Published yesterday in the science journal Nature, it says they can boast concentrations several times higher than Australian rivals.

Previous studies have generally established that a glass or two of red wine every day helps combat heart and circulatory disease. But the picture has been confused, because not all red wines have the same kinds of polyphenols or in the same concentrations.

In tests using endothelial cells – the cells that line the arteries and where polyphenols are believed to have their positive effect – British scientists identified the most active members of the polyphenol family, which are called procyanidins.

They then tested red wines from the Gers region in the French Pyrenees, and from Nuoro province on the Italian island of Sardinia, where men are famous for their longevity.

Wines from these areas had very high levels of procyanidins – often five to 10 times more than wines tested from Australia, South Africa and the US.

The secret lies partly in the grape seeds and in time-honoured wine growing methods, the paper says.

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