Both black and green teas are widely drank in the world, indeed they are the second most consumed beverages after water. Much is made of the health benefits of drinking green tea (and black tea to a lesser extent, and their consumption is thought to have many beneficial health aspects such as the reduction in levels of obesity and a lowering of the risks of developing cancer.

Anti-Carcinogenic Compounds in Tea

Some of the main components found in tea that have anti carcinogenic effects are polyphenols, such as catechins and theaflavins, which are known to have strong antioxidant properties. Caffeine has also been demonstrated to have a positive impact in the fight against cancers. Here we take a look into the relationship between tea consumption and the development of gastrointestinal tract cancer.

Drinking Tea and the Risk of Developing Gastrointestinal Tract Cancer

Research using hamsters has shown that the ingestion of 1.5% green tea was able to significantly reduce the induction of oral cancers. It was able to do this be reducing the proliferation of cancer cells and lowering the amount of epidermal growth factor receptors. Similar results have been demonstrated by the use of the green tea catechin EGCG in rats. In mice green tea extracts have been shown to lower intestinal tumours.

Black tea has also been shown to have an ability to fight the development of gastrointestinal cancer cells in rats. Human colon cancer cells have also been shown to have their growth inhibited by green tea catechins.

In humans drinking tea has been shown to reduce the risk of gastrointestinal cancers in cohort studies. These investigation looked into the effect of green tea consumption in people who drank alcohol or/and were smokers. The incidence of stomach cancer was 83% lower in alcoholics and that of esophageal cancer 31% lower in smokers who drank green tea. It has also been demonstrated that taking the green tea catechin EGCG orally is able to lower the formation of tumors in small intestines.

It is seen that drinking both black and green teas is likely to have important health benefits with regards to the risk of developing gastrointestinal cancers.

References

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Caderni et al. (2000). Effects of black tea, green tea and wine extracts on intestinal carcinogenesis induced by azoxymethane in F344 rats. Carcinogenesis 21: 1965 to 1969.
Ju et al.(2005). Inhibition of intestinal tumorigenesis in Apcmin/+ mice by (－)-epigallocatechin-3-gallate, the major catechin in green tea. Cancer Research 65: 10623 to 10631.
Khan and Mukhtar (2007) Tea polyphenols for health promotion. Life Sciences 81: 519 to 533.
Li et al. (1999). Tea preparations protect against DMBA induced oral carcinogenesis in hamsters. Nutrition and Cancer 35: 73 to.
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