Studying Tea Polyphenols and Their Protective Effects on Skin

Tea is the most consumed beverage worldwide, excluding water. Approximately 78% of the tea produced and consumed worldwide is black, 20-22% is green and less than 2% is oolong. These teas differ in their polyphenolic content due to fermentation during tea manufacturing, and green tea contains more catechins than black or oolong teas. The principal catechins, (-)-epicatechin, (-)-epicatechin-3-gallate, (-)-epigallocatechin and (-)-epigallocatechin-3-gallate, are shown to have the ability in many animal and in vitro models to protect the skin from the adverse effects of UV radiation, including lowering the risk of skin cancers. It has been suggested that tea catechins may favorably supplement sunscreen protection and be useful in skin diseases associated with solar UV radiation-induced inflammation, oxidative stress and DNA damage. Although research on green tea is very promising, future studies that take into consideration dietetic, environmental and life style factors are necessary to fully understand its contribution to human health.