Health benefit of green tea extract
Human research is still very early, but the potential green tea or green tea extract health benefits include antioxidant effects, cancer chemoprevention, antiviral effects, blood thinning properties, improving cardiovascular health, slowing mental decline, enhancing weight loss, arthritis protection, and protecting the skin from the damage caused by ionizing radiation. The compound EGCG found in green tea has been shown to regulate dozens of disease-specific molecular targets. Long term human research is required before we determine the appropriate dosage and amount of green tea or green tea extract required to provide these health benefits.

Green Tea Extract, 100 mg, yielding 35 mg EGCG - Source Naturals

Green Tea Extract offers a convenient way to get the benefits of green tea in a highly concentrated green tea pill form. This green tea extract is standardized for bioflavonoid-like antioxidants known as polyphenols, particularly (-)-Epigallocatechin Gallate (EGCG).  EGCG has been found in scientific studies to be a potent antioxidant. Green tea antioxidants are likely to become more popular with time.

Supplement Facts
Calcium
Green Tea Extract Yielding 35 mg epigallocatechin gallate

Suggested Use: 1 green tea extract tablet a few times a week with breakfast or lunch. Take green tea extract pill in the morning or midday before or with a meal. Evening use may lead to mild insomnia.

Green Tea Extract, 100 mg, yielding 35 mg EGCG - Source Naturals
Green Tea Extract offers a convenient way to get the benefits of green tea in a highly concentrated green tea pill form.  This green tea extract is standardized for bioflavonoid-like antioxidants known as polyphenols, particularly (-)-Epigallocatechin Gallate (EGCG).  EGCG has been found in scientific studies to be a potent antioxidant. Green tea antioxidants are likely to become more popular with time.

More information and benefit
Tea is the most widely consumed beverage aside from water. Green tea contains polyphenolic compounds, which account for 30% of the dry weight of the leaves. Most of the polyphenols are flavanols, of which (-)-epigallocatechin-3-gallate (EGCG) is the most abundant. Tea is manufactured in three basic forms:

Black Tea -- During black tea production, oxidation is promoted so that most of these substances are oxidized.
Green tea -- Green tea is prepared in such a way as to prevent the oxidation of green leaf polyphenols.
Oolong tea --  Oolong tea is a partially oxidized product. Of the approximately 3 million metric tons of dried tea manufactured, only 20% is green tea and less than 2% is oolong tea.

What's in Green Tea leaf extract?
Fresh green tea leaf is rich in polyphenols which constitutes up to 30% of the dry leaf weight. Polyphenols include catechins, flavanols, chlorogenic acid, EGCG, and one unique to tea, theogallin. Caffeine in green tea is present at an average level of 3% along with very small amounts of methylxanthines, theobromine and theophylline. The amino acid theanine (5-N-ethylglutamine) is also unique to tea.

Weight Loss - Green Tea Diet - Is it a fat burner?
Human studies regarding the benefit of green tea in weight loss have not shown consistent results. In one study mentioned below, daily consumption of green tea for 12 weeks reduced body fat. Green tea could enhance metabolism. Scientists are still evaluating whether a green tea pill by itself leads to weight loss. See below for more green tea and weight loss research information. If you plan to drink green tea for weight loss, avoid drinking after mid afternoon or early evening so that your sleep is not disturbed.

Anti-obesity effects of green tea: from bedside to bench.
Mol Nutr Food Res. 2006. DSM Nutritional Products, Department of Human Nutrition and Health, Basel, Switzerland.
Green tea, green tea catechins, and epigallocatechin gallate (EGCG) have been demonstrated in cell culture and animal models of obesity to reduce adipocyte differentiation and proliferation, lipogenesis, fat mass, body weight, fat absorption, plasma levels of triglycerides, free fatty acids, cholesterol, glucose, insulin and leptin, as well as to increase beta-oxidation and thermogenesis. Adipose tissue, liver, intestine, and skeletal muscle are target organs of green tea, mediating its anti-obesity effects. Studies conducted with human subjects report reduced body weight and body fat, as well as increased fat oxidation and thermogenesis and thereby confirm findings in cell culture systems and animal models of obesity. There is still a need for well-designed and controlled clinical studies to validate the existing and encouraging human studies.

Additional Health Benefits
Green tea extract has several potential health benefits that are slowly being discovered, here are some preliminary results:
 
Anti-platelet (blood thinning) activity of green tea catechins is mediated by inhibition of cytoplasmic calcium increase.

Some green tea catechins are chondroprotective (protecting cartilage) in lab studies, and that consumption of green tea may benefit the arthritis patient by reducing inflammation and slowing cartilage breakdown. Further studies will be required to determine whether these compounds access the joint space in sufficient concentration and in a form capable of providing efficacy when ingested as tea or capsule.

