Tea & Health
Tea doesn't just taste great, there is growing medical evidence to confirm what the Chinese have believed for 5,000 years - that tea promotes good health and protects against a range of illnesses.
Here is a synopsis of conditions that may be prevented or improved by drinking tea:
Anti-cancer properties
An article in New Scientist magazine mentions that green tea protects against a range of cancers including lung, prostate and breast cancer, and drinking several cups of green tea each day may substantially reduce a person's risk of cardiovascular disease. According to the U.S. National Cancer Institute, in laboratory studies using animals, catechins inactivated oxidants before cell damage occurred, reduced the number and size of tumors, and inhibited the growth of cancer cells.
Increases metabolic rate
Clinical trials conducted by the University of Geneva and the University of Birmingham indicate that green tea raises metabolic rates, speeds up fat oxidation and improves insulin sensitivity and glucose tolerance. In addition to caffeine, gree n tea contains catechin polyphenols that raise thermogenesis (the rate at which calories are burned), and hence increases energy expenditure.
Boosts immune system
On 21 April 2003 the Brigham and Women's Hospital released details of a research project which indicated that theanine may help the body's immune system response when fighting infection, by boosting the disease-fighting capacity of gamma delta T cells. The study included a four-week trial with 11 coffee drinkers and 10 tea drinkers, who consumed 600ml of coffee or black tea daily. Blood sample analysis found that the production of anti-bacterial proteins was up to five times higher in the tea-drinkers.
Effects on HIV
A recent study appearing in the Journal of Allergy and Clinical Immunology stated that epigallocatechin gallate (EGCG) found in green tea can lead to the inhibition of HIV virus binding and may be used as a complementary therapy for HIV patients. However, the the study was a test-tube study, not an in vivo study, which only tested effects of a chemical in green tea.
Effects associated with caffeine
A cup of green tea contains between 15 and 50 mg of caffeine. Certain cognitive benefits are associated with caffeine consumption, such as a reduction in the likelihood of Parkinson's disease and a temporary increase in short term memory. Further, caffeine consumption has been linked with greater athletic performane, healthy weight loss, reduction in duration and severity of headaches and is effective in treating the symptoms of asthma.
Bacterial and fungal infections
A study at Pace University found that white tea extracts effective at treating bacterial infections such as pneumonia, Staphylococcus, Streptococcus and dental caries. White tea was also found to be effective in treating fungal infections. Researchers also reported that white tea extracts shoed a greater effect than green tea extracts.