Answer: Tea, in all varieties, is one of the most consumed beverages in the world and its consumption has been associated with lower incidences of diseases such as cardiovascular disease and certain cancers. The potential health benefits of tea have been attributed in part to the antioxidant and free radical scavenging ability of its components including epigallocatechin gallate (EGCG) and other related flavanoids.
Green tea has a higher concentration of polyphenols and especially epigallocatechin gallate (EGCG) than most other teas and therefore may have greater benefits.
Research indicates that high green tea consumption may be associated with reduced levels of breast, prostate, stomach, pancreatic, colon, and lung cancers. These potential benefits are influenced by the amount and type of tea consumed. Additionally, EGCG from green tea has become a popular ingredient in weight loss supplements because of its ability to increase energy expenditure (calorie burning) and fat oxidation. But keep in mind it may not only be the tea that delivers the benefits to those who drink so much – it may be a combination of lifestyle habits that contribute to their health and weight outcomes.
The amount of green tea that may yield its purported benefits is 3 to 10 cups per day, or 270 mgs of polyphenols made up predominately of EGCG.
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Black, green, white and red tea are all made from the leaves of the same plant species, Camellia sinensis, but it’s the way the leaves are processed after harvest that determine what type of tea it will become. Depending on harvest time, soil content and depth of processing, teas contain various ranges of polyphenols, notably flavanoids, which are considered to be the constituents of tea that give the drink its purported disease-preventing effects. As mentioned above, one of the flavanoids contained in tea that’s thought to be responsible for most of its potential health benefits is the catechin epigallocatechin gallate (EGCG), and green teas appear to have the greatest concentration. In fact, one cup of green tea may supply 10-40 mgs of polyphenols and has greater antioxidant activity than a serving of broccoli, spinach, carrots or strawberries.
Potential health benefits:
It appears that GTP/EGCG has the ability to inhibit angiogenesis and to impair cell cycle progression (both actions may help ward off cancer growth). EGCG combinations have been shown to induce glutathione S-transferase and to decrease the production of reactive oxygen species (or free radicals). This demonstrates the compound’s antioxidant abilities and possible reasons for its purported cardioprotective qualities, including lower LDL cholesterol in regular tea drinkers.
Potential weight control benefits:
As mentioned above, EGCG has the ability to increase 24-hour energy expenditure and fat oxidation beyond what caffeine alone can do, while also potentially destroying fat cells (inducing apoptosis). Recent research has confirmed that green tea can cause weight loss via multiple pathways. In addition to being an appetite suppressant, green tea compounds alone have been shown to increase thermogenesis, preferentially burning fat over protein in a similar manner to many other thermogenics (e.g. caffeine, synephrine, etc.).