green tea

Uh, five or more cups of green tea?  Won't that make us a bit jittery?  Is green tea as caffeinated as black tea?

Tina

Paulette, I also read a hint from Martha that you soak the teabag in the boiling water for 20 seconds, then throw out that water and proceed to steep the teabag as usual.  This will get rid of most of the caffeine.  BUT does this also get rid of the good stuff?  Anybody know?

Tina

abbadoodles, they make decaf green tea too. I drink that in the p.m. I don't know about the epigallactins, which i think is what helps out, and 20 seconds of extraction to avoid the caffeine. We should look.



bingbing, I don't see why not! Green tea is green tea. An added benefit, but unfortunately in high doses that get too close to the safety comfy zone, is green tea appears to speed up your metabolism and cause weight loss.



Tender

I was told by a nutritionalist that spoke to our support group, (and I'm just repeating what she told us),  that one cup of coffee has 11 times more caffine than one cup of tea. She said not to drink decaffinated tea, because it is processed twice to get the caffine out of it, and that also takes away it's effectiveness.    Kate

http://www.republicoftea.com/pages/caffeine.html

The above will give you an idea of how much caffeine is in green tea.  I only brew mine for 1 1/2 mins.  I use the loose tea and that can get strong fast.

I think I read that green tea can be a problem in doses equivalent to 50 cups or more daily. That was a warning for those taking it in pill form.

The caffeine in green tea is also thought to be helpful for weight loss, but there are other compounds in green tea that induce thermogenesis (raise your metabolic rate). This can help you lose weight and, so far, has not been seen as interfering with those who have to deal with hypothyroid issues.

Recently, an article pointed out that some green tea is grown in areas where the water is high in fluoride and the plants take it up, too. The locals suffer from overdoses of the fluoride. According to one source, the level of fluoride is high when the level of EGCG is low--this is the case for older, more mature leaves. For those who use green tea as a supplement, you'll be looking for high EGCG levels.

Here's one article on the fluoride issue and the lack of US government regulation surrounding the levels in green tea:

http://www.foodnavigator-usa.com/news/ng.asp?id=58604-calls-for-fda 

BBS, 50 cups a day?  I wonder how much I am taking via pills.  Should I just drink the green tea?  Oh, geez!  Why does this have to be so hard?

Shirley

Shirley, I believe 8-16 cups of green tea is equivalent to approx. 800 mg EGCG. When you drink the tea, you spread the dose out over time. I'm sure the content varies by the type of tea, but especially by the age of the leaves.

http://www.newscientist.com/article.ns?id=dn11786
Green tea can be harmful in large quantities

* 10:00 05 May 2007

* Chung Yang, Rutgers University

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).

This may be the relevant article for you, Shirley. Also note, too much green tea can elevate liver enzymes--and I know some folks on this site were having issues with this and trying to determine the cause...

 Diet and Nutrition: Temperance in Green Tea
M. Nathaniel Mead


Throughout China and Japan, green tea is considered a staple beverage. Many epidemiologic studies have linked frequent tea intake with a lower incidence of cancer, cardiovascular disease, and neurodegenerative disorders. Consumer interest in the tea's health benefits has led to the inclusion of green tea extracts in multivitamins and other dietary supplements. But too much of a good thing could prove harmful, according to a review in the April 2007 issue of Chemical Research in Toxicology that analyzed the toxic potential of green tea polyphenols.

Currently there are no published epidemiologic studies on the toxicity of green tea supplements. But laboratory research with both rodents and dogs has shown that high doses of the most heavily studied green tea polyphenol, (-)-epigallocatechin-3-gallate (EGCG), cause liver, kidney, and gastrointestinal toxicities.

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," says lead author Joshua Lambert, an assistant research professor in the Department of Chemical Biology at Rutgers University. "In some cases, the subject stopped taking the supplement and the symptoms resolved, and then the subject started taking the supplement again and liver toxicity returned." Such observations, albeit anecdotal, suggest that green tea supplements are not without risk.

Cell culture studies have shown that EGCG can cause oxidative stress, although these data now need to be confirmed in animal models. The Rutgers team speculates that some susceptible individuals may carry a particular polymorphism of the gene that codes catecholamine-o-methyltransferase, an enzyme critical to the protection of cells against EGCG-mediated oxidative stress and hepatotoxicity. About a quarter of the population have a polymorphism that is associated with low activity of this enzyme. "This is just a hypothesis that we are testing," says coauthor Chung S. Yang, a chemical biology professor at Rutgers.

Toxic effects tend to arise when people take green tea supplements, which can contain more than 50 times as much polyphenol as a single cup of tea. "People who take less than 500 mg [of green tea concentrate or preparation] per day and spread the dose out over the course of the day are unlikely to have toxic side effects," says Yang.

Yang adds that some Japanese publications report beneficial effects for the consumption of 10 cups of green tea a day with no apparent harmful effects. At most, people may experience stomach irritation after drinking strongly brewed green tea on an empty stomach. Commercial preparations such as the bottled green teas found in the United States and green tea-flavored gum, bread, candy, ice cream, and desserts found in Asia have very low levels of polyphenols.

At the present time there is no established upper tolerable limit for green tea consumption. The Rutgers review points to the need for epidemiologic studies to test the potential concerns of taking green tea supplements at 500-mg doses or higher. Yang and Lambert hypothesize that people with oxidative stress-related liver diseases such as hepatitis or cirrhosis may be at greater risk of toxic side effects from ingesting high doses of green tea polyphenols. "When a person's liver is already under stress, toxic effects tend to become amplified," Yang says. Conversely, he notes there are data showing that low or moderate amounts of green tea have a protective effect against both toxicity and carcinogenesis in target organs-once again supporting the adage "everything in moderation, nothing to excess."

I forgot to say, I agree with "everything in moderation."  I've been rethinking lately about some of my supplements and thinking perhaps it's not good to take too much.  But, what's too much?  I sort of go by the instructions on the bottles. <confused>