Green Tea has a beneficial effect on human health by reducing the risk of heart and blood vessels, reducing the risk of cancer, has anti-inflammatory properties, and is used as a stimulant as it contains caffeine. It was used even in Ancient China for medical purposes to treat headaches and depression.
Legend says that the Chinese Emperor Shen Nung, around 2750th BC, while resting of the hard hunting cooked up water from the stream accidentally has fallen a few leaves of evergreen tree that is relative to magnolia, which today we call tea. Pleasant odor reached up to his nostrils and the Emperor could not resist trying the potion.
This bushy tree is planted in large tea gardens at altitudes of 100-2000 meters, and depending on the chemical treatment process, we differ three basic types of tea derived from this plant: green tea, oolong and black tea.
The leaves of black tea are fully fermented, while the leaves of green tea is processed under steam and is fried in pan wherewith is preventing oxidation changes in the leaves. In this way, green tea sustains its color and there is no loss of enzymes and other favorable ingredients.
Green tea is rich with vitamin B, ascorbic acid, essential oil, proteins, chlorophyll, organic acids, and amino acids (the most notable is theanine), and most important is the alkaloid caffeine that gives stimulating effect, and slight amount of other xanthine alkaloids (theophylline, theobromine, dimethylxanthine, xanthines and adenine). Caffeine is present in an amount of 1-5%.
It also contains six primary polyphenols, phytochemicals with antioxidant properties that gives a distinctive, slightly bitter taste, of which the most important are catechins. The most active and most studied catechin from green tea is EGCG (epigallocatechin-3-gallate), which can neutralize the protein in sperm that serves as a vector for the transmission of the virus during sexual intercourse.
A study from the 2009 has shown that consumption of green tea in combination with ascorbic acid (vitamin C) dramatically increases the absorption and the activity of antioxidants from green tea during digestion.
A cup of tea contains about 50-100 mg of caffeine and 300-400 mg of polyphenols.
As an important junction, theanine affects the increase of dopamine which affects the emotions in the brain, which increase is perceived as pleasure.
What are the health benefits of green tea
For the antioxidant effect of green tea are responsible caffeine and polyphenols, that influence on enzyme activity and detoxification processes in the small intestine, liver and lungs and prevent the action of the enzyme urokinase, which feeds cancer cells in the body.
In addition, catechin, as an important ingredient of green tea, reduces the absorption of cholesterol in the digestive system. Also helps with Crohn’s disease and strengthens the immune system of the entire body.
It is also associated with a faster metabolism and fast fat burning, and is mentioned its strongest protection against developing cancer of digestive system.
Because of its antibacterial action, it helps in preventing cavities, and tooth decay.
The recommended daily intake of green tea is 1200 milliliters (5-6 cups). The only negative effect of green tea can be a large amount of caffeine, but if it’s consumed in the recommended amount is not the case.
Green Tea or Coffee?
When the caffeine was first discovered in tea, they called it theine, but since there is no difference between theine and caffeine, in use caffeine remains the only term.
Caffeine (chemical name: 1, 3, 7 trimethylxanthine) is an alkaloid discovered in the 19th century with bitter taste and no odor. It’s a source of antioxidants, shows diuretic properties, accelerates the metabolism and affects as a mild laxative.
Green Tea contains 30% less caffeine than coffee, but caffeine in tea does not have adverse effects on the heart and circulatory system, but increases blood flow in the brain. Degradation of caffeine in coffee is already done in the stomach, while caffeine from green tea mainly degrades intestinal juice.
Caffeine from coffee arrives rapidly into the bloodstream and works after 5 to 10 minutes and disappears for 30 minutes, while the process of tea is flowing peacefully and the action of caffeine is biggest after 40 minutes, and disappears after 70 minutes.
How to prepare green tea
It is important to point out that green tea should not be prepared with boiling water (100 °C), but with water with temperature of 70°C (some species with 90 °C) and should not be hold in hot water more than 3 minutes. In this way we take the best from the green tea.