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Green Tea Health Benefits

Archeological evidence suggests that tea leaves steeped in boiling water were consumed as many as 500,000 years ago. Historical evidence from China indicates that tea infusions have been used as a beverage for approximately the past 4700 years. The cultivation of tea is believed to have begun in China or India. Today, tea is the world's most popular beverage next to water. Green tea, black tea, oolong tea and white tea are all derived from the camellia sinensis plant and all have traditionally been consumed for their health benefits. The differences in the teas is in their processing. Green tea is made from unfermented leaves and is reputed to contain the highest concentration of polyphenols. In traditional Chinese and Ayurvedic medicine, green tea has been used as a stimulant, diuretic, astringent, and heart tonic.

Antioxidant properties of Green Tea

The polyphenols in green tea are antioxidants. Antioxidants neutralize free radicals that can damage cells and induce genetic mutations. Free radicals contribute to the aging process and the development of cancer and heart disease. Green tea contains six primary catechin compounds: catechin, gallaogatechin, epicatechin, epigallocatechin, epicatechin gallate, and apigallocatechin gallate (EGCG). The polyphenol that has been most researched and is believed to have the most potent health benefits is EGCG. Green tea contains roughly 30% to 40% polyphenols and black tea contains only 3% to 10% polyphenols. The average cup of green tea contains about 50 to 150 mg polyphenols.

Green Tea and Heart health

Epidemiological studies indicate that the antioxidant properties of green tea may help prevent atherosclerosis, particularly coronary artery disease. Green tea lowers total cholesterol and raises HDL ("good") cholesterol in both animals and people. One epidemiological study found that men who drink green tea are more likely to have lower total cholesterol thank those who do not drink green tea. Polyphenols in green tea may block the intestinal absorption of cholesterol and promote its excretion from the body.

Green Tea and Cancer

Epidemiological, animal and clinical studies have demonstrated anti-cancer properties for green tea. The polyphenols in green tea are believed to play an important role in the prevention of cancer. In addition to their antioxidant properties, green tea polyphenols are believed to help kill cancer cells and stop its progression.

The types of cancers that may be favorable affected by green tea polyphenols includes bladder cancer, breast cancer, colorectal cancer, esophageal cancer, lung cancer, pancreatic cancer, prostate cancer, skin cancer, and stomach cancer. While there is evidence that green tea polyphenols may inhibit the growth of many types of cancer cells, there is enough contradictory and inconclusive results from studies to make it difficult to draw hard conclusions based on published research. Some studies show that green tea may reduce cancer rates while others suggest that it may actually increase cancer rates.

Antiviral Properties of Green Tea

Results from several animal and human studies suggest that the polyphenols present in green tea may help treat viral hepatitis. In these studies, catechin was isolated from green tea and used in very high concentrations. It has not been proven that drinking green tea confers these same benefits to people with hepatitis.

The catechins in green tea have also demonstrated activity against Influenza A and B viruses. EGCG was observed to have the highest antiviral activity but the other polyphenols also contributed to antiviral activity and the natural combination was more effective than any of the isolates. Recent studies done in Japan and China demonstrated that green tea catechins in general could inhibit the reverse transcriptase or polymerases of several types of viruses including HIV-1 and herpes simplex 1. Various polymeric oxidation products of polyphenols have also been found to inhibit the herpes simplex virus.

Tea and tea extracts have also been used as a topical treatment for herpes virus outbreaks. A patent has been virtuald in the UK (Number 2,293,548). Joan Hibberd , a medical doctor, found that ordinary tea works better than acyclovir as a topical treatment for herpes lesions. According to Dr Hibberd, within four or five days the lesions crust over, then disappear and do not recur for at least several months after treatment.

Green Tea and Weight Loss

Green tea extract may boost metabolism and help burn fat. This effect may be attributed to the catechins in the green tea. In addition to the polyphenols, green tea also contains alkaloids including caffeine, theobromine, and theophylline. These alkaloids provide green tea's stimulant effects. Green tea has been used traditionally to control blood sugar in the body and may help regulate glucose in the body. Animal studies suggest that green tea may help prevent the development of type 1 diabetes and slow the progression once it has developed. Obesity is often associated with the development of diabetes.

