Health Benefits of Green Tea, Black Tea and White Tea
Here's how tea helps your health:
Saves arteries. Drinking tea helps prevent deadly clogging of arteries and reverses poor arterial functioning that can trigger heart attacks and strokes, two major new studies have found. In a large 10-year study in the Netherlands, men who consumed the amount of antioxidants called catechins found in three cups of black tea were 50% less likely to die of ischemic heart disease, caused by narrowed clogged arteries, than were men who consumed only the catechins in half a cuof tea. In another recent test, Joseph Vita, M.D., of the Boston University School of Medicine, had heart patients drink either plain water or four cups of black tea daily. In a month, impaired blood vessel functioning (a risk factor for heart attack and strokes) improved about 50% in the tea drinkers.
Inhibits cancer growth. Tea has long been tied to a lower risk of stomach, colon and breast cancer, although the connection is not proven. Now lab studies find that tea chemicals actually may stocancer growth. Rutgers University researchers showed that a compound in black tea called TF-2 caused colorectal cancer cells to commit suicide; normal cells were unaffected. The effect is quite dramatic, said Rutgers professor Kuang Yu Chen, who speculates that the chemical might one day be made into an anti-cancer drug.
Tames inflammation. Researchers at Case Western Reserve University gave arthritis-prone mice either green tea or water. The human equivalent of four cups of green tea daily halved the mice's risk of developing arthritis. Also intriguing: TF-2, the newly discovered anti-cancer compound in black tea, suppresses the Cox-2 gene that triggers inflammation, says research at Rutgers. That's the same way the drugs Vioxx and Celebrex work. Also, in a UCLA study of 600 Chinese men and women, drinking green tea halved the risk of chronic stomach inflammation, which can lead to cancer.
Wipes out viruses. Previous tests prove tea can neutralize germs, including some that cause diarrhea, pneumonia, cystitis and skin infections. New research by Milton Schiffenbauer of Pace University finds that black tea and green tea deactivates viruses, including herpes. When you drink tea, he says, chances are good you will wipe out viruses in your mouth. Flu viruses, too? Possibly. A recent Japanese study showed that gargling with black tea boosted immunity to influenza. Recent research at Harvard indicated that tea chemicals stimulated gamma-delta T-cells that bolster immunity against bacteria and viruses.
Burns calories. Most surprising, green tea's antioxidant EGCG stimulates the body to burn calories, notably fat. In a Swiss study, a daily dose of 270mg EGCG (the amount in 2 to 3 cups of green tea) caused men to burn 4% more energy - about 80 extra calories a day. Green tea did not increase heart rate, and the calorie burning was not due to caffeine.
Plus: Canadian researchers block cavities in mice by replacing their water with tea. Indian eye researchers have retarded cataracts in rats by feeding the animals tea extract. Israeli scientists block Parkinson's-like brain damage in mice by giving them green tea extract or pure EGCG.
For the best benefit ... Drink both black and green tea, the regular kind sold in bags or leaves in grocery stores. Their antioxidants are equal. But green tea boasts special-acting EGCG. Bottled tea and instant tea have few antioxidants, research shows. Herbal teas do not have the same health properties as real tea (Camellia sinensis). Tea with caffeine has slightly more antioxidant activity. Steetea leaves or bags in hot water 3 to 5 minutes to thoroughly release antioxidants. Adding milk to tea does not block absorption of antioxidants, new Dutch research finds. Don't give much tea to kids. Tea chelates iron, removing it from the body. That may helcombat chronic disease but can cause anemia in young people.
Tea saves your arteries Arts IC, Am J Clin Nutr 2001 Aug; 74(2): 227-32. Vita, J, Circulation, July 10, 2001.
Tea tames inflammation Haqqi TM, Proceedings of the Nat. Academy of Sciences, 1999; 96;4524-4529. Zuo-Feng Zhang, International Journal of Cancer 2001; 92:600-604.
Tea wipes out viruses Chou CC. Int J Food Microbiol 1999; 48:125-130. Interview with Milton Schiffenbauer of Pace University. Kansenshogaku Zasshi 1997 Jun; 71(6): 487-94. Jack F. Bukowski, Harvard Medical School, Science News, August 21, 1999. . 127.
Tea burns calories Dulloo, AG. Am J Clin Nutr 1999; 70:1040-5.
Tea vs. cavities Touyz LZ, Quintessence Int 2001 Se; 32(8): 647-650.
Tea vs. cataracts Thiagarajan G., ExEye Res 2001 Se; 73(3): 393-401.
Tea vs. Parkinson's-like brain damage Levites Y. J Neurochem 2001 Se; 78(5): 1073-82.
As if the huge variety of exquisite, sensory pleasures that fine tea affords us werent enough, the medical community continues to shower praise in the form of reports about the positive effects tea has on health and well being. As you continue reading you will find a brief summary of the more substantiated accounts. Many of the studies were conducted in Japan and China, predominantly green tea-drinking countries, and are therefore based on green tea. Currently there are, however, countless research programs being run in Europe and America to examine the benefits of black tea - so we can expect new results in the near future.
To understand the health benefits of tea, we must look at the properties of teas that are most frequently referred to in the reports:
Polyphenols - the primary biological active ingredients of (green) tea are powerful antioxidants (catechins). Antioxidants counteract free radicals in the body, which are thought to contribute to cancer.
Essential Oils - they develoduring the production process from the active substances in the leaves and give tea much of its aroma and fragrance.
Vitamins and Nutrients - Vitamin C makes an impressive appearance in green teas. It is stated that 2 small cups of green tea have as much Vitamin C as a large glass of orange juice. Tea is also a good source of manganese, potassium, niacin, folic acid and trace amounts of Vitamins B1, B2 and K.
Summary of Health Benefits of Tea
Cancer - Laboratory studies have shown that the antioxidant properties of tea have an effect against cancer by inhibiting formation of cancer causing substances. This is one of the most important and widely studied areas of the health benefits of tea.
Immunity - Polyphenols have been shown to helincrease the white blood cell count which is responsible for fighting infection. The high vitamin C content found in green tea also contributes, as it is a well studied and accepted use in helping prevent and fight colds.
Cardiovascular - Cardiovascular research suggests that a diet rich in the antioxidants found in tea, is able to prevent heart disease and stroke. The tea constituents have been shown to stimulate the circulatory system, to strengthen the blood vessels and to decrease the cholesterol level in the blood stream.
Digestion - Essential oils and polyphenols aid digestion by increasing the flow of digestive juices. Drinking tea during or after a high-cholesterol meal has been shown to lower the increase in the fat content of the blood.
body Weight - There are indications that certain teas such as Pu-Erh can assist in reducing weight by having an effect on the fats in the blood stream and in the tissues.
Teeth and Bones - Many dentists recommend drinking tea because it is rich in fluorides, a mineral that strengthens both tooth enamel and bones in a fight against osteoporosis. The Polyphenols in tea were shown to affect the bacteria in the mouth, thereby reducing the formation of plaque.
Germicide and Antibacterial - Some studies indicate that tea acts as a mild germicide. In the digestive tract it helps fight food poisoning and diseases like cholera, typhoid, and dysentery. (Did you say that you were going to Bangladesh this year?). Its antibacterial properties inhibit certain throat infections. In China, green tea is being used as a home remedy to disinfect cuts and abrasions and to cure or prevent skin disease and athletes foot.
Mental Activity - Tests have shown that tea drinking improves concentration, alertness and problem-solving ability.
Longevity - The sum of the curative and preventive health benefits of tea tends to indicate a healthier and longer life. Research continues to work at finding more evidence by studying the different tea drinking cultures.