To determine the effects of EGCG on HIV infection, peripheral blood lymphocytes infected with HIV were incubated with increasing concentrations of EGCG. This substance strongly inhibited the replication of the HIV virus.

It has preventive effects on both chronic inflammatory diseases and lifestyle-related diseases (including cardiovascular disease and cancer).

Flavanol (-)epigallocatechin-3-gallate is shown to be a potent natural inhibitor of leukocyte elastase that may be used to reduce elastase-mediated progression to emphysema and tumor invasion.

Green tea extract capsules, when given to humans, increase the production of such as glutathione S-transferase (GST) enzymes which are helpful in detoxification and cancer prevention. Dr. H.-H. Sherry Chow, of the University of Arizona, Tucson, gave volunteers four green tea extract capsules, each containing 200 mg of epigallocatechin gallate, every morning prior to eating. This provided the equivalent amount of epigallocatechin gallate obtained from drinking 8 to 16 cups of green tea daily. Those with the lowest GST levels at the start of the study and who took the green tea extracts were found to have glutathione S-transferase (GST) enzymes increased by 80 percent. Those who had good levels of glutathione S-transferase did not have much of a change in their levels. Cancer Epidemiology, Biomarkers and Prevention, 2007.

Cancer
Green tea and its major constituent epigallocatechin gallate (EGCG) have been extensively studied as a potential treatment for a variety of diseases, including cancer. Epidemiological data have suggested that EGCG may provide protective effects against hormone related cancers, namely breast or prostate cancer. Extensive in vitro investigations using both hormone responsive and non-responsive cell lines have shown that EGCG induces apoptosis and alters the expression of cell cycle regulatory proteins that are critical for cell survival and apoptosis.

Green tea linked to reduced breast cancer risk
Compounds in green tea may help protect women against breast cancer. Rats who drank water containing green tea had reductions in the size and malignancy of breast tumors compared with rats that drank only water. Additionally, the tumors of tea-drinking rats developed later and were less invasive.
   While more research needs to be conducted, the findings, coupled with observations of lower rates of breast cancer in countries where green tea is consumed daily, suggest that green tea may benefit women as part of an overall healthy diet.
   According to the report in the July issue of the Journal of Cellular Biochemistry, polyphenols, compounds that are abundant in green tea, red wine and olive oil, may protect against various types of cancer. Polyphenols are potent antioxidants, compounds that help neutralize disease-causing free radicals. These cell-damaging molecules occur naturally in the body and are linked with heart disease, aging and a number of other disorders.
   Dry green tea leaves, which are about 40% polyphenols by weight, may also reduce the risk of cancer of the stomach, lung, colon, rectum, liver and pancreas, study findings have suggested.
   Breast cancer is the second-leading cause of cancer death among US women, according to the American Cancer Society.

Cholesterol
Consumption of green tea is associated with lower serum concentration of total cholesterol in Japanese healthy workers age 40-69 years.

A green tea extract lowers plasma cholesterol by inhibiting cholesterol synthesis and upregulating the LDL receptor in the cholesterol-fed rabbit.
Atherosclerosis. 2006; Wellcome Trust Centre of Human Genetics, University of Oxford, Roosevelt Drive, Oxford, United Kingdom; CSIRO, Health Sciences and Nutrition, Adelaide, SA 5000, Australia; University of Adelaide, SA, Australia.
Green tea extracts enriched in catechins decrease plasma cholesterol in hamsters, mice and rats. The aims of this study were to determine whether a catechin-enriched extract of green tea could lower plasma cholesterol in the cholesterol-fed rabbit and to determine the mechanism of action. Conclusion: These results suggest that green tea catechins lowered plasma, liver and aortic cholesterol in the cholesterol-fed rabbit by lowering cholesterol synthesis and upregulating the hepatic LDL receptor.

Green tea extact and allograft survival
Green Tea Extract Prolongs Allograft Survival as an Adjunctive Therapy Along With Low Dose Cyclosporine A.
J Surg Res. 2008. Tripathi S, Bruch D, Gatto LA, Kittur DS. Department of Surgery, The State University of New York (SUNY) Upstate Medical University, Syracuse, New York.
The present study aims to study the efficacy of green tea extract in combination with low dose cyclosporine A (CyA) in prolonging allograft survival in mice. Numerous studies have reported the anti-inflammatory and immunomodulatory properties of green tea extract and its various catechin components. Green tea extract is also known to attenuate CyA induced nephrotoxicity. Therefore, we hypothesized that green tea extract alone or in combination with CyA will prolong graft survival. Our study demonstrates that green tea extract in combination with low dose CyA significantly prolongs graft survival as well as increase the production of immunosuppressive cytokine, IL-10. Green tea extract also decreases CyA induced high TGF-beta production, which is incriminated in CyA induced nephrotoxicity. We also observed that green tea extract inhibits both nonspecific and antigen-specific proliferation of T cells in vitro. These results indicate the potential of green tea extract as an adjunctive therapy in combination with CyA to prolong allograft survival and to reduce CyA induced nephrotoxicity.

