Green tea

Green tea

The appearance of green tea in three different stages: (from left to right) the infused leaves, the dry leaves, and the liquid. (Notice that the infused leaves look greener than the dry leaves.)
Type Tea
Country of origin China
Region of origin East Asia
Ingredients Tea leaves

Green tea is a type of tea that is made from Camellia sinensis leaves that have not undergone the same withering and oxidation process used to make oolong and black tea.[1] Green tea originated in China, but its production has spread to many countries in Asia.

Several varieties of green tea exist, which differ substantially because of the variety of C. sinensis used, growing conditions, horticultural methods, production processing, and time of harvest.

History

The tea fields in the foothills of Gorreana, Azores Islands, Portugal: the only European region other than Georgia to support green tea production.

Tea consumption has its legendary origins in China during the reign of Emperor Shennong.[2]

A book written by Lu Yu in 600-900 AD (Tang Dynasty), "Tea Classic" (simplified Chinese: 茶经; traditional Chinese: 茶經; pinyin: chájīng), is considered important in green tea history. The Kissa Yojoki (喫茶養生記 Book of Tea), written by Zen priest Eisai in 1191, describes how drinking green tea may affect five vital organs, the shapes of tea plants, flowers and leaves, and how to grow and process tea leaves.

Brewing and serving

Steeping, or brewing, is the process of making tea, generally using two grams of tea per 100 ml of water or about 1 teaspoon of green tea per 150 ml cup. Higher-quality teas, like gyokuro, use more tea leaves and are steeped multiple times for short durations.

Steeping temperatures range from 61°C (142°F) to 87°C (189°F) and times from 30 seconds to three minutes.

Generally, lower-quality green teas are steeped hotter and longer while higher-quality teas are steeped cooler and shorter, but usually for multiple times (2-3 typically). Steeping too hot or for too long results in the release of excessive amounts of tannins, leading to a bitter, astringent brew, regardless of initial quality. The brew’s taste is also affected by the steeping technique. Two important techniques are to warm the steeping container beforehand to prevent the tea from immediately cooling down and to leave the tea leaf in the pot and gradually add more hot water as you drink the tea.

Extracts

Green tea extracts have been used in traditional Chinese and Indian medicine for a variety of uses.[3]

Green tea leaves are initially processed by soaking in an alcohol solution, which may be further concentrated to various levels; byproducts of the process are also packaged and used. Extracts may be sold in liquid, powder, capsule, or tablet form.[4] Decaffeinated versions are also available.[5]

Green tea extract supplements are accessible over the counter in various forms. Standardized green tea extract is 90 percent total polyphenols, and 1 capsule equals 5 cups of tea.[6][7]

Health effects

Brewed, regular green tea
Nutritional value per 100 g (3.5 oz)
Energy 4 kJ (0.96 kcal)
0 g
0 g
0.2 g
Vitamins
Thiamine (B1)
(1%)

0.007 mg

Riboflavin (B2)
(5%)

0.06 mg

Niacin (B3)
(0%)

0.03 mg

Vitamin B6
(0%)

0.005 mg

Vitamin C
(0%)

0.3 mg

Minerals
Calcium
(0%)

0 mg

Iron
(0%)

0.02 mg

Magnesium
(0%)

1 mg

Manganese
(9%)

0.18 mg

Potassium
(0%)

8 mg

Sodium
(0%)

1 mg

Other constituents
Water 99.9 g
Caffeine 12 mg
Link to Full USDA Nutrient Report
Percentages are roughly approximated using US recommendations for adults.

Regular green tea is 99.9% water, provides 1 Calorie per 100 mL serving, is devoid of significant nutrient content (table) and contains phytochemicals, such as polyphenols and caffeine. Polyphenols found in green tea include epigallocatechin gallate (EGCG), epicatechin gallate, epicatechins and flavanols,[1] which have antioxidant, anticarcinogen, anti-inflammatory, and anti-radiation biochemical effects in vitro.[4] Other components include three kinds of flavonoids, known as kaempferol, quercetin, and myricetin.[8] A remarkably higher content of myricetin is detected in tea and its extracts than in many other plants, and this high concentration of myricetin may have some implications for the experimentally-observed bioactivity of tea and its extracts in vitro.[4]

Although numerous claims have been made for the health benefits of green tea, human clinical research has not provided conclusive evidence of any effects.[1][9][10] In 2011, a panel of scientists published a report on the claims for health effects at the request of the European Commission: in general they found that the claims made for green tea were not supported by sufficient scientific evidence.[9] Although the mean content of flavonoids and catechins in a cup of green tea is higher than that in the same volume of other food and drink items that are traditionally considered to promote health,[11] flavonoids and catechins have no proven biological effect in humans.[9][12]

