Page last updated: Friday, June 3, 2005
XXVth World Congress of the Office Internationale de la Vigne et du Vin (OIV) by Creina Stockley
The XXVth World Congress of the Office International de la Vigne et du Vin (OIV) was hosted by France. There were delegates and observers from the 46 member countries of the OIV. The wine and health scientific sessions were presided over by Dr Serge Renaud, of which the overall theme was new knowledge, new developments in the field of wine and public health. Following on from epidemiological studies presented which discussed the J-shaped relationship between alcohol, and hence wine, consumption and the risk of death from cardiovascular disease, papers were presented on potential biological mechanisms of cardioprotection.

Dr Serenella Rotondo (Italy) discussed the initial results of the FAIR CT 987 3261 "wine and cardiovascular disease" project of the European Union, which is a multi-centre study evaluating potential biological mechanisms for the phenolic components of red wine in relation to atherosclerosis and thrombosis. The study, undertaken by seven centres within the EU, is specifically evaluating the effects of these isolated phenolic components on vascular tone, in haemostasis or thrombosis and in the development of atherosclerotic lesions. The preliminary results indicated that these isolated phenolic compounds exerted protective and/or restorative effects in all three areas, which implies that the mechanisms for cardioprotection may be multi-factorial. Concerning thrombosis, the phenolic components were observed to down-regulate cellular adhesion processes, which are responsible for the recruitment and activation of red blood cells and their subsequent clotting together at the site of vascular damage. It was previously considered that the ethanol component of wine was solely responsible for the reduced risk of thrombosis observed following the consumption of wine and other alcoholic beverages. Dr Jean-Claude Stoclet (France) directs one the multi-centre studies. His centres research has focussed on the role of phenolic compounds in the preventing endothelial dysfunction caused by impaired nitric oxide production. Endothelial dysfunction, which is an alteration in the ability of the endothelium to relax, whereby the blood vessels are constricted and hence narrowed, is also associated with the initiation of atherosclerosis. They observed that particular wine-derived phenolic compounds, such as the oligomeric condensed tannins and anthocyanins, could act directly on endothelial cells to restore or increase their production of nitric oxide, and hence restore their ability to relax with concomitant dilation of the blood vessels. This vaso-relaxation also had a beneficial effect on blood pressure.

Dr Erna Mansvelt (South Africa) presented a paper on the effect of regular red wine consumption on platelet aggregatability in thrombosis. Volunteers consumed 350 ml of red wine per day for 28 days. Confirming the results of two previously performed studies, the onset of platelet aggregation was delayed and extent was significantly reduced following the consumption of wine. The data displayed suggested that platelet reactivity was significantly reduced via inhibition of the arachidonic acid pathway and subsequent synthesis of thromboxane, where thromboxane is an inducer of platelet aggregation. The data were unclear, however, as to whether the ethanol or phenolic component of the red wine was exerting this inhibition.

Professor Federico Leighton (Chile) presented the results of a clinical study which assessed the impact of dietary fat on the antioxidation effects of regular and moderate (250 ml/day) wine consumption versus those of fruits and vegetables. A diet high in fats increases oxidative stress and hence promotes oxidative damage to cells, such as LDL and DNA. The consumption of red and white wine, and less significantly fruit and vegetables, was observed to increase the plasma concentration of high density lipoprotein (HDL), an effect attributed to the ethanol component of wine. The consumption of red wine alone, however, increased endothelial function, that is, the ability to dilate, which is decreased in the pathogensis of atherosclerosis. The consumption of red wine also decreased oxidative damage to DNA . These effects have been attributed to wine-derived phenolic compounds.

The pharmacology of the wine-derived phenolic compounds is still little understood, however, although in vitro and in vivo studies have demonstrated that they are absorbed across the small intestine into the blood. Dr Claude-Louis Leger (France) has assessed the bioavailability of wine-derived phenolic compounds and their subsequent cellular concentration. He provided evidence that the wine-derived phenolic compounds pass through the wall of the small intestine and are transported, partly associated, to LDL where they are adsorbed onto the surface of lipoproteins. Different phenolic compounds were more or less associated with LDL, which may influence their antioxidant activity. The cellular concentration present of the phenolic compounds was submicromolar. Dr José-Antonio Brunet (Italy) then explained that the phenolic compounds, catechin and procyanidin, were actually transported in blood bound to a protein of approximately 35 kDa, apo-A-I. Apo-A-I, is the major protein component of HDL, and is central to reverse cholesterol transport, where LDL is transported by HDL from the body tissues to the liver for elimination from the body. The fact that catechin and procyanidin were observed to bind to this protein suggests that phenolic compounds may have a role in this transport, which was previously only attributed to the ethanol component of wine.

In conclusion, these presented papers demonstrated that the consumption of wine, and in particular red wine, is cardioprotective, for which there are plausible biological mechanisms. What was also highlighted is that the roles of the ethanol and phenolic components of wine in protection may be inter-related, where a synergistic combination of the differential effects of the different phenolic compounds may be necessary for maximum cardioprotection.

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