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102-469: Several varieties of green tea exist, which differ substantially based on the variety of C. sinensis used, growing conditions, horticultural methods, production processing, and time of harvest. Tea consumption has its legendary origins in China during the reign of mythological Emperor Shennong . A book written by Lu Yu in 618–907 AD, The Classic of Tea ( Chinese : 茶 經 ; pinyin : chájīng ),

204-607: A natriuresis (increase in saline excretion); it is mediated via proximal tubular adenosine receptor blockade. The acute increase in urinary output may increase the risk of dehydration . However, chronic users of caffeine develop a tolerance to this effect and experience no increase in urinary output. Minor undesired symptoms from caffeine ingestion not sufficiently severe to warrant a psychiatric diagnosis are common and include mild anxiety, jitteriness, insomnia, increased sleep latency, and reduced coordination. Caffeine can have negative effects on anxiety disorders . According to

306-489: A 2011 literature review, caffeine use may induce anxiety and panic disorders in people with Parkinson's disease . At high doses, typically greater than 300 mg, caffeine can both cause and worsen anxiety. For some people, discontinuing caffeine use can significantly reduce anxiety. In moderate doses, caffeine has been associated with reduced symptoms of depression and lower suicide risk. Two reviews indicate that increased consumption of coffee and caffeine may reduce

408-513: A certain flower petals. These include: Shennong Shennong ( 神農 ), variously translated as "Divine Farmer" or "Divine Husbandman", born Jiang Shinian ( 姜石年 ), was a mythological Chinese ruler known as the first Yan Emperor who has become a deity in Chinese and Vietnamese folk religion . He is venerated as a culture hero in China and Vietnam. In Vietnamese, he is referred to as Thần Nông . Shennong has at times been counted amongst

510-410: A decrease in performance on their standardized tests, and caffeine causes a significant improvement. When alcohol and caffeine are consumed jointly, the effects of the caffeine are changed, but the alcohol effects remain the same. For example, consuming additional caffeine does not reduce the effect of alcohol. However, the jitteriness and alertness given by caffeine is decreased when additional alcohol

612-534: A distinct diagnostic category, which closely mirrors the DSM-5 's proposed set of criteria for "caffeine-use disorder".   Caffeine use disorder refers to dependence on caffeine characterized by failure to control caffeine consumption despite negative physiological consequences. The APA , which published the DSM-5, acknowledged that there was sufficient evidence in order to create a diagnostic model of caffeine dependence for

714-456: 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 flavour. 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

816-507: A higher risk of alcohol-associated injury. Smoking tobacco has been shown to increase caffeine clearance by 56% as a result of polycyclic aromatic hydrocarbons inducing the CYP1A2 enzyme. The CYP1A2 enzyme that is induced by smoking is responsible for the metabolism of caffeine; increased enzyme activity leads to increased caffeine clearance, and is associated with greater coffee consumption for regular smokers. Birth control pills can extend

918-412: A marked reduction in consumption, a minimum of 3 of these signs or symptoms is required to meet withdrawal criteria: difficulty concentrating, depressed mood / irritability , flu -like symptoms, headache , and fatigue . Additionally, the signs and symptoms must disrupt important areas of functioning and are not associated with effects of another condition. The ICD-11 includes caffeine dependence as

1020-408: A maximum daily caffeine intake of no more than 2.5 milligrams per kilogram of body weight. Based on average body weights of children, this translates to the following age-based intake limits: Health Canada has not developed advice for adolescents because of insufficient data. However, they suggest that daily caffeine intake for this age group be no more than 2.5 mg/kg body weight. This is because

1122-521: A maximum daily caffeine intake of no more than 300 mg, or a little over two 8 oz (237 mL) cups of coffee. A 2017 systematic review on caffeine toxicology found evidence supporting that caffeine consumption up to 300 mg/day for pregnant women is generally not associated with adverse reproductive or developmental effect. There are conflicting reports in the scientific literature about caffeine use during pregnancy. A 2011 review found that caffeine during pregnancy does not appear to increase

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1224-438: A mild form of drug dependence  – associated with withdrawal symptoms such as sleepiness, headache, and irritability – when an individual stops using caffeine after repeated daily intake. Tolerance to the autonomic effects of increased blood pressure and heart rate, and increased urine output, develops with chronic use (i.e., these symptoms become less pronounced or do not occur following consistent use). Caffeine

1326-644: A mountain in current Changwon . 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. 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

1428-554: A number of adenosine receptor types, inhibiting the centrally depressant effects of adenosine and enhancing the release of acetylcholine . Caffeine has a three-dimensional structure similar to that of adenosine, which allows it to bind and block its receptors. Caffeine also increases cyclic AMP levels through nonselective inhibition of phosphodiesterase , increases calcium release from intracellular stores, and antagonises GABA receptors, although these mechanisms typically occur at concentrations beyond usual human consumption. Caffeine