Cancer

There is no conclusive evidence that green tea helps to prevent or treat cancer in people.[10][13] A review of existing studies concluded that while suggestive evidence existed, it did not amount to a clear indication of benefit.[13]

Daily consumption of black tea (but not green tea) has been associated with a significant reduction in death from all cancers.[14] There is limited evidence to suggest that green tea consumption may be associated with a slightly lower risk of esophageal cancer in the Chinese population, a lower risk of lung cancer in women, and a lower risk of oral cancer in Asian people.[15][16][17] A 2015 meta-analysis of nine prospective cohort studies concluded that a high amount of green tea consumption may be associated with a lower risk of liver cancer in Asian women.[18] This association was not seen in Asian men or when one cup of green tea was consumed daily.[18] Similarly, another analysis of observational data conducted in 2012 suggested that green tea consumption may have a favorable effect on lung cancer risk. The observed effect was strongest in those who consumed more than seven cups of green tea daily.[19] A 2011 meta-analysis of epidemiological studies found limited evidence that green tea consumption may be associated with a moderately reduced risk of liver cancer in Chinese and Japanese people.[20] Limited evidence suggests that green tea consumption is not associated with the risk of developing pancreatic cancer or prostate cancer.[21][22] The link between green tea consumption and stomach cancer risk is unclear due to inconsistent evidence.[23]

Green tea interferes with the chemotherapy drug bortezomib (Velcade) and other boronic acid-based proteasome inhibitors, and should be avoided by people taking these medications.[24]

Cardiovascular disease

Observational studies have shown a correlation between daily consumption of green tea and a lower risk of death from cardiovascular disease. In a 2015 meta-analysis of such observational studies, an increase in one cup of green tea per day was correlated with a 5% lower risk of death from cardiovascular causes.[14] Green tea consumption may be correlated with a reduced risk of stroke.[25][26][27] Meta-analyses of randomized controlled trials have found that green tea consumption for 3–6 months appears to lower systolic and diastolic blood pressures a small amount (about 3 mm Hg each).[27][28][29][30][31]

Glycemic control

Green tea consumption lowers fasting blood sugar but in clinical studies the beverage's effect on hemoglobin A1c and fasting insulin levels was inconsistent.[27][32][33]

Hyperlipidemia

Drinking green tea or taking green tea supplements decreases the blood concentration of total cholesterol (about 7 mg/dL), LDL cholesterol (about 2 mg/dL), and does not affect the concentration of HDL cholesterol.[27][34] A 2013 Cochrane review performed a meta-analysis of longer-term randomized controlled trials (>3 months duration) and concluded that green tea consumption lowers total and LDL cholesterol concentrations in the blood.[27][28]

Inflammation

A 2015 systematic review and meta-analysis of 11 randomized controlled trials found that green tea consumption was not significantly associated with lower plasma levels of C-reactive protein levels (a marker of inflammation).[35]

Mortality risk

Daily consumption of green tea is significantly correlated with a lower risk of death from any cause; an increase of one cup of green tea per day is linked with a 4% lower risk of death from any cause.[14] A separate analysis found that an increase of three cups of tea or green tea per day was associated with a lower risk of total mortality in Asians and women.[25]

Weight loss

There is no conclusive evidence that green tea aids in weight loss.[36]

Toxicity

Moderate, regular, and habitual consumption of green tea is safe;[10] however, there are reports of liver toxicity in humans after consuming high doses (10–29 mg/kg/day) of green tea extract dietary supplements,[37] and high doses may act as a pro-oxidant to damage DNA.[4]

Production

Growing, harvesting and processing

Hand-rolling green tea after steaming

Green tea is processed and grown in a variety of ways, depending on the type of green tea desired. As a result of these methods, maximum amounts of polyphenols and volatile organic compounds are retained, affecting aroma and taste. The growing conditions can be broken down into two basic types − those grown in the sun and those grown under the shade. The green tea plants are grown in rows that are pruned to produce shoots in a regular manner, and in general are harvested three times per year. The first flush takes place in late April to early May. The second harvest usually takes place from June through July, and the third picking takes place in late July to early August. Sometimes, there will also be the fourth harvest. It is the first flush in the spring that brings the best-quality leaves, with higher prices to match.

