alot more fiber.

[niner]

i currently take Now EGCg (2 x 400 mg) one after breakfast and one after lunch. so a total of 800mg a day. EGCg makes me feel great. i was wondering if anyone using EGCg has had a liver function blood test? i am currently in afghanistan, so i cant get one right now or else i would.

i just started back on EGCg because it does burn fat and gives me energy. im in pretty good physical shape. the reason i stopped is because it was constipating me. but now its fine because i intake alot more fiber.

I really doubt that you'll have a problem since you're splitting the dose and taking it after meals. I've been taking egcg for years, (500mg on an empty stomach) and I get liver enzymes done as part of my routine bloodwork, probably once a year or so. That's just my doctor's standard thing, not because I'm particularly worried about GTE. At any rate, I've never had a problem. It's pretty easy for liver enzymes to get out of range, like if you have a few drinks too close to the blood draw.

[RJ100]

What's the reasoning behind you folks taking your EGCG Green Tea supplement on an empty stomach? Wondering because the bottle I have (NOW brand) explicitly states to take it with a meal. In fact it says "Do not take this product on an empty stomach"

Edited by RJ100, 01 February 2013 - 02:24 PM.

[pleb]

Can someone throw light on exactly what is green tea,
i have read that green tea is made from the tips from the stems on the bush, and that black tea is the older leaves from lower down the stems, but have no other information than that,
also that 2-1/2 times the amount of black tea has the same effect as 1 cup of green tea,
and as i already drink about 7 to 8 mugs of black tea a day (with sugar and milk), what would the results be from that in comparison,

Edited by pleb, 01 February 2013 - 02:49 PM.

[Dolph]

Just curious, could similar problems arise with different polyphenols? Or could several polyphenols add to eachother, leading to a cumulative risk?