1530-472: A progenitor to, or to have had as one of his ministers, Chiyou (and like him, was ox -headed, sharp-horned, bronze-foreheaded, and iron-skulled). Shennong is also thought to be the father of the Huang Emperor ( 黃帝 ) who carried on the secrets of medicine, immortality, and making gold. According to the eighth century AD historian Sima Zhen 's commentary to the second century BC Shiji (or, Records of

1632-455: A reduced risk of stroke . Meta-analyses of randomized controlled trials found that green tea consumption for 3–6 months may produce small reductions (about 2–3 mm Hg each) in systolic and diastolic blood pressures . A separate systematic review and meta-analysis of randomized controlled trials found that consumption of 5–6 cups of green tea per day was associated with a small reduction in systolic blood pressure (2 mmHg), but did not lead to

1734-402: 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 a fourth harvest. The first flush in the spring brings the best-quality leaves, with higher prices to match. Green tea

1836-462: A significant difference in diastolic blood pressure. Green tea consumption lowers fasting blood sugar but in clinical studies the beverage's effect on haemoglobin A1c and fasting insulin levels was inconsistent. Drinking green tea or taking green tea supplements decreases the blood concentration of total cholesterol (about 3–7 mg/dL), LDL cholesterol (about 2 mg/dL), and does not affect

1938-454: A study on drug abuse liability published in an NIDA research monograph. Some state that research does not provide support for an underlying biochemical mechanism for caffeine addiction. Other research states it can affect the reward system. "Caffeine addiction" was added to the ICDM-9 and ICD-10. However, its addition was contested with claims that this diagnostic model of caffeine addiction

2040-745: 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. Popular Japanese green teas include: 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 ,

2142-474: A wide range of unpleasant symptoms including nervousness, irritability , restlessness, insomnia , headaches , and palpitations after caffeine use. Caffeine overdose can result in a state of central nervous system overstimulation known as caffeine intoxication, a clinically significant temporary condition that develops during, or shortly after, the consumption of caffeine. This syndrome typically occurs only after ingestion of large amounts of caffeine, well over

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2244-577: Is hepatotoxic with evidence of liver damage. A 2020 review by the Cochrane Collaboration listed some potential adverse effects of green tea extract including gastrointestinal disorders , higher levels of liver enzymes, and, more rarely, insomnia, raised blood pressure, and skin reactions. Cancer Council Australia and Cancer Research UK have stated that there is not enough reliable evidence that green tea can prevent cancer. The National Cancer Institute have noted that "the evidence regarding

2346-399: Is 99.9% water, provides 1 kcal per 100 mL serving, is devoid of significant nutrient content (table), and contains phytochemicals such as polyphenols and caffeine . Numerous claims have been made for the health benefits of green tea, but human clinical research has not found good evidence of benefit. In 2011, a panel of scientists published a report on the claims for health effects at

2448-457: Is a central nervous system (CNS) stimulant of the methylxanthine class and is the most commonly consumed psychoactive substance globally. It is mainly used for its eugeroic ( wakefulness promoter), ergogenic (physical performance enhancing), or nootropic (cognition improving) properties. Caffeine can supposedly, after a person grows used to it, have a lesser effect on wakefulness. Caffeine acts by blocking binding of adenosine at

2550-464: Is a central nervous system stimulant that may reduce fatigue and drowsiness . At normal doses, caffeine has variable effects on learning and memory , but it generally improves reaction time , wakefulness , concentration, and motor coordination . The amount of caffeine needed to produce these effects varies from person to person, depending on body size and degree of tolerance. The desired effects arise approximately one hour after consumption, and

2652-540: Is a bitter, white crystalline purine , a methylxanthine alkaloid , and is chemically related to the adenine and guanine bases of deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). It is found in the seeds, fruits, nuts, or leaves of a number of plants native to Africa, East Asia and South America and helps to protect them against herbivores and from competition by preventing the germination of nearby seeds, as well as encouraging consumption by select animals such as honey bees . The best-known source of caffeine

2754-418: Is a book on agriculture and medicinal plants, attributed to Shennong. Research suggests that it is a compilation of oral traditions, written between about 200 and 250 AD. Reliable information on the history of China before the 13th century BC can come only from archaeological evidence because China's first established written system on a durable medium, the oracle bone script , did not exist until then. Thus,

2856-823: Is associated with certain geographic localities including Shennongjia , in Hubei, where the Calamoideae ladder which he used to climb the local mountain range is supposed to have transformed into a vast forest. The Shennong Stream flows from here into the Yangtze River . Three Exalted Ones: Suiren · Fuxi · Taihao · Nüwa · Zhurong · Shennong · Yandi · Gonggong · Yellow Emperor (Huangdi) Four Perils: Gonggong · Huandou · Gun · Sanmiao · Hundun · Qiongqi · Taowu · Taotie Five Primal Emperors: Yellow Emperor (Huangdi) · Shaohao · Zhuanxu · Ku · Zhi · Yao · Shun Caffeine Caffeine

