Green tea certainly won't make you immune to cance; however, green tea may play a role in reducing your risk of developing certain cancers, according to the National Institutes of Health's MedlinePlus. Nonetheless, overall evidence remains inconclusive at the time of publication. Green tea makes a good addition to a healthy diet combined with an active lifestyle in an effort to prevent cancer.
General Evidence
The National Cancer Institute provides a frequently updated review into claims of green tea and cancer prevention. At the time of publication, the NCI suggests that tea contains substances called polyphenols that could prove useful in cancer prevention; however, the institute also points out that clinical evidence of the cancer-prevention benefits of tea in humans is limited. Population-based studies also fail to provide conclusive evidence. They conclude that tea, including green tea, is not recommended as a way to reduce cancer risks or to treat the disease.
Possible Benefits
Despite the lack of definitive evidence, MedlinePlus concludes that available studies do point to green tea offering some preventative benefits for specific cancers. These include esophageal, bladder, pancreatic and ovarian cancers. In one study, cited in a 2005 issue of "Archives of Internal Medicine," scientists looked at possible links between green tea and ovarian cancer in 61,057 women. Results showed that women drinking no green tea at all had almost double the risk of ovarian cancer than women drinking two cups or more each day.
Breast Cancer
Some studies appear to show that green tea helps lower the chances of developing breast cancer. For example, in a 2001 study published in "Cancer Letters," scientists looked for links between breast cancer in 1,160 women and green tea consumption. They concluded that women with previous early-stage tumors who drink green tea regularly appear to lower their risk of breast cancer recurrence. The University of Maryland also points to studies that show how polyphenols slow the growth of breast cancer cells in animals and test tube environments.
Polyphenols
Green tea contains high amounts of polyphenolic substances called catechins, as well as other types of polyphenols. These have strong anti-oxidant properties. Anti-oxidants work as sponges for harmful molecules in the body called free radicals. Anti-oxidants bond with these reactive chemicals, making them less likely to bond with other molecules, such as those found in cell walls. This may help reduce inflammation in the body. In test tube studies, the polyphenols in the green tea slow the progress of tumor cell growth. It's likely that any potential anti-cancer benefits from green tea come from these substances.
References
- National Cancer Institute; Tea and Cancer Prevention: Strengths and Limits of the Evidence; November 2010
- MedlinePlus; Green Tea; May 2011
- "Archives of Internal Medicine"; Tea Consumption and Ovarian Cancer Risk; S.C. Larsson, et al.; December 2005
- University of Maryland Medical Center; Green Tea; September 2010
- "Cancer Letters"; 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; M. Inoue, et al.; June 2001
Member Comments