How might tea help prevent cancer?
Tea is made from the leaf of the plant Camellia sinensis. Shortly after harvesting, tea leaves begin to wilt and oxidize. During oxidation, chemicals in the leaves are broken down by enzymes, resulting in darkening of the leaves and the well-recognized aroma of tea. This oxidation process can be stopped by heating, which inactivates the enzymes. The amount of oxidation and other aspects of processing determine a tea’s type. Black tea is produced when tea leaves are wilted, bruised, rolled, and fully oxidized. In contrast, green tea is made from unwilted leaves that are not oxidized. Oolong tea is made from wilted, bruised, and partially oxidized leaves, creating an intermediate kind of tea. White tea is made from young leaves or growth buds that have undergone minimal oxidation. Dry heat or steam can be used to stop the oxidation process, and then the leaves are dried to prepare them for sale.
Tea is composed of polyphenols, alkaloids (caffeine, theophylline, and theobromine), amino acids,carbohydrates, proteins, chlorophyll, volatile organic compounds (chemicals that readily produce vapors and contribute to the odor of tea), fluoride, aluminum, minerals, and trace elements. The polyphenols, a large group of plant chemicals that includes the catechins, are thought to be responsible for the health benefits that have traditionally been attributed to tea, especially green tea. The most active and abundant catechin in green tea is epigallocatechin-3-gallate (EGCG).
Black tea contains much lower concentrations of these catechins than green tea. The extended oxidation of black tea increases the concentrations of thearubigins and theaflavins, two types of complex polyphenols. Oolong tea contains a mixture of simple polyphenols, such as catechins, and complex polyphenols. White and green tea contain similar amounts of EGCG but different amounts of other polyphenols.
Although iced and ready-to-drink teas are becoming popular worldwide, they may not have the same polyphenol content as an equal volume of brewed tea. The polyphenol concentration of any particular tea beverage depends on the type of tea, the amount used, the brew time, and the temperature. The highest polyphenol concentration is found in brewed hot tea, less in instant preparations, and lower amounts in iced and ready-to-drink teas. As the percentage of tea solids (i.e., dried tea leaves and buds) decreases, so does the polyphenol content. Ready-to-drink teas frequently have lower levels of tea solids and lower polyphenol contents because their base ingredient may not be brewed tea. The addition of other liquids, such as juice, will further dilute the tea solids. Decaffeination reduces the catechin content of teas.
Among their many biological activities, the predominant polyphenols in green tea―EGCG, EGC, ECG, and EC―and the theaflavins and thearubigins in black teas have antioxidant activity . These chemicals, especially EGCG and ECG, have substantial free radical scavenging activity and may protect cells from DNA damage caused by reactive oxygen species . Tea polyphenols have also been shown to inhibit tumor cell proliferation and induce apoptosis in laboratory and animal studies . In other laboratory and animal studies, tea catechins have been shown to inhibit angiogenesis and tumor cell invasiveness. In addition, tea polyphenols may protect against damage caused by ultraviolet (UV) B radiation, and they maymodulate immune system function. Furthermore, green teas have been shown to activate detoxification enzymes, such as glutathione S-transferase and quinone reductase, that may help protect against tumor development. Although many of the potential beneficial effects of tea have been attributed to the strong antioxidant activity of tea polyphenols, the precise mechanism by which tea might help prevent cancer has not been established.
Tea has long been regarded as an aid to good health, and many believe it can help reduce the risk of cancer. Most studies of tea and cancer prevention have focused on green tea. Although tea and/or tea polyphenols have been found in animal studies to inhibit tumorigenesis at different organ sites, including the skin, lung, oral cavity, esophagus, stomach, small intestine, colon, liver, pancreas, and mammary gland, the results of human studies—both epidemiologic and clinical studies—have been inconclusive.
This information is provided by: The website of the National Cancer Institute (http://www.cancer.gov).
By George Orwell
Evening Standard, 12 January 1946.
If you look up ‘tea’ in the first cookery book that comes to hand you will probably find that it is unmentioned; or at most you will find a few lines of sketchy instructions which give no ruling on several of the most important points.
This is curious, not only because tea is one of the main stays of civilization in this country, as well as in Eire, Australia and New Zealand, but because the best manner of making it is the subject of violent disputes.
When I look through my own recipe for the perfect cup of tea, I find no fewer than eleven outstanding points. On perhaps two of them there would be pretty general agreement, but at least four others are acutely controversial. Here are my own eleven rules, every one of which I regard as golden:
First of all, one should use Indian or Ceylonese tea. China tea has virtues which are not to be despised nowadays — it is economical, and one can drink it without milk — but there is not much stimulation in it. One does not feel wiser, braver or more optimistic after drinking it. Anyone who has used that comforting phrase ‘a nice cup of tea’ invariably means Indian tea.
Secondly, tea should be made in small quantities — that is, in a teapot. Tea out of an urn is always tasteless, while army tea, made in a cauldron, tastes of grease and whitewash. The teapot should be made of china or earthenware. Silver or Britanniaware teapots produce inferior tea and enamel pots are worse; though curiously enough a pewter teapot (a rarity nowadays) is not so bad.
Thirdly, the pot should be warmed beforehand. This is better done by placing it on the hob than by the usual method of swilling it out with hot water.
Fourthly, the tea should be strong. For a pot holding a quart, if you are going to fill it nearly to the brim, six heaped teaspoons would be about right. In a time of rationing, this is not an idea that can be realized on every day of the week, but I maintain that one strong cup of tea is better than twenty weak ones. All true tea lovers not only like their tea strong, but like it a little stronger with each year that passes — a fact which is recognized in the extra ration issued to old-age pensioners.
Fifthly, the tea should be put straight into the pot. No strainers, muslin bags or other devices to imprison the tea. In some countries teapots are fitted with little dangling baskets under the spout to catch the stray leaves, which are supposed to be harmful. Actually one can swallow tea-leaves in considerable quantities without ill effect, and if the tea is not loose in the pot it never infuses properly.
Sixthly, one should take the teapot to the kettle and not the other way about. The water should be actually boiling at the moment of impact, which means that one should keep it on the flame while one pours. Some people add that one should only use water that has been freshly brought to the boil, but I have never noticed that it makes any difference.
Seventhly, after making the tea, one should stir it, or better, give the pot a good shake, afterwards allowing the leaves to settle.
Eighthly, one should drink out of a good breakfast cup — that is, the cylindrical type of cup, not the flat, shallow type. The breakfast cup holds more, and with the other kind one’s tea is always half cold before one has well started on it.
Ninthly, one should pour the cream off the milk before using it for tea. Milk that is too creamy always gives tea a sickly taste.
Tenthly, one should pour tea into the cup first. This is one of the most controversial points of all; indeed in every family in Britain there are probably two schools of thought on the subject. The milk-first school can bring forward some fairly strong arguments, but I maintain that my own argument is unanswerable. This is that, by putting the tea in first and stirring as one pours, one can exactly regulate the amount of milk whereas one is liable to put in too much milk if one does it the other way round.
Lastly, tea — unless one is drinking it in the Russian style — should be drunk without sugar. I know very well that I am in a minority here. But still, how can you call yourself a true tealover if you destroy the flavour of your tea by putting sugar in it? It would be equally reasonable to put in pepper or salt. Tea is meant to be bitter, just as beer is meant to be bitter. If you sweeten it, you are no longer tasting the tea, you are merely tasting the sugar; you could make a very similar drink by dissolving sugar in plain hot water.
Some people would answer that they don’t like tea in itself, that they only drink it in order to be warmed and stimulated, and they need sugar to take the taste away. To those misguided people I would say: Try drinking tea without sugar for, say, a fortnight and it is very unlikely that you will ever want to ruin your tea by sweetening it again.
These are not the only controversial points to arise in connexion with tea drinking, but they are sufficient to show how subtilized the whole business has become. There is also the mysterious social etiquette surrounding the teapot (why is it considered vulgar to drink out of your saucer, for instance?) and much might be written about the subsidiary uses of tealeaves, such as telling fortunes, predicting the arrival of visitors, feeding rabbits, healing burns and sweeping the carpet. It is worth paying attention to such details as warming the pot and using water that is really boiling, so as to make quite sure of wringing out of one’s ration the twenty good, strong cups of that two ounces, properly handled, ought to represent.
(taken from The Collected Essays, Journalism and Letters of George Orwell, Volume 3, 1943-45, Penguin ISBN, 0-14-00-3153-7)
Not that you would put salt in your teacup, but there are plenty of other ways to ruin a cup of tea. The best way to enjoy tea (especially GLF White Tea) is in its natural state. To experience the flavor and absorb the incredible health benefits, leave out the extra additives and let the leaves do their magic. Adding milk reduces the health benefits because milk proteins bind with the polyphenols. The precious antioxidant content is reduced even more with low-fat milk.