2958-478: Is associated with reduced perceived exertion. While this effect is not present during exercise-to-exhaustion exercise, performance is significantly enhanced. This is congruent with caffeine reducing perceived exertion, because exercise-to-exhaustion should end at the same point of fatigue. Caffeine also improves power output and reduces time to completion in aerobic time trials, an effect positively (but not exclusively) associated with longer duration exercise. For

3060-514: Is classified by the U.S. Food and Drug Administration (FDA) as generally recognized as safe . Toxic doses, over 10 grams per day for an adult, are much higher than the typical dose of under 500 milligrams per day. The European Food Safety Authority reported that up to 400 mg of caffeine per day (around 5.7 mg/kg of body mass per day) does not raise safety concerns for non-pregnant adults, while intakes up to 200 mg per day for pregnant and lactating women do not raise safety concerns for

3162-1123: Is considered important in green tea history. The Book of Tea ( Kissa Yōjōki , lit. Record [of] Drinking Tea [for] Nourishing Life ), written by Zen priest Eisai in 1211, 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. Steeping , or brewing, is the process of making tea from leaves and hot water, generally using 2 grams (0.071 oz) of tea per 100 millilitres (3.5 imp fl oz; 3.4 US fl oz) of water or about 1 teaspoon of green tea per 150 millilitres (5.3 imp fl oz; 5.1 US fl oz) cup. Steeping temperatures range from 61 °C (142 °F) to 87 °C (189 °F) and steeping 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 multiple times (2–3 typically). Higher-quality teas like gyokuro use more tea leaves and are steeped multiple times for short durations. Steeping too hot or too long results in

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3264-444: Is consumed. Alcohol consumption alone reduces both inhibitory and activational aspects of behavioral control. Caffeine antagonizes the effect of alcohol on the activational aspect of behavioral control, but has no effect on the inhibitory behavioral control. The Dietary Guidelines for Americans recommend avoidance of concomitant consumption of alcohol and caffeine, as taking them together may lead to increased alcohol consumption, with

3366-589: Is important to inspect tea leaves including aracha from the viewpoint of consumers' safety." In 2018, the US Food and Drug Administration updated its import status on Japanese products deemed to be contaminated by radionuclides , indicating that tea from the Ibaraki prefecture had been removed from the list by the Government of Japan in 2015. Loose leaf green tea has been the most popular form of tea in China since at least

3468-442: Is never at all appropriate; instead pigs and sheep are acceptable. Fireworks and incense may also be used, especially at the appearance of his statue on his birthday, lunar April 26, according to popular tradition. Under his various names, Shennong is the patron deity of farmers, rice traders, and practitioners of traditional Chinese medicine. Many temples and other places dedicated to his commemoration exist. As noted above, Shennong

3570-750: Is no evidence that coffee stunts a child's growth. The American Academy of Pediatrics recommends that caffeine consumption, particularly in the case of energy and sports drinks, is not appropriate for children and adolescents and should be avoided. This recommendation is based on a clinical report released by American Academy of Pediatrics in 2011 with a review of 45 publications from 1994 to 2011 and includes inputs from various stakeholders (Pediatricians, Committee on nutrition, Canadian Pediatric Society, Centers for Disease Control & Prevention , Food and Drug Administration , Sports Medicine & Fitness committee, National Federations of High School Associations). For children age 12 and under, Health Canada recommends

3672-936: Is no good evidence that green tea aids in weight loss or weight maintenance. Excessive consumption of green tea extract has been associated with hepatotoxicity and liver failure. In 2018, a scientific panel for the European Food Safety Authority reviewed the safety of green tea consumption over a low-moderate range of daily EGCG intake from 90 to 300 mg per day, and with exposure from high green tea consumption estimated to supply up to 866 mg EGCG per day. Dietary supplements containing EGCG may supply up to 1000 mg EGCG and other catechins per day. The panel concluded that EGCG and other catechins from green tea in low-moderate daily amounts are generally regarded as safe, but in some cases of excessive consumption of green tea or use of high-EGCG supplements, liver toxicity may occur. In 2013, global production of green tea

3774-574: Is no known antidote or reversal agent for caffeine intoxication. Treatment of mild caffeine intoxication is directed toward symptom relief; severe intoxication may require peritoneal dialysis , hemodialysis , or hemofiltration . Intralipid infusion therapy is indicated in cases of imminent risk of cardiac arrest in order to scavenge the free serum caffeine. Death from caffeine ingestion appears to be rare, and most commonly caused by an intentional overdose of medications. In 2016, 3702 caffeine-related exposures were reported to Poison Control Centers in

3876-541: Is not supported by evidence. The American Psychiatric Association 's DSM-5 does not include the diagnosis of a caffeine addiction but proposes criteria for the disorder for more study. Withdrawal can cause mild to clinically significant distress or impairment in daily functioning. The frequency at which this occurs is self-reported at 11%, but in lab tests only half of the people who report withdrawal actually experience it, casting doubt on many claims of dependence. and most cases of caffeine withdrawal were 13% in

