National alcohol consumption guidelines vary substantially:
- in the USA, for example, there is an upper limit of 196 g per week (about 11 standard UK glasses of wine or pints of beer per week) is recommended for men, and an upper limit of 98 g per week is recommended for women
- similar recommendations apply in Canada and Sweden
- guidelines in Italy, Portugal, and Spain recommend low-risk limits almost 50% higher than these
- UK guidelines recommend low-risk limits for men that is substantionally lower than recommended by US guidelines - 14 units of alcohol per week (112 g per week)
The study undertaken by Wood et al sought to analysis the risks of all-cause mortality and cardiovascular disease associated with different amounts of weekly alcohol consumption (1).
Low-risk limits recommended for alcohol consumption vary substantially across different national guidelines
Study Aim
- 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
Methodology:
- 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)
- 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
- 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
- assessed alcohol consumption in relation to all-cause mortality, total cardiovascular disease, and several cardiovascular disease subtypes
Results
- in the 599912 current drinkers included in the analysis
- there were recorded 40310 deaths and 39018 incident cardiovascular disease events during 5.4 million person-years of follow-up
- for all-cause mortality
- recorded a positive and curvilinear association with the level of alcohol consumption, with the minimum mortality risk around or below 100 g per week
- for cardiovascular disease
- 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 to <=100 g (mean 56 g) per week, those who reported drinking
>100 to <=200 g per week had lower life expectancy at age 40 years of approximately 6 months,
>200 to <=350 g per week had lower life expectancy at age 40 years of approximately of 1-2 years,
>350 g per week had lower life expectancy at age 40 years of approximately 4-5 years
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
Notes:
- 100g of alcohol per week is equivalent to approximately 12.5 units of alcohol per week
Reference: