Green Tea: Benefits, Properties?
PROPERTY 'TEA' GREEN
The leaves of green tea have been known for at least 4000 years as carriers of health.
Green tea is made from the leaf buds and young leaves of the plant known as "camellia sinensis." Its origins are lost in time; in China it is said that Emperor Shen Nung was the first drink of tea to 2700 BC, placing the plant's leaves in a jug of boiling water so starting this custom.
From the second century A.D. some Chinese medical texts bring the benefits obtainable from the tea, while a monaco Japan, Eisai in 1211 AD wrote a book called "maintaining health by drinking tea" where he wrote: "The tea is a miraculous medicine to maintain health, has the extraordinary power to prolong life."
In the sixteenth century, European explorers who first tried the tea claimed to have used to combat fever, headache, joint pain, and stomach pain.
Believe it or not these stories, we know that the leaves of this plant are used for at least 4000 years and have always been known as the bearers of salute.Tecnicamente, to be called tea, the product must be made from the leaves of the "camellia sinensis ", an evergreen plant of the tea. There are only three types of tea: black, oolong and green, as classified according to the method of lavorazione.Essi differ from the duration of the fermentation of the leaves:
the black one is dried and fermented, the partially fermented oolong, while the green is only washed and heated to prevent fermentazione.I various names by which is usually identified relate to the region where the plant grows (Ceylon, Darjeeling, Souchong , etc.), however, all types come from the camellia sinensis.
Green tea and cancer.
One of the most interesting developments of research in recent years has been the discovery of the extraordinary properties of anti-aging and anti-cancer properties of green tea. It was found that countries with high consumption (mainly China and Japan) have a lower percentage of cancer patients. In Japan, women who teach the tea ceremony (thus taking a lot more tea than the average), are known for their longevity; cases of cancer death in this group are very rari.Le pecentuali of breast cancer, colon, skin, pancreas, esophagus and stomach are extremely low among drinkers of green tea.
Likewise, it was noted that the Japanese smokers who consume green tea seem to enjoy protection against cancer polmone.Difatti, in the industrialized world, the Japanese have both the highest rate of smoking that the lowest lung cancer. searches in vitro and in animals have shown that it may also be effective against a wider variety of cancers, including leukemia and glioma.
This is due to the power of its components that include carotenoids, chlorophyll, polysaccharides, fats, vitamin C and E, manganese, potassium and zinc.
However, experts agree that there is a type of constituents in particular that provides the greatest benefits for health: they are the polyphenols. These are the catechins with powerful anti-oxidants. They are a subgroup of flavonoids, phytoestrogens compounds that can be found in many vegetables, fruits, tea, coffee, chocolate and wine rosso.Tutti the three types of tea polyphenols contegono; in the oxidation of green tea catechins is minimal, so as to leave unchanged the antioxidant properties, while the fermentation necessary for the production of other types of tea reduces the content of catechins losing especially those most strongly bioactive: the epigallocatechin-gallate (EGCG). the EGCG are given by experts as the most important for the prevention of cancer. They have also been shown to have an antioxidant 20 times stronger than vitamin E in protecting the brain lipids, which are very sensitive to oxidative stress (Chem Pharm Bulletin 38-1990).
Recently, a study performed at the Karolinska Institute in Stockholm, a group of researchers led by dr. Yihai Cao found that green tea can block angiogenesis-the development of new blood vessels that tumors need to grow and form metastasi.Il dr. Cao pointed out, however, that you may need a high consumption of tea for a long time to get those benefits.
Another study (University of Shizuoka, Japan) has shown that green tea can prevent the formation of metastases. Cancer cells secrete a particular enzyme to penetrate and colonize various tissues of the body. And 'the process of metastasis that is lethal, not the primary tumor. So, finding substances which prevent metastasis is paramount to defeat cancer.
This study found that EGCG inhibit the secretion of the enzyme that causes metastasis by cancer cells, thus blocking their ability to invade other similar tessuti.Risultati were presented at the conference of 38.mo 'American Society for Cell Biology in San Francisco by a group of researchers at Purdue University. Their findings showed that drinking four or more cups of green tea per day could provide enough active compounds to slow or prevent the growth of cells tumorali.Forse the most surprising result of the recent research has been the discovery that green tea may protect against skin cancer (melanoma). in one study a group of researchers has found that drinking green tea can inhibit the formation of tumors associated with exposure to sunlight UVB.In some cases with tumors already formed due to UVB, its intake slowed their growth and in some cases it has reduced the size.
