Tea is an old herbal drink known for its stimulating qualities, mainly due to caffeine. The medicinal properties of tea are attributed to flavonoid phytochemicals called polyphenols. The polyphenols present in tea belong mainly to a subtype called catechins.
Green tea contains more catechins than black tea (about 25% versus 4%), mainly because of differences in harvesting and processing. Black tea leaves are fermented, resulting in the oxidation of a larger number of catechins. The green tea leaves are steamed, so they retain up to 30% of their dry weight in catechins.
The main catechin in green tea is epigallocatechin gallate or EGCG. A cup of this tea, properly brewed, contains 20 to 35 mg of EGCG. The EGCG is 100 times more potent than vitamin C and 25 times more potent than vitamin E. Antioxidants slow down the signs of aging from the outside and provide nutrients beneficial to general health when & # 39; They are taken internally.
Research suggests that EGCG can inhibit skin cancer because of its protective properties. Studies in animals and humans have credibly demonstrated that topical formulations of polyphenol reduce skin damage. The EGCG appears to exert protection against sunlight by quenching free radicals and reducing inflammation rather than blocking UV rays. Therefore, EGCG can synergistically enhance sun protection when it is used in addition to sunscreen. It is best to combine green tea with zinc oxide sunscreens because zinc oxide is chemically inert and should not react with it, especially in the sun.
Given their well-documented antioxidant and anti-inflammatory activities, topical polyphenols may slow the development of some signs of aging. As you get older, the skin loses its firmness and elasticity. This is partly due to the action of free radicals, or unstable molecules, that damage skin proteins. The cells then divide and die much faster and, if they are not removed, accumulate and turn into wrinkles. In fact, green tea slows the effect of free radical oxidation and inhibits this cell division, making the skin smoother.
Polyphenols also promote the formation of collagen, which helps the skin to stay firm and elastic. In a 2005 study, 40 women with moderate aging photo were randomly selected to use a regimen of 10% green tea cream and 300 mg twice daily oral green tea supplementation, or placebo for 8 weeks. The histological classification of skin biopsies showed a significant improvement in the elastic tissue content of the treated samples compared to the placebo groups.
Just applying a green tea cream may or may not bring the benefits you expect. Like most other antioxidants, polyphenols are oxidized and lose their activity when exposed to air. It is unclear whether commercial creams retain their antioxidant activity and vary from product to product.
Drinking three to five cups of green tea a day or taking 100 to 150 mg of standardized extract (which should contain 80% of total polyphenols and 50% of EGCG) three times a day can provide your skin with enough of polyphenols through the blood to slow aging skin.
