EGCG Content in Green Teas

Made from leaves that have not been oxidized.

Jan 28th 09 3:38 am
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EGCG Content in Green Teas

by vooymoon » Jan 28th 09 3:38 am

has anyone done any research on which varieties of green tea have the highest EGCG/catechin content? My mother has cancer, and I've been trying to figure out which teas would be best for her to consume regularly.

According to Richard Beliveau's "Foods to Fight Cancer," the Japanese green teas have the highest EGCG concentrations (3-5% of leaf weight), with the exception of "Pilo chun emperor" (biluo chun?). I'm not sure where he gets this from or how many samples or brands of tea were studied.

Does anyone know where I can find more extensive studies? Or suggest varieties of tea that are more likely to have high EGCG content? According to Beliveau, "the catechin content of green tea varies greatly depending on the area of cultivation, the diversity of plants used, the harvest season and, not least, the processing techniques."

I don't have any experience with Japanese green tea, so we have been consuming lots of Biluo chun purchased from My Cup of Tea in Montreal. An 80g bag cost me around $15, and according to their website, their teas are organic (http://www.my-cup-of-tea.com/en/news/16/ ). Also, what online merchants would you recommend?

Thanks

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by vooymoon » Jan 28th 09 5:03 am

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Source: Richard Beliveau and Denis Gingras, Foods to Fight Cancer (New York: DK Publishing, 2007), pp. 113-115.

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by Space Samurai » Jan 28th 09 6:24 am

I read the article you posted, and unfortunately it reads like most of the hype surrounding green tea. Lots of maybe's and could be's and linked to's with a little science tossed in but still lacking hard data.

While the article suggests that certain green teas have more catechins and provides a nice graph, it doesn't provide specific details about the teas sample, no harvest information, location, or even types of the plant.

I have not seen any data that proves one type of green tea is better than any other, but Japanese tea certainly isn't any worse. I honestly can't imagine that tea grwon in Uji will do a better job of fighting your mother's cancer than a tea grown in Shizuoka, Kagoshima, or Fujian.

Also, steeping green tea for nine minutes is going to make a very nasty brew. I'm guessing they didn't drink their science exeriment. If you are concerned with getting all of the antioxidants out of the leaves, you can use the same leaves for several infusions.

Good Vendors for Japanese Green Tea (I am assuming you want to stick with organic):

www.rishi-tea.com (will have both organic Japanese and Chinese green tea)
www.zencha.com (has organic japanese tea)

These are two sited that I know of and have used.

I hope this helps and good luck.

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by silverneedles » Jan 28th 09 8:35 pm

just be careful that
- ingesting lots of tea does not interfere with medication/chemo
- having too much fluid isnt healthy either.
- also consider- does the tea/polyphenols/catechins/flavonoids/antioxidants/egcg have a beneficial effect for the endpoint - does it prolong life? for ex: ace-inhibitors, beta-blockers are given for treatment of Heart failure because they improve symptoms and decrease mortality. vs calcium channel blockers which improve symptoms but do not decrease mortality. so B-blockers and ACEinhibitors are first in line.
There is no logic in pumping a patient with substances ...just because (but...everyone makes their own choices).
- There are guidelines for cancer treatment to try to not only improve quality of life(decrease pain etc) but also to try to eradicate the cancer - do not avoid these, for alternatives that havent been (yet)proven to be beneficial.

you can find studies on >> medline-pubmed (unless you're in a university library you will probably only see abstracts, some may have a brief conclusion) & most of the studies are in the lab - on cell cultures, or mice.

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by joelbct » Jan 29th 09 2:42 am

Japanese Green is your best bet for catechins/polyphenols. Sencha and Matcha are where it's at. Japanese tea will probably also have lower pesticide content than most Chinese tea. Although for variety's sake, I would add some decent black tea as well.

A caveat, I would talk to a Cancer Specialist, the diuretic effect of too much caffeine could be a problem for someone who is ill.

To sidestep that issue, i love pomeggranate juice concentrate, very high ORAC value, high in EGCG. Try the Jarrow Concentrate, much more economical than bottled non-concentrate pom juices. High epcg content.

