Green Tea & Cancer - Read what noted Oncologist Dr. Mitchell Gaynor's has to say about green tea. Select from our updated articles database for specific cancers:
Colorectal Cancer: General
Clinical studies on the effects of green tea on colon or rectal cancer have produced conflicting results. Some clinical studies show decreased risk in those who drink the tea, while others show increased risk. In one study, women who drank 5 or more cups of green tea per day had a significantly lower risk of colorectal cancer compared to non-tea-drinkers. There was no effect in men, however. Other studies show that regular tea consumption may reduce the risk of colorectal cancer in women. Further research is needed before researchers can recommend green tea for the prevention of colorectal cancer.
Green Tea & Colo-Rectal Cancer - Case Western Study
Department of Medicine, Case Western Reserve University reserachers found that green tea constituent epigallocatechin-3-gallate inhibits topoisomerase I activity in human colon carcinoma cells. DNA topoisomerases I and II are essential for cell survival and play critical roles in DNA metabolism and structure. Inhibitors of topoisomerase constitute a novel family of antitumor agents with demonstrated clinical activity in human malignancies. The clinical use of these agents is limited due to severe toxic effects on normal cells. Therefore, there is a need to develop novel, nontoxic topoisomerase inhibitors that have the ability to spare normal cells. Recent studies have shown that green tea and its major polyphenolic constituent, epigallocatechin-3-gallate (EGCG), impart growth inhibitory responses to cancer cells but not to normal cells. Based on the knowledge that EGCG induces DNA damage, cell cycle arrest, and apoptosis, the reserachers considered the possibility of the involvement of topoisomerase in the antiproliferative response of EGCG. Here, for the first time, we show that EGCG inhibits topoisomerase I, but not topoisomerase II in several human colon carcinoma cell lines. Based on this study it is tempting to suggest that combination of EGCG with other conventional topoisomerase inhibitors could be an improved strategy for treatment of colon cancer. They concluded the role of EGCG as a chemotherapeutic agent needed to be investigated.
Green Tea & Colo-Rectal Cancer - Rutgers Study
The Laboratory for Cancer Research at the College of Pharmacy of, Rutgers University studied the effects of green and black tea polyphenols on normal human colon mucosa and colon cancers were investigated. The results indicated that tea polyphenols can affect arachidonic acid metabolism in human colon mucosa and colon tumors, and this action may alter the risk for colon cancer in humans.
References: Life Extension Magazine and other studies added.
Asano Y, Okamura S et al. Effect of epigallocatechin gallate on leukemic blastcells from patients with acute myeloblastic leukemia. Life Sci 1997; 60:135-42 Berger SJ, et al. Green tea constituent (--)-epigallocatechin-3-gallate inhibits topoisomerase I activity in human colon carcinoma cells. Biochem Biophys Res Commun 2001;288:101-5.
Challa A et al. Interactive suppression of aberrant crypt foci induced by azoxymethane in rat colon by phytic acid and green tea. Carcinogenesis 1997; 10:2023-26
Chen ZP, et al. Green tea epigallocatechin gallate shows a pronounced growth inhibitory effect on cancerous cells but not on their normal counterparts. Cancer Lett 1998; 129:173-79
Chung FL et al. Inhibition of lung carcinogenesis by black tea in Fischer rats treated with a tobacco-specific carcinogen: Caffeine as an important constituent. Cancer Res 1998;58:4096-4101
Deng ZY, Tao BY, et al. Effect of green tea and black tea on blood glucose, triglycerides, and antioxidants in aged rats. J Agricult Food Chem 1998;46:3875-78
Francheschi S et al. Influence of food groups and food diversity on breast cancer risk in Italy. Int J Cancer 1995; 63:785-89
Goodwin Sarah Federation of American Societies for Experimental Biology 18-Apr-2004
Hamilton-Miller JM. Anti-cariogenic properties of tea (Camellia sinensis). J Med Microbiol 2001;50:299-302
Hara Y. Influence of tea catechins on the digestive tract. J Cel Biochem 1997; Suppl 27: 52-58
Hibasami H et al. Induction of apoptosis in human stomach cancer cells by green tea catechins. Oncol Repetition 1998; 5:527-29
Hirose M et al. Inhibition of mammary gland carcinogenesis by green tea catechins and other naturally occurring antioxidants in female Sprague-Dawley rats pretreated with MDBA. Cancer Lett 1994; 83:149-56
Hong J, et al. Effects of purified green and black tea polyphenols on cyclooxygenase- and lipoxygenase-dependent metabolism of arachidonic acid in human colon mucosa and colon tumor tissues. Biochem Pharmacol 2001;62:1175-83
