Saturday, March 19, 2011

Good health your cup of tea? Have a sip

The health benefits of drinking teas have been known for centuries, but in recent years scientists have begun investigating the medicinal properties of green, black, oolong and other teas as well as herbal teas.

After water, tea is the world's most widely consumed beverage. Tea sales in the United States have quadrupled since 1990 and total about $7 billion annually, according to the Tea Association of the USA. The major reason: Scientific evidence that the polyphenols and other antioxidants in tea may reduce the risk of cancer, heart disease and other afflictions.

Beth Johnston, CEO and founder of Teas, Etc., a premium and specialty tea importer and blender based in West Palm Beach, said it's important to distinguish between true teas that are derived from the age-old camellia sinensis tea bush and herbal teas, which are infusions derived from anything other than the tea bush. Chamomile tea, for example, is an herbal.

"In the U.S., everything we drink hot that is not coffee or hot cocoa, we call tea. Truly tea comes from the plant camellia sinensis," said Johnston, whose 13-year-old company sells true teas and herbals.

Harvard University Medical School researchers have said that tea's health benefits are largely due to its high content of flavonoids - plant-derived compounds that are antioxidants. They identified green tea as the best source of a group of antioxidants called catechins. They are also found in wine, dark chocolate and vegetables.

In test tubes, catechins are more powerful than vitamins C and E in halting oxidative damage to cells and appear to have other disease-fighting properties. Studies have found an association between consuming green tea and a reduced risk for several cancers, including, skin, breast, lung, colon, esophageal and bladder, according to Harvard Women's Health Watch.

Benefits also in bottles?

What about those pricey pre-brewed bottled teas claiming to be loaded with cancer-fighting flavonoids and antioxidants?

Save your money and stick with home-brewed tea, says the American Chemical Society in Washington.

The fancy bottled teas contain fewer polyphenols than a single cup of home-brewed green or black tea, scientists reported last year. Some contain such small amounts that consumers would have to drink 20 bottles to get the polyphenols present in one cup of tea.

"Consumers understand very well the concept of the health benefits from drinking tea or consuming other tea products," said Rutgers University chemist Shiming Li. "However, there is a huge gap between the perception that tea consumption is healthy and the actual amount of the healthful nutrients - polyphenols - found in bottled tea beverages. Our analysis of tea beverages found that the polyphenol content is extremely low."

The six teas Li analyzed contained 81, 43, 40, 13, 4, and 3 milligrams of polyphenols per 16-ounce bottle. One average cup of home-brewed green or black tea, which costs only a few cents, contains 50 milligrams to 150 milligrams of polyphenols.

Health claims about teas can only go so far before the U.S. Food and Drug Administration cracks down on manufacturers for making unqualified claims, said Johnston, of Teas, Etc.

"There are a lot of claims. The slippery slope comes in making claims that have not been accepted by the FDA," Johnston said.

"Green tea has been found to potentially deliver benefits that help to reduce the risk of certain cancers. Black tea has been found to possibly reduce the risk of heart disease and stroke."

Some studies have suggested that tea has bone-density building benefits, and some people say drinking certain types of tea has helped lower their cholesterol, Johnston said. White teas are said to help build the immune system.

"I think health benefits have been a big driver for the industry. People are seeking a longer, higher quality of life," she said.

Researchers are making progress identifying the benefits of herbal teas as well. Tufts University scientists recently conducted a clinical trial that found volunteers who drank three cups of hibiscus tea a day had a 7 point drop in their systolic blood pressure (the top number), while those who drank a placebo beverage had a 1 point drop.

Whether you choose to believe the health claims or not, there's no doubt that drinking tea can have a calming effect.

"Tea requires you stop and take a minute," Johnston said. "It requires a little bit more mindfulness. It is not difficult. You select it, you prepare it, then drink it.

~ susan_salisbury@pbpost.com

The tea story

Teas are grown in different regions around the world. The most widely recognized are China, Japan and India.

When tea leaves are harvested, a natural oxidation begins to occur. This oxidation is environmental, not man-made, and is halted by heating the tea leaves. This heating is done by firing or steaming the leaves. Oxidation, or the lack of oxidation, is the basic difference in tea s.

    * White and green teas are both harvested and then heated immediately, making them non-oxidized. They produce a fragrant, vegetal character, and when brewed the tea liquor will appear light and clear with a pale green or yellow hue. These delicate teas should never be made with boiling water.
    * Oolong teas are allowed to oxidize for various lengths of time (15 percent to 75 percent oxidation), allowing for a wide range of character and caffeine content; the darker, or more oxidized, the higher the caffeine content.
    * Black teas are fully oxidized, giving them a rich, dark appearance, the greatest amount of caffeine and a strong, brisk flavor. Black teas prevent heart disease and stroke, and like green, white and oolong tea, provide antioxidants.

Source: Beth Johnston, Teas, Etc., West Palm Beach; www.TeasEtc.com

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