Issue Date: November 18, 2001 Scientific sources for this article Ask Jean Carper a question!
The most potent health drink ever...
It's tea time, say intriguing new research findings. Recent studies in leading medical journals declare tea a potential heart tonic, cancer blocker, fat buster, immune stimulant, arthritis soother, virus fighter and cholesterol detoxifier. Not bad for a lowly shrub soaked in a little hot water.
"Tea is beating all scientific expectations as the most potent health beverage ever," says researcher John Weisburger at the American Health Foundation. "The many ways tea can promote health is truly astonishing."
Bottom line: Each day you should drink three to six 8-ounce cups of tea. It can be black or green, hot or iced, decaf or not.
Here's how tea helps your health:
Saves arteries. Drinking black 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 cup of 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 stop cancer 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 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. W
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. Steep tea 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 help combat 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. p. 127.
Tea burns calories Dulloo, AG. Am J Clin Nutr 1999; 70:1040-5.
Tea vs. cavities Touyz LZ, Quintessence Int 2001 Sep; 32(8): 647-650.
Tea vs. cataracts Thiagarajan G., Exp Eye Res 2001 Sep; 73(3): 393-401.
Tea vs. Parkinson's-like brain damage Levites Y. J Neurochem 2001 Sep; 78(5): 1073-82.