Talk:Green tea/Archive 2

Page contents not supported in other languages.
From Wikipedia, the free encyclopedia
Archive 1 Archive 2

Wiki Education Foundation-supported course assignment

This article is or was the subject of a Wiki Education Foundation-supported course assignment. Further details are available on the course page. Peer reviewers: Cmart35.

Above undated message substituted from Template:Dashboard.wikiedu.org assignment by PrimeBOT (talk) 21:58, 17 January 2022 (UTC)

Japanese tea

Just making a quick note that the redirect Japanese tea points to a nonexistent section of this article, but it may be better to spin off a separate article for that. Since most Japanese teas are green teas, I can understand why the redirect was there, but surely Japanese teas are worthy of an article of their own, since there are already articles for the individual teas. Right now there is no good place on Wikipedia to find a good overview on the subject of Japanese teas. --diff (talk) 20:08, 18 March 2017 (UTC)

That sounds like a doable article, I also miss Indian tea. We do have History of tea in Japan and History of tea in India. Gråbergs Gråa Sång (talk) 17:58, 19 March 2017 (UTC)

Unsourced section

moving here per WP:PRESERVE as this section is almost entirely unsourced. Per WP:BURDEN do not restore without adding reliable sources at the same time.

Green tea by country
China

Green tea is the most popular form of tea in China. Chinese green teas are made from over 600 different cultivars of the Camellia sinensis plant, giving plenty of variety and regional teas. Chinese green teas are traditionally pan-fired, unlike the Japanese steaming process. Other processes in China include oven-dried and sun-dried. Due to the different production process, Chinese teas are said to have a more "earthy" taste than Japanese teas.

  • Zhejiang Province is home to the most famous of all teas, Xi Hu Longjing (西湖龙井), as well as many other high-quality green teas.
Maybe the most well-known green tea in China; originates from Hangzhou (杭州), the capital of Zhejiang Province. Longjing in Chinese literally means dragon well. It is pan-fired and has a distinctive flat appearance. The tasteless frying oil is obtained from tea seeds and other plants. There are many fake Longjings on the market[1] and in less-scrupulous tea houses around the country.
Named after a temple in Zhejiang.
A tea from Kaihua County known as Dragon Mountain.
A tea from Tiantai County, named after a peak in the Tiantai mountain range.
A tea from Tian Mu, also known as Green Top.
This popular tea is also known as zhuchá, originates in Zhejiang but is now grown elsewhere in China. This tea is also the quintessential ingredient in brewing Maghrebi mint tea, which is brewed green tea with fresh mint.
A plate of Bi Luo Chun tea, from Jiangsu Province in China
A Chinese famous tea also known as Green Snail Spring, from Dong Ting. As with Longjing, inauthentic Bi Luo Chun is common and most of the tea marketed under this name may, in fact, be grown in Sichuan.
A tea from Nanjing.
originate in Jin Tan city of Jiangsu Province.
Camellia sinensis, the tea plant
  • Fujian Province is known for mountain-grown organic green tea as well as white tea and oolong tea. The coastal mountains provide a perfect growing environment for tea growing. Green tea is picked in spring and summer seasons.
A tea with added jasmine flowers.
Meaning "furry peak".
  • 翠剑 Cui Jian
Meaning "jade sword".
A steamed tea also known as Gyokuro (Jade Dew) in Japanese, made in the Japanese style.
An example of a Chinese green tea, called Mao Jian.
A Chinese famous tea also known as Green Tip, or Tippy Green.
Meaning "precious eyebrows"; from Jiangxi, it is now grown elsewhere.
A well-known tea within China and recipient of numerous national awards.
A tea also known as Cloud and Mist.
A tea from Huangshan also known as Big Square suneet.
A Chinese famous tea from Huangshan
A Chinese famous tea also known as Melon Seed
A Chinese famous tea also known as Monkey tea
A tea from Tunxi District.
A tea from Jing County, also known as Fire Green
Wuliqing was known since the Song dynasty. Since 2002, Wuliqing is produced again according to the original processing methods by a company called Tianfang (天方). Zhan Luojiu a tea expert and professor at the Anhui Agricultural University who revived its production procedure.
A medium-quality tea from many provinces, an early harvested tea.
Also known as Meng Ding Cui Zhu or Green Bamboo
A yellowish-green tea with sweet after taste.
  • 百美绿茶 Baimei Green Tea
A green tea from the Han Zhong.
Japan
Japanese green tea
Genmaicha
Aracha

Green tea (緑茶, Ryokucha) is ubiquitous in Japan and is commonly known simply as "tea" (お茶, ocha). Tea was first used in China, and in 1191, was brought to Japan by Myōan Eisai, a Japanese Buddhist priest who also introduced the Rinzai school of Zen Buddhism. Teas from Japan may be referred to as "Japanese tea" (日本茶, nihoncha).

