We all know that drinking too much is bad for us. But what about just a few glasses a week?
Red wine has antioxidants, we've been told, so a few glasses are apparently 'good for you'. Other studies have suggested that low-to-moderate drinkers are less likely to have a heart attack than those who avoid drinking altogether. Wine is even included (in moderation) in the Mediterranean diet, one of the healthiest food plans on the planet!
But a new study based on a huge data set from the United Kingdom now suggests that the J- or U- shaped curve of drinking is based on bad science; even having less than the currently recommended number of drinks per week in the UK is associated with an increased risk of cardiovascular issues.
"The so-called J-shaped curve of the cardiovascular disease-alcohol consumption relationship suggesting health benefits from low to moderate alcohol consumption is the biggest myth since we were told smoking was good for us," says cardiovascular physiologist Rudolph Schutte from Anglia Ruskin University (ARU).
The problem, the team of researchers from ARU and University College London suggest, is that many non-drinkers are not drinking because of current ill health, and so when they have heart attacks or other coronary issues, this is unrelated to them not drinking – and not suggestive that drinking a low or moderate amount of alcohol is protective.
The researchers looked at data from the UK Biobank covering a staggering 333,259 alcohol consumers and 21,710 people who had never drunk alcohol. They analyzed almost seven years of data, noting whenever one of the participants had a cardiovascular event, heart disease, or cerebrovascular disease.
The team specifically excluded former drinkers to try and limit data from people who may have stopped drinking due to their current health. Despite this, the never-drinkers were still older, had a higher BMI, higher blood pressure, and were less physically active than the cohort that drank.
"Using never drinkers as reference consistently drove the inverse protective relationship with all outcome measures and overrode more subtle associations with different drink types. Using this overriding analytical strategy enables authors to report overall cardiovascular protection from alcohol," the team writes in their study.
"In our cohort, never drinkers were older, less physically active, had a higher body mass index and socioeconomically less affluent. Even after adjusting for these cardiovascular risk factors, never drinkers had a 31, 51 and 46 percent higher risk of suffering an overall cardiovascular-, ischemic heart disease- or cerebrovascular disease event, respectively."
So, to remove these confounding factors, the team then compared the lightest drinkers to those that drank more, and found that wine was minimally protective from ischemic heart disease, but was not associated with other cardiovascular issues.
For other alcoholic drinks like beer and spirits, even for people consuming fewer than 14 units per week, which is the current recommended number of weekly drinks in UK's health guidelines (and the equivalent of 8 standard US drinks), the outcome looks much worse.
"Among drinkers of beer, cider, and spirits in particular, even those consuming under 14 units a week had an increased risk of ending up in hospital through a cardiovascular event involving the heart or the blood vessels," says Schutte.
"While we hear much about wine drinkers having lower risk of coronary artery disease, our data shows their risk of other cardiovascular events is not reduced."
With other studies finding that alcohol is one of the leading contributors of death and disease worldwide, now might be a good time to renew those new year's resolutions and cut back on drinking.
In the US, the Centers for Disease Control and Prevention recommend that adults can choose not to consume alcohol, or stick to two standard drinks per day for males, or one drink for women if it's a day when you choose to drink.
"Biases embedded in epidemiological evidence mask or underestimate the hazards associated with alcohol consumption. When these biases are accounted for, the adverse effects of even low-level alcohol consumption are revealed," says Schutte.
The research was published in the paper Clinical Nutrition.