Archaeological evidence that people have consumed tea leaves steeped in boiling water since 5,000 years ago. Its botanical evidence indicates that India and China are among some of the first countries to cultivate tea. Today, tea is the beverage most widely consumed in the world, second only to water.
Hundreds of millions of people around the world tea consumption and studies suggest green tea in particular has many health benefits.
What Is Green Tea ?
There are three main variations of the tea is green tea, black and oolong. The three types are derived from the leaves of Camellia sinensis plant, originally cultivated in East Asia. This plant grows like a bush / tree and is currently growing at around Asia and some Middle East and Africa. The third difference is the type found on how to process it. Green tea is made from leaves that are not fermented, while oolong tea is made from partially fermented leaves. Black tea is derived from fermented leaves. The more fermented, the lower the polyphenol content of tea and its higher caffeine content. Green tea reportedly contains the highest concentration of powerful antioxidants called polyphenols.
Where as black tea contains a 2-3x the caffeine content than green tea. Antioxidants are substances that scavenge free radicals which are usually damaging compounds in the body that alter cells, damaging DNA (genetic material) and even cause cell death. Free radicals arise naturally, but environmental toxins (including UV rays from the sun, radiation, cigarette smoke and air pollution) can also cause its destructive particles. Many researchers believe that free radicals play a role in the aging process as well as the growing number of health problems, including cancer and liver disease. Antioxidants such as polyphenols in green tea can neutralize free radicals and reduce and even prevent the damage it causes.
This type of green tea and oolong more frequently consumed by the Asian community while black tea is more popular among the U.S. public. Healthful properties of green tea polyphenols are mostly caused by. Antioxidant effects of these chemicals are likely even greater than vitamin C. Polyphenols in green tea are also likely to give a little bitter taste. Polyphenols contained in teas are classified as catechins.
Green tea contains six primary catechin components namely: Ketekin, Galokatekin, epicatechin, epigallocatechin, epicatechin error, and epigallocatechin gallate (also known as EGCG). EGCG is a polyphenol component of the most studied and most active. Green tea also contains alkaloids, including caffeine, theobromine, and theophylline. These alkaloids provide green tea stimulant effect while L-theanine, an amino acid compound found in green tea, has been studied for its sedative effect on the nervous system.
What Green Tea For Health Benefits ?
Green tea has been consumed throughout the year in China, India, Japan and Thailand. In traditional Chinese and Indian communities, health practitioners using tea as a stimulant, diuretic (to promote the excretion / expenditure urine), astringent (to control bleeding and help heal wounds) and to improve heart health. Some use the traditional green tea include treating flatulence (gas), regulating body temperature and blood sugar, improve digestive health, and improve mental function. Further studies on human, animal or laboratory experiments expressed green tea is also useful for health conditions such as:
Based on population studies (comparing a group of people who live in the environment and different cultures and different eating patterns), in indicating that the antioxidant properties of green tea help prevent atherosclerosis, particularly coronary artery disease. Researchers estimate even by consuming 3 cups of green tea a day can lower levels of heart attack by 11%.
* High Cholesterol
Studies show that green tea lowers total cholesterol and raise HDL (good cholesterol) in humans and animals. One of the results of studies with animals have suggested that polyphenols in green tea may block the intestines absorb cholesterol and increase the excretion from the body. In a study in male smokers found that green tea significantly lowers harmful LDL cholesterol.
Several types of studies such as the ateroskerosis showed that green tea and black tea also helps protect against cancer. Clinical studies it appears that polyphenols play a role in cancer prevention and is believed to help kill cancer cells and stop its development.
* Inflammatory Bowel Disease
Green tea helps reduce the inflammation associated with Crohn's disease and ulcerative colitis, two type of inflammatory bowel disease. If green tea is proven to help prevent colon cancer, this will add benefit for patients with inflammatory bowel disease because they have a lifetime risk for developing colon cancer.
Green tea has been used traditionally to control blood sugar in the body. Animal studies that green tea can prevent the development of diabetes and slow down its development when it has emerged.
* Liver Disease
Studies such as the ateroskerosis showed that men who consumed more than 10 cups of green tea are less likely to suffer from liver disorders. This tea seems to protect the liver from the damaging effects of toxic substances such as alcohol. Animal studies show that green tea helps protect against the development of liver tumors in mice. Results from some studies suggest that one of the polyphenols in green tea, known as catechins, may help treat viral hepatitis (liver inflammation from a virus).
* Weight Loss
Clinical studies of green tea extract states can increase metabolism and help burn fat.
How Green Tea Extract Dosage Consumption Every Day ?
Recommended consumption of green tea extract standardized recommended for adults approximately 2-3 cups a day (for a total of 240-320 mg of polyphenols) or 100-750 mg per day. There is also caffeine-free green tea products are recommended. As for children, the consumption of green tea is not recommended.
Green Tea Extract Side Effects
People with liver problems, kidney failure, stomach ulcers, and psychological disorders (especially anxiety) are advised not to consume green tea. Pregnant and breastfeeding women should also avoid green tea.
People who consume excessive caffeine (including caffeine from green tea) for prolonged period of time may experience problems such as irritability, insomnia, heart palpitations, and dizziness. Excess caffeine can cause nausea, vomiting, diarrhea, headache, and loss of appetite. If you consume too much tea and began vomiting or stomach cramps, you might caffeine poisoning. If symptoms are severe, reduce caffeine intake and consult a physician.
Green Tea Extract Interactions With Drugs Specific
Some drugs that should not be consumed with green tea extracts without consulting a doctor is adenosine, beta-lactam antibiotics, benzodiazepines, beta-blockers, propranolol, and metoprolol, aspirin, chemotherapy, clozapine, ephedrine, lithium, monoamine oxidase inhibitors (MAOIs), oral contraceptives, and phenylpropanolamine.
Most green tea dietary supplements sold in the form of dried tea leaves in capsule form. Even so a standardized extract of green tea is preferred. There is also a liquid extract made from leaves and leaf buds. The average cup of green tea contain 50-150 g of polyphenols. Decaffeinated green tea products contain concentrated polyphenols. Caffeine-free supplements are also available.