Leaves from the plant Camellia sinensis have been used over the centuries to brew tea.
Black tea leaves are fermented tea leaves.
Green tea leaves are unfermented leaves.
Fermentation of tea leaves causes the oxidation of the tea's phytochemicals or renders them inactive.
Fermentation reduces the bitterness of green tea and makes it a more appealing beverage. Unfortunately it also causes black tea to lose most of the beneficial effects of the green tea leaf.
Green tea leaves are unfermented leaves and therefore retain the original library of compounds or phytohormones nature created.
Among this group are the cherished polyphenols. Polyphenols are very strong antioxidants that confer a protective effect on the body. Polyphenols are one type of flavonoid.
Many of the healing attributes of green tea are due to this antioxidant activity. In fact, most of the healing attributes of plants are linked to their antioxidant activity.
For example, the anti-atherogenic effect of green tea is due to the tea's polyphenols preventing the oxidation of LDL-cholesterol (lousy cholesterol) into the truly lousy form of cholesterol (V-LDL).
Green tea polyphenols help in preventing cancer and atherosclerosis. They also possess anti-inflammatory and antimicrobial activity.
Green tea polyphenols are also advised for weight loss since catechins produce a thermogenic effect on the body, similar to that of caffeine.
Increased core temperature helps lower body weight.
Catechins are one type of polyphenol, which is one type of flavonoid. They are classified as polyphenols because they contain ore than one phenol ring in its chemical structure.
Catechins are the most medicinally important chemicals in green tea.
Green tea polyphenols are thought to prevent cancer, atherosclerosis, delay the appearance of wrinkles and aging, promote weight loss and even prevent infection by the AIDS virus. There are of are four types of catechins in green tea. This accounts for one third by weight of the tea.
Green tea polyphenols (catechins) help prevent cancers of the gastrointestinal tract and prostate. These phytonutrients are potent inhibitors of the enzyme tyrosine kinase, the enzyme that phosphorylates proteins, which is essential for cell mitosis and growth.
This interference by is believed to be the mechanism by which green tea prevents cancers of the gastrointestinal tract..
Green tea polyphenols are also able to cross the blood-brain barrier where they can neutralize the free radicals generated in the brain. Preventing free radical damage delays senile dementia and other chronic brain diseases.
Green tea polyphenols may also prevent AIDS by its ability to bind to membrane receptors. They may also prevent cancer by inhibiting certain enzymes and preventing the formation of nitrosamines.
Catechins cross the blood-brain barrier and stimulates fat oxidation.
Green tea catechins, specifically the EGCG (epigallocatechin gallate) model are believed to raise core body temperature. This thermogenic effect is similar to the one that caffeine produces, only of a longer duration.
Increased core temperature helps lower body weight. EGCG are now being used in natural weight loss formulas. EGCG is purported to reduce food intake, lower body weight and decrease blood cholesterol and triglyceride levels and is thought to interact with the leptin-appetite pathway to repress appetite