Written by Jianping Liu, Xun Li and the CAM-Cancer Consortium.
Updated February 13, 2014

Green tea (Camellia sinensis)

Does it work?

 

A total of 27 systematic reviews and/or meta-analyses of epidemiological studies investigated associations between green tea consumption and the risk of developing cancer. Details of the included reviews are presented in Table 1. None of studies detected an increased risk for any cancer.

Cancer in general 

Three recent systematic reviews 4 6 7 and a 2009 Cochrane review 25 concluded that there is insufficient and conflicting evidence to establish an association between green tea consumption and incidence of cancer. In general, inverse associations for green tea consumption and risk of gastrointestinal tract, oesophageal (women), lung (non-smoking women), ovarian, prostate and breast cancer were found. Evidence for a protective role of tea intake on the development of cancers of liver, colorectum, pancreas, urinary tract, prostate, glioma, lymphoma, and leukaemia was, however, insufficient. 

Lung cancer 

A 2009 meta-analysis of 12 studies indicated a borderline significant association between highest green tea consumption and reduced risk of lung cancer, and an increase in green tea consumption of two cups/day was associated with an 18% decreased risk of developing lung cancer.8 A newly published systematic review only included 5 human-related studies, and found insufficient evidence to support green tea use for preventing lung cancer.9 Another meta-analysis of 6 cohort/case control studies published in 2012 found significant nonlinear dose-response relationship between green tea consumption and risk of lung cancer, showing favourable effect of green tea consumption especially when the dose was more than 7 cups per day.10 

Esophageal cancer 

None of the three systematic reviews/meta-analyses published in 2012 11 and 2013 12 13 found a significant association between high/medium/low dose versus non/least of green tea consumption and cancer risk in overall population, but there seems to be reduced cancer risk with green tea consumption among female 11 12 and in the Chinese 13 population. 

Stomach cancer 

According to the latest systematic review (2013) including 7 cohort and 10 case control studies, 14 the association between green tea consumption and stomach cancer remains conflicting since the publication of the two meta-analysis in 2010 15 and 2009 16 and warmer tea seems to be associated with lower cancer risk. One systematic review based on a Japanese population published in 2012 found a consistent risk reduction of stomach cancer with green tea consumption in women only based on prospective data, whilst the inverse association among the general population was consistent according to retrospective studies. 17 

Liver cancer 

A meta-analysis of 13 studies published in 2011 found an inverse association with a borderline significance between tea consumption and primary liver cancer in both men and women. Green tea consumption was associated with a moderate reduction in risk (RR=0.79; 95% CI=0.68-0.93) for primary liver cancer.18 19 

Colorectal cancer 

A 2006 meta-analysis of 8 studies indicated a reduced risk of colorectal cancer with green tea consumption from combined results.19 The inverse association was observed only in case-control studies. Two systematic reviews published in 2012 both found reduced cancer risk in higher dose green tea consumption. 20 21 Inverse association of cancer risk and green tea consumption seems to focus in Asian population including Shanghai and Singapore people. 

Bladder cancer 

Among the three newly conducted meta-analyses,22 23 24 only one 22 (including one cohort and nine case control studies of different types of tea, two cohort and two case control studies of green tea) found protective effects on bladder cancer when pooling the data for green tea consumption only. 

Prostate cancer 

A systematic review published in 2009 found conflicting results for an association between green tea consumption and prostate cancer,6 while a later meta-analysis of seven studies published in 2011 indicated that consumption of green tea may have a protective effect on prostate cancer in Asian populations, especially in Chinese people.25 

Breast cancer 

A 2010 meta-analysis of nine studies found that increased green tea consumption (more than 3 cups a day) was inversely associated with breast cancer recurrence in the analysis of case-control studies but not in the cohort studies.26 An updated meta-analysis published in 2013 found no significant association among cohort nor case control studies, however, a linear but not significant dose-response association was detected.27 

Ovarian cancer 

Three systematic reviews found uniformly inverse association between green tea consumption and ovarian cancer risk.28 29 30

Citation Jianping Liu, Xun Li , CAM-Cancer Consortium. Green tea (Camellia sinensis) [online document]. http://ws.cam-cancer.org/The-Summaries/Herbal-products/Green-tea-Camellia-sinensis. February 13, 2014.

