Why is Tea Healthy?

An age-old story has it that some 5000 years ago, a few tea leaves blew into a cup of hot water held by the mythical Chinese emperor Shen Nung. The ruler declared the resulting brew a considerable improvement over plain water. Moreover, he recommended it as a remedy for kidney trouble, fever, chest infection and tumors "that come about the head."

Shen's prescriptions may have been extravagant. But today's biomedical researchers are finding evidence to confirm other centuries-old lore about the drink's powers to prevent illness and prolong life. "It appears that the components in tea might help reduce the risk of a number of major chronic diseases, such as stroke, heart attack and some cancers," says Dr John Weisburger, a senior member of the American Health Foundation, a research center in Valballa, New York. Drinking tea may even fight tooth decay. All this is good news for most of the planet: tea is the world's most widely consumed beverage, next to water, with an estimated one billion cups drunk daily.

Ancient Tonic
In countless cultures throughout history, tea has been regarded as a medicinal wonder. Over a thousand years ago Buddhist monks drank tea for religious reasons - to help them stay awake during meditation. (This effect we now know is caused by caffeine; tea has roughly half the caffeine of coffee).

The monks also believed tea has curative powers, and as Buddhism spread, so did tea - and the claims for it. The great 13th century Japanese Shogun Minamoto Sanetomo lay at death’s door from overfeasting when a monk prescribed a regimen of prayer and tea. When the shogun recovered, that was evidence enough for his countrymen to take up the brew.

The Dutch brought tea from China to Europe in the 17th century, where it was sold in apothecary shops, the forerunners for today’s pharmacies. Tea drinkers are “exempt from all maladies and reach an extreme old age,” said Dutch physician Nikolas Tulp in his Observationers Medicae in 1641.

There were detractors: A German physician claimed that tea hastened the death of those over 40. In England, the physician to George III warned that tea drove people crazy (but didn't say whether the brew was responsible for George's apparent insanity).

However, in the 18th century, fashion triumphed over medical debate when England’s Queen Anne chose tea over ale as her regular breakfast drink. Its popularity with women was boosted by the fact that tea shops admitted women while coffee shops did not.

All three types of tea, Green, Oolong and Black have healthful effects and contain biochemical compounds called polyphenols which include flavonoids. Also found in fruits and vegetables, flavonoids are antioxidants, which prevent cell damage thought to contribute to more than 50 diseases.

Green tea has been found to contain the flavonoid EGC, a potent antioxidant. Black tea has similar disease-preventing effects, reports biochemist Allan Conney of Rutgers University. Researchers have not yet determined whether decaffeination removes tea’s health benefits. In one Dutch study, men who drank between four and five cups of black tea a day had a nearly 70 per cent reduced risk of stroke compared with those who drank two cups or less. Another 1993 study reported that higher black-tea consumption corresponded with fewer fatal heart attacks.

“The key protective factor does appear to be the flavonoids,” says John Folts, director of the University of Wisconsin Medical School’s Coronary Artery Thrombosis Research and Prevention Center. He has found that black tea flavonoids inhibit blood platelets from clumping, preventing the dangerous clots that lead to almost all heart attacks and most strokes. Other studies have found that some tea drinkers have lower cholesterol levels and lower blood pressure - although it’s unclear if tea is the actual cause.

More than 20 studies have indicated that tea may prevent some cancers, including those of the digestive and respiratory tracts and the skin. Once again, polyhenols are thought to be the major disease preventing ingredients. “Along with eating plenty of fruits and vegetables, drinking tea may turn out to be a cheap and practical way to reduce the risk of certain cancers,” asserts Weisburger. Researchers at Case Western Reserve University in Cleveland found that applying green tea was up to 90 percent effective in preventing sunburns, which can lead to skin cancer, says dermatologist Hasan Mukhtar, who headed the unpublished study.