The threshold for the lowest risk for all-cause mortality attributable to alcohol consumption is approximately 100 g of alcohol or 5 to 6 drinks per week, according to the results of a study published in The Lancet.
Alcohol consumption guidelines vary considerably from one country to another. The recommended upper limit for men in the United States is 196 g, or approximately 11 glasses of wine or pints of beer per week; the upper limit for women is 98 g per week. In Italy, Portugal, and Spain, low-risk limit recommendations are 50% higher than that, whereas in the United Kingdom, low-risk limits for men are about half those recommended in the US guidelines. Suggestions that moderate drinking lowers the risk for cardiovascular disease have been challenged by recent studies.
Angela M. Wood, PhD, of the Department of Public Health and Primary Care, University of Cambridge, in Cambridge, UK, and colleagues conducted a combined analysis of individual-participant data from 3 large-scale data sources in 19 high-income countries to characterize risk thresholds for all-cause mortality and cardiovascular disease subtypes in current alcohol drinkers. They characterized dose-response relationships and calculated hazard ratios (HRs) per 100 g per week of alcohol across 83 prospective studies, adjusting for study or center, age, sex, smoking, and diabetes. They assessed alcohol consumption in relation to all-cause mortality, total cardiovascular disease, and several cardiovascular disease subtypes.
The investigators included 599,912 current drinkers from 83 prospective studies in the analysis and recorded 40,310 deaths and 39,018 incident cardiovascular disease events during 5.4 million person-years of follow-up. They found a positive and curvilinear association between alcohol consumption and all-cause mortality with the minimum mortality at or below 100 g per week and a roughly linearly association with a higher risk for stroke (HR per 100 g per week higher consumption: 1.14), coronary disease with the exception of myocardial infarction (HR: 1.06), heart failure (HR: 1.09), fatal hypertensive disease (HR: 1.24), and fatal aortic aneurysm (HR: 1.15). In contrast, however, increased alcohol consumption was log-linearly associated with a lower risk for myocardial infarction (HR: 0.94).
The authors note that for men, reducing alcohol consumption from 196 g per week (current US recommendations for upper limit of alcohol consumption) to 100 g week or less increased life expectancy by 1 to 2 years at age 40 years. Reducing consumption from over 350 g per week increased life expectancy by 5 to 6 years. Exploratory analyses suggested that the highest risk for all-cause mortality was associated with consumption of beer or spirits and with binge drinking.
The authors argue that these data support adoption of lower limits of alcohol consumption than are currently recommended in most guidelines.
Wood AM, Kaptoge S, Butterworth AS, et al. Risk thresholds for alcohol consumption: combined analysis of individual-participant data for 599 912 current drinkers in 83 prospective studies. Lancet. 2018;391:1513-1523.