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

Green tea (Camellia sinensis)

Abstract and key points

  • Green tea is derived from the shrubs Camellia sinensis through a non-fermenting process.
  • The evidence for an association between green tea consumption and the incidence of cancer is generally inconsistent.
  • Drinking green tea appears safe at regular, habitual and moderate use.


Green tea is derived from the shrub Camellia sinensis, the same plant as used for black tea, but is not fermented.


A total of 27 systematic reviews and/or meta-analyses investigated the association between green tea consumption and the risk 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.


Drinking green tea appears safe at regular, habitual and moderate use (3-9 cups per day).

Read about the regulation, supervision and reimbursement of herbal medicine at NAFKAMs website CAM Regulation.


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

Document history

Summary last updated and revised in February 2014 by Jianping Liu and Xun Li.
Summary fully updated and revised in May 2012 by Jianping Liu and Xun Li.
Summary fully updated and revised in April 2012 by Jianping Liu and Xun Li.
Summary first published in September 2005, authored by Jianping Liu.


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