From the research I've done, I know these powerful a-ox's will reduce cancer risk, . Not sure if they fight cancer that is already present, but they won't hurt, and very well could help.

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Hmm, how to put this gently....

by Intuit » Jan 29th 09 3:02 am

The benefits of tea drinking (not just green tea) are best reaped as a preventative or deterrent of malignancies, not a treatment per se.

What they do are act as free radical scavengers (free radicals being excess electron charge that can cause undesirable reactions between molecules) *especially* in the cell powerhouse, the mitochondria..and...they also induce highly damaged cells (from the aforementioned affects of free radicals) to undergo apoptosis - programmed cell death. That's how you stop cancerous/precancerous cells from undergoing unregulated cell division and also keeps them from altering their surface proteins and thus go wandering away to form cancers in other tissues.

Green tea therapy adjunct to traditional cancer treatment (chemo, radiation therapy) appears to be generally accepted by the medical community, although not without some reservations over ECGC effects on drug metabolism pathways in the liver.

http://cancer.ucsd.edu/outreach/publice ... eentea.asp
http://www.cancermonthly.com/iNP/view.asp?ID=221
http://cancernd.blogspot.com/2008/03/it ... eople.html

A healthy diet and above all, using various stress-busting methods to control chronic stress - a drain on naturally produced antioxidants in the body that predisposes us to disease - would be just as advantageous as adding ECGC as an oncologic treatment modality. Moreover, the natural antioxidants produced in the body act as reducing equivalents - that is, they convert oxidized antioxidants (both cell made and diet-supplied) back to their working state, after they have 'done their job'.

(start of minor professional rant)

A high dose of antioxidants given when a patient has insufficient natural reducing equivalents is just as bad or worse than not having enough antioxidant handy. If you think about it, this should make sense - and helps explain why recent medical studies of various antioxidants given for cancer treatment haven't been very effective (vitamin C, vitamin E, selenium). Either the medical research teams at National Cancer Institute/NIH are idiots or they forget simple rules of biochemistry learned in medical school:

1.Like everything else in nature, redox metabolism is a matter of natural chemical recycle in cells.
2. Redox systems act in molecular tandem - you need A to work with B to get the desired effect. You can just feed A in high dose and then say, gee whiz, it didn't work!!

(End of minor professional rant)

You can buy ECGC, but it had better be from a reputable source.

Standard disclaimer: ECGC should be administered under the guidance of a *knowledgeable* physician (including licensed alternative medical practitioners), that work with the primary oncologist when ECGC is used as adjunct therapy for cancer treatment.

So to answer your question, what you need to supply just enough, not a maximum dose, to do the job. While it sounds bass-ackwards, it's the chemical truth.

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by Ritva » Jan 29th 09 12:53 pm

There are japanese scientific studies about health effects of green tea. Some of the studies are published in peer-reviewed scientific journals which means that they should be reliable. The studies have shown some health effects of green tea, for example it seems to have anti-allergic effects. There were other effects as well (on cell cultures if I remember correctly) but I was mainly interested about the anti-allergy thing because I have hay fever.

The studies are made with tea cultivar "Benifuki" which has much higher catechin levels than other green tea cultivars. Catechins give tea a bitter taste, so unfortunately higher catechin levels mean bitter tasting tea. At least one japanese tea company (Maiko Tea) has started to sell powdered Benifuki tea for health purposes. http://www.maiko.ne.jp/english/shopping/benifuki.htm

I tried it last spring to see if it would help with my allergies but unfortunately my stomach couldn't take it. I've never been a coffee drinker so I think it might have been the amount of caffeine that upset my stomach. It was a powdered tea so you drink up all the leaves like in matcha. It wasn't very good either, quite a bitter taste. But if one would like to get the highest amount of catechins regardless of taste, that would be a top pick.

