The Diet Detective: The Everything Guide to Tea

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Tea is the most-consumed beverage worldwide next to water. And according to the Tea Association, Americans consumed well over 50 billion servings of tea in 2004, or more than 2.25 billion gallons. About 87 percent was black tea, 12.5 percent green tea and the rest was oolong tea. Whether you're a regular tea drinker or just starting out, here's what you need to know about tea.


Is it true that tea has more antioxidants than almost any whole fruit or vegetable?
Yes -- sort of. While it's hard to make a general comparison, a rough estimate suggests that two servings of tea equal one serving of your average antioxidant-packed veggie. Tea ranks among plants with the highest total flavonoid content.

"The idea started from research completed by Dr. Ron Prior of the USDA, where he compared tea to many fruits and vegetables and found it to be higher in antioxidant components," says Joe Simrany, president of the Tea Association of the USA Inc.

Do different teas come from different plants?
Tea, by definition, is a leaf from the Camellia sinensis bush, says James A. Kinsinger, Ph.D., of The Hain Celestial Group Inc. Only white tea comes from a different part of the plant than the others, while green, black and oolong are made from the upper leaves. To achieve a variety of tastes, the tea leaves are exposed to air, a process called fermentation.

When fermentation is completely arrested, the tea stays "green" or yellowish brown. When fermentation time is long, the leaves darken and become "black" tea. Somewhere in between, "oolong" tea is created.

Are herbal teas really teas?
Hot-water infusions made from herbs are also called "teas," but they are technically not teas because they aren't from the Camellia sinensis plant. Herbal teas were originally brewed for medicinal purposes.

Does tea have more caffeine than coffee?
No. A 6-ounce cup of tea usually contains 25 to 60 milligrams of caffeine, less than the typical 100 milligrams in 6 ounces of coffee.

Is green tea the healthiest of all teas?
"Individual compounds in green tea have been tested in more detail than individual compounds in black tea, and there have been more studies on a wide variety of health issues with green tea ... most with very positive results," says Kinsinger.

Black tea has the most human studies, with very positive results. White tea is the least studied, but it probably has more of the catechin antioxidants than either green or black tea. "So there is no clear winner, as all tea is beneficial."

A preliminary study at Oregon State University indicated that white tea may actually have more antioxidant power than green. And a separate study at the Chinese University of Hong Kong suggests that black tea has the same level of antioxidants as green tea.

Do you need to drink 10 cups a day to benefit?
"Most scientists have based their studies on 'normal' amounts of tea, three or four cups, but some scientists think that five or more cups a day are necessary," reports Simrany.

Does iced tea have the same benefits as hot tea?
Yes. If brewed, iced tea (85 percent of tea consumed in America) has the same amount of antioxidants, catechins and flavonoids as hot tea. However, instant iced tea contains negligible amounts of catechins.

Will adding lemon, sugar or milk eliminate health benefits?
No. Sugar, sweeteners, milk and lemon don't appear to have any effect on the antioxidant levels of tea.

Do green tea supplements provide the same health benefits as tea?
"No one knows if green tea supplements have the same health benefits as drinking tea itself," says Simrany. "Most scientists recommend consuming whole foods over supplements because of the possibility that other components within the foods are causing the positive outcome."

Does tea help you burn calories?
There's a slim chance. A few preliminary studies suggest green tea may burn extra calories and oxidize fat, perhaps specifically due to the compound epigallocatechin gallate (EGCG). One study found that green tea extract increases metabolism and fat burning at a rate of almost 80 calories per day.

Another recent study appearing in the American Journal of Clinical Nutrition demonstrated that tea containing 690 milligrams catechins significantly reduced body fat after 12 weeks.

What else does tea offer besides antioxidants?
The health benefits of drinking black or green tea include possible reduced risk for coronary heart disease, as well as gastric, breast, bladder, colon, rectal, esophageal and skin cancers. Tea and tea flavonoids have also been shown to help strengthen the body's immune system, protect teeth by inhibiting plaque bacteria and potentially fight free radicals produced during strenuous exercise.

And just recently, a study reported in the Archives of Internal Medicine found that women who consume two or more cups of tea daily may lower their risk of ovarian cancer by 46 percent.

What about the health benefits of herbal teas?
"Since the compounds in herbal tea are different, the health benefits are different. Many herbal ingredients have high levels of antioxidants. But these are different antioxidants, which react with different parts of the body," says Kinsinger.

Chamomile, for instance, purportedly helps calm the stomach. Peppermint may be a digestive aid, which is why restaurants often provide mints after a meal, but drinking peppermint tea will have the same effect. However, there is little or no evidence for these effects other than anecdotal.

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