Japanese green teas are mainly made from Yabukita (やぶきた), a cultivar of the camellia sinensis plant. Unlike Chinese green teas which are pan-fired, Japanese green teas are steamed giving them a more "vegetative" or "leafy" taste. The exception is hōjicha, a Japanese roasted tea. Japanese green teas are categorized by the age of the leaves: young leaves are called sencha[citation needed] and the more mature, larger leaves are called bancha. Types of tea are commonly graded depending on the quality and the parts of the plant used as well as how they are processed.[2] There are large variations in both price and quality within these broad categories, and there are many green teas that fall outside this spectrum. Here shows well-known tea-growing districts in Japan; Shizuoka Prefecture (Shizuoka-cha, the largest yield in Japan), Uji tea (宇治茶 Uji-cha) from Uji region of Kyoto Prefecture, Yame (八女, yame) region of Fukuoka Prefecture (Yame-cha), Kagoshima Prefecture (Chiran-cha).

The first and second flushes of green tea made from leaves that are exposed directly to sunlight. This is the most common green tea in Japan. The name describes the method for preparing the beverage.
Sencha, which, in the processing of the leaves, has been steamed two times longer than usual Sencha, giving it a deeper color and producing a fuller flavor in the beverage.
Gyokuro is a fine and expensive type that differs from Sencha (煎茶) in that it is grown under the shade rather than the full sun for approximately 20 days.[3] The name "Gyokuro" translates as "jade dew" and refers to the pale green color of the infusion. The shading causes the amino acids (Theanine) and caffeine in the tea leaves to increase, while catechins (the source of bitterness in tea, along with caffeine) decreases, giving rise to a sweet taste.[4] The tea also has a distinct aroma.
Kabusecha is made from the leaves grown in the shade prior to harvest, although not for as long as Gyokuro. It has a more delicate flavor than Sencha. It is sometimes marketed as Gyokuro.
Tamaryokucha has a tangy, berry-like taste, with a long almondy aftertaste and a deep aroma with tones of citrus, grass, and berries. It is also called Guricha.
Lower grade of Sencha harvested as a third- or fourth flush tea between summer and autumn. Aki-Bancha (autumn Bancha) is not made from entire leaves, but from the trimmed unnecessary twigs of the tea plant.
Kamairicha is a pan-fired green tea that does not undergo the usual steam treatments of Japanese tea and does not have the characteristic bitter taste of most Japanese tea.
  • By-product of Sencha or Gyokuro
A tea made from stems, stalks, and twigs. Kukicha has a mildly nutty, and slightly creamy sweet flavor.
  • Mecha (芽茶, buds and tips tea)
Mecha is green tea derived from a collection of leaf buds and tips of the early crops. Mecha is harvested in spring and made as rolled leaf teas that are graded somewhere between Gyokuro and Sencha in quality.
  • Konacha (粉茶, (coarse) powdered tea)
Konacha is the dust and smallest parts after processing Gyokuro or Sencha. It is cheaper than Sencha and usually served at Sushi restaurants. It is also marketed as Gyokuroko (玉露粉) or Gyokurokocha.
  • Other
A fine ground tea made from Tencha. It has a very similar cultivation process as Gyokuro. It is expensive and is used primarily in the Japanese tea ceremony. Matcha is also a popular flavor of ice cream and other sweets in Japan.
Half-finished products used for Matcha production. The name indicates its intended eventual milling into matcha. Because, like gyokuro, it is cultivated in shade, it has a sweet aroma. In its processing, it is not rolled during drying, and tencha, therefore, remains spread out like the original fresh leaf.
Bancha (sometimes Sencha) and roasted genmai (brown rice) blend. It is often mixed with a small amount of Matcha to make the color better.
A green tea roasted over charcoal (usually Bancha).
  • Aracha (荒茶, raw green tea)
Half-finished products used for Sencha and Gyokuro production. It contains all parts of the tea plant.
First flush tea. The name is used for either Sencha or Gyokuro.
Milled green tea, used just like instant coffee.　Another name for this recent style of tea is "tokeru ocha," or "tea that melts."
Korea
Green tea/Archive 2
tea field in Boseong, South Korea
Korean name
Hangul
녹차
Hanja
Revised Romanizationnokcha
McCune–Reischauernokch'a
IPA[nok̚.tɕʰa]
Further information: traditional Korean tea

Green tea, called nokcha (녹차; 綠茶) in Korean, can be classified into various types based on several different factors. The most common is flush, or the time of year when tea leaves are plucked.

  • cheotmul-cha (첫물차; "first flush") or ujeon (우전; 雨前; "pre-rain")
    Ujeon tea leaves, of "a bud", "a bud and a leaf", or "a bud and two leaves" stage, are plucked before gogu (around 20–21 April when the Sun reaches the celestial longitude of 30°).
  • dumul-cha (두물차; "second flush") or sejak (세작; 細雀; "thin sparrow"), also called jakseol (작설; 雀舌; "sparrow tongue")
    Sejak tea leaves, of "a bud and three leaves" stage, are plucked after gogu. The name jakseol was given as the tea leaves are plucked when they are about the size of a sparrow's tongue. The leaves plucked during the seven days starting from gogu is also referred to as gogu (곡우; 穀雨.
  • semul-cha (세물차; "third flush") or jungjak (중작; 中雀; "medium sparrow")
    Jungjak tea leaves, of "a bud and three leaves" stage, are plucked in May.
  • kkeutmul-cha (끝물차; "final flush") or daejak (대작; 大雀; "big sparrow")
    Daejak tea leaves are plucked in June and after.