3978-514: Is on the WHO Model List of Essential Medicines . It may confer a modest protective effect against some diseases, including Parkinson's disease . Some people experience sleep disruption or anxiety if they consume caffeine, but others show little disturbance. Evidence of a risk during pregnancy is equivocal; some authorities recommend that pregnant women limit caffeine to the equivalent of two cups of coffee per day or less. Caffeine can produce

4080-427: Is poor. It appears that caffeine in low doses improves airway function in people with asthma, increasing forced expiratory volume (FEV1) by 5% to 18% for up to four hours. The addition of caffeine (100–130 mg) to commonly prescribed pain relievers such as paracetamol or ibuprofen modestly improves the proportion of people who achieve pain relief . Consumption of caffeine after abdominal surgery shortens

4182-998: Is possible but the evidence is inconclusive. Caffeine may lessen the severity of acute mountain sickness if taken a few hours prior to attaining a high altitude. One meta analysis has found that caffeine consumption is associated with a reduced risk of type 2 diabetes . Regular caffeine consumption may reduce the risk of developing Parkinson's disease and may slow the progression of Parkinson's disease. Caffeine increases intraocular pressure in those with glaucoma but does not appear to affect normal individuals. The DSM-5 also includes other caffeine-induced disorders consisting of caffeine-induced anxiety disorder, caffeine-induced sleep disorder and unspecified caffeine-related disorders. The first two disorders are classified under "Anxiety Disorder" and "Sleep-Wake Disorder" because they share similar characteristics. Other disorders that present with significant distress and impairment of daily functioning that warrant clinical attention but do not meet

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4284-419: Is processed after picking 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. Processed green teas, known as aracha , are stored under low humidity refrigeration in 30- or 60-kilogram paper bags at 0–5 °C (32–41 °F). This aracha has yet to be refined at this stage, with

4386-422: 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

4488-408: Is reduced in pregnancy, especially in the third trimester, and the half-life of caffeine during pregnancy can be increased up to 15 hours (as compared to 2.5 to 4.5 hours in non-pregnant adults). Evidence regarding the effects of caffeine on pregnancy and for breastfeeding are inconclusive. There is limited primary and secondary advice for, or against, caffeine use during pregnancy and its effects on

4590-613: Is said in the Huainanzi to have tasted hundreds of herbs to test their medical value. The most well-known work attributed to Shennong is The Divine Farmer's Herb-Root Classic ( simplified Chinese : 神农本草经 ; traditional Chinese : 神農本草經 ; pinyin : Shénnóng Běncǎo Jīng ; Wade–Giles : Shen -nung Pen -ts'ao Ching ), first compiled some time during the end of the Western Han Dynasty — several thousand years after Shennong might have existed. This work lists

4692-525: Is the coffee bean , the seed of the Coffea plant. People may drink beverages containing caffeine to relieve or prevent drowsiness and to improve cognitive performance. To make these drinks, caffeine is extracted by steeping the plant product in water, a process called infusion . Caffeine-containing drinks, such as coffee , tea , and cola , are consumed globally in high volumes. In 2020, almost 10 million tonnes of coffee beans were consumed globally. Caffeine

4794-568: 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. Green tea can be blended with other ingredients. Green tea

4896-560: Is the most popular tea among the Vietnamese people . In 2011, it accounted for over 63% of overall retail volume sales. Vietnamese tea culture is ancient, but large scale cultivation was introduced in the late 19th century by French colonists who ran the first plantations in the Phú Thọ area . Though less well known than Japanese and Chinese green teas, there are various types of Vietnamese green tea and various cultivars. They have recently entered

4998-516: Is the world's most widely consumed psychoactive drug . Unlike most other psychoactive substances, caffeine remains largely unregulated and legal in nearly all parts of the world. Caffeine is also an outlier as its use is seen as socially acceptable in most cultures with it even being encouraged. Caffeine has both positive and negative health effects . It can treat and prevent the premature infant breathing disorders bronchopulmonary dysplasia of prematurity and apnea of prematurity . Caffeine citrate

5100-547: Is therefore not generally considered addictive. However, some diagnostic models, such as the ICDM-9 and ICD-10 , include a classification of caffeine addiction under a broader diagnostic model. Some state that certain users can become addicted and therefore unable to decrease use even though they know there are negative health effects. Caffeine does not appear to be a reinforcing stimulus, and some degree of aversion may actually occur, with people preferring placebo over caffeine in

5202-591: Is used for both prevention and treatment of bronchopulmonary dysplasia in premature infants. It may improve weight gain during therapy and reduce the incidence of cerebral palsy as well as reduce language and cognitive delay. On the other hand, subtle long-term side effects are possible. Caffeine is used as a primary treatment for apnea of prematurity , but not prevention. It is also used for orthostatic hypotension treatment. Some people use caffeine-containing beverages such as coffee or tea to try to treat their asthma . Evidence to support this practice

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5304-510: The Shennong-shi ( Chinese : 神農 氏 ; pinyin : Shénnóngshì ; lit. 'Shennong Clan'). In Chinese mythology , Shennong taught humans the use of the plow, aspects of basic agriculture, and the use of cannabis . Possibly influenced by the Yan Emperor mythos or the use of slash-and-burn agriculture, Shennong was a god of burning wind. He was also sometimes said to be

