Paris, 7 January 2010
The “French Paradox” revealedIt has long been established by many epidemiological studies that moderateconsumption of red wine reduces the risk of cardiovascular disease. The mechanismsbehind polyphenol action, however, remained a mystery. A team of research scientistsin Angers (Inserm UMR 771-University of Angers research unit “IntegratedNeurovascular Biology”) has identified the alpha subtype of the oestrogen receptor asplaying a key role in the transduction of wine polyphenols, thus providing anexplanation for what has become known as the “French Paradox”. Their results havebeen published in the journal PloS ONE.
Moderate consumption of wine – red wine in particular – is associated with reduced risk of cardiovascular disease. Until now, this strong suggestion was based solely on the results of an admittedly large number of epidemiological studies. Nothing was known, however, aboutthe mechanism involved or the molecular target responsible for the protective effects that redwine has on the cardiovascular system. This premise still needed to be scientificallydemonstrated.
Nonetheless, various studies, especially those conducted by the Angers team, havegradually led to the identification of a vasodilatory action of wine polyphenols through theproduction of nitric oxide (NO), also known as nitrogen monoxide, by endothelial cells.For the latest study, the researchers used molecular biology techniques to determine theaction mechanism of the polyphenols concerned. They felt that the oestrogen receptor wasprobably involved, since activation of the oestrogen receptor alpha subtype (ER
) is knownto stimulate the NO pathway inendothelial cells.Ramaroson Andriantsitohaina andhis team therefore began with theassumption that an ER
activatingcompound would be enough toactivate the NO pathway inendothelial cells and explain thereduced risk of cardiovascular disease observed.
Diagram illustrating the effects of red wine polyphenols on theendothelium of the vessel wallCopyright: M. Chalopin/U 771
Experiments showed that while red wine polyphenols – especially delphinidin – led toepithelium-dependent vascular relaxation in the arteries of wild mice, they failed to induce