First drunk nearly 5000 years ago green tea has been said to have various medical and generally beneficial properties to it. As well as simply being a refreshing drink it is commonly taken to inhibit tooth decay, protect against heart disease and help you to live a long life. There has for some years also been claims that it can help to prevent and alleviate some cancers; and recent research would seem to support this particularly regarding leukemia.
What is Green tea?
Green tea is quite simply produced by taking ordinary tea leaves directly form the tea plant; steaming them, rolling them and then allowing them to dry. The steaming of the leaves prevents a natural fermentation process from occurring, which results in the ‘black tea‘ that many of us are familiar with. The fact that the fermentation hasn’t occurred affects the tea in another significant way, other than just its color. The flavor of green tea is fuller, compared to the black tea, as the natural polyphenols in the tea leaves have been preserved. It is the presence of these polyphenols that gives green tea its herbal remedy qualities as they are strong anti-oxidants that help to keep our body cells strong and healthy. Other compounds in green tea with medicinal qualities are the tannins and catechins; it also has high levels of fluoride that help to protect our teeth.
Green tea as a herbal remedy for cancers.
It is simply a fact that green tea drinkers have a lower incidence of certain cancers than those who do not drink green tea. Even drinking green tea only occasionally can be beneficial to you according to one Chinese study, which showed that people who only drank green tea once a week had lower rates of rectal, pancreatic and colon cancers. For women the reduction in the incidences of those cancers occurring was nearly halved! Scientists are also gathering data regarding eh effects of green tea in preventing stomach and skin cancers. However, the very latest research is making a definite link between green tea and improving the survival chances of leukemia sufferers. It has been reported in the ‘Journal of Clinical Oncology’, that patients given high doses of green tea “saw significant improvements, including 50% reduction in the size of swollen lymph glands”. Although still in its early stages the research has been conducted on people with aggressive forms of the cancer such as chronic lymphocytic leukemia. The fact that green tea appears to assist in the regression of this cancer is extremely promising. A particular polyphenol is thought to be responsible for the anti-cancer properties of green tea – EGCG, epigallocatechin-gallate.
EGCG and as an anti-cancer compound.
The power of EGCG is derived from the fact that it is an anti-oxidant and protects the cells from damage. Furthermore it can boost the bodies own production of the all important anti-oxidant enzymes – producing a double effect boost to your system. According to one study in the USA, EGCG also encourages apoptosis, cell death. However, the really clever bit is that EGCG does only kills off the cancerous cells. This process of apoptosis occurs when the EGCG prevents another enzyme, urokinase, from developing – which is needed for cancerous cells to grow. Hence, with a supply of urokinase the cancer cells/tumors will reduce and shrink; in some cases bringing about complete remission from the cancer.
Keeping healthy with green tea.
An additional benefit derived from the anti-oxidant polyphenols in green tea is the protection they can give to your heart. Although only confirmed in laboratory tests green tea has been shown to suppress LDL cholesterol, one of the causes of the build up of plaque in the arteries; blood causing circulation problems. Already mentioned above is the protective effect toward your teeth by the fluoride in green tea; whilst there is also thought to be a benefit in taking green tea to alleviate arthritis and heal wounds. As an anti-oxidant the EGCG in green tea is said to be 100 times more powerful than vitamin C; and 25 times more effective in protecting DNA from damage, such as cancerous tumors, than vitamin E is.
How to take green tea.
The usual warnings regarding pregnant and nursing women or anyone with a known medical condition apply. However, generally speaking having two cups of green tea a day is regarded as perfectly safe. Green tea can be bought as capsules, tablets, liquid, powder or the leaves themselves. The recommended dose per cup is to have about 250mg of the polyphenol in each cup of green tea. If you decide to ‘brew your own tea’ with the leaves themselves; steep the green tea leaves in boiled water for 5 minutes, before draining the leaves out and drinking the fluid.
Side effects of green tea.
Both as a tea drink or a supplement – green tea is generally regarded as being safe to consume. However, being a tea it does contain caffeine, so if you have a low caffeine tolerance you may want to be circumspect in your use of green tea. Green tea leaves themselves, before being prepared, have large amounts of vitamin K in them. However, once the green tea leaves are brewed into a tea the vitamin K is lost. Also, green tea supplements, such as capsules or powder have the vitamin K removed. Anyone taking an anti-coagulant drug, who should avoid vitamin K, should be aware of this, and avoid ingesting any unprepared green tea leaves. There is a good reason for following the method suggested above for preparing green tea from the leaves themselves. Apart from improving the overall flavor, boiling hot green tea can damage your throat and oesophagus and there are some concerns that boiling hot green tea can be linked to some cancer growths. Finally, if you see green tea advertised as gunpowder tea – it is perfectly safe. This is a traditional green tea leaf preparation that makes the tea leaves unfold when placed in water.