For the regular drinker, this is a source of great comfort: the fat heap studies that say a daily drink is better for a longer life than avoiding alcohol altogether.
But a new analysis challenges that thinking, blaming the rosy message on flawed research that compares drinkers to people who are sick and sober.
Scientists in Canada delved into 107 published studies about people’s drinking habits and how long they lived. In most cases, they found, drinkers were compared to people who abstained or used very little alcohol, without taking into account that some had cut back or stopped due to ill health.
The finding means that between the abstainers and occasional drinkers there is a significant number of sick people, which lowers the group’s average health and makes light to moderate drinkers look better off by comparison.
“It was a propaganda coup for the alcohol industry to suggest that moderate use of their product lengthens people’s lives,” said Dr. Tim Stockwell, first author of the study and a scientist at the Canadian Institute for Research on Substance Use. the University of Victoria.
“The idea has had an impact on national drinking guidelines, estimates of alcohol’s disease burden worldwide and has been an impediment to effective policy-making on alcohol and public health,” he added. Details are published in the Journal of Alcohol and Drug Studies.
Many studies on the health impact of alcohol show a J-curve effect, where death rates are lowest among those who drink a little. When the Canadian team combined the data from the studies in their analysis, it suggested that light to moderate drinkers – those who had between one drink a week and two a day – had a 14% lower risk of dying over the study period. die compared to rememberers.
But the apparent advantage evaporated on closer inspection. In the highest quality studies, which included younger people and made sure that former drinkers and occasional drinkers were not considered abstainers, there was no evidence that light to moderate drinkers lived longer. This was only seen in the weaker research that failed to separate former drinkers and lifelong tea tollers.
“Estimates of the health benefits of alcohol have been exaggerated while its harms have been underestimated in most previous studies,” Stockwell said.
“The vast majority of previous studies compare drinkers to an increasingly unhealthy group of people who currently abstain or drink very little. We know people give up or cut back on drinking when they get sick and frail with age. The most biased studies included many people who had stopped or reduced their drinking for health reasons in the comparison group, making people appear healthy enough to continue drinking even healthier,” he added.
England’s former chief medical officer, Dame Sally Davies, said there was no safe level of alcohol intake. A great study published in 2018 supported the view. It found that alcohol led to 2.8 million deaths in 2016 and was the biggest risk factor for premature death and disability in 15- to 49-year-olds. Among the over 50s, around 27% of global cancer deaths in women and 19% in men are linked to their drinking habits.
Despite the growing evidence for harm at even low levels, adults in the UK are advised to keep the risk low by not drinking more than 14 units per week. A half pint of medium-strength lager contains one unit and a 125ml glass of wine contains around 1.5 units.
Last year, a great study of more than half a million Chinese men linked alcohol to more than 60 diseases, including liver cirrhosis, stroke, various gastrointestinal cancers, gout, cataracts and ulcers.
“Studies of alcohol and health can be subject to biases, even when well conducted,” said Dr Iona Millwood at the University of Oxford, a co-author on the study of Chinese men. “This is because drinking patterns tend to correlate with other factors such as smoking and socioeconomic status, and people often change their drinking patterns in response to poor health. We see increasing evidence that the apparent beneficial health effects of moderate drinking are unlikely to be causal.”
