Studies have found that tea is rich in nutrients and antioxidants like vitamin C, B-complex vitamins, copper and calcium, and in some cases, is a more concentrated nutrient source than fruits or vegetables. According to medical researchers in Singapore, minimally processed green tea is an excellent source of "P complex" nutrients, which has beneficial effects on circulation. Most of these nutrients have been found to remain intact after being exposed to high temperatures.
An analysis of several long-term studies by the Linus Pauling Institute showed a link between drinking three cups of black tea per day and an 11-percent reduction in the risk of myocardial infarction. Researchers noted black tea's ability to facilitate the dilation of arteries in people suffering from high cholesterol and coronary disease.
Green tea is especially valued as a weapon against various ailments, including cancer, arthritis and cardiovascular disease. It is also thought to promote longevity with anti-aging effects. The key quality of this ages-old elixir is its high levels of a type of chemicals known as catechin polyphenols, which have an antioxidant effect by inhibiting abnormal cell growth in blood vessels. One type of polyphenol, epigallocatechin gallate, can help lower cholesterol and inhibit cancer growth, according to researchers. Green tea also contains significant amounts of flavonoids, which aid in the metabolism of Vitamin C. Because green tea leaves are minimally processed through steaming, its health effects are much greater than other varieties of tea that are fermented.
According to Japanese researchers, polyphenols and compounds known as polysaccharides found in green tea can positively influence blood sugar levels. This means drinking green tea could aid in the treatment of diabetes, which stems from irregularities in the secretion of insulin, the hormone that regulates blood glucose.
Green tea may also have an effect on everyday health issues, from morning breath to stress.
One study by Swiss scientists found that ingesting green tea extract in conjunction with caffeine, a stimulant, enhanced fat burning more than caffeine alone. Apparently, while the moderate amounts of caffeine in green tea may help promote calorie expenditure, polyphenols could also play a role in reducing fat levels in both blood and bodily tissues, according to animal studies.
Adding to green tea's mystique as a cure-all, scientists have also found that green-tea polyphenols can help combat halitosis by neutralizing chemical activity in the mouth that produces the notorious sulfur stink characteristic of bad breath. Moreover, black, green and Oolong teas all contain significant levels of fluoride, which helps protect against cavities.
Green tea may also help calm the nerves with the amino acid theanine, a precursor to catechins that helps regulate the stress-inducing hormone cortisol.
Nevertheless, despite promising research findings, scientists say that with regard to major diseases like cancer, more research must be done before drawing any conclusive determination on tea's health benefits. In the meantime, however, since no significant adverse health effects have been associated with regular tea consumption, it seems safe to follow the regimen that the Chinese have sworn by for thousands of years: drink your tea.