Kristin Peña


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Origins of Green Tea (Camellia Sinensis)


All tea originates from the same plant, the Camellia Sinensis. The way the plant is produced however is what differentiates from the other two major teas; oolong and black tea. Green tea originates in China and is an ancient traditional drink and herbal remedy in Chinese culture. (The Tea Guardian, 2010) The plant has been used for medicinal purposes as well as for drinking throughout history. More recently green tea has become popular in the west with a wide range of teas being available in grocery stores. Green tea has been subjected to many studies and tests with the purpose of determining the legitimacy of the health benefit claims of the herb. These benefits include consumers being at a lower risk for heart disease, certain types of cancers and as green tea boosting the metabolic rate. (Zieve, 2010)

Harvesting and Brewing


The production of green tea is broken down into the ways green tea is harvested; the sun or the shade to maximize the amount of antioxidants in the plant. The plant can be harvested three times a year and sometimes four. The fourth harvest which takes place in the spring produces the highest quality leaves. The leaves are kept at low refrigeration with the earliest harvest being able to last the longest. The plants are processed for desired variety of green tea that consists of steaming and drying the leaves throughout the year. (How green tea) Green tea is brewed by having the tea leaves seeped in hot water for a very specific amount of time.
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It is typically brewed in teabags here in the west, but in the Asian countries from where it originates, loose leaves were more commonly found. (The Tea Guardian, 2010)

Video of how green tea is processed from YouTube:



The quality of green tea is determined by the location in which the tea is grown and the parts it produces. Whether it was grown in the shade or in the sun and what time during the year it was grown are all factors in determining the quality and the price of the plant.

In the form of tea is not the only way is consumed. In the US and in other western countries, the extract of green tea can also be consumed.
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This extract is called epigallocatechin gallate which is supposedly the strongest catechin in green tea due to the high level of antioxidants. (Zieve, 2010) It is usually consumed as a supplement in the form of a tablet and can be taken 2-3 times a day depending on the dosage. For a more detailed explanation of the catechins in green tea, go to "Scientific Evidence" below.


Traditional Uses


Green tea has been and is used for a variety of purposes. It is used for certain cancers as well as for much simpler ailments like stomach disorders, vomiting and headaches. These much more traditional uses are likely as a result of the lack of fermentation that goes into the process of production. Unlike black and oolong, green tea does not go through a process of fermentation and so has those extra benefits that have been used to reduce puffiness under eyes and used to heal wounds or sores. Green tea is also used for mental alertness. One of the recently more common uses has been as a dietary supplement in the form of pills. Because green tea is said to increase the metabolic rate, it is taken with the purpose of weight loss. These are just a few of the traditional uses of green tea as a both a supplement and in the form of tea and in the form of just the tea bag itself. These uses have been the subject of many studies to determine the effectiveness of green tea.

Benefits


Of the three major teas, oolong, black and green, green tea contains the highest number of antioxidants. The unfermented leaves in green tea contain an antioxidant called polyphenol that scientists think actually does neutralize free radicals in the body. The free radicals that are not naturally found in the body are caused by toxins in the air. (Zieve, 2010) The main antioxidant in green tea extract is catechins. The four main catechins are: epicatechin (EC), epigallocatechin (EGC), epicatechin gallate(ECG), and epigallocatechin gallate (EGCG). The most potent part of EGCG is found in the leaves which is where the extract comes from (tea bags can contain leaves and stems).
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Green tea extract which is a highly concentrated form of green tea contains many beneficial nutrients such as Vitamin C and E and is 20 times antioxidant rich than Vitamin C. (Magaziner, 2000) Green tea also contains alkoloids such as caffeine, theobromine, and theophylline. These are what gives green tea stimulants and aids in mental alertness.

Effectiveness


Because the plant is not fermented, during the steaming process, it maintains a lot of the beneficial polyphenols. The actual benefits of polyphenols has not been scientifically proven, but studies done in vitro have had various outcomes. It is still unclear if the effects are the same in people. (NIH, 1995) Studies show that these polyphenols do help to block cholesterol from entering the body. Although there are no proven effects of green tea in actually preventing cancer, statistically, certain cancers are not found quite as often in Japan and China which are heavy green tea drinkers as in the rest of the world. (Zieve, 2010)

Other research studies done were slightly more ambiguous. Some studies claimed that there is no proven weight loss effects from green tea (NIH, 1995) while others showed that green tea extracts do in fact raise the metabolic rate (Zieve, 2010). What most sources agreed upon however is that green tea helps to improve bone density and decrease inflammation in cartilage.



Sources


The Tea Guardian. "Green Teas: A (very) Brief History". Retrieved 20 December 2010.

Green tea. (2010, July 01). Retrieved from National Center for Complementary and Alternative Medicine, NCCAM

Zieve, D. (2010, September 20). University of maryland medical center. Retrieved from http://www.umm.edu/altmed/articles/green-tea-000255.htm

How green tea is processed. (n.d.). Retrieved from http://www.o-cha.com/green-tea-processing.htm

NIH. (1995). Green tea [Medline Plus]. Retrieved from http://www.nlm.nih.gov/medlineplus/druginfo/natural/960.html

A. Magaziner, The complete idiot's guide to living longer & healthier, New York: N.Y. Alpha Books, 2000, p. 6.