That moderate quantities of alcohol, consumed on a regular basis, offers cardiovascular protection is now medically accepted. As a cautious pamphlet from the Australian Wine Research Institute says: “research suggests that the regular and moderate consumption of alcohol, and in particular wine, may reduce your risk of cardiovascular disease by up to 50%”. Which sounds like great news – except the picture is more complicated than most of the cheery wine and health stories would suggest. Several years ago, I interviewed Professor Tim Stockwell, then director of the National Drug Research Institute in Australia, who made the point that the exact nature of the benefits had yet to be properly teased out. Does drinking wine help the under-45s? Was the consumption of red wine itself the sign of a healthy lifestyle? The same people who prefer red wine, apparently, are also more like to exercise and eat properly.

And while there is, indeed, solid research that says wine has health benefits, the key to unlocking those benefits rests on moderate consumption. As Professor Stockwell said, too few people actually do drink moderately. Yet consumption of alcohol beyond three or four serves a day for men, or two for women, is positively poisonous, and strongly linked to breast and prostate cancer, among other diseases.

In a time when the prohibition lobby is again on the march, it’s important that the wine industry not make claims that can’t stand up to scrutiny. Which is why it’s time to sober up when it comes to the reporting of resveratrol.

In August 2003, Dr David A. Sinclair and Dr Konrad T. Howitz sparked worldwide interested when they announced they’d found a class of chemicals, one of which was resveratrol, which extended the life span of yeast and fruit flies. There was a scientific stampede to study resveratrol, and the resulting reports make the compound sound near miraculous: not only has it apparently got anti-cancer, anti-obesity and blood sugar-lowering abilities, but it may even protect against radiation exposure. Unfortunately, the life extending properties have not yet been demonstrated in mammals, while the other purported benefits can so far only be had – if at all – by drinking such vast quantities of red wine that you would promptly die of alcohol poisoning.

Wine lovers are well within their rights to demand good information about wine and health. What, for example, is the amount that pregnant women can safely drink? The advice from UK and US government bodies is unnecessarily contradictory and confusing. But the wine industry is on shaky grounds when it either claims health benefits that are yet to be proven, or it overstates the case, while failing to recognise the very real harm that alcohol does. How many people know, for example, that while French cardiovascular rates are lower, their death rate from liver cirrhosis is higher than that of the US?

If the wine community wants to talk about wine and health, one legitimate way would be to stump up the cash for medical research – something it has, so far, been slow to do, despite its willingness to discuss the results of such research. Another would be to undertake a concerted campaign to help the public understand what moderate drinking is.

Or maybe it could just defend the right to drink wine on the basis that wine’s very enjoyable, and if adults choose to open a bottle, that’s their business, as long as they stay within the law when it comes to drinking and driving and so on. If wine has health benefits as well, then that’s a bonus.