5406-553: The Southern Song dynasty . 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. Other processes employed in China today include oven-firing, basket-firing, tumble-drying and sun-drying. Green tea is the most widely produced form of tea in China, with 1.42 million tons grown in 2014. Popular green teas produced in China today include: Tea seeds were first brought to Japan in

5508-584: The Three Sovereigns (also known as "Three Kings" or "Three Patrons"), a group of ancient deities or deified kings of prehistoric China. Shennong has been thought to have taught the ancient Chinese not only their practices of agriculture , but also the use of herbal medicine. Shennong was credited with various inventions: these include the hoe , plow (both leisi ( 耒耜 ) style and the plowshare ), axe , digging wells , agricultural irrigation, preserving stored seeds by using boiled horse urine (to ward off

5610-669: The DSM-5, but they noted that the clinical significance of the disorder is unclear. Due to this inconclusive evidence on clinical significance, the DSM-5 classifies caffeine-use disorder as a "condition for further study". Tolerance to the effects of caffeine occurs for caffeine-induced elevations in blood pressure and the subjective feelings of nervousness. Sensitization , the process whereby effects become more prominent with use, may occur for positive effects such as feelings of alertness and wellbeing. Tolerance varies for daily, regular caffeine users and high caffeine users. High doses of caffeine (750 to 1200 mg/day spread throughout

5712-680: The Grand Historian ), Shennong is a kinsman of the Yellow Emperor and is said to be an ancestor , or a patriarch , of the ancient forebears of the Chinese. After the Zhou dynasty , Shennong was thought to have existed within it by some "ancient Chinese historians" and religious practitioners as the "deified" form of "mythical wise king" Hou Ji who founded the Zhou. As an alternative to this view, Shennong

5814-750: The International Classification of Diseases (ICD-11), cases of very high caffeine intake (e.g. > 5 g) may result in caffeine intoxication with symptoms including mania, depression, lapses in judgment, disorientation, disinhibition, delusions, hallucinations or psychosis, and rhabdomyolysis . High caffeine consumption in energy drinks (at least one liter or 320 mg of caffeine) was associated with short-term cardiovascular side effects including hypertension, prolonged QT interval , and heart palpitations. These cardiovascular side effects were not seen with smaller amounts of caffeine consumption in energy drinks (less than 200 mg). As of 2007 there

5916-615: The Korean culture itself. 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. Tea culture of Korea was actively suppressed by the Japanese during the Japanese forced occupation period (1910‒1945), and

6018-694: The United States, of which 846 required treatment at a medical facility, and 16 had a major outcome; and several caffeine-related deaths are reported in case studies. The LD 50 of caffeine in rats is 192 milligrams per kilogram of body mass. The fatal dose in humans is estimated to be 150–200 milligrams per kilogram, which is 10.5–14 grams for a typical 70 kg (150 lb) adult, equivalent to about 75–100 cups of coffee. There are cases where doses as low as 57 milligrams per kilogram have been fatal. A number of fatalities have been caused by overdoses of readily available powdered caffeine supplements, for which

6120-542: The amounts found in typical caffeinated beverages and caffeine tablets (e.g., more than 400–500 mg at a time). According to the DSM-5, caffeine intoxication may be diagnosed if five (or more) of the following symptoms develop after recent consumption of caffeine: restlessness, nervousness, excitement, insomnia, flushed face, diuresis , gastrointestinal disturbance, muscle twitching, rambling flow of thought and speech, tachycardia or cardiac arrhythmia , periods of inexhaustibility, and psychomotor agitation . According to

6222-537: The birthplace of Korean tea culture. Green tea was commonly offered to Buddha, as well as to the spirits of deceased ancestors. Tea culture continued to prosper during the Goryeo period, with the tea offering being a part of the biggest national ceremonies and tea towns were formed around temples. Seon -Buddhist manners of ceremony prevailed. During the Joseon period, however, Korean tea culture underwent secularization, along with

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6324-641: The blending order by the tasters and packed for sale. On 17 June 2011, at Charles de Gaulle airport in Paris, France, radioactive caesium of 1,038 becquerels per kilogram was measured in tea leaves imported from Shizuoka Prefecture , Japan as a result of the Fukushima Daiichi nuclear disaster on 11 March, which was more than twice the restricted amount in the European Union of 500 becquerels per kilogram. The government of France announced that they rejected

6426-629: The book popularly known in English as I Ching . Here, he is referenced as coming to power after the end of the house (or reign) of Paoxi ( Fu Xi ), also inventing a bent-wood plow, a cut-wood rake, teaching these skills to others, and establishing a noonday market. Another reference is in the Lüshi Chunqiu , mentioning some violence with regard to the rise of the Shennong house, and that their power lasted seventeen generations. The Shénnóng Běn Cǎo Jīng

