By Roger Highfield in Bordeaux
RED wine could provide the inspiration for new ways to treat Aids, sleeping sickness, heart disease and cancer, and even to rejuvenate blood and skin, experts told the first symposium on blood and wine yesterday.
Scientists from a range of disciplines assembled to discuss the health benefits at the University Victor Segalen in Bordeaux, home of famous appellations such as Pomerol, St Emilion, Medoc and Graves.
Innumerable studies suggest that regular, moderate drinking of red wine affords protection against disease. However, it emerged yesterday that scientists are still struggling to explain the healing effects of this complex chemical cocktail.
The first hint that there is more to wine than the pleasure of drinking came with the discovery of the "French paradox", in which French people, particularly in the south, were found to suffer less cancer and heart disease than predicted.
The health benefits of living in France, noted as early as 1890 by an Irish physician, were thought to lie in the local diet, notably red wine. But alcohol was found to increase the risk of harmful clotting an hour after consumption.
However, Prof Serge Renaud of the University Victor Segalen, said that this effect was absent in red wine, probably because it contained polyphenols, substances that had been shown to have remarkable biological properties, responsible for the colour of grapes and found in their skins and seeds.
Polyphenols are also found in tea, vegetables and chocolate. But red wine, particularly made by traditional methods, is a rich source. It contains at least 200 phenolic compounds at an overall level some 10 times that of white wine.
Just how this complex mixture cuts heart disease is still a mystery, but Prof Ludovic Drouet of the Hopital Lariboisiere in Paris, said studies suggested that wine had a subtle effect on three factors affecting furring of arteries - high cholesterol, cell proliferation and blood clotting.
A study published in the British Journal of Pharmacology also linked an extract of red wine to the relaxation of blood vessels, reducing blood pressure, said Prof Joseph Vercauteren of the University Victor Segalen.
One of the key effects of polyphenols is that they act as antioxidants, that is, they mop up damaging chemical intermediates in the body called free radicals, as do vitamins C and E. But the use of individual vitamins to prevent diseases linked with radical damage suggested that they had little effect when used alone, he said.
The complex cocktail of phenolic compounds found in red wine could be better than single vitamin supplements because some are fat soluble and others water soluble, said Prof Vercauteren.
At Chateau Smith Haut Lafitte, Bordeaux, where the Cathiard family makes fine wines, a process developed by Prof Vercauteren is now in use to extract the cocktail for skin products - centuries after Marie Antoinette washed her face in red wine to protect against wrinkles.
Evidence that one particular family of polyphenols, resveratrols, can rejuvenate blood was reported by Dr Marie-Claude Garel of the ICGM Maternite de Port-Royal, Paris. She told the meeting that studies suggested that resveratrol could reactivate the manufacture of foetal blood in the body.
The action is similar to that of an existing drug, called hydroxyurea, suggesting that resveratrol could be useful for the treatment of blood diseases such as sickle cell anaemia and thalassaemia.
Polyphenols could also be of value in treating Aids, the meeting was told by Dr Marvin Edeas of the Hopital Antoine Beclere in Clamart, who is planning human studies. Polyphenols could be used to augment conventional Aids treatments, without the risk of side effects, he said. But research is needed to find the best source of polyphenols in a normal diet.
Resveratrol also possesses anti-cancer properties, the meeting was told by Dr Francis Raul of the University Louis Pasteur, Strasbourg. He said it inhibited the proliferation of human intestinal cancerous cells and the formation of tumours in mice predisposed to intestinal tumours.
However, the potential of resveratrol was questioned by Prof Djavad Mossalayi of the Victor Segalen University, who has tested it on human cells, both normal and cancerous, and found it to be toxic to both.
This suggested that there were other polyphenols in wine, such as flavonoids, which were more important than resveratrols, he said.
The action of wine on cancer cells did not seem to be linked to its antioxidant properties but the way it acted on the basic process of cell division.
Resveratrol could reduce inflammation in studies on human blood cells, the meeting was told by Prof Philippe Vincendeau of the University Victor Segalen. The effect observed in test tube studies, bigger than that caused by aspirin, could be exploited in treatments, for instance of the trypanosomes that cause sleeping sickness and kill at least 500,000 people annually.
Resveratrol not only damped down the body's harmful inflammatory response but also killed the parasite, said Prof Vincendeau, adding that resveratrol could provide the inspiration for a new generation of drugs to treat the disease.