In a further study, the researchers applied the components of the tea directly on the skin and then exposed it to the rays UVB.La protected skin has suffered less damage than unprotected. Some manufacturers of sunscreen have thus begun to use green tea in their prodotti.Altri studies performed mainly in Japan and the United States have proven its properties with other types of cancer, such as leukemia (inhibition of tumor cell proliferation), cancer breast, ovarian, stomach, liver, prostate, esophagus, etc.. One of these studies at the University of Shizuoka has found that green tea may work synergistically with chemotherapy drugs, increasing the effectiveness and can protect cells from damage caused by exposure to radiation.
The most recent discoveries.
The most interesting findings are directed to the treatment and prevention of rheumatoid arthritis, but perhaps the most exciting is the one that has reported a study conducted by the Cancer Chemotherapy Center in Tokyo, Japan and demonstrating that green tea goes far beyond its simple, but still strong antioxidant. If the studies are confirmed, will catapult this ancient drink of law at the center of the science of 21.mo secolo.E 'has been shown that EGCG strongly and directly inhibit telomerase. Telomerase is the enzyme that makes "immortal" cancer cells while maintaining the final part of their chromosomes (telomeres). The ability of tumor cells to maintain their telomeres in DNA, may be the secret of their "immortality." Therefore, being able to eliminate the telomeres so as to cause the death of tumor cells, it may be one of the ways to defeat this disease. The first natural inhibitor of telomerase to be discovered are precisely the tea EGCG verde.Malattie cardiovascolari.Le cardiovascular diseases are associated with different risk factors.
Surprisingly, it seems that green tea lessens many of these risks. Reduces the levels of LDL cholesterol and triglycerides. The powerful antioxidant effect of green tea inhibits the oxidation of LDL cholesterol in the arteries, the main cause in the formation of atherosclerosis. Formation of blood clots (thrombosis) is the leading cause of heart attacks and strokes, green tea has been shown to inhibit the formation of these clots as effectively as aspirin. it can also increase the levels of HDL, the good cholesterol, which helps remove plaque from the walls of atherosclerosis arterie.Pressione sanguigna.Una of the causes of high blood pressure is the loss of elasticity of the arteries. Green tea is hypotensive, lowering the pressure in the sanguigna.Zuccheri sangue.Quando assume starches with the power, the enzyme amylase is necessary to transform them into simple sugars that can be absorbed into the blood.
From studies performed: green tea polyphenols inhibit 'amylase activity by 87%; extracts of green tea reduce the normal increase in glucose and insulin when they ingest 50 grams of amidi.Alti levels of glucose and insulin in the blood predispose to diabetes and diseases cardiovascolri and are associated with accelerated aging. For many people, the sugars are the major causes of fat accumulation. An animal study showed a reduction in body fat result of integrazioini with green tea catechins.
What else can you do?
Historically, green tea has been used to correct diseases such as allergies, arteriosclerosis, asthma, cholera, colds, congestion, cough, depression, diarrhea, digestive infections, diarrhea, fatigue, headache, hepatitis, and typhoid.
Medicines produced in China with tea polyphenols are used to treat hepatitis, nephritis, and leukemia.
Green tea can kill bacteria. Taking it with food may reduce the risk of food poisoning, can eliminate oral bacteria that cause tooth decay and bad breath.
The Japanese drink green tea to prevent bad breath caused by certain foods. The effects of air fresheners its leaves are known for centuries, in fact, have traditionally been used as a deodorant.
Green tea represses several viruses, including hepatitis and, most recently at the University of Nagoya, Japan, it was shown that it can inhibit the enzyme used by HIV for its reproduction.
Excessive use can cause irritability of green tea (contains caffeine) and aggravate an ulcer.
People suffering from insomnia should avoid it, while those with high blood pressure should consume it under medical supervision.
How to prepare it properly.
In order not to destroy part of the active ingredients of green tea is recommended that the water that is poured into the cup or teapot (depending on the method chosen) is not hot, but some lower grade (about 80 ° C); leave to infuse for no more than 1.5-2 minutes.
Also valid for other beverages: do not drink hot liquids, better tiepidi.Con so many benefits for your health, it would be wise if we Italians, instead of the croissant and cappuccino, we begin to consider and appreciate this drink, a precious gift of nature.