So why does anyone put milk in tea? Green and black teas have a short shelf life of 1 to 2 years. After that they lose flavor and health benefits. The tea becomes less tasty; therefore people will add milk, sugar, honey, flowers or herbs to bring it back to a state of enjoyment. Also, brewing tea too long will cause it to become bitter. Inserting some additives will cover up the bitterness. This also turns a very healthy beverage into a calorie-filled cup of potential weight gain. If a person really needs to add something, use a citrus fruit such as lemon, oranges, or grapefruit. This method will increase the polyphenol content and add some good ol’ vitamin C.
At GLF Tea USA we like our liquid kept natural. One of the benefits of white tea is the fact that as it ages it actually increases the polyphenol content, lowers the caffeine, and enriches the flavor and aroma. Why would anyone want to cover up something that Mother Nature has done such a great job of creating?
Haven’t tried the best white tea yet? Visit our GLF Tea Store and enter the code: GLFNEWS during checkout for a 10% discount on your purchase!
Re-purposing used tea leaves
In this age of “waste not, want not” we are always looking for ways to use things completely before they end up in the trash. Tea is no exception. In fact, used tea leaves have more value than many things we toss in the landfills. An extensive search of the Internet reveals thousands of blogs telling us what we can do with these seemingly worn-out jewels. Maybe there aren’t 5,000 uses, but there’s enough to squeeze out every last morsel of these life-giving by-products.
Tea is green in many ways. Besides the obvious use as the world’s second most popular drink (water being number one), tea drinkers can be the most ecologically-minded people on the planet. Let’s take a look at some of the clever ways we can re-purpose and even save money (to buy more tea, of course!) around the house.
Tea Tips from Steve Graham, Hometalk.com
Clean mirrors and windows: Tea can remove stubborn, greasy fingerprints from glass, and make it sparkle. Simply rub a damp teabag on the glass or fill a spray bottle with brewed tea.
Get rid of fishy smells: Rinse your hands with tea after eating or preparing fish (or other stinky foods) to eliminate odors.
Prevent fleas: Tea is also rumored to help prevent fleas, so sprinkle some dry used tea leaves around pet bedding.
Soothe a sunburn: Wet teabags can soothe sunburns and other minor burns. For a full-body sunburn, soak in a tea bath.
Soothe tired eyes: Warm, wet teabags can reduce puffiness and soothe pain around tired eyes – and teabags on your eyes look a little less ridiculous than cucumber slices.
Cure acne: Some acne sufferers swear by washing their faces with green tea to cure or reduce their acne.
Improve breath: Gargling with strong tea can help reduce halitosis
Add to compost: Pouring strong tea into a compost bin will help speed up the process and encourage more friendly bacteria to grow, improving the compost.
Dye fabrics: Green and black teas have long been used in dyes for fabric and paper, particularly for generating a beige faux- antique look.
Dye hair: Brewed tea also is a good natural hair dye. Mix rosemary and sage into dark black tea and let the mixture stand overnight. Strain the mix and thoroughly work it into your hair. Repeat as needed for the desired color.
Repel mosquitoes: Burning tea leaves is said to repel mosquitoes with none of the side effects of chemical bug sprays.
More Tea Tips from yayateahouse.co.nz
Use as incense: Use either a Japanese tea-leaf-burner (cha kouro) or an old skillet on the stove with low heat to roast the used leaves and get them smoking slightly. Not only does this smoke have a nice aroma, it is also very effective in absorbing and eliminating bad odors in your house.
Soothe sunburned skin: Wrap used, damp tea leaves in a cloth and press or gently rub on sunburned skin. The tannic acid in tea has a cooling effect and helps repair the skin.
Prevent rust in cast-iron kitchenware: Rub your cast-iron pans, pots or teapots (tetsubin) with used tea leaves. The antioxidants in tea react with iron and form a protective film that prevents the formation of rust.
Deodorize your refrigerator: Tea leaves are extremely efficient in absorbing odours (that’s why you should keep high quality tea in an air-tight container). Put used tea leaves in a bag and place it in your refrigerator to get rid of bad odors
Make a tea pillow: Stuff used tea leaves into a pillowcase. Granted, you’ll have to save the leaves of your tea for a little while until you have enough to fill a pillowcase, but the Chinese belief that tea-stuffed pillows soothe headaches, relieve insomnia and reduce blood pressure. The aroma of the tea leaves also acts as a natural sleep enhancer.
Searching Google for “uses for tea leaves” returns 5,460,000 results. Surely you can find 5,000 uses for those tea leaves. Now, pardon me while I do further research on dyeing gray hair.
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