Observed Effects of Alcohol Vary by Country Economic Level
The effects of alcohol on health seem to vary at the population level. Investigators studied a prospective sample of 114,970 adults from 12 countries and 5 continents. Median age was 50 years, 42% were men, and follow-up was a median of 4.3 years. People with current (past year) alcohol use (PCU) in low-income countries (LICs) were younger, less educated, and more likely to be male and smoke than those in high-income countries (HICs).
In analyses adjusted for age, body mass index, ethnicity, education, wealth, comorbidities, medications, physical activity, smoking, diet, and community, the authors found:
- No association between current drinking (even if low or “moderate”) and mortality, cardiovascular disease (CVD), or stroke, although high intake was associated with increased mortality (hazard ratio [HR], 1.3).*
- A reduction in myocardial infarction (HR, 0.76), an effect seen among those with low or “moderate” intake only, and in HICs and high-middle-income countries (HMICs) only.
- An increase in alcohol-related cancer (HR, 1.51) and injury (HR, 1.29).
- A pre-specified composite outcome (death, CVD, cancer, injury, hospital admission) was less common among PCU (HR, 0.84) and low (HR, 0.87) and ”moderate” (HR, 0.79) PCU in HICs and HMICs but not LICs or low-middle-income countries (LMICs); the composite outcome was more common among PCU with heavy episodes in LICs and LMICs but not HICs or HMICs.
* “Low”: <7 standard drinks in a week; “moderate”: 7–14 drinks in a week (women), 7–21 drinks in a week (men); “high”: >14 drinks in a week (women), >21 drinks in a week (men).
Comments:
The assumption that the health effects of alcohol are purely pharmacological is likely wrong. In this very large sample, the main message is twofold. First, most effects are of harm (cancer, injury, and death). Second, potentially beneficial effects appear to accrue only to those in high-income countries, which suggests that many of the observed beneficial health effects of alcohol are likely due to the characteristics of those who choose to drink and that the effects of alcohol vary according to other lifestyle factors.
Richard Saitz, MD, MPH
Reference:
Smyth A, Teo KK, Rangarajan S, et al. Alcohol consumption and cardiovascular disease, cancer, injury, admission to hospital, and mortality: a prospective cohort study. Lancet. 2015 [Epub ahead of print]. doi: 10.1016/S0140-6736(15)00235-4.