Green tea is processed using either artisanal or modern methods. Sun-drying, basket or charcoal firing, or pan-firing are common artisanal methods. Oven-drying, tumbling, or steaming are common modern methods.[38] Processed green teas, known as aracha are stored under low humidity refrigeration in 30- or 60-kg paper bags at 0–5 °C (32–41 °F). This aracha has yet to be refined at this stage, with a final firing taking place before blending, selection and packaging take place. The leaves in this state will be re-fired throughout the year as they are needed, giving the green teas a longer shelf-life and better flavor. The first flush tea of May will readily store in this fashion until the next year's harvest. After this re-drying process, each crude tea will be sifted and graded according to size. Finally, each lot will be blended according to the blending order by the tasters and packed for sale.[39]

Production by country

2006 Green tea production and export (in thousands of metric tons)[40]
Country Production Export
 China782.4 (80.8%)218.7 (83.0%)
 Japan91.8 (9.5%)1.6 (0.6%)
 Vietnam66.0 (6.8%)26.0 (9.9%)
 Indonesia20.0 (2.1%)9.1 (3.5%)
World968.1 (100%)263.5 (100%)

Import of Japanese tea

On 17 June 2011, radioactive cesium of 1,038 becquerels per kilogram was detected at Charles de Gaulle airport in France in tea leaves imported from Shizuoka Prefecture, Japan as a result of the Fukushima Daiichi nuclear disaster, which was more than twice as much as the restricted amount of 500 becquerels per kilogram designated by the European Union. The government of France announced that they rejected the tea leaves, which amounted to 162 kilograms (357 lb).[41] The governor of Shizuoka Prefecture Heita Kawakatsu stated that "there is absolutely no problem when they [people] drink them because it will be diluted to about ten becquerels per kilogram when they steep them even if the leaves have 1,000 becquerels per kilogram," which was a consequence of own examinations of the prefecture.[42] Minister for Consumer Affairs and Food Safety Renhō stated on 3 June 2011, that "there are cases in which aracha are sold as furikake [condiments sprinkled on rice] and so on and they are eaten as they are, therefore we think that it is important to inspect tea leaves including aracha from the viewpoint of consumers' safety."[43]

Green tea by country

China

Chinese name

Longjing, a green tea from Zhejiang, China
Traditional Chinese 綠茶
Simplified Chinese 绿茶
Hanyu Pinyin lǜchá

Loose leaf green tea has been the most popular form of tea in China since the Southern Song dynasty.[44][45] While Chinese green tea was originally steamed, as it still is in Japan, after the early Ming dynasty it has typically been processed by being pan-fired in a dry wok.[46] Other processes employed in China today include oven-firing, basket-firing, tumble-drying and sun-drying.[47] Green tea is the most widely produced form of tea in China, with 1.42 million tons grown in 2014.[48]

Popular green teas produced in China today include:

Japan

Sencha green tea, the most popular form of tea in Japan.

Tea seeds were first brought to Japan in the early 9th century by the Buddhist monks Saicho and Kukai. During the Heian period (794–1185), Emperor Saga introduced the practice of drinking tea to the imperial family. The Zen Buddhist priest Eisai (1141–1215), founder of the Rinzai school of Buddhism, brought tea seeds from China to plant in various places in Japan. Eisai advocated that all people, not just Buddhist monks and the elite, drink tea for its health benefits.[56]

The oldest tea producing region in Japan is Uji, located near the former capital of Kyoto.[56] It is thought that seeds sent by Eisai were planted in Uji, becoming the basis of the tea industry there.[57] Today, Japan's most expensive premium teas are still grown in Uji.[58] The largest tea producing area today is Shizuoka Prefecture, which accounts for 40% of total Japanese sencha production.[59][58] Other major tea producing regions include the island of Kyushu and the prefectures of Shiga, Gifu, and Saitama in central Honshu.[58]

All commercial tea produced in Japan today is green tea,[60] though for a brief period black tea was also produced in the late 19th and early 20th centuries. Japanese tea production is heavily mechanized, and is characterized by the use of modern technology and processes to improve yields and reduce labor. Because of the high cost of labor in Japan, only the highest quality teas are plucked and processed by hand in the traditional fashion.[61]

Japanese green teas have a thin, needle-like shape and a rich, dark green color. Unlike Chinese teas, most Japanese teas are produced by steaming rather than pan firing. This produces their characteristic color, and creates a sweeter, more grassy flavor. A mechanical rolling/drying process then dries the tea leaves into their final shape.[60] The liquor of steamed Japanese tea tends to be cloudy due to the higher quantity of dissolved solids.[62]

Most Japanese teas are blended from leaves grown in different regions, with less emphasis on terroir than in the Chinese market. Because of the limited quantity of tea that can be produced in Japan, the majority of production is dedicated to the premium tea market. Bottled tea and tea-flavored food products usually use lower-grade Japanese-style tea produced in China.[63]

Although a variety of commercial tea cultivars exist in Japan, the vast majority of Japanese tea is produced using the Yabukita cultivar developed in the 1950s.[64]

Popular Japanese green teas include:

Korea

Korean name

Hangul 녹차
Hanja 綠茶
Revised Romanization nokcha
McCune–Reischauer nokch'a
IPA [nok̚.tɕʰa]
Gakjeochong, a Goguryeo tomb, shows a knight drinking tea with two ladies (5-6th century)
Tea leaves: sejak (green tea), ujeon (green tea), and hwangcha (yellow tea) from Hadong County

