Nutrition Expert- Sana Shaikh, Dietitian at healthine clinic, Mumbai
Tea is one of the most popular beverages consumed worldwide. Tea, from the plant Camellia sinensis, is consumed in different parts of the world as green, black, or Oolong tea. Among all of these, however, the most significant effects on human health have been observed with the consumption of green tea.
To produce green tea, freshly harvested leaves are immediately steamed to prevent fermentation, yielding a dry, stable product. This steaming process destroys the enzymes responsible for breaking down the color pigments in the leaves and allows the tea to maintain its green color during the subsequent rolling and drying processes. These processes preserve natural polyphenols with respect to the health-promoting properties.
The major flavonoids of green tea are various catechins, which are found in greater amounts in green tea than in black or Oolong tea. There are four kinds of catechins mainly find in green tea: epicatechin, epigallocatechin, epicatechin-3-gallate, and EGCG
Health benefits of green tea
Studies have shown that green tea catechins provide some protection against degenerative diseases. Some studies indicated that green tea has an anti-proliferative activity on hepatoma cells and a hypolipidemic activity in hepatoma, as well as the prevention of hepatoxicity and as a preventive agent against mammary cancer post-initiation . Green tea catechins could also act as anti-tumorigenic agents and as immune modulators in immunodysfunction caused by transplanted tumors or by carcinogen treatment. Moreover, green tea, its extract, and its isolated constituents were also found to be effective in preventing oxidative stress and neurological problems.
Green tea consumption has also been linked to the prevention of many types of cancer, including lung, colon, esophagus, mouth, stomach, small intestine, kidney, pancreas, and mammary glands . Several epidemiological studies and clinical trials showed that green tea (and black and Oolong teas to a lesser extent) may reduce the risk of many chronic diseases. This beneficial effect has been attributed to the presence of high amounts of polyphenols, which are potent antioxidants.
Green tea extract (GTE) has many naturally occurring biological components of which polyphenolic epicatechins (ECs) are predominantly active.
Epigallocatechin gallate (EGCG), the most abundant form of catechin in green tea, has been known to be the main attributable factor of beneficial effects of green tea.
In particular, green tea catechins are involved in many biological activities such as antioxidation and modulation of various cellular lipid and proteins. Thus, they are beneficial against degenerative diseases, including obesity, cancer, cardiovascular diseases, and various inflammatory diseases.
Tip: Consume one cup of green tea everyday