green tea

History of tea in Asia

The Chinese are said to be the first ones to discover tea, and in China the most varieties of tea are found. Tea has been used in China as a medicinal beverage to promote health in mind and body for about 5000 years. The earliest known reference to tea as a health aid dates back to 2737 B.C. Tea was an expensive beverage in ancient China. Its use was confined to the wealthy segments of the population. Only in Ming dynasty after the fall of the Mongolian empire in 1368 A.D., tea drinking spread from the elite to the populace. When China was the sea power of the world (1405-1433), tea was among the indispensable supplies for the seamen. The amount of vitamin C in the tea drink consumed by the seafarers at that time was enough to prevent scurvy which would kill many European sailors more than 100 years later, but was essentially unknown to the medical officers assigned to the fleet of more than 27,000 men on their round voyage from China to Africa. The first shipment of tea to Europe in 1606 by the Dutch East India Company was green tea.^[1]

Chinese legend says that one day, an Emperor, named Shen Nong, was boiling some water on a fire, and a sudden wind swept by several small trees nearby. During this great gust of wind, a handful of leaves from the trees were blown off their branches, and landed in the emperor's kettle. He tasted the strange liquid that formed and was delighted at what he found. [1] The result was tea. Currently there are many different varieties of tea in the world from the Camellia sinensis plant.

In another version of the legend of how tea was discovered, Shen Nong, having quasi god-like abilities, discovered tea in a different way. Shen Nong was a ruler that was just and cared deeply about his people. When he saw that many people died from eating poisonous plants and became very sad. Because it was said that his belly was bright and transparent and one could see the contents of his organs, Shen Nong decided that he would try every single plant he could find and see what would happen as it went inside his stomach. One day, he tasted a tender and pointy little green leaf. When this leaf descended down his stomach, he saw that the leaf was brushing and cleaning his stomach from top to bottom and wiped his stomach perfectly clean. It was as if it is on a "searching and destroy" mission of dirt. Thus, Shen Nong named it 查, pronounced "CHA" and means "search" in Chinese. Later people called it 茶, or "tea," also pronounced "CHA" in Chinese. That is the legendary root of the word, "tea," as we know it today.

The first of the less processed teas were white teas, while further processing created green teas that could be stored for longer periods of time. During the Tang Dynasty, wild tea was gathered and then processed. Processing involved steaming the tea on a bamboo tray, grinding the tea into a fine pulp called tea mud and then placing this mud into moulds. The tea was then pressed and left to harden. It was then transferred out of the mould, dried in the sun, and baked to prevent rotting. This is very different to how green tea is processed today; while this practice of grinding tea continued into the Sung Dynasty by the Yuan Dynasty, it had all but vanished in favour of leaf teas. Compressed raw teas are still made in Yunnan and a few other provinces, they are very popular and are discussed in the Pu-erh tea article, however these teas are classified differently because they undergo a period of aging.

Tea has played a significant role in the culture of East Asia for centuries as a staple beverage, a curative and a symbol of status. It is not surprising its discovery is ascribed to religious or royal origins. Even the earliest texts discuss the health benefits of tea. One of the earliest known references in Japan is a 9th century text. It was the Heian Period (A.D. 794-1185) of peace, prosperity, and openness to ideas and cultures particularly from China. Many aspects of Chinese culture, Chinese writing system, and religion were introduced during this period including parts of the modern Japanese writing systems.

See also Tea History.

Chinese green teas

Zhejiang Province

Zhejiang is home to the most famous of all teas, Xi Hu Longjing, as well as many other high quality green teas.

Longjing

The most well-known of famous Chinese teas from Hangzhou, its name in Chinese means Dragon Well. It is pan-fried and has a distinctive flat appearance. Falsification of Longjing is very common and most of the tea on the market is in fact produced in Sichuan Province and hence not authentic Longjing.

Hui Ming

Named after a temple in Zhejiang.

Long Ding

A tea from Kaihua County known as Dragon Mountain.

Hua Ding

A tea from Tiantai County and named after a peak in the Tiantai mountain range.

Qing Ding

A tea from Tian Mu, also known as Green Top.

Gunpowder

A popular tea also known as zhuchá. It originated in Zhejiang but is now grown elsewhere in China.