Green Tea extract side effects
Green tea extract has side effects in high dosages. Since green tea extract has caffeine and methylxanthines, avoid drinking or taking the capsules in the evening due to possible insomnia. We have not come across any other common green tea extract side effects at this time except this one caution:

Caution: In rare cases extracts from green tea have been reported to adversely affect the liver. Discontinue use and consult a healthcare practitioner if you have a liver disorder or develop symptoms of liver trouble, such as abdominal pain, dark urine, or jaundice. If you plan to take green tea extract for prolonged periods, take a week off each month.

It is possible that high dosages of green tea extract could stimulate heart tissue to beat faster.

Availability
There are countless green tea products, including tea bags, green tea capsules, tablets, green tea powder, green tea gum, combinations of green tea with other supplements. Pure green tea is sold by raw material suppliers in different extracts, ranging from green tea extract 30%-95%, standardized to green tea catechins. You can also find organic green tea.

emails
Q. Is there caffeine free green tea extract pill available? I'm looking for decaffeinated green tea extract pill.
   A. Yes, there are companies that make caffeine free green tea extract. We are not sure, though, whether the process that extracts the caffeine from the green tea could also remove some of the beneficial polyphenols.

Q. How often should one take a supplement of green tea leaf extract?
   A. There is no right or wrong answer, but a few times a week should be fine for most people. Some may require more, others less.

Q. Is there an advantage to taking a liquid green tea extract as opposed to a capsule or tablet?
   A. We don't see any advantage to taking a liquid green tea extract over other types of green tea extract pill supplements.

Q. How effective is a green tea extract diet pill for weight loss?
   A. Green tea extract diet pill may reduce appetite or increase metabolism, but we feel green tea extract works better when combined with other herbs such as hoodia, ginger, etc.

Raw Material Supply
Green tea extract raw material suppliers literally have dozens of forms and extracts of green tea, for example the following:
Green tea caffeine 99% Caffeine (HPLC)
Green tea catechins 20% ~ 90%; EGCG 10% ~ 98%; L-theanine 20% ~ 35%; Polyphenols 20% ~ 98%; Saponins 50% ~ 70%.

October 9, 2007- Is green tea a fat burner?
The National Advertising Division (NAD) of the Council of Better Business Bureaus has recommended that Irwin Naturals, which markets the “Green Tea Fat Burner” dietary supplement, modify or discontinue certain claims for the product. As part of its routine monitoring program, NAD, the advertising industry’s self-regulatory forum, requested substantiation for performance claims that appeared on product packaging, the advertiser’s Website, and vendor Websites selling the product. Claims at issue included:

“Green Tea Fat Burner”
“The liquid soft-gel Green Tea Fat Burner is a powerful blend of natural herbal boosters and nutrients that, when used with a healthy diet plan, has a dual action effect on weight loss which helps you:
- Curb your appetite
- Kick-start & speed up your fat burning ability (thermogenesis)”
“Burn Fat & Speed Metabolism”
Contains Green Tea Extract, which “accelerates calorie burning through increased thermogenesis, particularly with fat calories.”

At the outset of the NAD inquiry, the advertiser said that it had modified many of its claims for its present formulations and packaging and would request that all of its online vendors update their sites to reflect the modifications. NAD examined evidence that included a number of studies that examined the effect of consumption of green tea on weight loss and weight maintenance. Following its review of the evidence, NAD determined consumers could take away the message that Green Tea Fat Burner would “burn fat” from the body of those using the product, a message not fully supported by the evidence in the record. NAD recommended that the advertiser either discontinue its claims, or modify them to reflect that evidence regarding positive effects of green tea extract and caffeine on weight or fat loss is as yet inconclusive, and is a product of emerging science. NAD further recommended that in future advertising the advertiser either discontinue the claim within the product’s name (“Green Tea Fat Burner”), or modify it to avoid conveying the unsupported message that the product will “burn” fat off the body. Additionally, NAD noted that the advertiser had provided a reasonable basis for claims indicating that Green Tea Fat Burner contains ingredients shown to have a positive effect on thermogenesis and fat oxidation, and to help maintain body weight. Finally, NAD noted its appreciation for the advertiser’s efforts in modifying or discontinuing certain challenged claims and in contacting distributors and directing that claims be updated in accordance with the advertiser’s changes to claims on its packaging. NAD recommended that the advertiser continue to monitor the advertising claims of its distributors to ensure that all claims regarding its products are truthful and accurate.

   Comments: Green tea extract may be helpful in weight management. Whether it does so by burning fat remains to b determined, but it could have benefits when included in a natural diet pill product. This appears to be a grey area at the moment and we can understand different points of view on this matter.