6528-457: The borers), trade , commerce, money , the weekly farmers market , the Chinese calendar (especially the division into the 24 jieqi or solar terms), and to have refined the therapeutic understanding of taking pulse measurements, acupuncture , and moxibustion , and to have instituted the harvest thanksgiving ceremony ( zhaji (蜡祭) sacrificial rite, later known as the laji (腊祭) rite). "Shennong" can also be taken to refer to his people,

6630-499: The concentration of HDL cholesterol or triglycerides . A 2013 Cochrane meta-analysis of longer-term randomized controlled trials (>3 months duration) concluded that green tea consumption lowers total and LDL cholesterol concentrations in the blood. 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 ). There

6732-704: The concrete existence of even the Xia dynasty , said to be the successor to Shennong, is yet to be proven, despite efforts by Chinese archaeologists to link that dynasty with Bronze Age Erlitou archaeological sites. However, Shennong, both the individual and the clan, are very important in Chinese cultural history , especially in regards to mythology and popular culture . Indeed, Shennong figures extensively in historical literature . Model humanity: Main philosophical traditions: Ritual traditions: Devotional traditions: Salvation churches and sects : Confucian churches and sects: According to some versions of

6834-407: The criteria to be diagnosed under any specific disorders are listed under "Unspecified Caffeine-Related Disorders". Caffeine is reputed to cause a fall in energy several hours after drinking, but this is not well researched. Consumption of 1–1.5 grams (1,000–1,500 mg) per day is associated with a condition known as caffeinism . Caffeinism usually combines caffeine dependency with

6936-606: The day) have been shown to produce complete tolerance to some, but not all of the effects of caffeine. Doses as low as 100 mg/day, such as a 6 oz (170 g) cup of coffee or two to three 12 oz (340 g) servings of caffeinated soft-drink, may continue to cause sleep disruption, among other intolerances. Non-regular caffeine users have the least caffeine tolerance for sleep disruption. Some coffee drinkers develop tolerance to its undesired sleep-disrupting effects, but others apparently do not. A neuroprotective effect of caffeine against Alzheimer's disease and dementia

7038-619: The desired effects of a moderate dose usually subside after about three or four hours. Caffeine can delay or prevent sleep and improves task performance during sleep deprivation. Shift workers who use caffeine make fewer mistakes that could result from drowsiness. Caffeine in a dose dependent manner increases alertness in both fatigued and normal individuals. A systematic review and meta-analysis from 2014 found that concurrent caffeine and L -theanine use has synergistic psychoactive effects that promote alertness, attention, and task switching ; these effects are most pronounced during

7140-463: The development of traditional Chinese medicine . Legend holds that Shennong had a transparent body, and thus could see the effects of different plants and herbs on himself. He is also said to have discovered tea , which he found it to be acting as an antidote against the poisonous effects of some seventy herbs he tested on his body. Shennong first tasted it, traditionally in ca. 2437 BC, from tea leaves on burning tea twigs, after they were carried up from

7242-495: The early 9th century by the Buddhist monks Saicho and Kūkai . 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

7344-528: The elite, drink tea for its health benefits. The oldest tea-producing region in Japan is Uji , located near the former capital of Kyoto . It is thought that seeds sent by Eisai were planted in Uji, becoming the basis of the tea industry there. Today, Japan's most expensive premium teas are still grown in Uji. The largest tea-producing area today is Shizuoka Prefecture , which accounts for 40% of total Japanese sencha production. Other major tea-producing regions include

7446-437: The estimated lethal amount is less than a tablespoon. The lethal dose is lower in individuals whose ability to metabolize caffeine is impaired due to genetics or chronic liver disease. A death was reported in 2013 of a man with liver cirrhosis who overdosed on caffeinated mints. Caffeine is a substrate for CYP1A2 , and interacts with many substances through this and other mechanisms. According to DSST , alcohol causes

7548-541: The fetus or newborn. The UK Food Standards Agency has recommended that pregnant women should limit their caffeine intake, out of prudence, to less than 200 mg of caffeine a day – the equivalent of two cups of instant coffee, or one and a half to two cups of fresh coffee. The American Congress of Obstetricians and Gynecologists (ACOG) concluded in 2010 that caffeine consumption is safe up to 200 mg per day in pregnant women. For women who breastfeed, are pregnant, or may become pregnant, Health Canada recommends

7650-434: The fetus or the breast-fed infants. A cup of coffee contains 80–175 mg of caffeine, depending on what "bean" (seed) is used, how it is roasted, and how it is prepared (e.g., drip , percolation , or espresso ). Thus it requires roughly 50–100 ordinary cups of coffee to reach the toxic dose. However, pure powdered caffeine, which is available as a dietary supplement , can be lethal in tablespoon-sized amounts. Caffeine

7752-509: The fire by the hot air, landing in his cauldron of boiling water. Shennong is venerated as the Father of Chinese medicine. He is also believed to have introduced the technique of acupuncture . Shennong is said to have played a part in the creation of the guqin , together with Fuxi and the Yellow Emperor . Scholarly works mention that the paternal family of famous Song dynasty General Yue Fei traced their origins back to Shennong. Shennong