Hoshiyama Y, et al. A prospective study of stomach cancer death in relation to green tea consumption in Japan. Br J Cancer 2002;87:309-13
Huang MT, et al. Effects of tea, decaffeinated tea, and caffeine on UVB light-induced complete carcinogenesis in SKH-1 mice: demonstration of caffeine as a biologically important constituent of tea. Cancer Res 1997;57:2623-9
Hsu SD, et al. Chemoprevention of oral cancer by green tea. Gen Dent 2002;50:140-6
Inoue M, Tajima K, et al. Tea and coffee consumption and the risk of digestive tract cancers: data from a comparative case-referent study in Japan. Cancer Causes Control 1998;9:209-16
Ito Y et al. Chromosome aberrations induced by aflatoxin B1 in rat bone marrow cells in vivo and their suppression by green tea. Mutat Res 1989; 222:253-61
Jian L, Xie LP, Lee AH, Binns, CW Protective Effect Of Green Tea Against Prostate Cancer: A Case Control Study In Southeast China Int J Cancer:108. 130-135 (2004)
Katiyar SK, Mukhtar H. Tea antioxidants in cancer chemoprevention. J Cell Biochem Suppl 1997; 27:59-67
Katiyar SK et al. Polyphenolic antioxidant epigallocatechin gallate from green tea reduces UVB-induced inflammatory responses and infiltration of leukocytes in human skin. Photochem Photobiol 1999; 69:148-53
Khafif A; Schantz SP, et al. Quantitation of chemopreventive synergism between epigallocatechin gallate and curcumin in normal, premalignant, and malignant oral epithelial cells. Carcinogenesis 1998;19:419-24
Kinjo J, et al. Activity-guided fractionation of green tea extract with antiproliferative activity against human stomach cancer cells. Biol Pharm Bull 2002;25:1238-40
Komori A, Yasunami J, et al. Anticarcinogenic activity of green tea polyphenols. Jpn J Clin Oncol 1993; 23:186-90
Kuroda Y, Hara Y. Antimutagenic and anticarcinogenic activity of tea polyphenols. Mutat Res 1999; 436:69-97
Larsson, Susanna, Wolk Alicja, Karolinksa Institute. A relationship between the amounts of tea a middle-age woman drinks and her risk for ovarian cancer. Archives of Internal Medicine. Dec. 12 issue.
Lean ME et al. Dietary flavonols protect diabetic human lymphocytes against oxidative damage to DNA. Diabetes 1999; 48:176-81
Lee IP et al. Chemopreventive effects of green tea against cigarette smoke-induced mutations in humans. J Cell Biochem 1997; Suppl 27:68-75
Lee YK, et al. VEGF Receptor Phosphorylation Status and Apoptosis is Modulated by a Green Tea Component, Epigallocatechin-3-gallate (EGCG) in B cell Chronic Lymphocytic Leukemia. Blood 2004;104(3):788-94
Liao S, Hipakka RA. Selective inhibition of steroid 5-alpha-reductase isozymes by tea epicatechin-3-gallate and epigallocatechin-3-gallate. Biochem Biophys Res Commun 1995;214:833-38
Liao S, Umekita Y et al. Growth inhibition and regression of human prostate and breast tumors in athymic mice by tea epigallocatechin gallate. Cancer Lett 1995; 96:239-43
Lin YL, Cheng CY, et al. Hypolipidemic effect of green tea leaves through induction of antioxidant and phase II enzymes including superoxide dismutase, catalase, and glutathione S-transferase in rats. J Agricult Food Chem 1998;46:1893-99
Lu LH, Lee SS, Huang HC. Epigallocatechin suppression of proliferation of vascular smooth muscle cells: correlation with c-jun and JNK. Brit J Pharmacol 1998;124:1227-37
McCarty MF. Polyphenol-mediated inhibition of AP-1 transactivating activity may slow cancer growth by impeding angiogenesis and tumor invasiveness. Med Hypoth 1998; 50:511-14
Morre D, Morre DJ. Findings on epigallocatechin gallate and tNOX inhibition presented at the 38th annual meeting of the American Society for Cell Biology; summary available at http//www.uns.purdue.edu
Naasani I et al. Telomerase inhibition, telomere shortening, and senescence of cancer cells by tea catechins. Biochem Biophys Res Commun 1998; 249:391-96
Nagata C et al. Associations of coffee, green tea, and caffeine intakes with serum concentrations of estradiol and sex hormone-binding globulin in premenopausal Japanese women. Nutr Cancer 1998; 30:21-24
Nakachi K, Suemasu K, et al. Influence of drinking green tea on breast cancer malignancy among Japanese patients. Jpn J Cancer Res 1998;89:254-61
Oguri A et al. Inhibitory effects of antioxidants on formation of heterocyclic amines. Mutat Res 1998; 402:237-45
Otsuka T, Ogo T, et al. Growth inhibition of leukemic cells by epigallocatechin gallate, the main constituent of green tea. Life Sciences 1998; 63:1397-1403
Parshad R, Sanford RR, et al. Protective action of plant polyphenols on radiation-induced chromatid breaks in cultured human cells. Anticancer Res 1998;18:3263-66
Pashka AG et al. Induction of apoptosis in prostate cancer cell lines by the green tea component, epigallocatechin gallate. Cancer Lett 1998;130:1-7
Pisters KM, et al. Phase I trial of oral green tea extract in adult patients with solid tumors. J Clin Oncol 2001;19:1830-8.
