Public Informations about Tea
Tea is the second most-consumed beverage in the world, after water. All tea comes from the Camellia sinensis plant, but different ways of harvesting and processing produce different teas. To make black tea, the leaves are wilted, bruised, rolled, and fully oxidized. Black tea accounts for 75 percent of the tea consumed in the world. Oxidization happens when the leaves are exposed to the air for long periods. Enzymes break down the chemicals in the leaves, producing their brown coloring and familiar smell. Green tea, in contrast, is made from leaves that are not oxidized. Oxidization may give black tea nutritional benefits that are not present in green tea, such as reducing the risk of several cancers, protecting the heart against atherosclerosis, and maintaining a healthy blood pressure.
Nutritional breakdown of black tea
According to the National Cancer Institute, tea contains: • alkaloids (caffeine, theophylline, and theobromine) • amino acids • carbohydrates • proteins • chlorophyll • fluoride • aluminum • minerals and trace elements • volatile organic compounds, which contribute to its odor and taste Black tea also contains polyphenols, chemical compounds that protect plants from ultraviolet radiation or harmful, disease-causing pathogens. Flavonoids are a kind of polyphenol. The benefits of red wine are thought to be related to flavonoids. When consumed by humans, these polyphenols have an antioxidant effect. Antioxidants can counter the activity of free radical cells. Free radicals can harm health and damage, change, and even kill cells in the body. Free radicals contribute to the development of many diseases and conditions, such as atherosclerosis and some cancers.
Possible health benefits of tea
Most studies on the potential health benefits of tea have focused on green tea. However, taking into account the oxidization process involved in making black tea, some studies have investigated the unique benefits that this may provide. Few studies on black tea are conclusive, as the tests have involved giving animals larger dosesthan would normally be consumed in an average human diet. Food and drink companies may overemphasize the health benefits of antioxidants to support sales.
Atherosclerosis is a buildup of plaque in the walls of any artery in the body. It can lead to coronary heart disease and chronic kidney disease. Free radicals heavily contribute to this condition. A 2004 study on hamsters by researchers at the University of Maryland linked the antioxidants available in green and black tea to combatting the free radicals that cause atherosclerosis. Three cups of black tea per day were estimated to reduce the risk of atherosclerosis by 11 percent. A review published in the European Journal of Clinical Nutrition suggests that drinking 3 or more cups of tea a day might offer protection against coronary heart disease.
Decreasing cancer risk
Findings cited by the National Cancer Institute suggest that the polyphenols in tea may decrease tumor growth. Laboratory tests and animal studies suggest they may protect against damage caused by ultraviolet B (UVB) radiation. Black tea has been linked to cancer in a similar way to green tea, although it affects fewer types of cancer. Studies have also indicated that black tea may have a positive impact on bladder, lung, and prostate cancer. As is the case in many studies related to tea and cancer, the results are inconclusive. Black tea has also been shown to stimulate genes that reduce the sensitivity to chemotherapytreatment in the cell. This suggests that back tea could weaken the effect of cancer treatment. Separate studies have found conflicting outcomes as far as black tea and cancer are concerned, noting that black tea both increased and decreased the risk of lung cancer in differing studies. Researchers have not been able to explain how antioxidants and cancer cells interact to reduce the risk of cancer development. However, one team concluded that drinking six cups of tea a day could enhance antioxidant status.
Reducing blood pressure
In a study carried out by the University of Western Australia in 2012, black tea was shown to reduce diastolic and systolic blood pressure. It also canceled out the impact on blood pressure of a high-fat meal. However, a global manufacturer of edible goods, including teas, funded this study. As the backing of the research is not impartial, readers are advised to approach such studies with caution.
Ways of consuming tea
More research is needed to confirm its active health benefits, but black tea remains a more healthful alternative to many products when seeking a daily caffeine boost. Caffeine is a stimulant that can boost focus and energy throughout the day. People can consume more black tea without affecting health than some caffeine-laden beverages. It has a low calorie count, and it can be used to add flavor to dishes without adding sugar or salt to the diet. Tips for using tea Here are 4 tips to incorporate black tea into solid meals. Tip 1: Use tea instead of soup stock Black tea can add a smoky flavor to soups with red meat or mushrooms. Tip 2: Add tea to poaching liquids Poaching food in black tea infuses the aroma into the protein of the food. Mushrooms poached in lapsang souchong black tea can be a particularly flavorsome option. Tip 3: Cook beans and grains with tea Swapping water for tea when cooking rice or beans adds a smoky nuance to their flavor. Tip 4: Tea works as part of a dessert The distinctive flavor of tea can be infused into warmed, whole-fat milk and added to puddings or custards. Infusing Earl Grey black tea into chocolate custards, for example, can give great results.