Green Tea Fluoride and Aluminum

Tea, including green tea, is known to contain high concentrations of fluoride and aluminum. There is evidence that in recent times the concentration of aluminum and fluoride in tea has increased as a result of exposure to increasing air and water pollution. It appears that the tea plant has a strong tendency to concentrate aluminum and fluoride. It is likely that plant concentrations of aluminum and fluoride are highly variable depending on the soil, water, cultivation practices and local pollution. This has not been adequately studied nor is it monitored.

Fluoride in particular is a serious political issue with proponents of fluoridation claiming that fluoride is good for us and pushing for fluoridation of drinking water, table sale and dental products. The opponents content that fluoride is harmful to human health and should be restricted. The proponents have the upper hand in politics and media, but a close examination of the science validates the opponents of fluoridation.

Fluoride is a chemical antagonist of iodine. Iodine is necessary for normal thyroid function. Much hypothyroidism is believed to be due in large part to suboptimum iodine levels. In addition, fluorosis, a disease affecting teeth and bones, especially in growing children and young adults has been epidemiologically associated with heavy tea consumption and increased consumption of caffeinated beverages which also tend to be high in fluorides.

The element aluminum is abundant and widely distributed in nature. It is usually chemically bound in ways that make it difficult for plants to concentrate it and for the human body to absorb it. Aluminum that is absorbed into the body is believed to contribute to the development of alzheimer's disease, renal and neurological disorders. The presence of high concentrations of fluorides makes aluminum more absorbable. Studies have shown that increased aluminum absorption is associated with tea consumption.

Green Tea Drug Interactions

The U.S. Food and Drug Administration (FDA) includes tea on their list of "Generally Recognized As Safe" substances.

Green tea does contain caffeine and people who drink excessive amounts may experience irritability, insomnia, heart palpitation, and dizziness. Caffeine overdose can cause nausea, vomiting, diarrhea, headaches, and loss of appetite.

Some (not all) of the potential drug interactions that can occur with green tea include:

  • Adenosine: The caffeine content in green tea may inhibit the hemodynamic effects of adenosine.
  • Atropine: The tannin content in green tea may reduce the absorption of atropine.
  • Iron supplements: The tannin content in green tea may reduce the bioavailability of iron. Green tea should be taken either 2 hours before or 4 hours following iron administration.
  • Codeine: The tannin content in green tea may reduce the absorption of codeine.
  • Benzodiazepines: Caffeine has been shown to reduce the sedative effects of benzodiazepines.
  • Beta-blockers: Caffeine may increase blood pressure in people taking propranolol and metoprolol.
  • Blood Thinning Medications: Green tea should not be taken with blood thinning medications because the herb may prevent platelets from clotting.
  • Chemotherapy: Green tea may increase the effectiveness of come chemotherapy medications, specifically doxorubicin and tamoxifen. Green tea may also have an adverse effect on prostate cancer.
  • Clozapine: Green tea may reduce the effectiveness of clozapine.
  • Ephedrine: Green tea may increase the effects of ephedrine.
  • Lithium: Green tea has been shown to reduce blood levels of lithium.
  • Monoamine oxidase inhibitors: Green tea may cause a severe increase in blood pressure when taken together with MAOIs used to treat depression.
  • Oral contraceptives: Oral contraceptives can prolong the amount of time caffeine stays in the body and may increase its stimulating effects.

Green Tea Summary

Tea, including green tea, clearly has some good and bad characteristics. Most of the clinical and laboratory research has focused on the antioxidant polyphenols. This research has demonstrated numerous benefits including weight loss, heart health, anticancer effects and antiviral effects. Its negative effects are attributed to its aluminum, fluoride, caffeine and other stimulants.

These negative effects are too well documented to be ignored. Until there is a system created to produce tea with low fluoride and aluminum content and certify its safety, consumption of tea in all forms should probably be limited. An alternative for individuals wishing to consume the beneficial polyphenols found in green tea is to use the standardized extracts that are widely available.

Green Tea Products

Here are some recommended Green Tea products.