Proniuk S, et al. Preformulation study of epigallocatechin gallate, a promising antioxidant for topical skin cancer prevention. J Pharm Sci 2002;91:111-6
Quin G et al. Inhibition of aflatoxin B1-induced initiation of hepatocarcinogenesis in the rat by green tea. Cancer Lett 1997; 112:149-54
Reuters. Green tea blocks angiogenesis. Internet Health News, 3-31-1999
Sai I, Kai S et al. Protective effects of green tea on hepatotoxicity, oxidative DNA damage and cell proliferation in the rat liver, induced by repeated oral administration of 2-nitropropane. Food Chem Toxicol 1998; 6:1043
Sartippour MR, et al. Green tea inhibits vascular endothelial growth factor (VEGF) induction in human breast cancer cells. J Nutr 2002;132:2307-11.
Sazuka M, Imazawa H, et al. Inhibition of collagenases from mouse lung carcinoma cells by green tea catechins and black tea theaflavins. Biosci Biotechnol Biochem 1997; 61:1504-06
Smith DM, et al. Green tea polyphenol epigallocatechin inhibits DNA replication and consequently induces leukemia cell apoptosis. Int J Mol Med 2001;7:645-52
Suganuma M, Okabe S, et al. Synergistic effects of epigallocatechin gallate with epicatechin, sunlilndac, or tamoxifen on cancer-preventive activity in the human lung cancer cell line PC-9. Cancer Res 1999;59:44-7
Sugiyama T, Sadzuka Y. Combination of theanine with doxorubicin inhibits hepatic metastasis of M5076 ovarian sarcoma. Clin Cancer Res 1999; 5:413-16
Sugiyama T, Sadzuka Y. Enhancing effects of green tea components on the antitumor activity of adriamycin against M5076 ovarian sarcoma. Cancer Lett 1998; 133:19-26
Sun CL, et al. Urinary tea polyphenols in relation to gastric and esophageal cancers: a prospective study of men in Shanghai, China. Carcinogenesis 2002;23:1497-503.
Tosetti F, Ferrari N, De Flora S. Angioprevention: angiogenesis is a common and key target for cancer chemopreventive agents. FASEB J 2002;16:2-14
Tsubono Y, et al. Green tea and the risk of gastric cancer in Japan. N Engl J Med 2001;344:632-6
Valcic S et al. Inhibitory effect of six green tea catechins and caffeine on the growth of four selected human tumor cell lines. Anticancer Drugs 1996; 7:461-68
Wang ZY, et al. Inhibitory effect of green tea on the growth of established skin papillomas in mice. Cancer Res 1992;52:6657-65.
Yamane T, Nakatsni H et al. Inhibitory effects and toxicity of green tea polyphenols for gastrointestinal carcinogenesis. Cancer 1996;77(suppl):1662-67
Yan YS. Effect of Chinese tea extract on the immune function of mice bearing tumors and their antitumor activity. Chung Hua Yu Fang 1992; 26:5-7
Yang CS, et al. Blood and urine levels of tea catechins after ingestion of different amounts of green tea by human volunteers. Cancer Epidemiol Biomarkers Prev 1998;7:351-4.
Yang CS, et al. Prevention of carcinogenesis by tea polyphenols. Drug Metab Rev 2001;33:237-53
Yang CS, et al. Human salivary tea catechin levels and catechin esterase activities: implications in human cancer prevention studies. Cancer Epidemiol Biomarkers Prev 1999;8:83-9
Yang FJ et al. Green tea polyphenols block endotoxin-induced tumor necrosis factor alpha production and lethality in murine model. J Nutr 1998; 128:2334-40
Yang GY, Liao J, et al. Inhibition of growth and induction of apoptosis in human cancer cell lines by tea polyphenols. Carcinogenesis 1998; 19:611-16
Zhang, M, Binns, CW, Lee, A Tea Consumption and Ovarian Cancer Risk: A Case control Study in China. Cancer Epidemiol Biomarkers Prev (2002) 11:713-718.
Zhen Y et al. Green tea extract inhibits nucleoside transport and potentiates the antitumor effect of antimetabolites. Chin Med Sci 1991; 6:1-5
Zhu BT, Taneja N et al. Effects of tea polyphenols and flavonoids on liver microsomal glucuronidation of estradiol and estrone. J Steroid Biochem Mol Biol 1998;64:207-15