Is it health-promoting to drink alcohol daily? Research in the area is booming. What is the relationship between daily alcohol intake and risk of death from all causes?
The claim that low-dose alcohol use protects against all-cause mortality in the general population continues to be controversial 1 . Observational studies tend to show that people classified as “moderate drinkers” have longer life expectancies and are less likely to die from heart disease than those classified as abstainers. Systematic reviews and meta-analyses of this literature 3 confirm J-shaped risk curves – a protective effect at low doses and increasing risk at higher doses. However, results from several studies suggest that these relationships may be due to systematic biases.
Let’s repeat: One unit of alcohol is 12.8 g of pure alcohol, which corresponds to 33 cl of beer, 12.5 cl of wine, 7.5 cl of mulled wine, or 4 cl of spirits.
The purpose of the current study was to re-examine the connection between alcohol use and death from all causes, and how sources of error can change the results.
The results are based on 107 cohort studies with close to 5 million participants and over 400,000 deaths. The analysis model involved adjustment for potential confounders. The meta-analysis found no significantly reduced risk of death from all causes compared with non-drinkers among those who
- drank alcohol occasionally: 0-1.3 g ethanol per day, relative risk (RR) 0.96
- or who had a low to moderate alcohol intake: 1.3-24.0 g ethanol per day, RR 0.93
In the fully adjusted analysis model, they found a non-significantly increased risk of death among drinkers who consumed 25-44 g per day (RR 1.05), and significantly increased risk for those who drank 45 to 64 and 65 grams or more per day (RR 1.19 and 1.35). There was a significantly higher risk of death among female drinkers compared to female non-drinkers (RR 1.22).
The authors conclude that in this updated systematic overview and meta-analysis, daily low to moderate alcohol intake was not significantly associated with mortality from all causes, but the risk was increased for those who drank heavily and where this limit was lower for women than for men.