Hubei Province

Yu Lu

A steamed tea known as Gyokuro (Jade Dew) made in the Japanese style

Henan Province

Xin Yang Mao Jian

A Chinese famous tea also known as Green Tip.

Jiangsu Province

Bi Luo Chun

A Chinese famous tea also known as Green Snail Spring from Dong Ting. As with Longjing falsification is common and most of the tea marketed under this name may, in fact, be grown in Sichuan.

Rain Flower

A tea from Nanjing.

Jiangxi Province

Chun Mee

Originally a tea in the shape of eyebrows from Jiangxi, it is now grown elsewhere.

Gou Gu Nao

A well-known tea within China and recipient of numerous national awards.

Yun Wu

A tea also known as Cloud and Mist.

Anhui Province

Anhui Province is home to three Chinese famous teas.

Da Fang

A tea from Mount Huangshan also known as Big Square

Huangshan Mao Feng

A Chinese famous tea from Mount Huangshan.

Lu An Guapian

A Chinese famous tea also known as Melon Seed.

Hou Kui

A Chinese famous tea also known as Monkey tea.

Tun Lu

A tea from Tunxi District.

Huo Qing

A tea from Jing County, also known as Fire Green.

Hyson

A mediocre quality tea from many provinces, an early harvested tea.

Japanese green teas

Green tea (ryokucha) is so ubiquitous in Japan that it is more commonly known as "tea" (ocha) and even "Japanese tea" (nihoncha). Types of tea are commonly graded depending on the quality and the parts of the plant used. There are large variations in both price and quality within these broad categories, and there are many specialty green teas that fall outside this spectrum. The very best Japanese green tea is said to be that from the Uji region of Kyoto.

玉露 Gyokuro, (jewel dew)

Selected from a grade of green tea known as tencha (天茶), Gyokuro's name refers to the pale green color of the infusion. The leaves are grown in the shade before harvest which alters their flavor.

抹茶 Matcha (rubbed tea)

A high quality powdered green tea used primarily in the tea ceremony. Matcha is also a popular flavour of ice cream and other sweets in Japan.

Sencha (roasted tea)

Common green tea in Japan. It is made from leaves that are exposed directly to sunlight.

玄米茶Genmaicha (popcorn tea)

bancha and genmai (roasted rice grain) blend.

Kabusecha (covered tea)

kabusecha is sencha tea where the leaves have grown in the shade prior to harvest, although not for as long as Gyokuru. It has a more delicate flavor than Sencha.

Bancha (common tea)

Sencha harvested as a second flush tea between summer and autumn. The leaves are larger than Sencha and the flavour is less full.

焙じ茶 Hōjicha ( pan fried tea)

A pan-fried or oven roasted green tea

Kukicha ( stalk tea)

A tea made from stalks produced by harvesting one bud and three leaves.

Other green teas

Mediocre quality tea is often produced to resemble the lower grades of Chinese or Japanese tea in appearance outside those countries, however there are some notable teas grown outside China and Japan.

• Green Tea from Ceylon
• Green Tea from Darjeeling
• Green Tea from Vietnam
• Green Tea from Assam

Brewing

Traditionally, unlike darker teas, green teas are usually brewed using water that is under the boiling point (about 80 - 90 °C), as water that is too hot is believed to turn the tea bitter.

Health benefits

See also: Health benefits of tea

Proponents of green tea note that its medicinal benefits have been described for over 1000 years. The Kissa Yojoki, or Book of Tea, written by Zen priest Eisai in 1191, describes how drinking green tea can have a positive effect on the five vital organs, especially the heart. The book discusses tea's medicinal qualities which include easing the effects of alcohol, acting as a stimulant, curing blotchiness, quenching thirst, eliminating indigestion, curing beriberi disease, preventing fatigue, and improving urinary and brain function. Part One also explains the shapes of tea plants, tea flowers and tea leaves and covers how to grow tea plants and process tea leaves. In Part Two, the book discusses the specific dosage and method required for individual physical ailments.