7854-801: The first hour post-dose. Caffeine is a proven ergogenic aid in humans. Caffeine improves athletic performance in aerobic (especially endurance sports ) and anaerobic conditions. Moderate doses of caffeine (around 5 mg/kg ) can improve sprint performance, cycling and running time trial performance, endurance (i.e., it delays the onset of muscle fatigue and central fatigue ), and cycling power output. Caffeine increases basal metabolic rate in adults. Caffeine ingestion prior to aerobic exercise increases fat oxidation, particularly in persons with low physical fitness. Caffeine improves muscular strength and power, and may enhance muscular endurance. Caffeine also enhances performance on anaerobic tests. Caffeine consumption before constant load exercise

7956-596: The general population of healthy adults, Health Canada advises a daily intake of no more than 400 mg. This limit was found to be safe by a 2017 systematic review on caffeine toxicology. In healthy children, moderate caffeine intake under 400 mg produces effects that are "modest and typically innocuous". As early as six months old, infants can metabolize caffeine at the same rate as that of adults. Higher doses of caffeine (>400 mg) can cause physiological, psychological and behavioral harm, particularly for children with psychiatric or cardiac conditions. There

8058-432: The high cost of labour in Japan, only the highest quality teas are plucked and processed by hand in the traditional fashion. Japanese green teas have a thin, needle-like shape and a rich, dark green colour. Unlike Chinese teas, most Japanese teas are produced by steaming rather than pan-firing. This produces their characteristic colour, and creates a sweeter, more grassy flavour. A mechanical rolling/drying process then dries

8160-494: The international market, usually at lower prices. Vietnam is fifth in the world for tea production today. There is a long tradition of growing and processing green tea in the Thái Nguyên area, north of Hanoi, which has been called the "cradle" of Vietnamese tea. This region is now known for its green tea, which is shipped internationally. There are also many scented varieties of Vietnamese green tea, most of which are scented with

8262-415: The island of Kyushu and the prefectures of Shiga , Gifu , and Saitama in central Honshu . All commercial tea produced in Japan today is green tea, 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 labour. Because of

8364-722: The leaves, which totalled 162 kilograms (357 lb). In response, the governor of Shizuoka Prefecture, Heita Kawakatsu , stated: "there is absolutely no problem when they [people] drink them because it will be diluted to about 10 becquerels per kilogram when they steep them even if the leaves have 1,000 becquerels per kilogram;" a statement backed by tests done in Shizuoka. Japanese Minister for Consumer Affairs and Food Safety Renhō stated on 3 June 2011 that "there are cases in which aracha [whole leaves of Japanese green tea] are sold as furikake [condiments sprinkled on rice] and so on and they are eaten as they are, therefore we think that it

8466-459: The maximum adult caffeine dose may not be appropriate for light-weight adolescents or for younger adolescents who are still growing. The daily dose of 2.5 mg/kg body weight would not cause adverse health effects in the majority of adolescent caffeine consumers. This is a conservative suggestion since older and heavier-weight adolescents may be able to consume adult doses of caffeine without experiencing adverse effects. The metabolism of caffeine

8568-406: 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, flavonoids and catechins have no proven biological effect in humans. Green tea leaves are initially processed by soaking in an alcohol solution, which may be further concentrated to various levels; byproducts of

8670-419: The moderate sense. Moderately physical dependence and withdrawal symptoms may occur upon abstinence, with greater than 100 mg caffeine per day, although these symptoms last no longer than a day. Some symptoms associated with psychological dependence may also occur during withdrawal. The diagnostic criteria for caffeine withdrawal require a previous prolonged daily use of caffeine. Following 24 hours of

8772-556: The myths about Shennong, he eventually died as a result of his researches into the properties of plants by experimenting upon his own body, after, in one of his tests, he ate the yellow flower of a weed that caused his intestines to rupture before he had time to swallow his antidotal tea: having thus given his life for humanity, he has since received special honor through his worship as the Medicine King ( 藥王 Yàowáng ). The sacrifice of cows or oxen to Shennong in his various manifestations

8874-499: The potential benefits of tea consumption in relation to cancer is inconclusive at present". 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. A meta-analysis of observational studies reported an increase in one cup of green tea per day was correlated with slightly lower risk of death from cardiovascular causes. Green tea consumption may be correlated with

8976-413: The pressure in various muscles, including the eyelids . Acute ingestion of caffeine in large doses (at least 250–300 mg, equivalent to the amount found in 2–3 cups of coffee or 5–8 cups of tea) results in a short-term stimulation of urine output in individuals who have been deprived of caffeine for a period of days or weeks. This increase is due to both a diuresis (increase in water excretion) and

9078-465: The process are also packaged and used. Extracts are sold over the counter in liquid, powder, capsule, and tablet forms, and may contain up to 17.4% of their total weight in caffeine, though decaffeinated versions are also available. Green tea extract is usable as a clean label food preservative , protecting fats from rancidity. The oil-soluble form used is palmitoylated green tea catechins, ruled generally recognized as safe in 2020. Regular green tea

