Antioxidants counteract free radicals in the body, which are thought to contribute to cancer by damaging healthy DNA and to heart disease by increasing oxidation-induced atherosclerosis. Other Green tea compounds also work against allergies, bacteria and some viruses.

In July 1994, the journal Science News quoted a Rutgers University researcher that said tea containing caffeine seemed somewhat more effective than decaffeinated teas.

1) NEW RESEARCH CONFIRMS GREEN TEA PROVIDES BEST ANTIOXIDANT PROTECTION
------------------------------------------------------------ Surpasses Vitamins E, C and Red Wine
SIMI VALLEY, Calif., Sept. 11 -- Researchers at the University of Kansas have found new evidence confirming that a compound in a green tea supplement provides stronger damage protection of cells and their genetic material (DNA) than the well-known antioxidants vitamins E and C and the antioxidant compound in red wine.

Announced today at the American Chemical Society annual meeting, the first side-by-side comparative antioxidant study led to an investigation of the protective power of epigallocatechin gallate (EGCG) against that of vitamins E and C, in addition to red wine and other teas. EGCG is a member of the family of chemicals known as polyphenols, antioxidant compounds which are found in green tea. EGCG and other green tea polyphenols work as antioxidants in the body. Antioxidants are compounds that attack the body's free radicals, which cause cellular damage including DNA (genetic material) breakage.

"The antioxidants in tea are more effective than the vitamins that are usually construed to be antioxidants," said Dr. John Weisburger, senior member, American Health Foundation. He adds, "We need both but green tea is more effective."

Using the Ames test, EGCG was added to DNA samples challenged with peroxide, a recognized powerful free radical. The research found EGCG to be a powerful antioxidant, offering 63 percent protection from DNA damage. Specifically, EGCG was approximately 100 times more effective than vitamin C, 25 times more effective than vitamin E, and nearly twice as effective as red wine.

2) GREEN TEA AND ESOPGAGEAL CANCER
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Researchers reporting on a case-control study, appearing in the June 1, 1994, issue of the Journal of the National Cancer Institute, found that Chinese men and women who drink tea have a reduced risk of up to 60 percent of developing esophageal cancer. Researchers from the National Cancer Institute (NCI) and the Shanghai Cancer Institute used a cancer registry to identify 902 esophageal cancer patients from urban Shanghai, People's Republic of China. This esophageal cancer study is part of a larger, multisite study that included pancreatic, colon, and rectal cancers.

Patients ages 30 to 74 years who were diagnosed with esophageal cancer between October 1990 and January 1993 were interviewed on their residential and medical history, height and weight, diet, smoking habits, alcohol use, tea consumption, family history of cancer, occupation, physical activity, and reproductive history. There were 1,552 people without the disease (control subjects) who answered the same questions. Information about tea consumption included types of tea consumed, frequency of consumption, and age at which tea drinking began. Researchers measured consumption in grams of tea leaves consumed per month. A tea drinker was defined as someone who drank at least one cup of tea per week for 6 months or longer.

The study found that drinking green tea was associated with a 50 percent lower risk of esophageal cancer in women. Among men, risk was also reduced, but this finding was not statistically significant. However, tea drinking was linked to a 60 percent reduction of esophageal cancer among both men and women who did not smoke. Scientists speculate that the protective effects of tea arise out of polyphenol compounds in the tea. Polyphenols are a class of compounds that have strong antioxidant properties (the ability to halt enzymes that produce carcinogens) and also are able to inhibit cancer cell growth.

3) GREEN TEA AND PROSTATE CANCER
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Mayo Clinic researchers have identified a plant substance in green tea that is a potent killer of prostate cancer cells. The researchers, led by Charles Y-F. Young, Ph.D., tested four common components of green tea on three different prostate cancer cell cultures. One of them, called EGCG, was found to be the most potent in inhibiting cell growth.

Dr. Young says this is a promising laboratory finding which is now being taken to the next level. The research team is now testing whether EGCG can reduce the development of cancers in a new, special strain of mice bred with prostate cancer. If results continue to be promising, the next step would be trials in humans. Dr. Young said that the chemical structure of EGCG is very similar to that of components found in red wine and other vegetables. He said plans are to also test the effectiveness of some of these related compounds in fighting prostate cancer.

The incidence of prostate cancer, the most common cancer in American males, is considerably lower in Asian countries than in the West. One reason advanced for this high incidence is the high consumption of plant foods in Asia. A number of laboratory studies have shown that green tea, one of the most widely used foods, has anti-tumor effects. The Mayo Clinic report, in the journal Cancer Letters, is the first evidence that EGCG is the active ingredient that kills prostate cancer cells.