The mode of preparation also differs:

  • ipcha (잎차; "leaf tea") or yeopcha (엽차; 葉茶; "leaf tea")
  • malcha (말차; 末茶; "powder tea") or garucha (가루차; "powder tea")
  • tteokcha (떡차; "cake tea") or byeongcha (병차; 餠茶; "cake tea")
  • jeoncha (전차; 錢茶; "money tea") or doncha (돈차; "money tea")

Leaf teas are processed either by roasting or steaming.

  • deokkeum-cha (덖음차; "roasted tea") or jeungje-cha (부초차; 麩炒茶; "roasted tea")
    Roasting is the most common and traditional way of tea processing in Korea. Roasted tea leaves are richer in flavour.
  • jeungje-cha (증제차; 蒸製茶; "steamed tea")
    Tea prepared with steamed tea leaves are more vivid in colour.

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.

  • Banya-cha (반야차; 般若茶; "prajñā tea")
    a steamed tea variety developed by Buddhist monks in Boseong. The tea is grown on sandy loam near mountains and sea.
  • Illohyang (일로향; 一爐香; "bamboo dew tea")
    a roasted tea variety developed by O'sulloc, using young tea leaves grown in Jeju
  • Jungno-cha (죽로차; 竹露茶; "bamboo dew tea")
    a roasted tea variety, made of tea leaves grown among the bamboo in Hadong

Green tea can be blended with other ingredients.

  • hyeonmi-nokcha (현미녹차; 玄米綠茶; "brown rice green tea")
    nokcha (green tea) blended with hyeonmi-cha (brown rice tea)
  • remon-nokcha (레몬 녹차; "lemon green tea")
    nokcha (green tea) blended with lemon
Other countries

References

  1. ^ http://www.chinadaily.com.cn/business/2010-02/23/content_9489252.htm
  2. ^ Heiss, Mary Lou; Heiss, Robert J. (2007), The Story of Tea: A Cultural History and Drinking Guide, Ten Speed Press, pp. 179–185, ISBN 1-58008-745-0
  3. ^ Illustrated explanation of the process for producing gyokuro tea, Ippodo-tea.co.jp, retrieved 2013-01-13
  4. ^ About the effects of the shading process, and the components of this tea compared to others, Ippodo-tea.co.jp, retrieved 2013-01-13

-- Jytdog (talk) 19:20, 23 February 2017 (UTC)

discussion

Agree entirely. The article has become a burdensome indiscriminate collection of Asian sources, with seemingly endless, unverifiable calligraphy not useful for the English encyclopedia. WP:IINFO and WP:V are violated. Some calligraphy could prevail for origins, but most of it among this long list should go. --Zefr (talk) 19:34, 23 February 2017 (UTC)

Do you understand that this your statement is obviously racist? Cathry (talk) 19:40, 23 February 2017 (UTC)
It's not a matter of race but of language and content per this. This is the English encyclopedia for people who read English. The native speakers of Asian languages have other sites to visit shown in the link. --Zefr (talk) 19:50, 23 February 2017 (UTC)
this wikipedia can use sources in any language https://en.wikipedia.org/wiki/Wikipedia:Verifiability#Reliable_sources Cathry (talk) 19:58, 23 February 2017 (UTC)
It can but that misses the issue that the content is almost entirely unsourced. Wikilinks are not sources; WP itself is not a reliable source. Jytdog (talk) 20:08, 23 February 2017 (UTC)
There are mostly links to rs in wp articles, as already said. Also, you deleted "Heiss, Mary Lou; Heiss, Robert J. (2007), The Story of Tea: A Cultural History and Drinking Guide" with text, which may be source to deleted info. Cathry (talk) 20:29, 23 February 2017 (UTC)
If there are refs there, then it will be not that much work to bring them here. You need to do that if you want to restore any content above. Yes, the bits of content that are reliably sourced can be restored. Jytdog (talk) 20:33, 23 February 2017 (UTC)
User:Cathry about this and this, as I noted here and here, if you add content to WP you must supply a source when you add it, per WP:BURDEN. Jytdog (talk) 19:39, 23 February 2017 (UTC)

It seems to me there is some loss of value in deleting all this material (though of course it has been preserved here, and I found it!). Namely: it used to provide a structure for understanding the variety of green teas that exist. After removal, there is a completely unstructured separate list https://en.wikipedia.org/wiki/List_of_Chinese_teas but that is Chinese only: nothing else for varieties of Japanese green tea. I am not the right person to start restoring: I am someone who buys curious teas and then tries to look up information on the names. Other sources seem to be mainly vendors' websites, which describe what they are selling: probably not Reliable Sources, but actually on the tea I have today (Kokeicha) they all say the same thing, that it is compressed & reformed Matcha, which is interesting information.

