Green Tea: A Promising Complement to a Healthy Diet

Posted on January 3rd, 2012 by Charlie | Posted in Newsletter Articles

What is green tea?

Green tea is a Chinese aromatic beverage prepared by adding water to cured leaves of Camellia sinensis, a rounded medium-sized evergreen shrub native to China and Southeast Asia. Black and white teas also come from C. sinensis, but are processed differently.

There are four subspecies of C. sinensis currently recognized, two of them (C. sinensis subsp. sinensis and subsp. assamica) yield our common green teas. The genetic variations of C. sinensis and subtle differences such as the location grown, the time leaves are picked, and the processing afterward create substantial difference in terms of green tea taste, antioxidant content, and varietal names.

Some Types of Green Tea

Gunpowder is traditionally grown in the Zhejian Province of China and, after processing, resembles muzzle loading black powder granules. Gunpowder is either rolled by machine or hand into small shiny pellets; this allows the leaves to retain more flavor and aroma as they are less susceptible to mechanical damage or breaking. During the brewing process these pellets open, “explode”, into long leaves. Its taste is usually thick and strong. Typically 1 tsp. per 5 fl oz is used for gunpowder tea.

Sencha is probably the most popular Japanese green tea. Leaves of this tea are exposed directly to sunlight. Sencha types vary through post processing preparation such as additional heat processing or blending with additional foodstuffs and herbs. Its leaves are processed without grinding. The flavor will change depending upon the season and location when produced; early to mid-spring, “shincha”, is considered ideal sencha. The color of the liquid should be greenish to golden and will change relative to the water temperature used to steep: not too hot will be a mellow flavor, near boil is more astringent.

Senchas are named according to season harvested. Early harvest is shincha/ichibancha (first-picked tea); middle harvest is nibancha (second-picked tea); and late harvest is sanbancha (third-picked tea), or kocha (last year’s tea). Senchas are also named according to length of shade: approximately 7 days is kabusecha, and approximately 21 days is gyokuro.

Matcha is a fine ground, powdered green tea usually manufactured in the Uji region of Japan. It is not the same as green tea powder/tea powder, which is sun grown sencha leaves, as matcha instead uses the inner parts of shade-grown gyokuro leaves (tencha). This tea is commonly used in the Japanese Tea Ceremony. Varieties of matcha are given tea names either by plantation, creator of blend, or a tea tradition Grand Master. The amount of liquid used will vary depending on the type of matcha chosen. Generally the water is warmed to a temperature less than traditional methods and is mixed, not steeped.

Thin Matcha, or Usucha, is light and bitter. Thick Matcha, or koicha, is mild and sweet. Koicha is generally from older tea trees, 30 or more years old.

Ceylon is green tea made mainly from Assamese tea stock (Camellia sinensis subsp. assamica) produced in what is now Sri Lanka. It is grown in Idalgashinna, inside the Uva Province. Ceylon green teas, due to their Assamese seed stock, generally have a fuller body and a more pungent, malty, nutty flavor character than traditional green teas. It’s usually darker in both dry and infused leaf form, with an overall richer flavor. Ceylon may be processed into familiar Chinese and Japanese forms such as gunpowder or open leaf (Chun Mee).

Chemical Composition

Green tea contains, according to some sources, over 700 different chemical compounds. The most biologically active chemicals in tea are flavonoids, bioflavonoids, caffeine, and fluoride. The amount of caffeine per 8 oz. of brewed green tea can vary from 9 to 50 mg.

The healthy compounds in green tea are its flavonoids (polyphenols) with the primary beneficial one being Epigallocatechin 3-gallate (EGCG).

Potential Benefits

The compounds in green tea have excellent health promoting and antioxidant properties. Because polyphenols and their derivatives counter regulate harmful effects and free radicals throughout the entire human body, the health benefits of green tea may be widespread. Regular and copious consumption of green tea (or green tea extract in capsules or liquid) may:

  • Improve neurological functions; protect and maintain your brain.
  • Enhance immune functions; boost Treg-cell production, support balanced inflammation response.
  • Support the cardiovascular system; protect cholesterol from oxidation and reduce arterial plaque.
  • Support the growth of friendly flora in the digestive system, from start to finish.
  • Support healthy liver functions; support balanced insulin response.
  • Normalize appetite.
  • Increase metabolic rate (but not heart rate).
  • Improve fat burning (with or without caffeine).

All of these potential benefits have been written about in peer reviewed medical literature. To read more about clinical research with EGCG and green tea, visit our website: lifesourcenaturalfoods. com and click on the Healthnotes- Vitamins and Herbs link.

For more comprehensive references and abstracts visit vitasearch.com and see the clinical pearls section.

Brewing Guidelines for Good Tasting Green Tea

Do:

  • Warm water to about 180 degrees: a steady column of steam.
  • Use 3-5 grams of whole tea: a “teaspoon” per cup.
  • Steep 30 seconds to 1 minute.

Don’t:

  • Bring water to a boil: less dissolved oxygen in the water means less reactive oxygen to extract tea substances.
  • Steep longer than 3-5 minutes or force the flavor from tea leaves: this will only bring out the bitterness of stems.

Note that these brewing guidelines are for flavor purposes. For higher polyphenol content you’ll sacrifice taste. Generally the higher temperature you steep, the longer you steep, and the more green tea you use will increase the polyphenol concentration but yield a bitter brew—the choice is yours.

The number of potential health giving effects of green tea, coupled with its inexpensive price and availability, make green tea a great complement to a nutritious diet.

Putting all the science aside, a hot cup of green tea simply tastes so good on a cold day. Sweeten it with a touch of stevia, agave or honey if you like, then sit back and enjoy the feel of the hot cup in your hands, the rising aroma, and that first sip.

Photo by: mckaysavage

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