According to Record of Gaya cited in Memorabilia of the Three Kingdoms, the legendary queen Heo Hwang-ok, a princess of the Ayodhya married to King Suro of Gaya, brought the tea plant from India and planted it in Baegwolsan, a mountain in current Changwon.[73]:3 However, it is a widely held view that systematic planting of tea bushes began with the introduction of Chinese tea culture by the Buddhist monks around the 4th century.[74] Amongst some of the earliest Buddhist temples in Korea, Bulgapsa (founded in 384, in Yeonggwang), Bulhoesa (founded in 384, in Naju) and Hwaeomsa (founded in Gurye, in 544) claim to be the birthplace of Korean tea culture.[74] Green tea was commonly offered to Buddha, as well as to the spirits of deceased ancestors.[74] Tea culture continued to prosper during the Goryeo Dynasty, with the tea offering being a part of the biggest national ceremonies and tea towns were formed around temples.[75] Seon-Buddhist manners of ceremony prevailed.[75] During the Joseon Dynasty, however, Korean tea culture underwent secularization, along with the Korean culture itself.[75] Korean ancestral rite jesa, also referred to as charye (차례; 茶禮, "tea rite"), has its origin in darye (다례; 茶禮, "tea rite"), the practice of offering tea as simple ancestral rites by the royal family and the aristocracy in Joseon.[75]

Tea culture of Korea was actively suppressed by the Japanese during the Japanese forced occupation period (1910‒1945), and the subsequent Korean War (1950‒1953) made Korean tea tradition even harder to survive.[76] The restoration of the Korean way of tea began in the 1970s, around Dasolsa.[76] Commercial production of green tea in South Korea also began only in the 1970s,[77] and was still 20% of Taiwan and 3.5% of Japan in 2012.[78][79] Green tea is not as popular as coffee or other types of Korean teas in modern South Korea. The annual consumption per capita of green tea in South Korea in 2016 was 0.16 kg (0.35 lb), compared to 3.9 kg (8.6 lb) coffee.[80] Recently however, as the coffee market reached a saturation point, South Korean tea production doubled during 2010‒2014,[81] as did tea imports during 2009-2015,[82] despite very high tariff rate (513.6% for green tea, compared to 40% for black tea, 8% for processed/roasted coffee, and 2% for raw coffee beans).

Korean green tea can be classified into various types based on several different factors. The most common is the flush, or the time of the year when the leaves are plucked (and thus also by leaf size).

The mode of preparation also differs:

Leaf teas are processed either by roasting or steaming.

Southern, warmer regions such as Boseong in South Jeolla Province, Hadong in South Gyeongsang Province, and Jeju Island are famous for producing high quality tea leaves.[94]

Green tea can be blended with other ingredients.

Other countries

In Canada, green tea is defined as a dry-based mixture and the sale of it is regulated by the Canadian Food Inspection Agency (CFIA). It is one of the foods for which a standard of identity is specified according to the Food and Drug Regulations. It should contain not less than 33% water-soluble extractive (determined by official method FO-37 which is the determination of water-soluble extractive in tea) and the total ash should between 4% to 7%.[98]