Lightly Caffeinated Mega Green Tea Extract (Life Extension Foundation Product Link )

Decaffeinated Mega Green Tea Extract (Life Extension Foundation Product Link )

Green Tea References

Click to Expand References

Song, JM, Lee, KH, Seong, BL, Antiviral effects of catechins in green tea on influenza virus, Antiviral Research, 2005 Nov; 68(2):66-74

Chou CC. Int J Food Microbiol 1999; 48:125-130.

Kansenshogaku Zasshi 1997 Jun; 71(6): 487-94.

Jack F. Bukowski, Harvard Medical School, Science News, August 21, 1999. p. 127.

Alic M. Green tea for remission maintenance in Crohn's disease? Am J Gastroenterol. 1999;94(6):1710.

Blumenthal M, ed. The Complete German Commission E Monographs. Therapeutic Guide to Herbal Medicines. Boston, Mass: Integrative Medicine Communications; 1998:47, 132.

Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications; 1998:126-129.

Brown MD. Green tea (Camellia sinensis) extract and its possible role in the prevention of cancer. Alt Med Rev. 1999;4(5):360-370.

Bushman JL. Green tea and cancer in humans: a review of the literature. Nutr Cancer. 1998;31(3):151-159.

Craig WJ. Health-promoting properties of common herbs. Am J Clin Nutr. 1999;70(suppl):491S-499S.

Dulloo AG, Duret C, Rohrer D, et al. Efficacy of a green tea extract rich in catechin polyphenols and caffeine in increasing 24-h energy expenditure and fat oxidation in humans. Am J Clin Nutr. 1999;70:1040-1045.

Ernst E, ed. The Desktop Guide to Complementary and Alternative Medicine: An Evidence-Based Approach. Mosby, Edinburgh; 2001:119-121.

Ernst E, Cassileth BR. How useful are unconventional cancer treatments? Eur J Cancer. 1999;35(11):1608-1613.

Fujiki H, Suganuma M, Okabe S, et al. Cancer inhibition by green tea. Mutation Research. 1998;307-310.

Fujiki H, Suganuma M, Okabe S, et al. Mechanistic findings of green tea as cancer preventive for humans. Proc Soc Exp Biol Med. 1999;220(4):225-228.

Gao Yt, McLaughlin JK, Blot WJReduced risk of esophageal cancer associated with green tea consumption. J Natl Cancer Inst. 1994 Jun 1;86(11):855-8.

Geleijnse JM, Launer LJ, Hofman A, Pols HA, Witteman JCM. Tea flavonoids may protect against atherosclerosis: the Rotterdam study. Arch Intern Med. 1999;159:2170-2174.

Gomes A, Vedasiromoni JR, Das M, Sharma RM, Ganguly DK. Anti-hyperglycemic effect of black tea (Camellia sinensis) in rat. J Ethnopharmocolgy. 1995;45:223-226.

Gruenwalkd J, Brendler T, Jaenicke C, scientific eds; Fleming T, chief ed. PDR for Herbal Medicines. 2nd ed. Montvale, NJ:Medical Economics Company; 2000:369-372.

Heck AM, DeWitt BA, Lukes AL. Potential interactions between alternative therapies and warfarin. [review]. Am J Health Syst Pharm. 2000 Jul 1;57(13):1221-1227.

Hu J, Nyren O, Wolk A, Bergstrom R, et al. Risk factors for oesophageal cancer in northeast China. Int J Cancer. 1994;57(1):38-46.

Imai K, Suga K, Nagachi K. Cancer-preventive effects of drinking green tea among a Japanese population. Prev Med. 1997;26(6):769-775.

Inoue M, Tajima K, Mizutani M, et al. Regular consumption of green tea and the risk of breast cancer recurrence: follow-up study from the Hospital-based Epidemiologic Research Program at Aichi Cancer Center (HERPACC), Japan. Cancer Lett. 2001;167(2):175-182.

Ji B-T, Chow W-H, Hsing AW, et al. Green tea consumption and the risk of pancreatic and colorectal cancers. Int J Cancer. 1997;70:255-258.