Looking at wine for comparison, I see I can go down from Wine to Bordeaux Wine, ... and get to Cotes de Bourg (for example) but no further on Wikipedia (not to individual vinyards). It seems to be that having something similar for green tea would be reasonable. So I guess I am hoping that someone with more knowledge picks this up and identifies sources for the list. They may all be in the deleted reference "The Story of tea" but that is published on paper and my enthusiasm does not extend to buying a copy. Alan-24 (talk) 18:50, 14 March 2017 (UTC)

I have to agree that there's a loss of value in the deletion. Sure, it takes time to gather up all the sources for the info and clean up everything that can't be sourced, but for the most part the overview is quite useful as a way to reach the more detailed articles, some of which have the sources we want. Now the article fails to serve one of the main purposes I would expect it to serve, and is totally lopsided. It would have been better to resolve the issue incrementally rather than blast the whole thing away all at once, which is lazy and forces somebody else to do the real work of writing, sourcing, and editing. --diff (talk) 04:57, 17 March 2017 (UTC)
Everyone is free to find reliable sources and rebuild. Per WP:BURDEN. Wasting time complaining is just that; wasting time. Jytdog (talk) 05:06, 17 March 2017 (UTC)
I agree that using time to find sources to reintroduce this material is a better use of time. TylerDurden8823 (talk) 05:53, 17 March 2017 (UTC)
WP:BURDEN says the burden is on the original author(s) who wrote the material to source it properly. It doesn't say the burden is on other editors who happen to work on that subject area. The way the article was before, with the problem tagged, said editors were "free to find reliable sources" whenever they could find the time for it. Now you're forcing them to do so as quickly as possible so the article can be usable again, because right now it's rather worthless and fails to adequately cover the subject, as has been pointed out. If you'd just brought it up on the talk page, you could've easily rounded up an editor or two to fix the section, instead of blanking it and making the article useless in the meantime. Anyway, what's done is done and I will volunteer to do some of the work on this. If someone else can help on the Japanese side of things, I can cover the Chinese section. --diff (talk) 18:30, 17 March 2017 (UTC)

Progress

Got a start on sourcing and cleaning up the China subsection today. Just a blurb and a list of links for now so people can get to the detail articles, but there should be enough in the sources to put together a sentence or two for each tea in the list in the second pass. I've also removed all the teas that either didn't seem notable enough or just didn't have solid enough sources readily available. If nobody wants to work on the Japan and Korea subsections, I could try my hand at those too, but it would be better to have someone with more knowledge in those areas. --diff (talk) 04:22, 19 March 2017 (UTC)

China and Korea are basically done (thanks Epulum). Still need Japan and other countries, so I moved the stub template down into those subsections. --diff (talk) 02:43, 23 March 2017 (UTC)

CJK characters

Since we don't seem to have established consensus in the previous discussion, and I don't want to start an edit war in the Korean subsection, I wanted to bring this up again. MOS:CHINESE explicitly says that when a term is wikilinked to an article that defines the Chinese characters for that term, the characters should not be provided again. If you want to see them, you can just click the link and go to the article. I like this policy quite a bit. I recognize that this policy doesn't apply to Korean or Japanese but the same reasoning applies. This is an encyclopedia, not a dictionary. We already have Wiktionary for that. The article text flows much better when you can focus on the actual content, not individual word translations. Long lists are already potentially problematic for flow, multiscript parentheticals inside lists are even worse. The literal definitions of the characters are even more irrelevant. We're already describing what the thing is, in plain English. If there's a wikilinked article, I would argue just use the WP:COMMONNAME, give a short description with citation, and that's it. Only if it's not wikilinked would I include the Korean language template for a term at all, but that's assuming we really need the term, and in many cases, we don't. For example, do we really need to define (multiple!) Korean terms for roasted tea, steamed tea, loose leaf tea, etc.? After all, we use the English language terms to describe these very things for teas from other cultures with no problem. --diff (talk) 04:06, 22 March 2017 (UTC)

Mortality risk

Is this section ok from the WP:MEDRS perspective? If so, I´ll consider buying some. The sources are [1] and [2]. Gråbergs Gråa Sång (talk) 09:06, 17 March 2017 (UTC)

Mortality risk

Daily consumption of green tea is significantly associated 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.(ref name="Tang2015"/) A separate analysis found an increase of three cups of green tea per day was associated with a lower risk of death from any cause.(ref name="Zhang2015"/)

The citations are both high-quality MEDLINE-indexed secondary sources (in this case systematic reviews/meta-analyses, granted of observational studies but at least they're prospective) and both of them are from journals with respectable impact factors. One reason to take the information with a grain of salt is that both studies came out of China and there have been concerns with study data being falsified there but otherwise these references are certainly MEDRS-compliant. TylerDurden8823 (talk) 13:27, 17 March 2017 (UTC)
The content should be tweaked to note that these are correlations only. There are boatloads of potential confounders (like other lifestyle choices) with studies like this. Will make those tweaks. Jytdog (talk) 09:33, 18 March 2017 (UTC)
True, the RRs had high heterogeneity so the confidence in these estimates is still shaky but stating that would be our interpretation of the cited SRs and thus WP:OR. We need secondary sources to interpret it and reflect what they say. I agree there are significant limitations to the available data used in these studies. These limitations come with the nature of observational evidence (though they're marginally better for using prospective cohorts out of observational evidence). Of course, SRs/MAs of RCTs would be preferable but there aren't any that address this specific aspect of green tea consumption yet. I check PubMed SRs/MAs now and again to see if anything new has popped up but not yet. TylerDurden8823 (talk) 02:18, 19 March 2017 (UTC)

