Time for coffee and tea
Green tea and the prevention of cancers
Green tea has many health benefits, in addition to its antioxidant properties that help to combat free radicals and decrease oxidative stress, there is a strong link between the consumption of tea and a lowering of the risk of developing cancers.
Some of the cancers that green tea has been shown to inhibit, include prostate, lung, skin, liver and stomach cancers. It is thought that the consumption of green tea may act both by decreasing cancer cell proliferation and by increasing the death rate of the carcinogenic cells. As it is a cancer preventative much research is being carried out into the compounds in green tea involved.
There are many ways that green tea has a role in the inhibition of cancers. These include:
1. Antioxidant activity
2. Detoxifying enzymes
3. Improving bacteria performance in the stomach
4. An ability to regulate cell fate
5. Anti-inflammatory role
One of the main antioxidants found in green tea is the catechin epigallocatechin-3-gallate. This compound has been shown to inhibit the growth of cancer cells.
It has also been reported that catechins found in green tea are able to act as a cytotoxin to carcinogenic breast cells. Again the most likely candidate is epigallocatechin-3-gallate. The application of this catechin is able to decrease the viability of breast carcinoma MCF-7 cancer cells by as much as 80% with out inhibiting the growth of normal cells. In cohort studies linking the risk of breast cancer with green tea consumption it has been put forward that green tea drinkers had a reduced risk of developing breast cancers than non-tea drinkers, and that the risk is inversely related to the amount of tea that is consumed.
As was found with breast cancer a study in China linked a decrease in prostate cancer risk with increased green tea consumption . Again this is thought to be down to the action of catechins. Experiments revealed that catechin found in green tea inhibited cancer adenoma cell growth and increased the rate of cancer cell death. Another cancer that has been shown to have reduced risk in tea drinkers is ovarian cancer.
Although many of the components of green tea are thought to play a role in reducing the risk of developing cancers much research still needs to be done on the topic to identify how. Additionally though much research have linked the consumption of tea with decreased risk, there are many papers that report no correlation between tea consumption and decreased cancer risk.References