Summary
Background
Low-risk limits recommended for alcohol consumption vary substantially across different
national guidelines. To define thresholds associated with lowest risk for all-cause
mortality and cardiovascular disease, we studied individual-participant data from
599 912 current drinkers without previous cardiovascular disease.
Methods
We did a combined analysis of individual-participant data from three large-scale data
sources in 19 high-income countries (the Emerging Risk Factors Collaboration, EPIC-CVD,
and the UK Biobank). We characterised dose–response associations and calculated hazard
ratios (HRs) per 100 g per week of alcohol (12·5 units per week) across 83 prospective
studies, adjusting at least for study or centre, age, sex, smoking, and diabetes.
To be eligible for the analysis, participants had to have information recorded about
their alcohol consumption amount and status (ie, non-drinker vs current drinker),
plus age, sex, history of diabetes and smoking status, at least 1 year of follow-up
after baseline, and no baseline history of cardiovascular disease. The main analyses
focused on current drinkers, whose baseline alcohol consumption was categorised into
eight predefined groups according to the amount in grams consumed per week. We assessed
alcohol consumption in relation to all-cause mortality, total cardiovascular disease,
and several cardiovascular disease subtypes. We corrected HRs for estimated long-term
variability in alcohol consumption using 152 640 serial alcohol assessments obtained
some years apart (median interval 5·6 years [5th–95th percentile 1·04–13·5]) from
71 011 participants from 37 studies.
Findings
In the 599 912 current drinkers included in the analysis, we recorded 40 310 deaths
and 39 018 incident cardiovascular disease events during 5·4 million person-years
of follow-up. For all-cause mortality, we recorded a positive and curvilinear association
with the level of alcohol consumption, with the minimum mortality risk around or below
100 g per week. Alcohol consumption was roughly linearly associated with a higher
risk of stroke (HR per 100 g per week higher consumption 1·14, 95% CI, 1·10–1·17),
coronary disease excluding myocardial infarction (1·06, 1·00–1·11), heart failure
(1·09, 1·03–1·15), fatal hypertensive disease (1·24, 1·15–1·33); and fatal aortic
aneurysm (1·15, 1·03–1·28). By contrast, increased alcohol consumption was log-linearly
associated with a lower risk of myocardial infarction (HR 0·94, 0·91–0·97). In comparison
to those who reported drinking >0–≤100 g per week, those who reported drinking >100–≤200
g per week, >200–≤350 g per week, or >350 g per week had lower life expectancy at
age 40 years of approximately 6 months, 1–2 years, or 4–5 years, respectively.
Interpretation
In current drinkers of alcohol in high-income countries, the threshold for lowest
risk of all-cause mortality was about 100 g/week. For cardiovascular disease subtypes
other than myocardial infarction, there were no clear risk thresholds below which
lower alcohol consumption stopped being associated with lower disease risk. These
data support limits for alcohol consumption that are lower than those recommended
in most current guidelines.
Funding
UK Medical Research Council, British Heart Foundation, National Institute for Health
Research, European Union Framework 7, and European Research Council.