The abstract for the second ref (Zhang 2015) does not say green tea, only "tea". Does anyone have access to the complete PDF? If the article is about tea it cannot be used as a reference for this entry. Green tea and tea have major differences in polyphenol types and total content. David notMD (talk) 00:50, 25 March 2017 (UTC)

Yes, you're right that the abstract does not explicitly specify green tea but it does within the article. I have access to the whole PDF (you can email me if you would like a copy) but here is the pertinent quote from the article verbatim: "Similarly, we found that a 3 cups per day increase in the consumption of tea was associated with a reduced risk of cardiac death if the participants were women, Asian, European, or consumption of green tea; an increase of 3 cups of tea per day was associated with a reduced risk of stroke if the participants were men, Asian, or consumption of green tea; an increment in tea con- sumption by 3 cups per day was associated with a reduced risk of total mortality if the participants were women, Asian, or consumption of green tea. (my bold)"
Thanks for sharing this, TylerDurden8823. So this is our source for "A separate analysis found an increase of three cups of green tea per day was associated with a lower risk of death from any cause." It seems to say that "total mortality" concerns people who are asian (and? or?) women, so perhaps we should be more specific too. Also, tea/green tea seems to have the same effect here, so we should change the text to "three cups of tea or green tea", otherwise we imply that green tea has this effect but tea doesn´t. Gråbergs Gråa Sång (talk) 09:46, 29 March 2017 (UTC)
We should specify green tea. Many studies have found that green tea and other teas (e.g., black tea) do not have the same effect when looking at certain outcomes and do have similar effects when looking at others (so it depends on what is being discussed). In this case, I think we should be specific. I have no objection to specifying that the separate analysis found this association in Asian people and women. TylerDurden8823 (talk) 13:59, 29 March 2017 (UTC)
Not in that sentence with that source we shouldn´t. The source (at least the part quoted) treats green tea as more of an afterthought. Gråbergs Gråa Sång (talk) 19:07, 29 March 2017 (UTC)
I don't know that I agree with that assessment. That's mere speculation on your part. We don't know that the authors were thinking that so it's merely interpretation which falls afoul of WP:OR. Also, "from any cause" refers to all-cause mortality (please note this is a very frequently used term in the medical literature). TylerDurden8823 (talk) 00:26, 30 March 2017 (UTC)
"Afterthought" might be a sloppy choice of words, how about "not more prominent than" (in this context). If "from any cause" is the usual term that´s ok, of course. My thinking was that to a lay-person such as myself it can (but probably won´t) be read as including things like murder and lightningstrikes, this article is not medical literature. Gråbergs Gråa Sång (talk) 06:47, 30 March 2017 (UTC)
The article in its entirety is not but the section in question is about its health-related properties. All-cause mortality is a very common and well-accepted synonym for total mortality. I think your rephrasing/revised word choice here on the talk page is more consistent with how I would read it. Of course, further study will be required before firm conclusions about green tea consumption and total/all-cause mortality can be reached. TylerDurden8823 (talk) 06:44, 1 April 2017 (UTC)

CJK Characters

Re [[3]], it seems to follow current WP style guide now. This is relevant to Wikipedia_talk:Naming_conventions_(Chinese)/Archive_6#Titles_of_articles_to_include_tone_marks.3F, but it's a significant loss that Chinese characters are removed leaving only English language guesses of the names. The same written Chinese name is typically universal across hundreds of dialects. Even if Mandarin and pinyin romanisation (as is policy), without the tone marks (which is also policy to leave out), it's unintelligible and guaranteed to be pronounced incorrectly or unrecognisable. Probably like the common Western perspective that "tea is tea", whereas actually there's more than hundreds of very different, distinct styles and varieties. I'm glad User:Cathry started disambiguating them. I'm a native English speaker, but when I read Chinese without any markers, spacing (or original characters to disambiguate), it's just completely lost all music, rhythm and character of the words - leaving only a letter jumble. Feels a bit like a bland, cold cup of tea left out overnight really. — Preceding unsigned comment added by 120.18.122.6 (talk) 06:22, 8 October 2017 (UTC)

caffeine content

Green tea is a globally important beverage and the encyclopedia should include useful information about its caffeine content. The current article includes a table with nutritional values based on a USDA report. This table does state a number, namely 12 mg of caffeine per 100 g of brew. This number is as good as useless for the following reasons: 100 g of green tea can be brewed with 1,5 g of dry tea leaf or with 6 g of dry tea leaf. Moreover the same amount of dry leaf can be used repeatedly for producing several cups of tea. Caffeine is a well known stimulant which at low dosage is believed to be beneficial to human health, but can be unhealthy if one ingests more than 500 mg per day. Using the USDA number the reader may think that up to 500/12 = 41 large cups of green tea can be drunk per day without ill effects due to the caffeine content, which may be dangerously misleading. I found an official table about the nutrients of Japanese Food which specifies the caffeine content of the most common Sencha variety of Japanese green tea at 2.3 g of caffeine for 100 g of dry leaf (or 23 mg of caffeine per gram of dry leaf). Thus the consumer can calculate that if she uses in total, for example, 5 g of dry leaf per day then no matter how many caps she brews with it she will imbibe at most 115 mg of caffeine, well below the unhealthy level. The Gyokuro variety of Japanese Green tea has more caffeine, namely 35 mg per gram of dry leaf. I couldn't find similar tables for Chinese green tea, but since the plant used is the same the caffeine content is probably similar too. Dianelos (talk) 13:34, 15 November 2017 (UTC)

