green tea A beverage prepared from the leaves of an eastern Asian evergreen shrub, Camellia sinensis, which is believed to have a carcinoprotective effect greater than that of black tea (which is produced from green tea by a fermentation process)
All teas (green, black, and oolong) are derived from the same plant, Camellia sinensis. The difference is in how the plucked leaves are prepared. Green tea, unlike black and oolong tea, is not fermented, so the active constituents remain unaltered in the herb. The leaves of the tea plant are used both as a social and a medicinal beverage.
Green tea contains volatile oils, vitamins, minerals, and caffeine, but the primary constituents of interest are the polyphenols, particularly the catechin called epigallocatechin gallate (EGCG). The polyphenols are believed to be responsible for most of green tea’s roles in promoting good health.
Green tea has been shown to protect against the oxidation of cholesterol to a more toxic molecule (oxidized cholesterol).Consumption of green tea increases antioxidant activity in the blood. Oxidative damage to LDL can promote atherosclerosis.
Green tea polyphenols have been shown to stimulate the production of several immune system cells, and have topical antibacterial properties—even against the bacteria that cause dental plaque.
Compounds in green tea, as well as black tea, may reduce the risk of dental caries
The polyphenols in green tea leaves may help protect against colon cancer.
Green tea contains polyphenols that have antioxidant and anti-inflammatory activity, and studies have suggested that these polyphenols can protect skin against ultraviolet rays.
Green tea extract rich in polyphenols may support a weight-loss program by increasing energy expenditure or by inhibiting fat digestion.
A meta-analysis of several studies found that green tea consumption may improve blood glucose control and insulin sensitivity.
Green Tea for Weight loss
Green tea is a good choice for people on a weight-loss program because it can help them to lead a healthier lifestyle. For example, substituting green tea for coffee with cream and sugar not only saves calories but also supplies a lot of healthful substances, such as polyphenols and flavonoids, that can help improve one’s overall health. Green tea contains a small amount of caffeine, so it serves as a mild appetite suppressant as well.
To brew green tea
1 tsp. of green leaves tea
1 cup of boiling water
Steep for three minutes
Drink green tea 3 times per day to obtain noticeable benefits from green tea ingestion.
Green tea is generally free of side effects. The most common adverse effects reported from consuming large amounts (several cups per day) of green tea are insomnia, anxiety, and other symptoms caused by the caffeine content in the herb.