See also

References

  1. 1 2 3 Khan N, Mukhtar H (2013). "Tea and health: studies in humans". Current pharmaceutical design (Literature Review). 19 (34): 6141–7. PMC 4055352 Freely accessible. PMID 23448443. doi:10.2174/1381612811319340008.
  2. ↑ Dattner, Christine; Boussabba, Sophie (2003). Emmanuelle Javelle, ed. The Book of Green Tea. Universe Books. p. 13. ISBN 978-0-7893-0853-5.
  3. ↑ "Green tea". Complementary and Alternative Medicine Guide. University of Maryland Medical Center. Retrieved 3 May 2015.
  4. 1 2 3 4 I.T. Johnson & G. Williamson, Phytochemical functional foods, Cambridge, UK: Woodhead Publishing, 2003, pp. 135-145
  5. ↑ "Update on the USP Green Tea Extract Monograph". USP. April 10, 2009.
  6. ↑ A.H. Pressman & S. Buff, The complete idiot's guide to vitamins and minerals, New York: New York Alpha Books, 1997, p. 283.
  7. ↑ A. Bascom, Incorporating herbal medicine into clinical practice, Philadelphia: F.A. Davis Company, 2002, p. 153.
  8. ↑ Committee on Diet, Nutrition, and Cancer, Assembly of Life Sciences, National Research Council, Diet, nutrition, and cancer, Washington: D.C National Academies Press, 1982, p. 286.
  9. 1 2 3 "Scientific Opinion on the substantiation of health claims related to Camellia sinensis (L.) Kuntze (tea), including catechins in green tea, and improvement of endothelium-dependent vasodilation (ID 1106, 1310), maintenance of normal blood pressure (ID 1310, 2657), maintenance of normal blood glucose concentrations (ID 1108), maintenance of normal blood LDL cholesterol concentrations (ID 2640), protection of the skin from UV-induced (including photo-oxidative) damage (ID 1110, 1119), protection of DNA from oxidative damage (ID 1120, 1121), protection of lipids from oxidative damage (ID 1275), contribution to normal cognitive function (ID 1117, 2812), "cardiovascular system" (ID 2814), "invigoration of the body" (ID 1274, 3280), decreasing potentially pathogenic gastro-intestinal microorganisms (ID 1118), "immune health" (ID 1273) and "mouth" (ID 2813) pursuant to Article 13(1) of Regulation (EC) No 1924/2006". European Food Safety Authority. 8 April 2011. Retrieved 9 November 2014.
  10. 1 2 3 Boehm K, Borrelli F, Ernst E, et al. (2009). "Green tea (Camellia sinensis) for the prevention of cancer". Cochrane Database Syst Rev (Systematic review) (3): CD005004. PMID 19588362. doi:10.1002/14651858.CD005004.pub2.
  11. ↑ USDA Database for the Flavonoid Content of Selected Foods, Release 2.1 (2007)
  12. ↑ EFSA Panel on Dietetic Products, Nutrition and Allergies (NDA)2, 3 European Food Safety Authority (EFSA), Parma, Italy (2010). "Scientific Opinion on the substantiation of health claims related to various food(s)/food constituent(s) and protection of cells from premature aging, antioxidant activity, antioxidant content and antioxidant properties, and protection of DNA, proteins and lipids from oxidative damage pursuant to Article 13(1) of Regulation (EC) No 1924/20061" (PDF). EFSA Journal. 8 (2): 1489. doi:10.2903/j.efsa.2010.1489.
  13. 1 2 Johnson R, Bryant S, Huntley AL (December 2012). "Green tea and green tea catechin extracts: an overview of the clinical evidence". Maturitas (Review). 73 (4): 280–7. PMID 22986087. doi:10.1016/j.maturitas.2012.08.008. In conclusion, whilst there is a considerable body of evidence for green tea with some of it suggesting a positive effect, it is difficult to be definitive as to its health benefits.
  14. 1 2 3 Tang J, Zheng JS, Fang L, Jin Y, Cai W, Li D (July 2015). "Tea consumption and mortality of all cancers, CVD and all causes: a meta-analysis of eighteen prospective cohort studies". Br J Nutr (Meta-analysis). 114: 1–11. PMID 26202661. doi:10.1017/S0007114515002329.
