Authors of a recent study published in the journal, Nature, found that procyanidins are the most biologically active polyphenols in red wine. Further the authors claim that the high level of procyanidins in the wines of certain areas (in Sardinia and southwest France) is the reason that the people there live longer.
The authors state that red wine polyphenols induce endothelium dependent dilatation of blood vessels and suppress the synthesis of endothelin-1 (ET-1), a peptide that has a vasoconstricting effect, and this may account for the antiatherosclerotic activity of red wine.
They used cultured endothelial cells to identify the most potent vasoactive polyphenols in red wine. These were shown by high-performance liquid chromatography with mass spectrometry to be straight-chain B-type oligomeric procyanidins (OPCs). To investigate how the OPC content of red wines from a particular region might relate to mortality in that region, the authors compared wines produced in areas where people have increased longevity of life (as an index of overall good health) with a broad selection of wines from different countries.
People living in Nuoro province, Sardinia, have great longevity, particularly men. In France, there are marked regional variations in mortality from coronary heart disease; the authors report that there are relatively more men aged 75 or over in the département of Gers in the Midi-Pyrenees in southwest France.
Wines from Nuoro and the Gers areas were found to have two to fourfold more biological activity and OPC content than wines from other parts of the world. The authors state that the higher OPC concentration in wines from southwest France is due to traditional wine-making, which ensures that high amounts of OPCs are extracted, and to the flavonoid rich grape Tannat, which makes up a large proportion of grapes used to produce local wines in the Gers area but is rarely grown elsewhere.
The authors conclude that procyanidins are the polyphenols in red wine that are the most biologically
active, and (unlike resveratrol and some other polyphenols) are present in high enough concentrations in certain red wines to be a major factor in the prevention of coronary heart disease. Corder and Crozier further conclude that wines from certain areas (the Nuoro province of Sardinia and the Gers area of France) are very high in these active procyanidins and may lead to the increased longevity reported for people in these regions.
Comments by professor R. Curtis Ellison: This interesting short report in Nature makes two major points. The first is that, of all of the polyphenols in red wine, the ones showing the greatest activity affecting the endothelial lining of arteries are procyanidins. This is important information and, if confirmed, helps demonstrate which of the many substances in wine may be the most important for prevention of atherosclerosis. In this study, the higher the levels of procyanidins, the greater the beneficial effects on the endothelium, and wines from certain areas of Sardinia and Southwest France had the highest levels.
The second point is that the procyanidins in wine from these selected areas are the cause of what the authors report as greater longevity of life of people in these regions. Here, there is certainly room for debate, as there are many reasons why there may be more old people living within homes in an area. Further, there are many lifestyle differences (e.g., diet, exercise levels) among people in different regions that are important in determining rates of cardiovascular disease and risk of mortality. Also, consumption of any type of alcoholic beverage has been shown to markedly reduce the risk of coronary disease and mortality in every part of the world, including Asia, where the consumption of grape wine is extremely low. Thus, while we agree that the finding of marked vasoactive properties of procyanidins is important, we believe that it is certainly too early to think that they are the only active and important substances within red wine.
Source: Corder R et al. Oenology: Red wine procyanidins and vascular health. Nature 2006;444:566-7.