I drink a lot of tea. In my family, every meal except breakfast was accompanied by a tall glass of iced tea, and today, I almost always have a glass of iced tea at hand when I’m watching TV, reading, or writing this column.
Which means that recent studies touting the health benefits of tea drinking tickle me pink. But first, some background.
Tea, the most popular beverage in the world, is created by pouring boiling water over the leaves of Camellia sinensis, an evergreen shrub native to Southeast Asia. Chinese legend states the emperor Shen-Nung learned how to brew tea in 2737 BC when a few leaves from the plant accidentally fell into water he was boiling. From China it spread to Japan, and from Japan to Java, the Dutch East Indies, and other tropical and subtropical areas. The East India Company, formed in 1600, introduced tea into England and its colonies.
Tea plants require lots of rainfall and rich, loamy soil. Although nowadays the plants are frequently cloned, traditionally, they’re planted in a nursery, then replanted when they’re between six and 18 months old. After two and a half to five years, depending on the altitude (the higher the altitude, the slower the plant grows but the better the tea tastes), they begin being harvested, by hand, several times a year.
To produce black tea, North America’s favorite, the leaves are spread out and partially dried for most of a day, then rolled in a machine that bruises and breaks them, releasing an enzyme that gives the tea its flavor and aroma. Next, the tea leaves are spread in a fermentation room to oxidize, which gives them a copper colour. Then they’re dried with hot air, which stops the fermentation process and turns them black; finally, they’re sifted, sorted, and graded.
The smallest leaves and buds make up the top grades, called Pekoe (PECK-o); the bottom grades, 80 percent of the crop, are leaf fragments and “dust.” (The “orange” in Orange Pekoe has nothing to do with flavor or color; it apparently comes from an old Chinese term for a size of leaf once scented with orange blossoms.)
Oolong tea is fermented for a shorter period, so that when it’s dried, the edges turn coppery and the centre remains green.
Green tea is steamed right after harvest to destroy the enzyme released in other teas when the leaves are broken. This prevents fermentation. Then the leaves are rolled and dried.
Buddhist monks used green tea to keep them awake during meditation. Tea contains approximately 60 milligrams of caffeine per cup (coffee contains about 100).
But that’s not all tea contains. Studies have shown that drinking green tea protects against cancers, particularly prostate cancer. A single cup contains 150 milligrams of a chemical called EGCG, which blocks the action of urokinase, an enzyme cancer cells need to attack neighboring cells. (Dr. Jerzy Nakun of the Medical College of Ohio, who headed the team that identified EGCG, was so impressed he started drinking two cups a day.)
EGCG is also one of several antioxidants contained in green tea. Oxidation strips electrons from molecules, which immediately grab replacement electrons from other nearby molecules. Within our bodies, all this zipping around of electrons damages tissue, leading to the diseases of aging, such as cancer, heart attacks and stroke. Antioxidants limit this process.
A couple of weeks ago, Lester A. Mitscher of Pennsylvania State University presented data showing that three of the antioxidants in green tea outperform many others: they were 100 times more powerful than vitamin C, 25 times more powerful than vitamin E, and also surpassed resveratol, found in grapes and wine. (Mitscher now takes a daily supplement of green-tea antioxidants.)
Does this leave us black tea drinkers out in the cold? Not at all. Black tea contains less of those powerful antioxidants–the fermentation process destroys 60 percent of them–but it still contains them. Besides, black tea confers other benefits. A recent study of 552 Dutch men showed that men who drank more than 4.7 cups of black tea a day had a 69-percent reduced risk of stroke over 15 years compared with men who drank less than 2.6 cups. That’s because black tea contains flavonoids–vitaminlike compounds that prevent both oxidation and blood clotting.
So drink green tea or black tea, hot tea or iced tea, but drink tea. It’s not just good for what ails you–it might keep you from ailing at all.