Green tea: Health benefits, side effects, and research
Toxic elements Black tea contains some minerals that are poisonous in high doses. Avoid brewing for over three minutes. All brewed tea contains minerals that, in excess, can be poisonous. Lead and aluminum are present in tea. These heavy metals, in large doses, can be toxic to humans. Minor traces of arsenic and cadmium can be found in some teas, but not in harmful quantities. Black tea has particularly high levels of manganese, which is toxic in excess. The longer tea is left to brew, the higher the concentration of these toxic elements, so it is advisable only to brew tea for a maximum of 3 minutes. Depending on where and how the tea is grown, there may also be traces of pesticides in the leaves, so moderate consumption is advised. A maximum of 10 cups per day is recommended. Effects of caffeine Black tea contains 2 to 4 percent caffeine. People who are particularly sensitive to caffeine could experience insomnia, anxiety, irritability, or an upset stomach when consuming tea in large quantities. Excessive caffeine intake may also lead to to: • cardiac arrhythmia, or an irregular heartbeat • diarrhea and irritable bowel syndrome • eye pressure, and possible glaucoma • affected blood sugar, and potential diabetes • increased blood pressure • increased dumping of calcium in the urine, and therefore weakened bones and possible osteoporosis Regular tea drinkers who experience any of the above symptoms should consider reducing their tea consumption. If symptoms continue, they should see a doctor. Anemia Tea has been found to decrease the bioavailability of iron when taken with meals. This means that it reduces the body's ability to absorb iron. People with a history of iron deficiency should take care to not consume tea when taking iron supplements or an iron-rich meal. They should also leave an hour between eating and drinking black tea. Interactions with drugs and supplements Black tea has been known to interact with a range of different medications and supplements. These include: • MAO inhibitors, used to treat depression • stimulants such as Ritalin • drugs to prevent arrhythmias, insomnia, heartburn, ulcers, or anxiety • folic acid Tea might increase blood pressure and heart rate if consumed with other stimulants, and it may reduce absorption of folic acid. Iced teas and ready-to-drink teas may not be as healthful as plain black tea, as the composition is different. Adding sugar to tea also reduces the health benefits. Always speak to a physician if black tea is a part of your diet and you are taking ongoing medications.
Green tea: Health benefits, side effects, and research
Green tea, native to China and India, has been consumed and hailed for its health benefits for centuries globally, but has only recently gained popularity in the United States. Tea is the most consumed beverage in the world behind water. However, 78 percent of the tea consumed worldwide is black and only about 20 percent is green. All types of tea, except herbal tea, are brewed from the dried leaves of the Camellia sinensis bush. The level of oxidation of the leaves determines the type of tea. Green tea is made from unoxidized leaves and is one of the less processed types of tea (with white tea the least) and therefore contains the most antioxidants and beneficial polyphenols.
Fast facts on green tea
Here are some key points about green tea. More detail and supporting information is in the main article. • green tea has been used in traditional Indian and Chinese medicine • there are many different types of green tea available • green tea may help prevent a range of ailments including cancer • more research is needed to prove many of the health claims surrounding green tea
Green tea health benefits
Listed below are the possible health benefits associated with green tea. Green tea was used in traditional Chinese and Indian medicine to control bleeding and heal wounds, aid digestion, improve heart and mental health, and regulate body temperature. Recent studies have shown green tea can potentially have positive effects on everything from weight loss to liver disorders, type 2 diabetes, and Alzheimer's disease. It is important to note that more evidence is required before these possible health benefit links are proved definitive.
Green tea and cancer prevention
According to the National Cancer Institute, the polyphenols in tea have been shown to decrease tumor growth in laboratory and animal studies and may protect against damage caused by ultraviolet UVB radiation. In countries where green tea consumption is high, cancer rates tend to be lower, but it is impossible to know for sure whether it is the green tea that prevents cancer in these particular populations or other lifestyle factors. Some studies have also shown the positive impacts of green tea on the following types of cancer: • breast • bladder • ovarian • colorectal (bowel) • esophageal (throat) • lung • prostate • skin • stomach Researchers believe that it is the high level of polyphenols in tea that helps kill cancerous cells and stop them from growing. However, the exact mechanisms by which tea interacts with cancerous cells is unknown. However, other studies have not found that tea can reduce cancer risk. The amount of tea required for cancer-preventive effects also varies widely in studies - from 2-10 cups per day. In 2005, the Food and Drug Administration (FDA) stated, "there is no credible evidence to support qualified health claims for green tea consumption and a reduced risk of gastric, lung, colon/rectal, esophageal, pancreatic, ovarian, and combined cancers."