Kaegi E. Unconventional therapies for cancer: 2. Green tea. [Review]. The Task Force on Alternative Therapies of the Canadian Breast Cancer Research Initiative. CMAJ. 1998;158(8):1033-1035.

Katiyar SK, Ahmad N, Mukhtar H. Green tea and skin. Arch Dermatol. 2000;136(8):989-94.

Katiyar SK, Mukhtar H. Tea antioxidants in cancer chemoprevention. [Review]. J Cell Biochem Suppl. 1997;27:59-67.

Kono S, Shinchi K, Ikeda N, Yanai F, Imanishi K. Green tea consumption and serum lipid provirtuals: a cross-sectional study in northern Kyushu, Japan. Prev Med. 1992 Jul;21(4):526-531.

Kuroda Y, Hara Y. Antimutagenic and anticarcinogenic activity of tea polyphenols. [Review]. Mutat Res. 1999;436(1):69-97.

Low Dog T, Riley D, Carter T. Traditional and alternative therapies for breast cancer. Alt Ther. 2001;7(3):36-47.

Luo M, Kannar K, Wahlqvist ML, O'Brien RC. Inhibition of LDL oxidation by green tea extract. Lancet. 1997 Feb 1;349(9048):360-361.

Luper S. A review of plants used in the treatment of liver disease: part two. Alt Med Rev. 1999;4(3):178-188.

Lyn-Cook BD, Rogers T, Yan Y, Blann EB, Kadlubar FF, Hammons GJ. Chemopreventive effects of tea extracts and various components on human pancreatic and prostate tumor cells in vitro. Nutr Cancer. 1999;35(1):80-86.

McKenna DJ, Hughes K, Jones K. Green tea monograph. Alt Ther. 2000;6(3):61-84.

Miura Y, Chiba T, Tomita I, et al. Tea catechins prevent the development of atherosclerosis in apoprotein E-deficient mice. J Nutr. 2001;131(1):27-32.

Mukhtar H, Ahmad N. Green tea in chemoprevention of cancer. [Review]. Toxicol Sci. 1999;52(2 Suppl):111-117.

Nakachi K, Suemasu K, Suga K, Takeo T, Imai K, Higashi Y. Influence of drinking green tea on breast cancer malignancy among Japanese patients. Jpn J Cancer Res. 1998;89(3):254-261.

Nagata C, Kabuto M, Shimizu H. Association of coffee, green tea, and caffeine intakes with serum concentrations of estradiol and sex hormone-binding globulin in premenopausal Japanese women. Nutr Cancer. 1998;30(1):21-24.

Ohno Y, Aoki K, Obata K, Morrison AS. Case-control study of urinary bladder cancer in metropolitan Nagoya. Natl Cancer Inst Monogr. 1985;69:229-234.

Ohno Y, Wakai K, Genka K, et al. Tea consumption and lung cancer risk: a case-control study in Okinawa, Japan. Jpn J Cancer Res. 1995;86(11):1027-1034.

Pianetti S, Guo S, Kavanagh KT, Sonenshein GE. Green tea polyphenol epigallocatechin-3 gallate inhibits Her-2/neu signaling, proliferation, and transformed phenotype of breast cancer cells. Cancer Res. 2002;62(3):652-655.

Picard D. The biochemistry of green tea polyphenols and their potential application in human skin cancer. Altern Med Rev. 1996;1(1):31-42.

Robbers JE, Tyler VE. Tyler's Herbs of Choice. New York: The Haworth Herbal Press; 1999: 249-250.

Sadzuka Y, Sugiyama T, Hirota. Modulation of cancer chemotherapy by green tea. Clin Cancer Res. 1998;4(1):153-156.

Sano T, Sasako M. Green tea and gastric cancer. N Engl J Med. 2001;344(9):675-676.

Sasazuki S, Kodama H, Yoshimasu K et al. Relation between green tea consumption and the severity of coronary atherosclerosis among Japanese men and women. Ann Epidemiol. 2000;10:401-408.

Setiawan VW, Zhang ZF, Yu GP, et al. Protective effect of green tea on the risks of chronic gastritis and stomach cancer. Int J Cancer. 2001;92(4):600-604.