  15. ↑ Zheng JS, Yang J, Fu YQ, Huang T, Huang YJ, Li D (January 2013). "Effects of green tea, black tea, and coffee consumption on the risk of esophageal cancer: a systematic review and meta-analysis of observational studies". Nutr Cancer (Systematic Review and Meta-Analysis). 65 (1): 1–16. PMID 23368908. doi:10.1080/01635581.2013.741762.
  16. ↑ Wang L, Zhang X, Liu J, Shen L, Li Z (October 2014). "Tea consumption and lung cancer risk: a meta-analysis of case-control and cohort studies". Nutrition (Meta-Analysis). 30 (10): 1122–7. PMID 25194612. doi:10.1016/j.nut.2014.02.023.
  17. ↑ Wang W, Yang Y, Zhang W, Wu W (April 2014). "Association of tea consumption and the risk of oral cancer: a meta-analysis". Oral Oncol (Meta-Analysis). 50 (4): 276–81. PMID 24389399. doi:10.1016/j.oraloncology.2013.12.014.
  18. 1 2 Huang YQ, Lu X, Min H, Wu QQ, Shi XT, Bian KQ, Zou XP (July 2015). "Green tea and liver cancer risk: A meta-analysis of prospective cohort studies in Asian populations". Nutrition (Meta-Analysis). 32: 3–8. PMID 26412579. doi:10.1016/j.nut.2015.05.021.
  19. ↑ Wang Y, Yu X, Wu Y, Zhang D (November 2012). "Coffee and tea consumption and risk of lung cancer: a dose-response analysis of observational studies". Lung Cancer (Meta-Analysis). 78 (2): 169–70. PMID 22964413. doi:10.1016/j.lungcan.2012.08.009.
  20. ↑ Fon Sing M, Yang WS, Gao S, Gao J, Xiang YB (May 2011). "Epidemiological studies of the association between tea drinking and primary liver cancer: a meta-analysis". European Journal of Cancer Prevention (Meta-Analysis). 20 (3): 157–65. PMID 21403523. doi:10.1097/CEJ.0b013e3283447497.
  21. ↑ Zeng JL, Li ZH, Wang ZC, Zhang HL (October 2014). "Green tea consumption and risk of pancreatic cancer: a meta-analysis". Nutrients (Meta-Analysis). 6 (11): 4640–50. PMC 4245553 Freely accessible. PMID 25353660. doi:10.3390/nu6114640.
  22. ↑ Lin YW, Hu ZH, Wang X, Mao QQ, Qin J, Zheng XY, Xie LP (February 2014). "Tea consumption and prostate cancer: an updated meta-analysis". World J Surg Oncol (Meta-Analysis). 12: 38. PMC 3925323 Freely accessible. PMID 24528523. doi:10.1186/1477-7819-12-38.
  23. ↑ Hou IC, Amarnani S, Chong MT, Bishayee A (June 2013). "Green tea and the risk of gastric cancer: epidemiological evidence". World J Gastroenterol (Review). 19 (24): 3713–22. PMC 3699047 Freely accessible. PMID 23840110. doi:10.3748/wjg.v19.i24.3713.
  24. ↑ Jia L, Liu FT (December 2013). "Why bortezomib cannot go with 'green'?". Cancer Biol Med (Review). 10 (4): 206–13. PMC 3860349 Freely accessible. PMID 24349830. doi:10.7497/j.issn.2095-3941.2013.04.004.
  25. 1 2 Zhang C, Qin YY, Wei X, Yu FF, Zhou YH, He J (February 2015). "Tea consumption and risk of cardiovascular outcomes and total mortality: a systematic review and meta-analysis of prospective observational studies". Eur J Epidemiology (Systematic Review and Meta-Analysis). 30 (2): 103–13. PMID 25354990. doi:10.1007/s10654-014-9960-x.
  26. ↑ Arab L, Khan F, Lam H (December 2013). "Tea consumption and cardiovascular disease risk". Am J Clin Nutr (Review). 98 (6 Suppl): 1651S–1659S. PMID 24172310. doi:10.3945/ajcn.113.059345.
  27. 1 2 3 4 5 Larsson SC (January 2014). "Coffee, tea, and cocoa and risk of stroke". Stroke (Review). 45 (1): 309–14. PMID 24326448. doi:10.1161/STROKEAHA.113.003131.
  28. 1 2 Hartley L, Flowers N, Holmes J, Clarke A, Stranges S, Hooper L, Rees K (June 2013). "Green and black tea for the primary prevention of cardiovascular disease" (PDF). Cochrane Database Syst Rev (Systematic Review and Meta-Analysis). 6: CD009934. PMID 23780706. doi:10.1002/14651858.CD009934.pub2.
  29. ↑ Liu G, Mi XN, Zheng XX, Xu YL, Lu J, Huang XH (October 2014). "Effects of tea intake on blood pressure: a meta-analysis of randomised controlled trials". Br J Nutr (Meta-Analysis). 112 (7): 1043–54. PMID 25137341. doi:10.1017/S0007114514001731.
  30. ↑ Khalesi S, Sun J, Buys N, Jamshidi A, Nikbakht-Nasrabadi E, Khosravi-Boroujeni H (September 2014). "Green tea catechins and blood pressure: a systematic review and meta-analysis of randomised controlled trials". Eur J Nutr (Systematic Review and Meta-Analysis). 53 (6): 1299–1311. PMID 24861099. doi:10.1007/s00394-014-0720-1.