Dianelos: First, when adding a new topic for discussion, it goes to the bottom of the page; see WP:BOTTOMPOST. The USDA nutrition table used in the article, containing the caffeine content of 12 mg per 100 g, is one of several green tea products analyzed and presented in the USDA tables here, and serves to standardize a representative sample. As there are numerous, uncontrollable variables across users in brewing tea that may affect caffeine content – cultivar and amount of tea leaves used, water temperature, brew time, as examples – it's reasonable to present one in the nutrition table with caffeine data determined by a reliable source such as the USDA. Other than for its stimulatory effects to enhance performance, discussed here, it seems to me your above claim of health benefits is overstated, and the analysis you present depends on too many uncontrolled variables to be discussed clearly in the encyclopedia; see WP:NOTTEXTBOOK, #s 1, 6. If you have a proposal for describing caffeine content in a concise way, you should present it here. --Zefr (talk) 15:04, 15 November 2017 (UTC)
Zefr: My referenced source is the Ministry of Education and Science and Technology of Japan, and is certainly reliable. My reason for adding that information is not about reliability but about usefulness. We know that large quantities of caffeine should not be imbibed; thus the Wikipedia article about caffeine mentions a maximum of 400 mg per day for adults (elsewhere I had read about 500 mg per day, but let me stay with the lower number). So it's important for a consumer to know about the caffeine content of the green tea she actually drinks. As a reader of wikipedia I was looking precisely for that information in the current article but did not find it in a form that is useful. As I explained above the USDA number can be dangerously misleading since the reader may think that imbibing 400/12 = 33 large 100 g cups of green tea per day is OK, which at least in some cases is false. For example a single 100 g cup of gyokuro green tea is sometimes brewed with 6 g of dry leaf (some recipes ask for 2 g per oz) and thus can theoretically have up to 6 x 35mg = 210 mg of caffeine. By informing the reader about the caffeine content in *dry leaf* the reader has a useful metric for computing the upper limit of caffeine she will imbibe and thus make certain she does not overstep the maximum recommended dosage. So, for example, if one uses 6 g of dry gyokuro leaf per day, no matter how one brews it one will not imbibe more than the 210 mg of caffeine that is physically present in the leaf. As for the commercial page I also referenced, it is not dubious but presents (and explicitly quotes) the information from the official Japanese government page. The advantage is that this page is exclusively in English and is more concise since it only includes teas whereas the official page mentions dozens of other foods also. I am not aware that there is a policy prohibiting the use of reliable information in commercial sources and I added that secondary source to make life easier for the reader. Dianelos (talk) 14:43, 16 November 2017 (UTC)
This was your edit: The amount of caffeine and of antioxidants in Japanese green teas varies significantly. For example caffeine content in Sencha green tea is 23 mg per one gram dry weight of leaves, whereas in Gyokuro it is 35 mg per one gram dry weight of leaves.[1][2]

References

  1. ^ "Standard tables of food composition in Japan" (PDF). Ministry of education/science and technology of Japan. Retrieved 15 November 2017.
  2. ^ "Components of Japanese green teas". Retrieved 7 September 2017.

1) The first reference is in Japanese and is too detailed as a table of numbers for English users, as one cannot decipher the desired information. 2) The second reference is from Ippodo, which led me to question the analyses as potentially commercial and not sufficiently objective. 3) Your quantitative statements for caffeine content seem incorrect as "per one gram dry weight"; should this be per 100 g? I also question how relevant this information from two types of Japanese leaves is for the general Wikipedia user, as these teas seem somewhat rare for common green tea consumers. If you can find a more general secondary reference that caffeine content may vary among green tea cultivars, then that would likely be sufficient to state. --Zefr (talk) 18:15, 16 November 2017 (UTC)

Mortality risk

This section states "Daily consumption of green tea is significantly correlated with a lower risk of death from any cause", this is a bold statement and I don't think is a serious one. — Preceding unsigned comment added by Souliaq (talk • contribs) 20:18, 18 July 2018 (UTC)