A recent study on an animal model examined the effects of different concentrations of green tea on prostate cancer cells. The cancer cells were also exposed to the male hormone, testosterone. The results revealed that there was a dose-dependent decrease in prostate cancer activity and growth with the green tea. Green tea inhibits prostate cancer growth and activity associated with testosterone, and may well be effective in preventing prostate cancer.

Other studies have shown a decreased incidence of skin, colon, lung, as well as prostate cancer in people who consume cups of green tea on a regular basis, this regardless of race or where they live. But these studies are difficult to interpret because they use "cups of tea" as a measure without defining the amount in the cup or looking at what concentrations of green tea polyphenols are achieved in the blood, urine and prostate itself. Studies looking at these concentrations have dealt with one-time ingestion rather than long-term exposure which produces much higher concentrations.

Since green tea is readily available, non-toxic and inexpensive, it may be an effective and easy way for men at risk of prostate cancer to reduce their chances of developing prostate cancer.

4) GREEN TEA AND SKIN CANCER
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New findings presented by the CSIRO Division of Human Nutrition at the inaugural Australian International Symposium on Tea and Health in Sydney today, have shown that tea may contribute significant protection against development of skin cancers caused by exposure to ultraviolet (UV) rays.

The latest research with mice found those given tea (with milk) experienced a reduction in the development of skin cancer of 50 per cent and a reduction in the development of papillomas of 70 per cent.

Australia has the highest rate of skin cancer in the world. Currently two out of three Australians develop some form of skin cancer during their lifetime.

Ultraviolet radiation is present in the sun's rays throughout the year. The level of UV varies from day to day, and even on a clear day in September or April it is strong enough to burn your skin

Tea is a rich source of special antioxidants called flavonoids, considered to be some of the most potent antioxidants in nature. Scientists believe antioxidants in the diet have an important role to play in the fight against diseases including cancer.

The important new CSIRO study examined the effect of providing tea with 10 %milk, (compared to just 10% milk or just water) as the sole drinking fluid on UVA+B induced skin cancer in mice. The key finding was a significant reduction in the development of skin cancers in mice drinking tea with milk.

"These findings are significant because initially it was thought milk may bind to the flavonoids, and impact on the antioxidant properties and potential health benefits of tea. The most recent findings would suggest that the flavonoids still play a protective role in the presence of milk," said Dr Ian Record of CSIRO Division of Human Nutrition.

"Intensive research is currently underway into tea flavonoids and how they may help protect the body from potentially harmful substances called free radicals. UV rays generate free radicals in the skin, which in turn inflict damage on the skin cells' - causing some cells to become cancerous," he added.

5) GREEN TEA AND ATHEROSCLEROSIS
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A study reported in the Japanese journal Zhongguo YAOLIXUE YU DULIXUE ZAZHI* found that green tea flavonoids were "anti-atherosclerotic" and lowered the ratio of LDL ('bad' cholesterol) in the blood. This was reportedly accomplished through the antioxidant properties preventing oxidation of serum lipids (keeping fats in the blood from going rancid). Serum lipid peroxidation causes reactive and dangerous compounds which the body then or slows down with white blood cells. This combination of oxidized lipids and white blood cells creates sticky 'foam cells' which then adhere to the lining of the heart and blood vessels in the waxy build-up called atherosclerosis.
* 1992, 6(4): pages 263-267

6) GREEN TEA AND ALLERGIES
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A study reported in the journal Yakugaku Zasshi* showed the effects of several green tea compounds including various catechins, caffeine and theophylline against allergies in rats (measured by passive cutaneous anaphylaxis - PCA). This study showed significant inhibitory effects on type-I allergic reactions.
*117 (7) 448-454 (1997)

7) GREEN TEA AND HERPES
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A patent has been filed for a simple cure for herpes infections (United Kingdom, Number 2,293,548). Joan Hibberd of Harley Street (a medical doctor) has found that ordinary tea works better than acyclovir, is far less expensive and has fewer side effects (New Scientist, p. 22, July 27th 1996). Tea, preferably Earl Grey, is brewed and the liquid cooled and applied to the herpes lesion (cold sores, genital herpes or shingles). The easiest way to do this is to stand a tea bag in boiling water for a few minutes, cool it, then apply it to the skin for a few minutes. According to the inventor, within four or five days the lesions crust over, then disappear and do not recur for at least several months after treatment. The inventor does not know why tea has this effect.