  31. ↑ Peng X, Zhou R, Wang B, Yu X, Yang X, Liu K, Mi M (September 2014). "Effect of green tea consumption on blood pressure: a meta-analysis of 13 randomized controlled trials". Sci Rep (Meta-Analysis). 4: 6251. PMC 4150247 Freely accessible. PMID 25176280. doi:10.1038/srep06251.
  32. ↑ Liu K, Zhou R, Wang B, Chen K, Shi LY, Zhu JD, Mi MT (August 2013). "Effect of green tea on glucose control and insulin sensitivity: a meta-analysis of 17 randomized controlled trials". Am J Clin Nutr (Meta-Analysis). 98 (2): 340–8. PMID 23803878. doi:10.3945/ajcn.112.052746.
  33. ↑ Zheng XX, Xu YL, Li SH, Hui R, Wu YJ, Huang XH (April 2013). "Effects of green tea catechins with or without caffeine on glycemic control in adults: a meta-analysis of randomized controlled trials". Am J Clin Nutr (Meta-Analysis). 97 (4): 750–62. PMID 23426037. doi:10.3945/ajcn.111.032573.
  34. ↑ Zheng XX, Xu YL, Li SH, Liu XX, Hui R, Huang XH (August 2011). "Green tea intake lowers fasting serum total and LDL cholesterol in adults: a meta-analysis of 14 randomized controlled trials". Am J Clin Nutr (Meta-Analysis). 94 (2): 601–10. PMID 21715508. doi:10.3945/ajcn.110.010926.
  35. ↑ Serban C, Sahebkar A, Antal D, Ursoniu S, Banach M (September 2015). "Effects of supplementation with green tea catechins on plasma C-reactive protein concentrations: A systematic review and meta-analysis of randomized controlled trials". Nutrition (Systematic review & meta-analysis). 31 (9): 1061–71. PMID 26233863. doi:10.1016/j.nut.2015.02.004.
  36. ↑ Jurgens TM, Whelan AM, Killian L, Doucette S, Kirk S, Foy E (2012). "Green tea for weight loss and weight maintenance in overweight or obese adults". Cochrane Database Syst Rev (Systematic review). 12: CD008650. PMID 23235664. doi:10.1002/14651858.CD008650.pub2.
  37. ↑ Lambert JD, Sang S, Yang CS (April 2007), "Possible controversy over dietary polyphenols: benefits vs risks", Chem Res Toxicol, 20 (4): 583–5, PMID 17362033, doi:10.1021/tx7000515
  38. ↑ Heiss & Heiss 2007, pp. 56–69.
  39. ↑ Green Tea Processing, O-cha.com, retrieved 2013-01-13
  40. ↑ Current situation and medium-term outlook (PDF), Intergovernmental Group on Tea, UN Food and Agriculture Organization, May 2008, p. 9
  41. ↑ "日本からの緑茶に基準超えるセシウム パリの空港で検出." (Japanese) Asahi Shimbun. 2011-06-18. Retrieved 2011-06-19.
  42. ↑ "静岡知事「飲用茶にすれば問題ない」 仏での検出受け." (Japanese) Asahi Shimbun. 2011-06-18. Retrieved 2011-06-19.
  43. ↑ "蓮舫内閣府特命担当大臣記者会見要旨（平成23年６月３日（金））." (Japanese) Consumer Affairs Agency. 2011-06-03. Retrieved 2011-06-19.
  44. ↑ Mair & Hoh 2009, p. 70.
  45. ↑ Benn 2015, pp. 7–8.
  46. ↑ Mair & Hoh 2009, pp. 110–111.
  47. ↑ Heiss & Heiss 2007, pp. 58–67.
  48. ↑ "国家数据". National Bureau of Statistics of China. 2014.
  49. 1 2 Heiss & Heiss 2007, p. 124.
  50. ↑ Chow & Kramer 1990, p. 125.
  51. ↑ Heiss & Heiss 2007, p. 65.
  52. 1 2 Heiss & Heiss 2007, pp. 124–125.
  53. ↑ Battle 2017, p. 106–107.
  54. ↑ Battle 2017, pp. 105-106.
  55. ↑ Chow & Kramer 1990, p. 143.
  56. 1 2 Heiss & Heiss 2007, pp. 164–166.
  57. ↑ Mair & Hoh 2009, pp. 85–86.
  58. 1 2 3 Heiss & Heiss 2007, pp. 176–179.
  59. ↑ Battle 2017, p. 156.
  60. 1 2 Heiss & Heiss 2007, pp. 169–170.
  61. ↑ Heiss & Heiss 2007, pp. 167–168.
  62. ↑ Heiss & Heiss 2007, p. 68.
  63. ↑ Heiss & Heiss 2007, pp. 174–175.
  64. 1 2 Battle 2017, p. 157.
  65. ↑ Heiss & Heiss 2007, p. 179.
  66. 1 2 Battle 2017, p. 162.
  67. 1 2 Heiss & Heiss 2007, pp. 182–183.
  68. 1 2 Heiss & Heiss 2007, p. 185.
  69. ↑ Heiss & Heiss 2007, p. 187.
  70. ↑ Battle 2017, pp. 163–164.
  71. ↑ Heiss & Heiss 2007, p. 182.
  72. ↑ Heiss & Heiss 2007, p. 171.
  73. ↑ Korean Tea Classics: by Hanjae Yi Mok and the Venerable Cho-ui. Translated by Anthony, Brother Anthony of Taizé; Hong, Kyeong-hee; Owyoung, Steven D. Seoul: Seoul Selection. 2010. ISBN 9788991913660.