2) Green tea heart benefits
A 2006 study published in the Journal of the American Medical Association concluded that green tea consumption is associated with reduced mortality due to all causes, including cardiovascular disease. The study followed over 40,000 Japanese participants between the ages of 40 and 79 for 11 years, starting in 1994. The participants who drank at least 5 cups of green tea per day had a significantly lower risk of dying (especially from cardiovascular disease) than those who drank less than one cup of tea per day. Green tea contains catechins, polyphenolic compounds that are thought to exert numerous protective effects, particularly on the cardiovascular system.
3) Green tea and lower cholesterol
An analysis of published studies in 2011 found that consuming green tea, either as a beverage or in capsule form, was linked to significant but modest reductions in total and LDL or "bad" cholesterol.
4) Stroke risk and green tea
Drinking green tea or coffee on a regular basis is associated with a reduced risk of stroke, according to a study published in the journal Stroke: Journal of the American Heart Association. The lead author of the study, Dr. Yoshihiro Kokubo, Ph.D., said, "This is the first large-scale study to examine the combined effects of both green tea and coffee on stroke risks. You may make a small but positive lifestyle change to help lower the risk of stroke by adding daily green tea to your diet."
5) Green tea for type 2 diabetes
Studies concerning the relationship between green tea and diabetes have been inconsistent. Some have shown a lower risk of developing type 2 diabetes for green tea drinkers than for those who consumed no tea, while other studies have found no association between tea consumption and diabetes at all.
6) Green tea and weight loss
Green tea may promote a small, non-significant weight loss in overweight and obese adults; however, since weight loss in the studies was so minimal, it is unlikely that green tea is clinically important for weight loss.
7) Green tea and inflammatory skin diseases
A 2007 study concluded that green tea could hold promise as a new treatment for skin disorderssuch as psoriasis and dandruff. Researchers studied an animal model for inflammatory skin diseases, often characterized by patches of dry, red, flaky skin caused by the inflammation and overproduction of skin cells. Those treated with green tea showed slower growth of skin cells and the presence of a gene that regulates the cells' life cycles.
8) Working memory and the effects of green tea
Research published in the journal Psychopharmacology suggests that green tea can enhance our brain's cognitive functions, particularly the working memory. The research team said their findings suggest that green tea could be promising in the treatment of cognitive impairments associated with neuropsychiatric disorders, such as dementia.
9) Green tea and Alzheimer's
In a study published in 2011, researchers tested the effect of a component of green tea, CAGTE (or "colon available" green tea extract), after it had been digested, to see how it affected a key protein in Alzheimer's disease. The Alzheimer's Society commented that "this study adds to previous research that suggests green tea might help to reduce the risk of Alzheimer's disease. However, the researchers used a far higher dose of the active green tea chemical than would ever be found in the human body. More research is needed to see whether green tea is protective at a much lower dose, and to understand the mechanism involved." Other studies have found that green tea might be helpful in preventing dental cavities, stress, chronic fatigue, treating skin conditions, and improving arthritis by reducing inflammation. Further research is needed to firm up these theories.
Nutritional breakdown of green tea
Unsweetened brewed green tea is a zero calorie beverage. The caffeine contained in a cup of tea can vary according to the length of infusing time and the amount of tea infused. In general, green tea contains a relatively small amount of caffeine (approximately 20-45 milligrams per 8 ounce cup), compared with black tea, which contains about 50 milligrams and coffee with 95 milligrams per cup. Green tea is considered one of the world's healthiest drinks and contains one of the highest amounts of antioxidants of any tea. Natural chemicals called polyphenols in tea are what are thought to provide its anti-inflammatory and anti-carcinogenic effects. Green tea is approximately 20-45 percent polyphenols by weight, of which 60-80 percent are catechins such as EGCG. Catechins are antioxidants that are said to help prevent cell damage.
Types of green tea
Green tea is available in many types, including: • bottled and sweetened with sugar or an artificial sweetener • in single tea bags • as loose-leaf • in instant-powder • green tea supplements, which are sold in capsule form or liquid extracts According to 2010 research presented at the American Chemical Society, bottled teas are not equivalent to brewed teas as some 16 ounce bottled teas can contain fewer polyphenols than one cup of brewed tea.
Green tea side effects and risks
There are little to no known side effects or contraindications to drinking green tea for adults. However, the following risks or complications should be made clear: • Caffeine sensitivity - those with severe caffeine sensitivities could experience insomnia, anxiety, irritability, nausea, or upset stomach. • Blood thinners - those taking blood thinners (anticoagulant drugs) such as Coumadin/warfarin should drink green tea with caution due to its vitamin K content. It's also recommended to avoid green tea and aspirin, because they both reduce the clotting effectiveness of platelets. • Other stimulants - if taken with stimulant drugs, green tea could increase blood pressure and heart rate. Green tea supplements contain high levels of active substances that can trigger side effects and interact with other herbs, supplements, or medications. Green tea supplements are unregulated by the FDA and may also contain other substances unsafe for health or with unproven health benefits. Always check with a doctor before starting any herb or supplement regimen. In particular, pregnant or breastfeeding women, those with heart problems or high blood pressure, kidney or liver problems, stomach ulcers, or anxiety disorders should not take green tea supplements or extracts.
