Green Tea and a Healthy Cancer Prevention Diet

Tea is the world’s most popular beverage after water and is made from the young leaves of the Camellia sinensis bush which is a shrub native to Asia. Research has shown that a number of readily available foods such as green tea, actually appear to have a major impact on cancer prevention. These cancer fighting foods seem to have the ability to interfere with the development of cancerous tumors. Cancer fighting foods all contain large amounts of certain phytochemicals. Phytochemicals were developed by nature to protect plants against damage caused by insects, disease and environmental stress. These phytochemical molecules are the ones that give fruits and vegetables their brilliant colors, provide the smell to garlic and the astringent taste to tea. It is very likely that these phytochemicals, not the vitamins and minerals, that are the source of the cancer prevention capabilities of these healthy foods.

The tea leaf contains large quantities of phytochemical polyphenols called flavonols, commonly known as catchetins. Although green tea and black tea start out from the same plant leaf, their chemical composition is different because of the way they are processed. Apart from an initial brief steam roasting to stop fermentation, the production of green tea is largely a manual process. Japanese green teas contain more catchetins than Chinese green teas. On the other hand black teas are allowed to go through a fermentation process before they are roasted. This process destroys most of the cancer fighting flavonols. Some black teas like Darjeeling still contain significant quantities of catchetins. Oolong tea is only partially fermented and retains cancer fighting properties somewhere between green tea and black tea.

Green tea has been thought for years to help lower cholesterol and blood pressure as well as improve digestion and help protect against ulcers. It has been promoted as an herb that can prevent certain bacterial infections. Green tea is widely consumed in Japan, China, and other Asian nations and is becoming more popular in Western nations. Some reports indicate green tea may have the ability to help prevent many types of cancers. However results of studies on human populations are still preliminary. On the other hand, studies on mice have shown that the catchetins in green tea give mice protection against all stages of cancer development. These catchetins may cause cancer cells to die just like normal cells and in a process called angiogenesis - it may also stop new blood vessels from forming to supply the tumor.

The amount of green tea needed to achieve beneficial effects is unknown. Asians usually drink at least 3 cups per day using 1 to 2 teaspoons of dried leaves steeped in a cup of boiling water. Tea should be steeped longer than 7 or 8 minutes to extract the maximum amount of catchetins. Green tea is generally considered safe as large numbers of people have consumed this tea for thousands of years with few dangerous side effects. However drinking large amounts of tea may cause problems because of the caffeine content which can cause nausea, sleeping problems and frequent urination. Women who are pregnant or breast-feeding should not drink green tea in large amounts as caffeine can cross the placenta and also be passed along in breast milk.

Eating a healthy balanced diet can provide our bodies with tens of thousands of different phytochemicals. Much of the available research on cancer prevention foods still comes from laboratory cell studies, animal studies and epidemiologic observational studies comparing populations. Clinical trials on humans are being conducted but it takes many years for results to be validated. Not all fruits, vegetables and other plant products provide the best anti-cancer phytochemicals. The ten best groups of anti-cancer foods are discussed in our website www.benefits-of-antioxidants.com . They include: berries and citrus fruits, cruciferous vegetables, garlic and onions, green tea, omega-3 essential fatty acids, olive oil, tomatoes, soy products, red wine and dark chocolate.

Mark Ransome is a contributing editor and writer for the popular new website – Benefits of Antioxidants. Visitors to http://www.benefits-of-antioxidants.com will have access to a summary of the ten best cancer prevention foods and a new free diet and weight loss program – The Psychiatrist’s Weight Loss Program.