References

  1. History of green tea [Website], accessed 28.12.13
  2. Green tea. Retrieved Feb. 25, 2012, from Wikipedia [Website], accessed 28.12.13
  3. Tanaka T, Ishii T, Mizuno D, et al. (-)-Epigallocatechin-3-gallate suppresses growth of AZ521 human gastric cancer cells by targeting the DEAD-box RNA helicase p68. Free Radical Biology and Medicine 2011, 50(10):1324-1335.
  4. Yuan JM, Sun C, Butler LM. Tea and cancer prevention: epidemiological studies. Pharmarcology research 2011, 64(2):123-135.
  5. Boehm K, Borrelli F, Ernst E, Habacher G, Hung SK, Milazzo S, Horneber M. Green tea (Camellia sinensis) for the prevention of cancer. Cochrane Database of Systematic Reviews 2009, Issue 3. Art. No.: CD005004. DOI:10.1002/14651858.CD005004.pub2.
  6. Sturgeon JL, Williams M, van Servellen G. Efficacy of green tea in the prevention of cancers. Nurs Health Sci. 2009 Dec;11(4):436-46. doi: 10.1111/j.1442-2018.2009.00476.x.
  7. Liu J, Xing J, Fei Y. Green tea (Camellia sinensis) and cancer prevention: a systematic review of randomized trials and epidemiological studies. Chin Med. 2008 Oct 22;3:12.
  8. Tang N, Wu Y, Zhou B, Wang B, Yu R. Green tea, black tea consumption and risk of lung cancer: a meta-analysis. Lung Cancer. 2009; 65: 274-83.
  9. Fritz H, Seely D, Kennedy DA, Fernandes R, Cooley K, Fergusson D. Green tea and lung cancer: a systematic review. Integrative cancer therapies. 2013;12(1):7-24. Epub 2012/04/26.
  10. Wang Y, Yu X, Wu Y, Zhang D. Coffee and tea consumption and risk of lung cancer: a dose-response analysis of observational studies. Lung cancer (Amsterdam, Netherlands). 2012;78(2):169-70. Epub 2012/09/12.
  11. Zheng P, Zheng HM, Deng XM, Zhang YD. Green tea consumption and risk of esophageal cancer: a meta-analysis of epidemiologic studies. BMC gastroenterology. 2012;12:165.
  12. Sang LX, Chang B, Li XH, Jiang M. Green tea consumption and risk of esophageal cancer: a meta-analysis of published epidemiological studies. Nutrition and cancer. 2013;65(6):802-12. Epub 2013/08/06.
  13. Zheng JS, Yang J, Fu YQ, Huang T, Huang YJ, Li D. Effects of green tea, black tea, and coffee consumption on the risk of esophageal cancer: a systematic review and meta-analysis of observational studies. Nutrition and cancer. 2013;65(1):1-16. Epub 2013/02/02.
  14. Hou IC, Amarnani S, Chong MT, Bishayee A. Green tea and the risk of gastric cancer: Epidemiological evidence. World journal of gastroenterology : WJG. 2013;19(24):3713-22. Epub 2013/07/11.
  15. Kang H., Rha SY, Oh KW, Nam CM. Green tea consumption and stomach cancer risk: a meta-analysis. Epidemiology and Health 2010; 32:e2010001.
  16. Myung SK, Bae WK, Oh SM, Kim Y, Ju W, Sung J, Lee YJ, Ko JA, Song JI, Choi HJ. Green tea consumption and risk of stomach cancer: a meta-analysis of epidemiologic studies. Int J Cancer 2009; 124:670-7.
  17. Sasazuki S, Tamakoshi A, Matsuo K, Ito H, Wakai K, Nagata C, et al. Green tea consumption and gastric cancer risk: an evaluation based on a systematic review of epidemiologic evidence among the Japanese population. Japanese journal of clinical oncology. 2012;42(4):335-46. Epub 2012/03/01.
  18. Sing MF, Yang WS, Gao S, ect. Epidemiological studies of the association between tea drinking and primary liver cancer: a meta-analysis. European Journal of Cancer Prevention. 2011, 20(3):157-165.
  19. Sun CL, Yuan JM, Koh WP, Yu MC. Green tea, black tea and colorectal cancer risk: a meta-analysis of epidemiologic studies. Carcinogenesis 2006; 27:1301-9.
  20. Wang XJ, Zeng XT, Duan XL, Zeng HC, Shen R, Zhou P. Association between green tea and colorectal cancer risk: a meta-analysis of 13 case-control studies. Asian Pacific journal of cancer prevention : APJCP. 2012;13(7):3123-7.
  21. Wang ZH, Gao QY, Fang JY. Green tea and incidence of colorectal cancer: evidence from prospective cohort studies. Nutrition and cancer. 2012;64(8):1143-52. Epub 2012/11/21.
