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Even though alcohol kills millions of people every year, humans have been imbibing for millennia. In the last few decades, wine, in particular, has gained a reputation for being good for our health. Red wine even has been linked with longevity and lower risk of heart disease.

But could wine really be good for us?

The first question, of course, is what we mean by “good for us”. Many people think of heart health when we think of the potential upsides of wine.

What is less well-known is that research has found strong links between alcohol and cancer. One bottle of wine per week is associated with an increased absolute lifetime cancer risk for non-smokers of 1% for men and 1.4% for women. This equates one bottle of wine per week to five cigarettes for men, or 10 for women.

“While a lot of work [has] been done to communicate the link between smoking and cancer, this is less so for alcohol because public health officials control messaging for smoking, whereas with alcohol, it’s largely been up to the alcohol industry to communicate this itself,” says Mark Bellis, director of policy, research and international development at Public Health Wales.

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The idea that research shows a tipple can be beneficial dates back to the 1970s, when scientists found that French people were less likely to have heart disease than other populations, despite eating more saturated fat. There was a clear relationship between lower levels of heart disease and wine consumption. This came to be known as the French paradox – a conundrum which scientists are still untangling today.

We have since been led to believe that moderate wine-drinking can reduce our risk of heart disease, high blood pressure, diabetes, and weight gain.

“Early research found that moderate levels of wine consumption had a ‘J’-shaped curve effect,” says Helena Conibear, co-director of The International Scientific Forum on Alcohol Research. “Small, regular amounts of wine seem to lead to longer life, better health and less cognitive decline. Since then, more than 1,000 papers have been published reiterating that.”

As a result, for a long time, the consensus was that abstaining from alcohol is unhealthier than consuming moderate amounts of alcohol (equivalent to one or two drinks a day).

But that “J”-shaped relationship between alcohol consumption, and death and disease, has come under criticism. It’s now widely understood that a lot of this data could be flawed: people abstaining from alcohol may be doing so because they’re unwell, rather than becoming unwell because they’re abstaining. (This challenge in sorting out cause from effect is the issue with many observational studies, which most nutrition studies are).

When controlling for this, one 2006 analysis of 54 previously published studies found no correlation between moderate alcohol consumption and lower risk of heart disease.

But in the years since, says Conibear, other studies have found the opposite. “Over the last five years, research has looked at confounding factors,” she says. “We know wine drinkers tend to be better off, better educated and have a less sedentary lifestyle – and adjusting for that, the J-shaped curve can’t be denied.”

She says researchers have got around this bias by using participants who’ve never drunk before, rather than those who used to drink and now abstain, as they’re more likely to abstain for health reasons.

In one 2019 study, researchers took a different approach to determine whether moderate alcohol intake really is linked to lower risk of heart disease. For 10 years, they followed more than 500,000 adults in China, where two genetic variants (ALDH2-rs671 and ADH1B-rs1229984) influence alcohol drinking patterns, rather than ill health. They also excluded people with poor health.

“Those with no defects can drink as much as they like,” says Zhengming Chen, one of the study’s authors and professor of Epidemiology, at the University of Oxford’s Nuffield Department of Population Health. “But those with a dysfunctional enzyme can’t tolerate alcohol at all,” he says.

The researchers also used Chinese women as a control group, because while many Chinese women can metabolise alcohol, many don’t drink for social, rather than health reasons, Chen says.