Alcohol consumption and the risks of morbidity and mortality across 39 diseases and conditions: A population‐based cohort study in Korea

BACKGROUND AND AIMS: Alcohol is embedded in social life; however, alcohol control policies remain insufficiently enforced in Korea. Comprehensive evidence linking alcohol intake to disease and mortality is limited. This study estimated associations between alcohol consumption in Korea and risks of morbidity and mortality for 39 diseases and conditions. DESIGN: Retrospective cohort study using National Health Insurance Service (NHIS) data linked with death records from Statistics Korea. SETTING: Population-based customized NHIS data, a mandatory single-payer system covering the entire Korean population, between 2006 and 2022. PARTICIPANTS: 6 214 569 participants (57.36% males) aged ≥20 years who underwent two general health examinations during 2006-2009 and were disease-free at baseline. MEASUREMENTS: Alcohol consumption was categorized by drinking status and daily pure alcohol intake (seven levels in 10 g/day increments), averaged across two measurements (2006-2007, 2008-2009). The reference group comprised current abstainers at both examinations. Outcomes included incident cases, all-cause and cause-specific deaths for 39 diseases, followed through 2022. Covariates included age, income, body mass index, smoking, physical activity and comorbidities. Hazard ratios and lifetime risks were estimated. FINDINGS: At baseline, 79.3% of men and 39.0% of women were current drinkers. For cancer (450 738 cases), alcohol consumption was statistically significantly associated with increased risks of seven cancers in men and four in women. On average, lifetime incidence rate of alcohol-related cancers was 9.96% [95% confidence interval (CI) = 9.83-10.09] among current drinkers and 7.88% (95% CI = 7.73-8.03) among current abstainers in men (2.1% difference). Among women, corresponding rates were 10.28% (95% CI = 10.07-10.50) vs. 9.89% (95% CI = 9.78-9.99) (0.4% difference). For diseases of the circulatory system (2 998 902 cases of ten subtypes), alcohol consumption was associated with increased risks of eight subtypes in men and two in women. In contrast, J- or U-shaped association was observed for ischemic heart diseases, heart failure (men) and cardiac arrhythmias (women), which was no longer evident in analyses using light drinking as the reference. Additionally, statistically significant positive association was exhibited in 14 other conditions among men and six among women. For mortality, alcohol consumption was associated with a lifetime incidence rate of death from any cause of 41.70% (95% CI = 41.40-42.01), compared with 39.06% (95% CI = 38.69-39.43) among current abstainers in men, a 2.6% difference. It was also associated with mortality from 15 diseases in men and nine in women. CONCLUSIONS: Alcohol consumption in Korea appears to be associated with numerous diseases and conditions, highlighting the need for strengthened national alcohol control policies. Protective effects of alcohol on cardiac health should be interpreted with caution.