  74. 1 2 3 Korean Tea Classics (by Hanjae Yi Mok and the Venerable Cho-ui). Translated by Brother Anthony of Taizé; Hong, Kyeong-hee; Owyoung, Steven D. Seoul: Seoul Selection. 2010. p. 3. ISBN 9788991913660.
  75. 1 2 3 4 정, 동효; 윤, 백현; 이, 영희 (2012). "한국 전통차문화생활의 연대". Cha saenghwal munhwa daejeon 차생활문화대전 (in Korean). Seoul: Hong Ik Jae. ISBN 9788971433515 – via Naver.
  76. 1 2 Brother Anthony of Taizé; Kyeong-Hee, Hong (2007). The Korean way of tea: an introductory guide. Seoul: Seoul Selection. pp. 97–98. ISBN 978-89-91913-17-2.
  77. ↑ Lee, Geumdong (February 2014). "韓国における主要3茶産地形成期のリーダーの役割 : 寶城郡, 河東郡, 済州道を事例に" [The Leaders' Contribution of the Formative Period of Korea's 3 Main Tea Producing Areas] (PDF). 佐賀大学農学部彙報 (in Japanese). 99: 1–20.
  78. ↑ "Crops Primary Equivalent". FAO Corporate Statistical Database. Food and Agriculture Organization of the United Nations. Retrieved 8 April 2017.
  79. ↑ "Crops". FAO Corporate Statistical Database. Food and Agriculture Organization of the United Nations. Retrieved 8 April 2017.
  80. ↑ 허, 건량 (23 July 2016). "커피보단 쉼이 있는 ‘차문화’ 부흥을". Segye Ilbo (in Korean). Retrieved 8 April 2017.
  81. ↑ 안, 지예 (12 October 2016). ""이제는 커피 대신 '차(茶)'다"…음료업계, 시장 선회". Sisa on (in Korean). ISSN 1976-9792. Retrieved 8 April 2017.
  82. ↑ 이, 새봄 (2016-10-13). "커피, 茶와의 동거…스타벅스 차 브랜드 `티바나` 10일만에 100만잔". Maeil Business Newspaper (in Korean). Retrieved 2017-02-19.
  83. 1 2 3 Brother Anthony of Taizé; Kyeong-hee, Hong (2007). The Korean Way of Tea: An Introductory Guide. Seoul: Seoul Selection. p. 13. ISBN 9788991913172.
  84. 1 2 3 4 5 6 Richardson, Lisa Boalt (2016) [2014]. Modern Tea: A Fresh Look at an Ancient Beverage 차 상식사전 (in Korean). Translated by 공, 민희. Seoul: Gilbut Publishing. p. 51. ISBN 9791160500370.
  85. 1 2 Jackson, Julie (14 June 2013). "Green as far as the eye can see". The Korea Herald. Retrieved 20 March 2017.
  86. 1 2 3 4 Kim, Young-mann, ed. (2004). "Tradition - The Way of Tea: A Lifestyle Aesthetic for Learning the Depth and Enlightenment of Life". Pictorial Korea. Korean Overseas Culture and Information Service. p. 26. OCLC 704162423.
  87. ↑ "yeopcha" 엽차. Standard Korean Language Dictionary. National Institute of Korean Language. Retrieved 20 March 2017.
  88. ↑ "garucha" 가루차. Standard Korean Language Dictionary. National Institute of Korean Language. Retrieved 20 March 2017.
  89. ↑ "malcha" 말차. Standard Korean Language Dictionary. National Institute of Korean Language. Retrieved 20 March 2017.
  90. ↑ "2015 Spring Harvest Hot Tea Class Champions". Global Tea Championship. Retrieved 20 March 2017.
  91. ↑ 정, 동효; 윤, 백현; 이, 영희, eds. (2012). "deokkeum-cha" 덖음차. 차생활문화대전 (in Korean). Seoul: Hong Ik Jae. ISBN 9788971433515. Retrieved 20 March 2017 – via Naver.
  92. ↑ 정, 동효; 윤, 백현; 이, 영희, eds. (2012). "bucho-cha" 부초차. 차생활문화대전 (in Korean). Seoul: Hong Ik Jae. ISBN 9788971433515. Retrieved 20 March 2017 – via Naver.
  93. ↑ 정, 동효; 윤, 백현; 이, 영희, eds. (2012). "jeungje-cha" 증제차. 차생활문화대전 (in Korean). Seoul: Hong Ik Jae. ISBN 9788971433515. Retrieved 20 March 2017 – via Naver.
  94. ↑ "The World of Korean Tea – Nokcha (Green Tea)". Korea Tourism Organization. Retrieved 20 March 2017.
  95. ↑ "banya-cha" 반야차. Standard Korean Language Dictionary. National Institute of Korean Language. Retrieved 20 March 2017.
  96. ↑ "jungno-cha" 죽로차. Standard Korean Language Dictionary. National Institute of Korean Language. Retrieved 20 March 2017.
  97. ↑ Lee, Young Ho (2002). Ch'oŭi Ŭisun: A Liberal Sŏn Master and an Engaged Artist in Late Chosŏn Korea. Fremont, CA: Jain Publishing. p. 267. ISBN 9780895819505.
  98. ↑ Branch, Legislative Services. "Consolidated federal laws of Canada, Food and Drug Regulations". laws-lois.justice.gc.ca. Retrieved 2017-07-19.

Works cited

This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.