Study backs alcohol UK limit of six glasses of wine a weekBMJ 2018; 361 doi: https://doi.org/10.1136/bmj.k1630 (Published 13 April 2018) Cite this as: BMJ 2018;361:k1630
A massive study supports the UK’s latest guidance on alcohol, which recommends a limit of 100 g alcohol a week—around five to six standard glasses of wine or pints of beer.1 This limit is much lower than that recommended in many other countries.
The study, published in the Lancet, includes data from 599 912 current drinkers taken from 83 prospective studies in 19 high income countries. It found an increase in all causes of death above 100 g alcohol a week.
The research was restricted to current drinkers who had no history of cardiovascular disease. Non-drinkers were excluded to minimise the possibility of reverse causality—for example, if former drinkers had abstained because of poor health. All the participants were followed up for at least one year, giving 5.4 million person years of follow-up.
Around half of the total study sample reported consuming more than 100 g of alcohol a week and 8.4% drank more than 350 g a week. There were 40 317 deaths from all causes and 39 018 cardiovascular disease events.
The researchers found a positive curvilinear association between alcohol use and premature death. The lowest risk of premature death was in people consuming 100 g of alcohol a week or less.
Alcohol consumption was roughly linearly associated with a higher risk of stroke (hazard ratio for each 100 g weekly higher consumption 1.14, 95% confidence interval 1.10 to 1.17), coronary disease excluding myocardial infarction (1.06, 1.00 to 1.11), heart failure (1.09, 1.03 to 1.15), fatal hypertensive disease (1.24, 1.15 to 1.33), and fatal aortic aneurism (1.15, 1.03 to 1.28). By contrast increased alcohol consumption was associated with a lower risk of non-fatal myocardial infarction (hazard ratio 0.94, 0.91 to 0.97).
Guidelines on alcohol consumption vary widely around the world. In the United States, for example, an upper limit of 196 g a week (about 11 glasses of wine or pints of beer) is recommended for men and an upper limit of 98 g a week is recommended for women. In Italy, Portugal, and Spain the low risk limits are almost 50% higher than those in the US. In 2016 the chief medical officers in the UK lowered the recommended alcohol limits to six glasses a week for both men and women.23
The researchers estimated that long term reduction of alcohol consumption from 196 g a week—the US recommended limit—to 100 g a week or below was associated with one to two years longer life expectancy in a 40 year old drinker.
The study’s lead author, Angela Wood, from the University of Cambridge, said: “The key message of this research for public health is that, if you already drink alcohol, drinking less may help you live longer and lower your risk of several cardiovascular conditions.”
She added: “Alcohol consumption is associated with a slightly lower risk of non-fatal heart attacks but this must be balanced against the higher risk associated with other serious—and potentially fatal—cardiovascular diseases.”
One limitation of the study is that it used self reported alcohol consumption. Participants were recruited between 1964 and 2010, and each participant had a minimum of 12 months’ follow-up, but the study did not look at the effect of alcohol consumption over a lifetime or account for people who may have reduced their consumption because of health complications.
The study was funded by the UK Medical Research Council, British Heart Foundation, National Institute for Health Research, European Union Framework 7, and the European Research Council.