Is moderate drinking actually good for you? How the “healthy glass of wine” fell apart

For about thirty years, one of the most welcome findings in medicine was that people who drank a little lived longer than people who did not drink at all. It appeared in study after study as a J-shaped curve: teetotallers on the left with raised risk, light drinkers at the bottom of the dip, heavy drinkers climbing steeply on the right. It launched a thousand articles about red wine and the French.

The curve was real. The interpretation was probably wrong, and the reason is one of the better detective stories in epidemiology. It comes down to a simple question nobody asked for decades: who, exactly, are the non-drinkers?

The problem with the people who do not drink

Imagine surveying a thousand 55-year-olds and sorting them by how much they drink. The “none” pile contains lifelong abstainers. It also contains people who stopped because their liver was failing, people on medication that does not mix with alcohol, people too unwell to go to the pub, and former heavy drinkers who quit after a health scare.

Compare moderate drinkers with that group and the moderate drinkers look wonderful. They have not been protected by wine. They are simply being compared with a group that includes the sick.

Researchers call this “sick quitter” or former drinker bias, and once you look for it, it is everywhere. The American College of Cardiology’s summary of the key paper states it plainly: earlier studies often mischaracterised former heavy drinkers as non-drinkers, and used inconsistent reference groups.

What happens when you fix the comparison

A team at the Canadian Institute for Substance Use Research went back through the literature to find out. Their 2023 meta-analysis in JAMA Network Open covered 107 cohort studies involving more than 4.8 million participants, and it did what the original studies had not: it adjusted for whether each study had separated lifelong abstainers from former and occasional drinkers, along with other quality markers.

With those corrections, the dip disappeared. The study found no significant reductions in risk of all-cause mortality for drinkers who drank less than 25 g of ethanol per day, roughly two standard drinks. For low-volume drinkers the relative risk was 0.93 with a P value of .07, which is not statistically distinguishable from no effect.

The authors’ conclusion: daily low or moderate alcohol intake was not significantly associated with all-cause mortality risk, while increased risk was evident at higher consumption levels, starting at lower levels for women than men. Or as the cardiologists’ one-line summary had it: no amount of alcohol consumption led to a longer life.

Note what this does and does not say. It does not say a drink a day will kill you. It says the benefit was an artefact. Light drinking looks neutral for overall mortality in these data, not protective.

The genetic evidence points the same way

Correcting old studies is one approach. A cleverer one uses genetics to get around the problem entirely.

Some people carry gene variants that make them drink a bit more or less across their whole lives. Those variants are handed out at conception, more or less at random, and they have nothing to do with income, exercise or whether you were ill last year. Comparing people by their genetic tendency to drink, a method called Mendelian randomisation, is a way of approximating a trial that nobody could ethically run.

A 2022 study led from Massachusetts General Hospital applied this to the UK Biobank, in a design built explicitly to examine confounding in epidemiologic associations between alcohol intake and cardiovascular diseases. The result: genetic evidence supported a nonlinear, consistently risk-increasing association between all amounts of alcohol consumption and both hypertension and coronary artery disease.

The shape of the curve is the useful part. Risk rose only modestly at light intake and then climbed steeply as amounts increased. There was no dip: at the low end the line was nearly flat, not protective.

Cancer changed the conversation

The heart was always the organ on which alcohol’s reputation rested. Cancer is where that reputation has come undone.

In January 2025 the US Surgeon General issued an advisory stating that alcohol consumption is the third leading preventable cause of cancer in the United States, after tobacco and obesity, responsible for about 100,000 cases of cancer and 20,000 cancer deaths annually. The link is established for at least seven cancers, and for breast cancer specifically, 16.4% of total breast cancer cases are attributable to alcohol consumption.

The line that matters for moderate drinkers is this one: for some cancers, including breast, mouth, and throat cancers, the risk of developing cancer may increase at one or fewer drinks per day. There is no threshold below which the cancer risk is zero.

What is not known

Whether a trial would agree. No large randomised trial of moderate drinking has been completed, so the question has never been settled experimentally. Everything above is observational or genetic.

Whether pattern matters as much as quantity. Seven drinks across a week and seven drinks on a Saturday are the same “average”. Most of the large analyses work from averages.

Whether wine is different. The Surgeon General’s advisory states the cancer link holds regardless of the type of alcohol. Claims for red wine specifically rest on the same confounded comparisons, plus the fact that wine drinkers tend to be wealthier.

How big the risk is for you. Relative risks from pooled studies do not translate neatly into an individual’s odds, and they vary with sex, genetics and family history.

So what should a person who likes a drink do?

Stop believing it is good for you. That is the only firm conclusion, and it is a useful one, because it removes the reason some people drink when they otherwise would not.

Beyond that, the honest picture is a dose-response curve that starts shallow and gets steep. One drink a few times a week sits on the shallow part: the added risk is small, and for most people it is a reasonable trade for something they enjoy. Two or three every night is on the steep part, particularly for women, for whom the mortality risk rises at lower levels.

This is not individual medical advice. If you are concerned about your drinking, or take medication that interacts with alcohol, speak to a clinician.

Common questions

Is a glass of wine a day good for your heart?

The evidence no longer supports that. A meta-analysis of 107 cohort studies found no significant mortality benefit below 25 g of alcohol a day once former drinkers were separated from lifelong abstainers, and genetic analysis found cardiovascular risk rising at all levels of intake.

Why did older studies say moderate drinking was healthy?

Mostly because the non-drinking comparison group included former heavy drinkers and people who had stopped because of illness. That made abstainers look unhealthy and moderate drinkers look protected.

Is any amount of alcohol safe?

No threshold has been found below which cancer risk is zero. The US Surgeon General’s advisory says risk for breast, mouth and throat cancers may increase at one or fewer drinks per day. At low intake the added risk is small.

Does alcohol cause cancer?

Yes. It is described as the third leading preventable cause of cancer in the United States, linked to about 100,000 cases and 20,000 deaths a year across at least seven cancer types, regardless of whether the drink is beer, wine or spirits.

The bottom line

The healthy glass of wine was a statistical illusion created by comparing drinkers with a group that included the unwell. Remove the illusion and light drinking looks roughly neutral for lifespan and slightly negative for cancer and blood pressure, with risk climbing fast beyond a drink or two a day. Drink because you enjoy it, in amounts that keep you on the flat part of the curve, and not because anyone told you it was medicine.