Whole leaf grades
The grades for whole leaf orthodox black tea are: Ceylon orange pekoe (OP) grades • OP—Orange Pekoe: main grade, consisting of long wiry leaf without tips • OP1—more delicate than OP; long, wiry leaf with the light liquor • OPA—bolder than OP; long leaf tea which ranges from tightly wound to almost open • OPS—Orange Pekoe Superior: primarily from Indonesia, similar to OP • FOP—Flowery Orange Pekoe: high-quality tea with a long leaf and few tips, considered the second grade in Assam, Dooars, and Bangladesh teas, but the first grade in China • FOP1: limited to only the highest quality leaves in the FOP classification • GFOP—Golden Flowery Orange Pekoe: higher proportion of tip than FOP. Top grade in Milima and Marinyn regions, uncommon in Assam and Darjeeling • TGFOP—Tippy Golden Flowery Orange Pekoe: the highest proportion of tip, main grade in Darjeeling and Assam • TGFOP1—limited to only the highest quality leaves in the TGFOP classification • FTGFOP[a]—Finest Tippy Golden Flowery Orange Pekoe: highest quality grade • FTGFOP1 or STGFOP or SFTGFOP—limited to only the highest quality leaves in the FTGFOP classification
Broken leaf grades
• BT—Broken Tea: Usually a black, open, fleshy leaf that is very bulky. Classification used in Sumatra, Ceylon(Sri Lanka), and some parts of Southern India. • BP—Broken Pekoe: Most common broken pekoe grade. From Indonesia, Ceylon(Sri Lanka), Assam and Southern India. • BPS—Broken Pekoe Souchong: Term for broken pekoe in Assam and Darjeeling. • FP—Flowery Pekoe: High-quality pekoe. Usually coarser with a fleshier, broken leaf. Produced in Ceylon(Sri Lanka) and Southern India, as well as in some parts of Kenya. • BOP—Broken Orange Pekoe: Main broken grade. Prevalent in Assam, Ceylon(Sri Lanka), Southern India, Java, and China. • F BOP—Flowery Broken Orange Pekoe: Coarser and broken with some tips. From Assam, Ceylon(Sri Lanka), Indonesia, China, and Bangladesh. In South America coarser, black broken. • F BOP F—Finest Broken Orange Pekoe Flowery: The finest broken orange pekoe. Higher proportion of tips. Mainly from Ceylon's "low districts". • G BOP—Golden Broken Orange Pekoe: Second grade tea with uneven leaves and few tips. • GF BOP1—Golden Flowery Broken Orange Pekoe 1: As above, but with only the highest quality leaves in the GFBOP classification. • TGF BOP1—Tippy Golden Flowery Broken Orange Pekoe 1: High-quality leaves with a high proportion of tips. Finest broken First Grade Leaves in Darjeeling and some parts of Assam.
• PF—Pekoe Fannings • OF—Orange Fannings: From Northern India and some parts of Africa and South America. • FOF—Flowery Orange Fannings: Common in Assam, Dooars, and Bangladesh. Some leaf sizes come close to the smaller broken grades. • GFOF—Golden Flowery Orange Fannings: Finest grade in Darjeeling for tea bag production. • TGFOF—Tippy Golden Flowery Orange Fannings. • BOPF—Broken Orange Pekoe Fannings: Main grade in Sri Lanka, Indonesia, Southern India, Kenya, Mozambique, Bangladesh, and China. Black-leaf tea with few added ingredients, uniform particle size, and no tips.
• D1—Dust 1: From Sri Lanka, Indonesia, China, Africa, South America, and Southern India. • PD—Pekoe Dust • PD1—Pekoe Dust 1: Mainly produced in India.
|BPS||Broken Pekoe Souchohg|
|BOP||Broken Orange Pekoe|
|BP1||Broken Pekoe One|
|FOP||Flowery Orange Pekoe|
|FOP1||Flowery Orange Pekoe One|
|TGFOP||Tippy Golden Flowery Orange Pekoe|
|GFOP||Golden Flowery Orange Pekoe|
|TGFBOP||Tippy Golden Flowery Broken Orange Pekoe|
|GBOP||Golden Broken Orange Pekoe|
|FBOPF||Flowery Broken Orange Pekoe Fannings|
|FBOP||Flowery Broken Orange Pekoe|
|BOP1||Broken Orange Pekoe One|
|BOPF||Broken Orange Pekoe Fannings|