The Importance of Polyphenols as Functional Food in Health

Polyphenols which are produced by plants are very important functional foods in our nutrition. Because of their diverse chemical structures, they are subject to main classification among them. The main groups of polyphenols are; flavanoids, lignans, stilbenes and phenolic acids. At the present time, the health effects of them have been investigated in several in vivo and in vitro studies. In addition to their antioxidant effects, they are known to have a pro-oxidant character. Polyphenols have important effects in protecting the body against external factors and the cleansing of reactive oxygen species which occur as a consequence of some diseases. Furthermore, polyphenols have effects on protection from specific diseases and stop their progression with certain mechanisms. In this review, various effects of polyphenols including antioxidant, pro-oxidant, cytotoxic, anti-inflammatory, antihypertensive, anti-diabetic are discussed which obtained from in vitro, in vivo experimental animal and clinical investigations.