Four different types of tea (white, green, oolong and black) come from the same source: The leaves of the plant Camellia sinensis. ( "Herbal" tea or herbal tea is not true, as a tea, because it contains no leaves of Camellia sinensis, and is more likely derived from the dried flowers, stems, leaves and berries, which many other plants.)

What distinguishes the four types of tea is true, as the leaves are between the time at which they are picked, and the time when they are packed:

White tea is the product mainly in the leaves of the tea buds. Because there is so little treats, it also will be possible mighty fight against the disease. So far, however, there is relatively little research on the effects on health.

To green tea, the leaves are harvested and stored (usually in the steam and bicarbonate), in order to prevent the process of fermentation (oxidation).

To oolong and black tea, the leaves are harvested and in the air during a specific period. During the fermentation. The oolong tea is exposed to the sun, and the partially ferment, black tea is fully fermented.

The fermentation process slightlychanges mainly by the chemical composition of the tea. The leaves are used to fermentation, the weak, tea Natural History in the file on the fight against cancer, while the caffeine content of tea leaves, growing steadily.

Approx. Green tea has half to one third thecaffeine of black tea.

EGCG is the active component of green tea, and it is a stronger antioxidant than vitamin C or E. For this reason it is so intense green tea.
Green tea of data: A selection of the scientific literature

While in the People's Republic of China and Japan, green tea is a staple food of the diet, particularly among the older generation. Epidemiological studies (especially in the Asian population) have always associated with the consumption of green tea with lower impact of various types of cancer.

A study from 1989 in the Journal of Nutrition Japanese that in the tea-growing areas in Japan (where the residents use the green tea in various forms, including gum, sweets and desserts) cancer, stomach mortality rate is lower than in the other regions in Japan.
One of the first studies to suggest a protective effect of green tea, published in the journal Cancer Research 1994. The authors of the study found that the rate of lung cancer in smokers Japanese were half of the smokers in America, and postulated that this difference was probably due to the differences in the consumption of tea between the two populations.

In a case-control study conducted by the Institute for Cancer-Shanghai, China, published in the Journal of the National Cancer Institute 1994, the green tea drinkers have a stake of 50 percent to reduce the risk of cancer - the esophagus.

Green tea appears to disrupt the process of stomach cancer in another Chinese case-control study. A reduction of 50 1995.

1997, a case-control study among men in Shanghai found that the regular consumption of green tea will be assigned important (between 12 and 53 percent) of the cuts risk for cancer of the colon, rectum and pancreas. The study was published in the International Journal of Cancer.

A landscape Japanese cohort of 8552 1997 has shown that green tea has a protective effect against cancer in all fora, including the stomach, lung, colorectum And in the liver. This effect was more pronounced in women drink 10 cups of green tea per day. (Note: A typical Japanese teacup holds 4 fluid ounces or 120 ml of tea, a typical American teacup holds 6 fluid ounces, or about 180 ml of tea.)

A Japanese study in 1998 in Cancer Causes Control, the consumption of seven or more cups of green tea per day reduces the risk of gastric cancer by 31 percent.

A study of 1998 on the Phase I and Phase II breast cancer in Japan has shown that the issues that drank more than five cups of green tea per day had a lower dropout rates, and without a long-term illness, the subjects who drank less than or four cups per day. This study, in which it was also shown that the consumption of green tea has no effect on the return of Phase III breast cancer, was in the Japanese newspaper for cancer research.

In 1999, a study of the Phase I / Phase II study, we found that people who drank green tea in the short-term reduction in the level of specific lipids (prostaglandin E2), the suspects, a factor that role in the development of the Rektumkarzinoms in the tissues. The study was published in the journal Cancer Epidemiology, Biomarkers and Prevention.

A study of 1160 patients with breast cancer, we found that the consumption of three or more than three cups of green tea per day, together with the significant reduction in the phase I of recurrence of breast cancer after seven years. The effects of consuming tea recurrence of Phase II was smaller. The study was published in the journal Cancer Letters 2001.

Iowa Women's Health Study cohort of 34651 women after menopause has examined 12 years and has come to the conclusion that the provision of catéchines tea with lower risks to the rectum. This appeared in the journal Cancer Causes Control 2002.

A case-control study conducted at the US-Asian women in the county of Los Angeles was of the view that the green tea drinkers showed a significant reduction in the risk of breast cancer, is dose-dependent. Those who drank more of 85.7 ml (about 3 ounces liquids or  ½ an American teacup) per day showed 47 percent lower risk of developing breast cancer than non-tea drinkers green. The study was in the "International Journal of Cancer 2003.

A case-control study conducted in southern China has shown that the risk for prostate cancer were regularly in the position, quantity, frequency and duration of green tea consumption increased. The study was in the "International Journal of Cancer 2004.

A case-control study conducted Taixing, China, and in the April 2005 issue of the International Journal of Cancer, found that regular consumption of green tea was associated with a reduction of 41 percent of the risk of gastric cancer.

In a study carried out in the May 2005 issue of Carcinogenesis, the inclusion of green tea was 13 percent more low estrogen circulating assets among a small group of women with postmenopausal Chinese. In the same group, the consumption of black tea is the amount of circulating estrogen were 19 percent higher than non-tea drinkers. (Increase in blood sex hormones such as estrogen, apparently in connection with an increased risk for certain types of cancer.)

A meta-analysis published in June 2005 in the journal Integrative Cancer Therapies reviewed the epidemiological data on green tea and breast cancer and came to the conclusion that on this day, the consumption of 5 or more cups of green tea per day shows statistically A trend not significant prevention of breast cancer. The evidence also shows that consumption of green tea may help prevent a recurrence of stage I and stage II breast cancer.

Currently, several NIH funded clinical trials are currently available for the study of green tea (and some extracts from green tea) tests for safety and effectiveness in humans. The tests are the primary prevention, cancer and the repeated threat integrative cancer therapy (combination of green tea with drugs against cancer.)

The laboratory or experimental evidence from the green tea in general (and in particular EGCG) in the cancer prevention is considerable, and more and more. Many potential biological mechanisms are currently being investigated. A database search of published scientific literature has shown that more than 100 scientific articles on the EGCG against cancer services were in the year 2005 be reviewed.