Evidence for a protective effect of polyphenols-containing foods on cardiovascular health: an update for clinicians.

Growing evidence suggests that polyphenols could be serious candidates to explain the protective effects of plant-derived foods and beverages. Based on current studies, a general consensus has been achieved to sustain the hypothesis that the specific intake of foods and beverages containing relatively high concentrations of flavonoids may play a meaningful role in reducing cardiovascular disease (CVD) risk through an improvement in vascular function and a modulation of inflammation. This review aims at providing an update on the effects of the consumption of polyphenols-rich foods on intermediate clinical markers of CVD in humans, namely cholesterolemia, blood pressure, endothelial function and platelet function. To date, on the basis of clinical studies, the demonstration is particularly convincing for flavonoids from cocoa-derived products and to a lesser extent for those of tea. While additional studies in this area are clearly needed, incorporating plant foods that are rich in flavanols in the diet of healthy individuals could help to reduce CVD risk. For flavonoids from fruits such as berries, pomegranate, grapes or citrus fruits and those from beverages such as red wine or coffee, the evidence is so far inconclusive. This is primarily due to the limited number and the weakness of experimental designs of the studies performed with these dietary sources. Future long-term well-designed investigations with polyphenols-rich foods but also with isolated phenolic compounds would provide valuable information to establish public health recommendations on polyphenols, taking into account both the nature of the compounds and the optimal dose, for cardiovascular health protection.