  22. Wang X, Lin YW, Wang S, Wu J, Mao QQ, Zheng XY, et al. A meta-analysis of tea consumption and the risk of bladder cancer. Urologia internationalis. 2013;90(1):10-6. Epub 2012/10/12.
  23. Wu S, Li F, Huang X, Hua Q, Huang T, Liu Z, Liu Z, Zhang Z, Liao C, Chen Y, Shi Y, Zeng R, Feng M, Zhong X,Long Z, Tan W, Zhang X. The association of tea consumption with bladder cancer risk: a meta-analysis. Asia Pac J Clin Nutr. 2013;22(1):128-37. doi: 10.6133/apjcn.2013.22.1.15.
  24. Qin J, Xie B, Mao Q, Kong D, Lin Y, Zheng X. Tea consumption and risk of bladder cancer: a meta-analysis. World J Surg Oncol. 2012 Aug 25;10:172. doi: 10.1186/1477-7819-10-172.
  25. Zheng J, Yang B, Huang T, Yu Y, Yang J, Li D. Green tea and black tea consumption and prostate cancer risk: an exploratory meta-analysis of observational studies. Nutrition and Cancer 2011; 63(5):663-672.
  26. Ogunleye AA, Xue F, Michels KB. Green tea consumption and breast cancer risk or recurrence: a meta-analysis. Breast Cancer Res Treat. 2010; 119:477-484.
  27. Wu Y, Zhang D, Kang S. Black tea, green tea and risk of breast cancer: an update. SpringerPlus. 2013;2(1):240. Epub 2013/06/12.
  28. Trudel D, Labbe DP, Bairati I, Fradet V, Bazinet L, Tetu B. Green tea for ovarian cancer prevention and treatment: a systematic review of the in vitro, in vivo and epidemiological studies. Gynecologic oncology. 2012;126(3):491-8. Epub 2012/05/09.
  29. Butler LM, Wu AH. Green and black tea in relation to gynecologic cancers. Molecular Nutrition & Food Research 2011; 55(6):931-940.
  30. Nagle CM, Olsen CM, Bain CJ, etc. Tea consumption and risk of ovarian cancer. Cancer Causes and Control 2010; 21(9):1485-1491.
  31. Brown MD. Green tea (Camellia sinensis) extract and its possible role in the prevention of cancer. Altern Med Rev 1999;4:360-70.
  32. Mazzanti G, Menniti-Ippolito F, Moro PA, Cassetti F, Raschetti R, Santuccio C, Mastrangelo S. Hepatotoxicity from green tea: a review of the literature and two unpublished cases. Eur J Clin Pharmacol. 2009 Apr;65(4):331-41. doi: 10.1007/s00228-008-0610-7. Epub 2009 Feb 6.
  33. Bettuzzi S, Brausi M, Rizzi F, Castagnetti G, Peracchia G, Corti A. Cancer Res. Chemoprevention of human prostate cancer by oral administration of green tea catechins in volunteers with high-grade prostate intraepithelial neoplasia: a preliminary report from a one-year proof-of-principle study. 2006 Jan 15;66(2):1234-40.
  34. Nguyen MM, Ahmann FR, Nagle RB, Hsu CH, Tangrea JA, Parnes HL, Sokoloff MH, Gretzer MB, Chow HH. Randomized, double-blind, placebo-controlled trial of polyphenon E in prostate cancer patients before prostatectomy: evaluation of potential chemopreventive activities. Cancer Prev Res (Phila). 2012 Feb;5(2):290-8. doi: 10.1158/1940-6207.CAPR-11-0306. Epub 2011 Nov 1.
  35. Jatoi A, Ellison N, Burch PA, Sloan JA, Dakhil SR, Novotny P, Tan W, Fitch TR, Rowland KM, Young CY, Flynn PJ. A phase II trial of green tea in the treatment of patients with androgenindependent metastatic prostate carcinoma. Cancer. 2003 Mar 15;97(6):1442-6.
  36. Thomas F, Holly JM, Persad R, ect. Green tea extract (epigallocatechin-3-gallate) reduces efficacy of radiotherapy on prostate cancer cells. Urology 2011; 78(2):421-475.
  37. Qiao J, Gu C, Shang W, ect. Effect of green tea on pharmacokinetics of 5-fluorouracil in rats and pharmacodynamics in human cell lines in vitro. Food and Chemical Toxicology 2011; 49(6):1410-1415.
  38. Bannerman B, Xu L, Jones M et al. Preclinical evaluation of the antitumor activity of bortezomib in combination with vitamin C or with epigallocatechin gallate, a component of green tea. Cancer Chemother Pharmacol. 2011;68(5):1145-54.
  39. Golden EB, Lam PY, Kardosh A et al. Green tea polyphenols block the anticancer effects of bortezomib and other boronic acid-based proteasome inhibitors.Blood. 2009;113(23):5927-37.
  40. Sarma DN, Barrett ML, Chavez ML, Gardiner P, Ko R, Mahady GB, Marles RJ, Pellicore LS, Giancaspro GI, Low Dog T. Safety of green tea extracts: a systematic review by the US Pharmacopeia. Drug Saf. 2008;31(6):469-84.