In more recent times, many studies have investigated a link between the consumption of green tea and a lower incidence of a range of cancers in populations, with mixed results. Green tea enthusiasts have claimed ^{citation needed]} it to be useful for

• Cognition
• Stopping certain neurodegenerative illnesses such as Alzheimers
• Preventing/treating cancer
• Treating arthritis
• Treating multiple sclerosis
• Preventing the degradation of cell membranes by neutralizing the spread of free radicals (which occurs during the process of oxidation). [2]
• Increases fat oxidation (helps the body use fat as an energy source) and raises metabolism. [3]
• Lowering LDL cholesterol (in high doses in lab tests)
• Preventing lowered T-Cells due to HIV - In lab tests, EGCG, found in green tea, was found to prevent HIV from attacking T-Cells. However, it is not known if this has any effect on humans yet. [4]

The U.S. Food and Drug Administration (FDA) has rejected claims of health benefits for green tea. [5]

• "There is no credible scientific evidence that drinking green tea reduces the risk of heart disease".
• "FDA concludes there is no credible evidence to support qualified health claims for green tea or green tea extract and a reduction of a number of risk factors associated with CVD" (cardiovascular disease).
• The FDA has said that green tea likely does not reduce breast, prostate or any other type of cancer risk.

Contradicting the FDA, A 2006 study published in the September 13 issue of the Journal of the American Medical Association shows that adults who consumed three or more cups of green tea per day had a lower risk of death due to cardiovascular disease. The study, conducted by the Tohoku University School of Public Policy in Japan, followed 40,530 Japanese adults, ages 40 to 79 years, with no history of stroke, coronary heart disease or cancer at baseline beginning in 1994. The study followed all participants for up to 11 years for death from all causes and for up to 7 years for death from a specific cause. Participants who consumed 5 or more cups of tea per day had a 16 percent lower risk of all-cause mortality and a 26 percent lower risk of cardiovascular disease than participants who consumed less than 1 cup of tea per day. The study also states, "If green tea does protect humans against CVD or cancer, it is expected that consumption of this beverage would substantially contribute to the prolonging of life expectancy, given that CVD and cancer are the two leading causes of death worldwide."

A 2006 study published in The American Journal of Clinical Nutrition (Vol. 83, pp 355-361) showed that elderly Japanese people who drank more than 2 cups of green tea a day had a 50 percent lower chance of having cognitive impairment than those who drank less or who consumed other tested beverages. [6] The high amount of catechins found in green tea is thought to be the reason.

In May 2006, researchers at Yale University School of Medicine weighed in on the issue[7] with a review article that looked at more than 100 studies on the health benefits of green tea. They pointed to what they called an "Asian paradox," which refers to lower rates of heart disease and cancer in Asia despite high rates of cigarette smoking. They theorized that the 1.2 liters of green tea that is consumed by many Asians each day provides high levels of polyphenols and other antioxidants. These compounds may work in several ways to improve cardiovascular health, including preventing blood platelets from sticking together and improving cholesterol levels, said the researchers, whose study appeared in the May issue of the Journal of the American College of Surgeons. Specifically, green tea may prevent the oxidation of LDL cholesterol (the "bad" type), which, in turn, can reduce the buildup of plaque in arteries, the researchers wrote.

Green tea has also been claimed to reduce stress and produce alpha waves. This is thought to be due to high antioxidant levels and the presence of l-theanine, which is a glutamate analog present in green tea that can cross the blood-brain barrier and reduce glutamate excitotoxicity during stress and ischemia. [8]

When a doctor should be contacted prior to consuming

• If someone is pregnant or is planning to become pregnant.
• If someone is breast-feeding.
• If someone has insomnia (too much green tea can cause insomnia because of its caffeine contents).
• If someone is anemic (the antioxidant properties of tea can reduce an individual's ability to absorb iron).

See also

• Chinese tea ceremony
• Chinese tea culture
• Japanese tea ceremony
• Reactive oxygen species
• White tea
• Yellow tea

References

• Master Lam Kam Cheun et al (2002). The way of tea. Gaia Books. ISBN 1-85675-143-0.

External links

• American Cancer Society - Information about green tea
• Introduction to Green Tea
• Health Benefits of Green Tea - Information about green tea's medicinal properties
• An Introduction to Tea Ceremony
• Types of Japanese Tea