The National Cancer Institute estimates that more than 220,000 new cases of lung cancer will be diagnosed in the United States in 2010. Unlike most cancers, there are known risk factors that can increase the patient's chance of developing lung cancer. The majority of lung cancers are associated with smoking, while other risk factors include radon gas, asbestos, air pollution, family history and age. Treatment can involve surgery, chemotherapy and/or radiotherapy.
Green Tea
All teas derive from the plant Camellia sinensis, but processing and variety of the plant determines tea type. Green tea is being studied for a number of its health benefits. Tea is a combination of biologically active components, which include flavonoids and catechins. The catechins are polyphenols which are believed to have the majority of health benefits. The major polyphenol in green tea is epigallocatechin 3 gallate and is the most studied.
Laboratory Studies
Epigallocatechin 3 gallate, or EGCG, is the major polyphenol in green tea and has been widely tested in the laboratory. The April 2008 journal "Histology and Histopathology" reviewed the laboratory data for epigallocatechin 3 gallate. It concluded that studies showed that polyphenol blocks many biological pathways involved in cancer, while inhibiting growth in cancer cells and causing cancer cells to undergo cell death in the laboratory.
Clinical Studies
A trial from Taiwan studied patients with and without lung cancer. Published in March 2010 in "Oncology Times," the research suggests that smokers who did not drink green tea had a 12.71-fold increase in developing lung cancer, compared to those who drank a minimum of one cup of green tea a day. The researchers also showed, however, that a number of genes also altered the risk of developing cancer.
Antioxidant Properties
Green tea contains antioxidants; antioxidants act by protecting the body from oxidants or free radicals. Free radicals cause damage to the cells and the cells genetic material, DNA. Damage caused by free radicals can lead to cancer. Green tea contains more antioxidants than other tea types because it is less processed.
Warning
The January 2010 issue of "Food Chemical Toxicology" suggests that green tea is associated with an increased incidence of some cancers, and in high doses, can be toxic to the liver. A review of 51 studies that was published in the July 2009 issue of the "Cochrane Database Systematic Reviews" concluded, however, that drinking green tea is safe with moderate, regular use. The evidence remains conflicting regarding its use in preventing cancers.
Drug Interactions
Though green tea is considered natural, a number of natural products are known to interact with other drugs. The University of Maryland Medical Center lists a number of medications that may interact with green tea including some antibiotics, beta blockers, and birth control pills. The "International Journal of Oncology" published in July 2010 showed that green tea can alter the effectiveness of some chemotherapy drugs. The consumption of green tea should be discussed with a medical practitioner by anyone taking medications or starting chemotherapy.
References
- National Cancer Institute: Lung Cancer
- "Histology and Histopathology"; Tea Polyphenols, Their Biological Effects and Potential Molecular Targets. D. Chen et al.; April 2008
- "Oncology Times"; Research Roundup: AACR-IASLC Joint Conference on Molecular Origins of Lung Cancer; RS Tuma; March 2010
- "Food and Chemical Toxicology"; Hepatotoxicity of High Oral Dose (-) -Epigallocatechin -3-Gallate in Mice; JD Lambert, et al.; January 2010
- "Cochrane Database of Systematic Reviews"; Green Tea (Cameilla sinensis) For The Prevention of Cancer; Boehm K., et al.; July 2009
- University of Maryland Medical Center: Possibel Interactions with: Green Tea
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