Shim JH, Kang MG, Kim YH, Roberts C, Lee IP. Chemopreventive effect of green tea (Camellia sinensis) among cigarette smoke. Cancer-Epidemio-Biomarkers-Prev. 1995;Jun; 4(4): 387-91.

Shiota S, Shimizu M, Mizushima T, Ito H, et al. Marked reduction in the minimum inhibitory concentration (MIC) of ß-lactams in methicillin-resistant Staphylococcus aureus produced by epicatechin gallate, an ingredient of green tea (Camellia sinensis). Biol. Pharm. Bull. 1999;22(12):1388-1390.

Suganuma M, Okabe S, Kai Y, Sueoka N, et al. Synergistic effects of (-)-epigallocatechin gallate with (-)-epicatechin, sulindac, or tamoxifen on cancer-preventive activity in the human lung cancer cell line PC-9. Cancer Res. 1999;59:44-47.

Suganuma M, Okabe S, Sueoka N, et al. Green tea and cancer chemoprevention. Mutat Res. 1999 Jul 16;428(1-2):339-344.

Sugiyama T, Sadzuka Y. Combination of theanine with doxorubicin inhibits hepatic metastasis of M5076 ovarian sarcoma. Clin Cancer Res. 1999;5:413-416.

Sugiyama T, Sadzuka Y. Enhancing effects of green tea components on the antitumor activity of adriamycin against M5076 ovarian sarcoma. Cancer Lett. 1998;133(1):19-26.

Taylor JR, Wilt VM. Probable antagonism of warfarin by green tea. Ann Pharmacother. 1999;33(4):426-428.

Tewes FJ, Koo LC, Meisgen TJ, Rylander R. Lung cancer risk and mutagenicity of tea. Environ Res. 1990;52(1):23-33.

Thatte U, Bagadey S, Dahanukar S. Modulation of programmed cell death by medicinal plants. [Review]. Cell Mol Biol. 2000;46(1):199-214.

Tsubono Y, Nishino Y, Komatsu S, et al. Green tea and the risk of gastric cancer in Japan. N Engl J Med. 2001;344(9):632-636.

van het Hof KH, de Boer HS, Wiseman SA, Lien N, Westrate JA, Tijburg LB. Consumption of green or black tea does not increase resistance of low-density lipoprotein to oxidation in humans. Am J Clin Nutr. 1997 Nov;66(5):1125-1132.

Wakai K, Ohno Y, Obata K, Aoki K. Prognostic significance of selected lifestyle factors in urinary bladder cancer. Jpn J Cancer Res. 1993 Dec;84(12):1223-1229.

Wang Z, et al. Antimutagenic activity of green tea polyphenols. Mutation Research. 1989;223:273-285.

Wargovich MJ, Woods C, Hollis DM, Zander ME. Herbals, cancer prevention and health. [Review]. J Nutr. 2001;131(11 Suppl):3034S-3036S.

Wei H, Zhang X, Zhao JF, Wang ZY, Bickers D, Lebwohl M. Scavenging of hydrogen peroxide and inhibition of ultraviolet light-induced oxidative DNA damage by aqueous extracts from green and black teas. Free Radic Biol Med. 1999;26(11-12):1427-1435.

Weisburger JH. Tea and health: a historic perspective. Cancer Letters. 1997;114:315-317.

Windridge C. The Fountain of Health. An A-Z of Traditional Chinese Medicine. London, England: Mainstream Publishing; 1994:259.

Yamane T, Nakatani H, Kikuoka N, et al. Inhibitory effects and toxicity of green tea polyphenols for gastrointestinal carcinogenesis. Cancer. 1996;77(8 Suppl):1662-1667.

Yang TT, Koo MW. Hypocholesterolemic effects of Chinese tea. Pharmacol Res. 1997;35(6):505-512.

Yang TTC, Koo MWI. Chinese green tea lowers cholesterol level through an increase in fecal lipid excreiton. Life Sciences. 1999:66:5:411-423.

Yu GP, Hsieh CC, Wang LY, Yu SZ, Li XL, Jin TH. Green-tea consumption and risk of stomach cancer: a population-based case-control study in Shanghai, China. Cancer Causes Control. 1995;6(6):532-538.


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