Drink of good health
Tea is commonly consumed as a stimulant and as a refreshing drink at different times of the day. Besides its immediate benefits, tea provides invaluable long term benefits to the human body, which are a subject of ongoing research. All four varieties of tea – black, green, white and oolong – possess remarkable disease fighting properties.
First of all it is critical to understand these different tea varieties. While all of them come from the same tea plant, the difference between these varieties lies in their processing methods.
For preparation of green tea, the leaves are withered and then steamed or pan fired, before they are rolled and dried. This tea undergoes very little oxidation. Green tea constitutes of catechins (catechin, epicatechin, epigallocatechin, epicatechin gallate, epigallocatechin gallate) in monomeric form. On the other hand, during black tea manufacturing, both withering and fermentation are carried out. As a result of the oxidation process, the monomeric catechins in green leaves are converted to the aflavins (dimeric form) and the arubigins (oligomeric form) during manufacture of black tea. Flavonoids like kaempferol, quercetin and myricetin glycosides are present in both green and black tea. During the preparation of oolong tea, the leaves are partially fermented. White tea is prepared with the least processing. Immature tea leaves are picked just before their buds open completely. The name comes from the silvery fuzz covering the buds that becomes white after drying.
Scientific research has established a strong connection between black tea consumption and health. The human body creates millions of free radicals (molecule/atom with unpaired electron in its outer orbit) on a continuous basis in order to carry out its metabolic process. They need to be checked by antioxidant enzymes in the body or antioxidants in the food that we eat. Excessive presence of free radicals disturbs this balance and causes cell damage that leads to most chronic diseases like arthritis, emphysema and bronchitis, atherosclerosis or heart disease, peptic ulcer in the stomach, type 2 diabetes, kidney problems, liver problems and also aging, which includes wrinkling of skin.
Black tea polyphenols neutralize the effect of free radicals. It also has fat burning properties that help boost body metabolism and reduce appetite. Polyphenols in black tea help in the prevention of viral, bacterial and inflammatory reactions. Dimeric and oligomeric catechins present in black tea improve insulin signaling and glucose control that is beneficial in protecting the body from damages caused by excess blood sugar after the onset of type 2 diabetes. Black tea is also a vital defense against cancer and cardiovascular diseases. It has L Theanine, which improves alpha brain wave activity, thereby aiding in relaxation and bringing down stress.
Just like black tea, green tea is also rich in antioxidant polyphenols - catechins, flavonols, the aflavins and the arubigins. The most significant departure is the catechin epigallocatechin gallate (EGCg), which is found in its highest concentration in green tea and has been found to be a powerful antioxidant. In addition, EGCg has the ability to destroy cancer cells without causing any harm to healthy tissue as well as lower LDL cholesterol and controlling the abnormal functioning of blood clots. It’s also been found to be good for bone health, oral health, weight loss and improvement in brain function.
Oolong tea shares common characteristics with both black tea and green tea due to its manufacturing process. It is more suitable for people who prefer a low caffeine option. White tea is considered to be a far greater source of antioxidants than green tea because the leaves undergo minimum processing.