The chemical structure of polyphenols consisting of aromatic rings, capable of 
quenching free radicals, makes them ideal candidates to protect against 
oxidation. Polyphenols are present in a variety of foods including grapes, 
berries, dark chocolate, coffee and tea to mention a few. A number of studies 
have shown that dietary polyphenols exert a protective effect against 
hypertension, dyslipidemias, inflammation, endothelial function and 
atherosclerosis, conditions associated with increased risk for cardiovascular 
disease. Studies indicate that by decreasing cholesterol absorption, polyphenols 
alter hepatic cholesterol homeostasis resulting in decreases in plasma lipids 
and reduction in atherogenic lipoproteins thus having a protective effect 
against atherosclerosis; polyphenols have also been shown to decrease the 
activity of enzymes involved in the renin-angiotensinaldosterone system and 
improve blood pressure. Further, they have been recognized to increase nitric 
oxide production and to improve endothelial function. In this review we will 
present some of the evidence derived from epidemiological studies, clinical 
interventions as well as animal and cell studies supporting the cardioprotective 
effects of dietary polyphenols.