Saturday, September 30, 2006

Green tea helps fight the flu

Roman Bystrianyk, "Green tea helps fight the flu", Health Sentinel, November 29, 2005,

Each year there is a mounting fear as the flu season approaches. With much of the attention given to the avian flu this year, the level of anxiety has increased in many people. With these concerns there is an interest in finding alternatives that can help fight the flu.

Several studies show that green tea – in particular chemicals called polyphenols – decrease the infectivity of the influenza virus. A study conducted at Pace University indicated that green tea extracts and polyphenols have an adverse effect on bacteria that cause strep throat and other infections. Milton Schiffenbauer, PhD, a microbiologist and biology professor at Pace University in New York City, stated in a news release that, “Our research shows tea extracts can destroy the organism that causes disease. If we can stimulate the immune system and at the same time we are destroying the organisms then it makes sense to drink more tea.”

Green tea is produced from the leaves of an evergreen plant called Camellia sinensis. The major active ingredient in green tea is believed to be the polyphenol compounds called catechins. These key compounds include EGCG, EGC, and ECG.

A study in the August 2005 journal Antiviral Research, examines these compounds against three currently circulating influenza viruses. The authors performed a number of experiments to examine the effects of green tea on these flu strains.

They found that these compounds were effective in reducing the plaque forming capabilities of the viruses. A plaque is produced when a virus infects a cell, replicates, and then kills that cell. EGCG and ECG at 50 μM (micromolar) inhibited more than 50% of the plaque forming ability of the influenza viruses. However, when all the polyphenols were combined the mixture reduced the plaque forming by over 90% and in the case of one flu strain (A/Chile/1/83 – H1N1) by nearly 100%.

Other experiments showed that the greater the concentration of green tea polyphenols the more of the flu virus was inhibited. “The results suggest that the antiviral effect is exerted not only in the initially infecting viruses but newly propagated viruses as well.”

After drinking 1 cup of tea, the maximum blood concentration of EGCG in humans reaches 60 micromoles in adults weighing 60 kg (132 pounds). Some authors recommend as many as 10 cups of green tea per day to achieve green tea’s optimal benefits, although the study authors caution that this study was done outside the human body and should be interpreted with some caution.

The author’s emphasize that the “total tea extract” was much more effective than any single of the green tea polyphenols that were tested in isolation. They note that, “dietary uptake of tea would be beneficial for direct intervention of influenza virus infection.”

SOURCE: Antiviral Research, August 2005

Tuesday, September 12, 2006

Tea Terms

Assam - Tea harvested originally in Assam, India (used in Irish breakfast teas). It is actually a different varietal of tea, Camellia Assamus.

Black Tea - These teas are fully fermented or oxidized. Darjeeling, Assam, are included in this type of tea. The longer the leaves are fermented, the darker they become, which is why black tea is darker than oolong, and oolong is darker than green tea.

Brick Tea
- Green tea steamed, dried, then pulverized into brick form.

Camellia Sinensis
- The Tea Plant. The differences between the over three thousand types of tea result from variations in the processing of the leaves after they are harvested. Tea is an evergreen shrub which grows in tropical or sub-tropical climates. See Green Tea, Black Tea, Oolong and White Tea. Assam is actually Camellia Assamus.

Ceylon
- Black Tea harvested in Sri Lanka, which used to be called Ceylon.

Cha
- The way to say "Tea" in China.

Chanoyu
- Japanese Tea Ceremony with its roots in Zen Buddhism.

Darjeeling
- Tea harvested in the Darjeeling region of India.

Dragonwell
Tea
- Green Tea from China, which is noted for its cooling effect in hot weather.

Genmaicha
- also called "popcorn tea", this is Japanese Green sencha leaves blended with roasted rice, which sometimes pops during shipment, and resembles popcorn.

Green Tea
- These leaves are light green and are not fermented. The supposed benefits of Green Tea include a longer life and recent studies have associated this tea with anti-carcinogens. There are two types of green tea, Steamed and Kiln-roasted. Steaming the tea takes out its bitter taste.

Gunpowder Tea
- Green Tea from China that is rolled into fine pellets that "pop" when infused. Morrocans use this for mint tea.

Herbal Tea
- Not considered Tea by purists, but a tea nontheless. Jasmine, Chamomile and Mint are some popular varieties. Berries, herbs and spices are included in Herbal teas.

Hojicha
- Green tea that is left flat (not rolled) and oven roasted after manufacture.

Infusion
- simply put, herbal tea, called Tisane in France.

Keemun
- Black Tea harvested in the Anwhei Province of China, appreciated because, unlike other teas, it actually gets better with age. (Hao Ya is the finest grade of this type of tea.)

Kung
Fu Tea
- Kung Fu is a Chinese phrase for anything that requires special skills. Mostly known as Kung Fu (cantonese for Gong Fu) martial arts, but can also apply to skillful tea preparation (kung fu style) or tea processing without breaking leaves.

Lapsang
Souchong
- Black Tea harvested in the Fujian Province of China. It had a smoky flavor, from drying leaves over pine fires.

Luk
Yu
- (or Lu Yu, depending on who's translating) The Tang dynasty writer and poet who wrote the Cha Jing (The Tea Classic) which summarized the entire tea industry at the time from cultivation to enjoyment.

Matcha
- Literally, "Liquid Jade" in Japanese, this is a finely ground green tea used in Chanoyu.

Nilgiri
- Black Tea harvested in Southern India

Oolong
- Partially fermented tea. A cross between black and green tea. They are mainly produced in Taiwan and the Fuchien and Chianghsi provinces of China. Formosa Oolong (Oolong from Taiwan) is considered the best.

Pekoe
- (pronounced Peck-o) from Pek Ho which is Cantonese for Bai Hau, meaning the bud of the tea plant after processing. Pekoe, and Orange Pekoe have come to mean the name of any whole leaf black tea that is flavored, and have nothing to do with the bud anymore.

Pu-Erh
- Tea harvested in the Yunnan province of China, the leaves are large, and are used to make black, green and oolong teas. Valued more for its medicinal value than it's taste, it is often blended with chrysanthemum.

Red Tea
- The same thing as Black Tea, called so in China, because of its reddish color when brewed.

White Tea
- A rare tea found in China. These amber leaves are not fermented, and are comprised only of the tips of the tea plant. They stand up on end in the cup when served. Considered a delicacy. Pai Mu Tan is a type of white tea.

Yixing
teapot
- This unglazed pot comes from the purple clay in the Yixing region of China, and is touted for its flavor and ability to conserve heat. It is said if one uses this porous pot for many years, one can get a great pot of tea simply by adding water to an empty Yixing pot! (It remains the connoisseur's choice of material for making teapots.)

Yunnan
- Black Tea harvested in the Yunnan Province of China, not to be confused with Pu-Erh. Yunnan Black is served complete with buds, to produce a golden color and flavor.