There is a supporting reference from a reliable source. Correlation is not the same as causation but an association has been found per that research. It is a serious statement. TylerDurden8823 (talk) 20:53, 18 July 2018 (UTC)
Whooa - this is Chinese research making exceptional claims. We need something a bit more reputable for that per WP:REDFLAG. Removed for now. (add: in fact the Health Effects section is riddled with Chinese research making strong suggestive claims). Alexbrn (talk) 04:16, 19 July 2018 (UTC)
I disagree. That is insufficient cause to remove well-sourced WP:MEDRS-compliant MEDLINE-indexed secondary sources from journals with very reasonable impact factors in their respective fields. Your citation of WP:VALID is actually invalid and does not apply. TylerDurden8823 (talk) 07:41, 19 July 2018 (UTC)
Sorry, I meant WP:REDFLAG as above (VALID was an error). I don't think this is well-sourced since Chinese research into TCM is known to be rife with fraud, as has been discussed at length before at WT:MED. Why are we using it when we have decent sources (like Cochrane) which have a rather less sensational take? Looking deeper, I am also concerned about this material being stated as "Health effects" when even in its own terms most of it is only invoking associations, not "effects" at all. Alexbrn (talk) 09:00, 19 July 2018 (UTC); amended 10:05, 19 July 2018 (UTC)
Hmm, I disagree again and here's why. REDFLAG does not apply here since we have multiple high-quality journals cited to support the material. These sentences do not meet any of the REDFLAG criteria. Furthermore, although green tea may be used in TCM, I think it's a big stretch to state green tea consumption is a "TCM" modality. Please support your premise by providing high-quality references here that demonstrate that all Chinese research, or even the majority of it is "rife with fraud" and is not trustworthy when published in reputable journals.
I am aware that China has been plagued by difficulties. From what I can see, it looks like China has indeed had a long-term problem with fraud in academia but it centered around peer review in the country per this article [4]. I disagree with the notion that simply because research came out of China that it is by definition invalid or suspect. I examined the cited journals' respective editorial boards and they are not Chinese journals or from Chinese institutions. Many primary studies of green tea are conducted in China and green tea consumption is an integral part of Chinese culture so it's logical that much of the literature would come from there. I have found a few other reliable non-Chinese sources to include for reinforcement in some of the other health effects sections which I will add today to attempt to allay some of your concerns. I'm not going to dig through the enormous archives of WT:MED to find one thread since you're raising the objection to longstanding stable and well-sourced material. Which Cochrane source(s) are you referring to specifically? I'm aware that most of the data cited here is derived from observational studies and the difficulties of drawing conclusions from such research; however, nothing is said to be causal in these paragraphs. Therefore, I think your concerns are unwarranted. The article carefully uses terms such as association and correlation (see Correlation does not imply causation). If you have alternate wording to propose, then I'm listening. TylerDurden8823 (talk) 17:02, 19 July 2018 (UTC)
I think that framing this material as "Health effects" - causal - and then having so much material about what green tea drinking is "linked with" (like the worst newspaper reporting), depending so heavily on Chinese sources is definitely a problem. For cancer, I'd cut the lot and just have a statement from (say) CRUK saying that there is no real evidence green tea is of any use in the field of cancer (which is what they say[5]). That neatly summarizes accepted knowledge. I'll ping WT:MED. Alexbrn (talk) 17:46, 19 July 2018 (UTC)
Alex, where is the word "causal" used in the article? There is nothing that frames the material in the health effects section as causal. Your assessment that the way the information is presented here is in anyway even comparable to how media presents it is nonsense. I disagree entirely with your proposal to "cut the lot". We already have a sentence that says there is no definitive evidence that green tea prevents/treats cancer. This is the first sentence of the cancer section: "There is no conclusive evidence that green tea helps to prevent or treat cancer in people.[10][13] ". That's more than sufficient.
In response to your concerns, I have also added a few non-Chinese reviews (also from reliable sources) that review or discuss those studies and came to similar conclusions.TylerDurden8823 (talk) 16:47, 20 July 2018 (UTC)
That it's in a "Health effects" section implies that these are ... health effects. Perhaps a separate sectional called "Associations" might solve that? Or add some explanatory text as suggested at WT:MED? Alexbrn (talk) 17:12, 20 July 2018 (UTC)
I disagree with your assessment. I think you read too much into it but I'm open to the idea of rewording the name of the section. What explanatory text are you suggesting we add? A sentence stating that correlation is not synonymous with causation? The WL to correlation goes to that page but if you think a sentence explicitly stating that is necessary, that's a suggestion we can discuss. I don't think renaming the section "associations" is the right way to go but something more general such as health impact or something similar seems reasonable. Some of these effects actually are consistent across studies (e.g., in the cardiovascular section) even if the effect sizes are small to moderate. TylerDurden8823 (talk) 17:21, 20 July 2018 (UTC)
Some qualifying text would be good, but saying these are health "impacts" is not, as the whole point is these associations might be entirely incidental. Alexbrn (talk) 17:34, 20 July 2018 (UTC)
Well, the purpose of the text is to provide more context and nuance. If you don't like the idea of health impacts, aside from "associations", what else do you suggest? And what are your specific suggestions for qualifying text? Please be specific. TylerDurden8823 (talk) 17:51, 20 July 2018 (UTC)
That was a suggestion from another editor at WT:MED - I await their proposed wording. Hiving this stuff off to a separate sectionwith one qualifying caveat would be neater that having to repeat the qualifier for every mention. Alexbrn (talk) 18:00, 20 July 2018 (UTC)
If you're referring to Ozzie, I see no mention of anything like that. If you're referring to WAID, I see no mention of that either. I think your suggestion would oversimplify the matter and strongly disagree with that proposal. TylerDurden8823 (talk) 19:59, 20 July 2018 (UTC)

