If you plan to visit France this summer, be sure to try a bottle or two of Madiran. The appellation, which is just within sight of the Pyrenees, produces what may be the healthiest wine in the world. Madiran, made with at least 40 per cent tannat grapes, is deep purple, tannic and delicious with a bowl of hearty vegetable soup. And its levels of a plant chemical that is essential for heart health are among the highest of any wine.

Madiran wine can be bought in Britain through a few specialist merchants, but it is generally regarded as too tannic for we British, who are more accustomed to the highly processed, over-sweet, easy-drinking wines of the New World.

To Roger Corder, these wines from the Gers region of south-west France have a special appeal. Corder, a pharmacologist and Professor of Experimental Therapeutics at the William Harvey Research Institute at St Bartholomew’s Hospital in London, was drawn to the region by a puzzle that has long taxed doctors: why is it that the French eat a diet with similar levels of fat to ours, and have similar levels of blood cholesterol, yet four Britons die of heart disease for every one Frenchman?

Doctors traditionally put this so-called French Paradox down to something present in red wine, but not in white, that protected the heart. But this did not satisfy Corder. If red wine is protective, why does it work better in some parts of France than others? The Gers region has twice the French national average of men aged 90 or more. Are some wines more protective than others?

So it has proved. When he analysed the wines of the Gers, Corder found that they contained high levels of a plant chemical (or polyphenol) called procyanadin. This was partly thanks to the area’s grapes, and partly to the region’s old-fashioned production methods that involve a long fermentation and maceration process.

Previous research by scientists, including Corder - his first paper on the subject was published in Nature in 2001 - had shown that drinking wine high in procyanadins improved the function of the lining of the blood vessels and protected against atherosclerosis, the thickening of the artery wall.

This is critical for heart health. All the risk factors we know about - high blood pressure, High cholesterol, lack of exercise - damage the lining of the blood vessels and makes them more prone to “furring up” with fatty deposits. Procyanadins appear to counteract this effect by improving the elasticity of the blood vessels. But where to find procyanadins? Though they are abundant in cranberries and dark chocolate, modern wine-making methods often eliminate them. This is an issue for the consumer, who may mistakenly believe that all red wine is healthy.

Corder has published his findings in a book, The Wine Diet, based on his research over a decade. “My central message is for the consumer to be more discerning. People think they are doing themselves good by knocking back quantities of red alcoholic plonk. The wines to look for [with high levels of procyanadins] are those with firm tannins made in the traditional way. It is not just about Madirans. There are plenty of choices out there from other parts of the world. What I would like to see is wines produced that are less alcoholic, less sweet, more tannic and more traditional.”

For more than a decade, it has been claimed that another substance in red wine, resveratrol, is the source of its health-giving properties. The chemical, found in the skins of red grapes, boosts the activity of proteins called sirtuins, which help to defend the body’s cells against the effects of ageing. A study in the journal Cell, published in November, claimed to demonstrate the benefits of resveratrol by showing that it boosted endurance and cut the risk of diabetes in mice. But Corder dismisses these claims. ” As a source of resveratrol, wine is just a waste of time. To replicate the findings in the mice, a human would have to drink 1,000 litres a day. It has no relevance.”

In addition to the wines of Madiran, Corder is also fond of hearty Sardinian reds such as those from Mandrolisai, a cantina in the centre of the island. Sardinia, which has an exceptionally high number of centenarians, provided the base for his research into longevity.

On the other side of the world, the wines of Washington State, produced from vines between the Rockies and the Pacific, also have high procyanadin levels. The grapes, grown at high altitude in a cold, dry environment, only ripen just before winter.

However, the way the wine is made is also important. The most procyanadin-rich wines are those where the grapes (seeds, skins and all) remain in contact with the wine during fermentation and afterwards. This is a style of wine-makknown as vinifie’ a` l’ancienne.

Information on procyanadin content is not carried routinely on wine labels, although Corder believes it soon will be. Until then, he suggests checking wine-makers’ websites, which will often contain technical information about their wines. “Look for a contact time [between grapes and wine] of at least 10 days,” he says. “Good wine merchants should be able to provide information on how their wines are made.”

What’s needed now are clinical trials comparing the effects of procyanadin-rich wines against the rest, but grant-giving bodies are reluctant to put money into research on wine because they fear that it will promote drinking. Yet the outcome, if the health benefits are confirmed, could help to curb our binge-drinking culture. Unlike modern, processed wines of the kind swallowed by the bucketful in pubs and clubs, the tannic wines produced by traditional methods need to be accompanied by food to be palatable.

“A Madiran wine is not something you can knock back in huge quantities,” Corder says. “But with a nice fillet steak, it makes a perfect combination.”

The Wine Diet by Roger Corder is published by Sphere (£9.99)

Cheers: the medicinal claims of red wine

Heart Disease

The most commonly cited health benefit of red wine brings comfort to borderline alcoholics the world over. A glass of red per day (or two for men) can supposedly reduce the risk of a heart attack in middle age by half.

Wine spa

Wine contains powerful antioxidants; thus, the wine bath has become a high-class spa treatment known as vinotherapy. Teri Hatcher is among the glitterati thought to indulge in the odd champagne facial, crushed cabernet scrub or grape massage. Visitors to some enterprising vineyards can now soak in a merlot-infused tub before they enjoy their evening tasting.

Herpes

If your alcohol consumption is the cornerstone of a debauched lifestyle, you may be pleased to hear that an ingredient of red wine can halt the spread of herpes. However, the treatment is less appealing than you might imagine. Instead of drinking the stuff, sufferers are required to daub it on to their infectious sores.

Gum disease

Red wine can block the production of the molecules that cause gum disease, but dentists aren’t about to start recommending a glass a day; the acidic content of red wine can cause plenty of problems for teeth, so you’re probably best to stick to flossing.

Alzheimer’s

Red wine can reduce your chances of suffering from Alzheimers, according to researchers at New York’s Mount Sinai School of Medicine. Their lab mice, despite ingesting significant quantities of cabernet sauvignon over a seven-month period, experienced less “Alzheimers Disease-type deterioration of spatial memory function” than their peers, who were given the less appetising ethanol or water diet.

Cancer

Wine contains a merry band of industrious phytochemicals, including polyphenol compounds, which are thought to inhibit the development of some cancers. Red wine contains more of these clever chemicals because they come originally from the skin of the grape, which is removed during the production of white wine.

The Common Cold

A Spanish study found that people who drank more than two glasses of wine per day were 44 per cent less likely to contract a common cold than others, though of course they are probably prone to more serious conditions such as gout or cirrhosis.

Tim Walker