Researchers found that men and women who drank tea on a daily basis for at least a year were much less likely to develop hypertension than those who didn’t, and the more tea they drank, the bigger the benefits. Those who drank at least a half-cup of moderate strength green or oolong tea per day for a year had a 46-percent lower risk of developing hypertension than those who didn’t drink tea. Among those who drank more than two and a half cups of tea per day, the risk of high blood pressure was reduced by 65 percent.The evidence that tea helps prevent cancer is overwhelming.
Since the 1990s, hundreds of studies have been performed showing that Oolong tea can inhibit the formation of tumors, and slow the growth of those already formed. In 1997, researchers at the University of Kansas discovered that the antioxidant power of EGCG is about 100 times greater than vitamin C and twenty-five times greater than vitamin E in protecting DNA from the kind of free radical damage that is thought to increase the risk of cancer. Researchers also found that EGCG is able to signal cancer cells to stop reproducing by promoting apoptosis, a normal cellular process leading to the death of a cell—without harming any healthy cells. One study out of Purdue University in 1998 found that an enzyme called quinol oxidase, or NOX, is necessary for the growth of both normal and cancerous cells. The overactive form of NOX is known as tNOX, for tumor-associated NOX. In test tubes, using purified NOX protein solutions, researchers found that low doses of EGCG—such as those that could be consumed by drinking several cups of tea a day—were capable of inhibiting the activity of the tNOX cells but did not inhibit the NOX activity of healthy cells.
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