What I deleted

I'm all for Green Tea, and I hope that it is correlated with a lower risk of death from any cause, because I drink it all day long. That being said, that makes very little sense. By not even specifying what it that literally says is that death from any cause be it cancer, heart disease, gun shot wound, car accident, gas pipeline explosion, all of these are less likely to happen to me because I drink tea. So if that came from the New England Journal of Medicine, Johns Hopkins, Tsinghua, Seoul University, Oxford from a longitudinal Study, I probably still wouldn't believe it but fair enough, but the source isn't reliable for such a claim, especially not when the rest of the article is loaded with reputable sources saying that no such claim can be made. Second I deleted a sentence about black tea decreasing the likelihood of all cancers, like I said in the comment, this article is about green tea, not black, what's more is that the same source was used, and for the strength of the claim, and the amount of other sources it goes against, it doesn't cut it. So I took those two out. If someone wants to include that, and can find rock solid sources to support the claim, I'm all for it, and like I said I hope it's true, but until that point, it's not up to wiki standards. Alcibiades979 (talk) 21:05, 13 June 2019 (UTC)

Also a slew of sources mainly, though not exclusively from China, refuting the hitherto made assertions on green tea, and black from journals such as "Oral Oncology," "Nutrition and Cancer," and "World Journal of Surgical Oncology". [1][2][3][4][5]

References

  1. ^ 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. doi:10.1016/j.oraloncology.2013.12.014. PMID 24389399.
  2. ^ 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. doi:10.1016/j.lungcan.2012.08.009. PMID 22964413.
  3. ^ Zheng J, Yang B, Huang T, Yu Y, Yang J, Li D (June 2011). "Green tea and black tea consumption and prostate cancer risk: an exploratory meta-analysis of observational studies". Nutr Cancer (Meta-Analysis). 63 (5): 663–72. doi:10.1080/01635581.2011.570895. PMID 21667398.
  4. ^ 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. doi:10.1186/1477-7819-12-38. PMC 3925323. PMID 24528523.{{cite journal}}: CS1 maint: unflagged free DOI (link)
  5. ^ 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. doi:10.1080/01635581.2013.741762. PMID 23368908.
This section has been previously discussed[6] at WT:MED. On balance, I think the deletions are good. Alexbrn (talk) 06:40, 14 June 2019 (UTC)
I mean on the face of it the claim is just so absurd. Death from any cause? That includes lightning strike, I'm not trying to be obtuse, but that's ridiculous. Making the claim that green tea decreases chances of dying from all things including lightning, is insane. What's more from a logical stand point the sentence is fallacious. Not to be morbid however, everyone's chances of dying from some cause, non specific, are 100%. Tea or no, I'll die from something, as have countless other tea drinkers. Alcibiades979 (talk) 15:08, 14 June 2019 (UTC)
It was indeed WP:CB. Alexbrn (talk) 15:13, 14 June 2019 (UTC)

Confusion

When i look at the regular english article, i see that it mostly debunks some health claims of green tea, i see the opposite in the simple english article. What??????? Darubrub (talk) 19:23, 26 December 2020 (UTC)

If there are problems over there, discuss them there. I don't think there are any problems in this matter here ... or are there some good sources we're missing? Alexbrn (talk) 20:18, 26 December 2020 (UTC)
For what it's worth, I just looked in the Talk section to see if people had mentioned the way the page is organised. It seems strange to have so much early focus on cataloguing various kinds of medical studies (most of which boil down to "no evidence of health benefits") while the sections on actual tea production and the different varieties get pushed to the bottom. I get that the "health benefits" section kinda follows the "preparation and drinking" part, but it feels like it would be better at the end, to me, since it's more tangential. The abstract already mentions there's no evidence of health benefits but leaves that til the final sentence, and it seems like every other translation puts health and medical topics after cultivation and production too. It's a useful reference to have, but it feels weirdly placed and interrupts the flow of the article IMO Redset (talk) 17:42, 13 April 2021 (UTC)

Green tea

English 2803:A200:3A:B9D:6DA3:135:6654:4ADA (talk) 23:19, 20 February 2023 (UTC)

Green Tea

Green tea has been associated with various health benefits due to its rich content of antioxidants and other bioactive compounds. MultiHub (talk) 11:54, 11 November 2023 (UTC)

There's a whole Health section in the article; most of the claims are just hype. Bon courage (talk) 12:01, 11 November 2023 (UTC)
The article cites reviews of epidemiological studies between 2013 and 2015, there are easily dozens of reviews from this period on the article. I would suggest updating the article with more recent systematic reviews.
Here are 5 recent umbrella reviews [7], [8], [9], [10], [11]. Recent systematic reviews from 2022 and 2023 [12], [13]. The only two recent reviews of controlled trials I found were [14] and [15]. This was the only literature I could see [16]. MultiHub if you want to go through any of this and have a look. I would agree though that many of the claims are hype. The recent evidence says green tea can reduce CVD risk (because it lowers LDL cholesterol). I wouldn't say there is much new out there. Psychologist Guy (talk) 13:09, 11 November 2023 (UTC)

Tea reputed to be healthy is a myth.

In earlier times, water was not healthy due to bacteria it contained, tea became popular because the water had to be boiled to make it, thus killing off harmful germs. 51.9.35.165 (talk) 07:06, 25 February 2024 (UTC)

Interesting, do you have any references for that claim? Psychologist Guy (talk) 12:41, 25 February 2024 (UTC)
Retrieved from "https://en.wikipedia.org/w/index.php?title=Talk:Green_tea/Archive_2&oldid=1220716093"