It’s probably the one bit of healthy living advice many of us remember without being reminded – drink red wine (in moderation) to cut the risk of illnesses such as cancer, heart disease and dementia.

As part of a Mediterranean-style diet (which is rich in olive oil, fish, vegetables and legumes), red wine has, for years, enjoyed a reputation as one of the secrets to a longer, healthier life.

Studies – many of them on animals – have shown that one or two glasses a day along with meals can halve the risk of some cancers, protect against heart disease and cut the chances of developing dementia by more than a quarter.

But now a major new study, published in the journal Nutrients, has concluded that red wine – even in moderation – is no better than white wine at warding off cancer. In fact, the study found, neither of them reduced the risk at all – for any type of tumour.

Researchers at Brown University in Rhode Island, US, crunched the numbers from more than 40 studies looking at the relationship between wine consumption and cancer in nearly 100,000 people.

Pooling data from lots of studies like this produces a more powerful result than those from smaller stand-alone studies – and in this case it was conclusive.

As the researchers said in their report: ‘We found no difference between them. This challenges the common belief that red wine is healthier than white wine.’

Red wine’s anti-cancer reputation had been pinned on the fact that grape skins are packed with health-boosting compounds, in particular an antioxidant called resveratrol, which, laboratory studies suggest, can prevent the kind of damage to the body’s cells which allows cancers to form.

As part of a Mediterranean-style diet, red wine has enjoyed a reputation for many years as one of the secrets to a longer, healthier life

Red grapes have much higher concentrations of resveratrol than white, hence their cancer-fighting reputation.

But if red wine is so rich in resveratrol – and laboratory tests show it can stop cancers of the breast, bowel, skin, stomach and kidneys developing – why does it now seem to have no protective effect at all?

One reason put forward by the US researchers is that it may simply be that alcohol itself is carcinogenic (i.e. cancer-causing), offsetting any potential benefit from resveratrol.

Another possible explanation is that resveratrol, no matter how much we consume, is poorly absorbed by the body. In fact, studies show that 75 per cent of what we consume is removed as waste before it can come into contact with cells that could become cancerous.

This, the researchers said, may partly explain why – for all its anti-tumour effects in the laboratory – resveratrol has little or no impact on cancer in the human body.

Summarising their findings, they said: ‘Low levels of resveratrol after consuming red wine may not result in bio-effective concentrations that make differences in health outcomes.’

But it’s not just in cancer that red wine’s reputation is crumbling. Once touted as being good for the heart, most cardiologists now agree there is no good evidence from large-scale studies that it protects against heart attacks and strokes.

So how did red wine win its reputation as heart healthy?

Naveed Sattar, a cardiologist and a professor of cardiometabolic medicine at Glasgow University, says red wine should be removed from the Mediterranean diet guidelines – but you can still enjoy ‘the odd tipple’

Professor Francisco Leyva-Leon says red wine got its healthy reputation thanks to a seemingly low rate of heart disease in France. This was later discovered to be underreported instead

‘It all stems from the Seven Countries Study in the 1980s,’ says Professor Francisco Leyva-Leon, a cardiologist at Queen Elizabeth Hospital in Birmingham. 

This international study compared heart disease rates across Europe and investigated possible reasons for any differences. Scotland had the highest death toll, while parts of France and Spain had the lowest.

It gave rise to the so-called French paradox – the idea that red wine was the reason why heart disease rates were lower there, despite diets high in fat and salt.

Now it’s recognised that back then, heart disease deaths were significantly under-reported in France. But, says Professor Leyva-Leon: ‘At the time, this [paradox] was attributed to the fact that they drank a lot of red wine and it has a lot of antioxidants in it.

‘Yet there has never been any proof – just observational data. There is nothing to say red wine is better than anything else at protecting against heart disease.’

The picture has been further blurred by the fact that research shows modest amounts of any alcohol – within the UK guidance of no more than 14 units a week – does seem to be linked with slightly fewer heart attacks and strokes.

Teetotallers are more at risk, though this may be because some at least are former heavy drinkers who still suffer poor health.

The European Research Council announced last year it was funding a study in Spain involving 10,000 people to see how wine consumption or going teetotal affected health. The findings, due in 2028, could also dictate whether red wine is dropped from the list of food and drinks that make up a healthy Mediterranean diet.

‘I think it should be removed from the Mediterranean diet,’ says Naveed Sattar, a cardiologist and a professor of cardiometabolic medicine at Glasgow University.

In 2017, when he was appointed chair of the Scottish Intercollegiate Guidelines Network (which produces treatment guidance), alcohol (of any kind) was recommended to people who’d had a heart attack but did not drink – as it might stop them having another one.

‘I got that removed,’ says Professor Sattar.

‘I don’t want to be a killjoy – by all means enjoy the odd tipple of red wine – but don’t do it in the hope it will reduce your risk of heart disease.’