The Impact of Polyphenols on Human Health

Polyphenols are found ubiquitously in plants and are therefore abundant in human diet. Increased polyphenol consumption has been associated with a reduced risk of development of a range of chronic diseases, such as cancer, cardiovascular and neurodegenerative disorders.Initially the antioxidant property of polyphenols was believed to underlie their beneficial effects in vivo. However, recent evidence suggest that polyphenols may express their beneficial properties through their interaction with cellular signalling pathways and related machinery that mediate cell function under both normal and pathological conditions. In thisChapter we aim to provide an overview of the different classes of polyphenols and their sources and to highlight the role that polyphenols play in the prevention of, cancer,cardiovascular disease and neurodegeneration. We present epidemiological data, human intervention study finding, as well as animal and in vitro studies in support of these actions and in each case we consider how their actions at the cellular level may underpin their physiological effects.