The artery-clogging effects of a fatty Christmas dinner can best be counteracted by washing it down with a red from south west France or Sardinia, new research has suggested.

British scientists have discovered that red wines from the two regions boast the highest concentrations of a chemical that underlies the drink’s well-publicised benefits for cardiovascular health.

Wines from Nuoro province in Sardinia, and the Gers departement in the foothills of the Pyrenees, are particularly rich, containing up to 10 times more of the beneficial compounds than alternatives from Australia, South Africa and the United States.

The notion that a daily glass or two of red wine is good for the heart has been established by studies showing that moderate drinkers are less likely to suffer from heart disease than those who never touch it.

Regular red wine consumption has also been proposed as an important element of the “Mediterranean diet”, which is thought to explain the greater longevity of people living in southern Europe.

These benefits are known to derive at least in part from a group of antioxidant chemicals called polyphenols, which protect the condition of the blood vessels.

The new study, published in the journal Nature, has now identified that one particular group of polyphenols, known as polymeric procyanidins, offer the greatest degree of protection to human blood-vessel cells. Procyanadins suppress production of endothelin-1, a protein that constricts blood vessels.

The team, led by Professor Roger Corder of Queen Mary, University of London and Professor Alan Crozier of the University of Glasgow, then sought to establish whether wines from any particular regions were especially rich in procyanidins.

Reds from Nuoro, such as Cannonau, and from Gers, such as Madiran, were found to have between two and four times more procyanidins than other red wines. They also had the greatest effect on endothelin-1 production in the laboratory.

This may have an effect on the wider health of the local populations: both regions were selected for testing because of census data showing that they have above-average longevity, particularly for men.

Two small 125 millilitre glasses of Madiran wine a day would provide between 200 and 300 milligrams of procyanidins, which studies of grape extract suggest is enough to lower blood pressure. More research is needed, however, to determine how procyanidins in wine affect human health.

Professor Corder said: “There is a 19th century expression — ‘A man is only as old as his arteries’ – which can be taken to mean that those with the healthiest arteries live longer.

“Since the most important protective effect of procyanidins we can show in the laboratory is on arterial function, our hypothesis was that areas of greater longevity might have a protective dietary factor, which could include the type of wine that was drunk. So it was of great interest to us when we found both in Sardinia and in south west France that the wines made in these in areas had higher levels of procyanidins.”

The traditional wine-making techniques used in these two regions probably explain much of their higher procyanidin content. The compound comes chiefly from grape seeds, and are extracted most efficiently by long fermentation periods with seeds and skins of three to four weeks.