Green Tea
The unfermented green tea is known for its health benefits and there are many reports suggesting that it could prevent disease. The leaves have not gone through any oxidation process (fermentation), thus, it is not as processed as black tea. Therefore most of the nutrients in the leaves remain after production and is then released into your cup of tea. Green tea is therefore rich in antioxidants, vitamins and minerals.
Chinese and Japanese Green Tea
The Chinese method of producing green tea includes roasting the leaves in large pans. This is done to inactivate the enzymes that would otherwise start the fermentation process, when the leaves are rolled. Chinese green tea has a bright orange color, but the leaves remain green.
The Japanese metod is a little different than the Chinese. Hot steem blasts are used to inactivate the enzymes, and the oxidation is thereby avoided. Japanese green tea has a green to yellow color.
Disease Prevention
Since long ago green tea has been used as a natural medicine. Many people still drink it because it is regarded a healthy beverage, and it tastes good too! It is possible that green tea may help prevent heart disease that is common in the Western world.
Both cancer and cardiovascular disease are less common in Asia, where practically everybody drinks green tea. Their eating habits are also often better than in the West. For example, they eat plenty of fish that is high in omega-3 fatty acids, which can also prevent disease.
Green tea is rich in antioxidants called polyphenols. A subgroup of these are called catechins, and the catechin the appears to be most effective in cancer fighting is called EGCG (Epigallocatechin Gallate). This catechin appears to be able to kill the cancer cells by stopping new blood vessel to form. These vessels would otherwise help the cancer cells to grow.
It is mainly in laboratories and animal tests that green tea have shows positive results against cancer. There are also some studies on human subject with good results, but there are also other studies with no positive effects.
Live Longer with Green Tea
Green tea may prolong life expectancy, at least if you are from Japan. In an epidemiological study 40 000 adult Japanese men and women participated. They were followed for eleven years (1995-2005), but when the researchers looked only at cause specific deaths it was just for seven years (1995-2001).
The researchers investigated whether consumption of green tea was correlated to deadly cancer, cardiovascular disease, and a number of other causes of death. In this study a connection between green tea consumption and premature death was found.
One to two cups of green tea per day reduced the risk of dying prematurely (all causes). The effect was greatest for women, cardiovascular disease and a high tea consumption.
Women who drank a high amount of green tea, five cups or more per day, reduced the risk of dying prematurely (all causes) by 23 percent, compared to those who drank less than one cup per day. For men the reduced risk was only 12 percent.
When isolating the numbers for cardiovascular disease, women had a 31 percent risk reduction and for men it was 22 percent. The researchers found no evidence that green tea would have any protective effect against cancer.
Other Uses
Green tea is also used as an ingredient in skin lotions and other skin care products, because the tea leafs can protect the skin from the sun.
In Japan it is common to drink green tea with food, because it is good for the digestion. However, some studies suggest that green tea may reduce the absorption of non-heme iron. The iron absorption could, however, be improved if your meal is rich in vitamin C. It is mainly those who suffer from anaemia who need to be careful.
Storing and Preparing Green Tea
Green tea is more delicate than black tea. It is therefore important to store it correctly, and use a water temperature of about 80-85 degrees Celsius when preparing your tea. Let the boiling water cool for a while, or add some cold water to lower the temperature. Use one tablespoon tea leaves per cup and steep for 2-3 minutes.