Why is green tea in skin care?
Significant amounts of research have established that tea, including black, green, and white tea, has many intriguing health benefits, including antiaging. Dozens of studies point to tea's potent antioxidant as well as anticarcinogenic properties. However, most of this research is on animal models or human skin fragments, which do not directly relate to effects on intact human skin. Still, research is ongoing and very promising, and topical use of green tea doesn't cause any adverse effects.
What are the benefits of green tea?
The Journal of Photochemistry and Photobiology (December 31, 2001) stated that the polyphenols "are the active ingredients in green tea and possess antioxidant, anti-inflammatory and anticarcinogenic properties. Studies conducted by our group on human skin have demonstrated that green tea polyphenols (GTP) prevent ultraviolet (UV)-B…-induced immune suppression and skin cancer induction." Green tea and the other teas (e.g., white tea, which is what green tea begins as) show a good deal of promise for skin, but they are not the miracle that cosmetics and health food companies make them out to be. As the Annual Review of Pharmacology and Toxicology (January 2002, pages 25–54) put it, "Tea has received a great deal of attention because tea polyphenols are strong antioxidants, and tea preparations have inhibitory activity against tumorigenesis. The bioavailability and biotransformation of tea polyphenols, however, are key factors limiting these activities in vivo [in humans]. Epidemiological studies … have not yielded clear conclusions concerning the protective effects of tea consumption against cancer formation in humans."
What about green tea for anti-aging benefits?
Most researchers agree that tea (black, green, or white) has potent anti-inflammatory properties and that it is a potent antioxidant whether consumed orally or applied topically. Current research also indicates that epigallocatechin-3-gallate (EGCG), an extract of tea, can prevent collagen breakdown and reduce UV damage to skin, which is a very good reason to use skin-care products that contain one or more forms of tea (Sources: Cosmetic Dermatology, October 2010, pages 446-449; Archives of Dermatological Research, March 2010, pages 71–83; Skin Pharmacology and Physiology, September 2009, pages 299–304; Skin Research and Technology, August 2009, pages 338–345; Dermatologic Surgery, July 2009, pages 1,057–1,065; Experimental Dermatology, June 2009, pages 522–526; Food and Chemical Toxicology, April 2008, pages 1,298–1,307; Photodermatology, Photoimmunology, and Photomedicine, February 2007, pages 48–56; Journal of Dermatological Science, December 2005, pages 195–204; and Skin Pharmacology and Applied Skin Physiology, 2001, pages 69–76).