9180-715: 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 leaves in the pot and gradually add more hot water during consumption. Polyphenols found in green tea include epigallocatechin gallate (EGCG), epicatechin gallate , epicatechins and flavanols , which are under laboratory research for their potential effects in vivo . Other components include three kinds of flavonoids , known as kaempferol , quercetin , and myricetin . Although

9282-550: The request of the European Commission : in general they found that the claims made for green tea were not supported by sufficient scientific evidence. Although green tea may enhance mental alertness due to its caffeine content, there is only weak, inconclusive evidence that regular consumption of green tea affects the risk of cancer or cardiovascular diseases , and there is no evidence that it benefits weight loss . In some cases of excessive consumption, green tea extract

9384-494: The results of observational studies, suggests that women who consume large amounts of caffeine (greater than 300 mg/day) prior to becoming pregnant may have a higher risk of experiencing pregnancy loss. Caffeine in coffee and other caffeinated drinks can affect gastrointestinal motility and gastric acid secretion. In postmenopausal women, high caffeine consumption can accelerate bone loss . Caffeine, alongside other factors such as stress and fatigue, can also increase

9486-410: The risk of congenital malformations , miscarriage or growth retardation even when consumed in moderate to high amounts. Other reviews, however, concluded that there is some evidence that higher caffeine intake by pregnant women may be associated with a higher risk of giving birth to a low birth weight baby, and may be associated with a higher risk of pregnancy loss. A systematic review, analyzing

9588-450: The risk of depression. Some textbooks state that caffeine is a mild euphoriant, while others state that it is not a euphoriant. Caffeine-induced anxiety disorder is a subclass of the DSM-5 diagnosis of substance/medication-induced anxiety disorder. Whether caffeine can result in an addictive disorder depends on how addiction is defined. Compulsive caffeine consumption under any circumstances has not been observed, and caffeine

9690-684: The rulers directly preceding the Yellow Emperor were of the house (or societal group) of Shennong. Sima Zhen , who added a prologue for the Records of the Grand Historian ( 史記 ), said his surname was Jiang ( 姜 ), and proceeded to list his successors. An older and more famous reference is in the Huainanzi ; it tells how, prior to Shennong, people were sickly, wanting, starved and diseased; but he then taught them agriculture, which he himself had researched, eating hundreds of plants — and even consuming seventy poisons in one day. Shennong also features in

9792-560: The subsequent Korean War (1950‒1953) made it even harder for the Korean tea tradition to survive. The restoration of the Korean way of tea began in the 1970s, around Dasolsa . Commercial production of green tea in South Korea only began in the 1970s,. By 2012 the industry was producing 20% as much tea as Taiwan and 3.5% as much as Japan. 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

9894-534: The tea leaves into their final shape. The liquor of steamed Japanese tea tends to be cloudy due to the higher quantity of dissolved solids. 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. Cheaper bottled teas and tea-flavoured food products usually use lower-grade Japanese-style tea produced in China. Although

9996-409: The time to recovery of normal bowel function and shortens length of hospital stay. Caffeine was formerly used as a second-line treatment for ADHD . It is considered less effective than methylphenidate or amphetamine but more so than placebo for children with ADHD. Children, adolescents, and adults with ADHD are more likely to consume caffeine, perhaps as a form of self-medication . Caffeine

10098-408: The various medicinal herbs, such as lingzhi ,and marijuana that were discovered by Shennong and given grade and rarity ratings. It is considered to be the earliest Chinese pharmacopoeia , and includes 365 medicines derived from minerals, plants, and animals. Shennong is credited with identifying hundreds of medical (and poisonous) herbs by personally testing their properties, which was crucial to

10200-518: Was 0.16 kg ( 5 + 1 ⁄ 2  oz), compared to 3.9 kg (8 lb 10 oz) coffee. Recently however, as the coffee market reached saturation point, South Korean tea production doubled during 2010‒2014, as did tea imports during 2009–2015, 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

10302-702: Was also thought of in the era of the Hundred Schools of Thought as a culture hero rather than a god, but one with a supernatural digestive system who ate a specimen of every single plant that existed in the time of the Hundred Schools to find which ones were edible by humans. In the third century BCE, during times of political crisis and expansionism and wars among Chinese kingdoms, Shennong received new myths about his status as an ideal prehistoric ruler who valued laborers and farmers and "ruled without ministers, laws or punishments." Sima Qian ( 司馬遷 ) mentioned that

10404-468: Was approximately 1.7 million tonnes , with a forecast to double in volume by 2023. As of 2015, China provided 80% of the world's green tea market, leading to its green tea exports rising by 9% annually, while exporting 325,000 tonnes in 2015. In 2015, the US was the largest importer of Chinese green tea (6,800 tonnes), an increase of 10% over 2014, and Britain imported 1,900 tonnes, 15% more than in 2014. Green tea

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