Some examples of scientific articles:
Nagai et al. 2005: The development of a suitable manufacturing process for "Benifuuki" green tea beverage with anti-allergic effects. Journal of the Science of Food and Agriculture 85: 1606-1612.
Maeda-Yamamoto et al. 2007: In vitro and in vivo anti-allergic effects of ‘benifuuki’ green tea containing O -methylated catechin and ginger extract enhancement. Cytotechnology 55:135-142

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by ryux » Jan 30th 09 4:01 pm

On the side note, does anyone know effects of drinking too MUCH tea? Like would it be bad for health?

I drink ~5-7 cups of tea a day (mostly green tea) which I assume is higher than what average tea drinkers would drink.

With my limited knowledge, I can't think of any side-effects other than "can't sleep at night" if you drink too late during the day. I'd love to hear some opinions/facts on effects of drinking too much tea if anyone has them

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by silverneedles » Jan 30th 09 4:08 pm

how much fluid(oz/ml) does 1 of your cups represent?

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by ryux » Jan 30th 09 4:13 pm

it's about 4oz or 120ml-ish. sorry I should have mentioned this before.

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by Beidao » Jan 30th 09 6:42 pm

Well you can get flourosis (flour overdose). And some researchers say that drinking alot for several years will highten your risk for urinary incontinence. This has to do with drinking in general, not with tea, but I would guess it could be worsened by the diuretic effect of coffeine.

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by Chip » Jan 30th 09 7:30 pm

*slurp* mmmmm, great tea.

If my tea has EGCG in it, and it is good for me, better yet. But it is not likely to affect my tea choice or habits. I will let the guys and gals in lab coats sort it out and hope one day all will be revealed.

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by silverneedles » Jan 30th 09 8:38 pm

there are some documented reports of people Imagewith hepatotoxicity-hepatitis (but mechanism is not known)

and the poor Image who were forced to ingest high concentrations of green tea extract induce acute toxicity in rat liver cells,

high doses of Imageepigallocatechin gallate has been associated with extensive Imageliver necrosis in animals
Image

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by Salsero » Jan 30th 09 9:10 pm

Science is so much cuter these days.

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Heh, older studies cited.

by Intuit » Jan 31st 09 1:42 am

A 2007 journal article reported that 4 cups per day of green tea appears to have a very positive effect on inflammation response in men, particularly lung inflammation in male smokers. The authors suggest that smokers might reduce their lung cancer and COPD risk by consuming green tea.

Frankly, I can't see that happening. Most smokers are bonzo coffee drinkers because the effects of nicotine accentuates the addictive and mental stimulatory effects of caffeine (vasodilation and dopamine agonists).

Recent articles (2005-2008) have also documented cardiovascular effects on plaque formation (atherosclerosis) that is most pronounced in women.

Another article I read at last night compared results of two dozen statistically-vetted published studies of the health effects of teas and found that the majority found inverse relation between disease (cancer, heart disease, inflammation) and regular tea ingestion.

Tea is the most significant source of flavenols in US diets; flavenols are also supplied by citrus fruits and grapes (juices and pulps).

The negative effect on liver reported above stems from certain ECGC components that bind to select cytochrome P450s known to be involved in drug metabolism and one of the steps in bile acid synthesis.

Cytochrome CYP2E1 is upregulated by epigallocatechin; a 2007 paper suggests that it may counter fatty liver disease (NASH) alcoholic syndrome, with a corresponding marked reduction in the two liver enzymes that are characteristically measured for general liver health.

Note that NASH-like fatty liver disease also occurs in diabetics.

Effect of Dietary Epigallocatechin-3-gallate on Cytochrome P450 2E1-Dependent Alcoholic Liver Damage: Enhancement of Fatty Acid Oxidation. Bioscience, Biotechnology, and Biochemistry (2007) , 71(12):2999-3006

http://www.jstage.jst.go.jp/article/bbb ... 9/_article

My general rule of thumb is to mimic nature: use whole plants or enriched extracts rather than purified compounds because bioactive plant compounds tend to act in couples, rather than as solitary receptor modulators.

Edit - Explanation of the term 'chemical couples': think of it as a 'push-pull' effect, one working in opposition to the other. Cells produce these 'couples' to modulate chemical activity at large protein receptors sites.