Background & Aims: High alcohol consumption is associated with an increased risk of severe liver disease. Current recommendations suggest it is safe for men to consume 30 grams of alcohol per day. We investigated the association between alcohol consumption early in life and later development of severe liver disease.

Methods: We used data on alcohol consumption at conscription to military service from 43,296 men (18-20 years) in Sweden between 1969 and 1970. Outcomes were defined as incident diagnoses of severe liver disease from systematic national registration of clinical events until the end of 2009. A Cox regression model adjusted for body mass index, smoking, use of narcotics, cognitive ability and cardiovascular capacity was applied.

Results: During a mean follow-up of 37.8 years, 383 men developed severe liver disease. Alcohol consumption was associated with an increased risk of development of severe liver disease in a dose-response pattern (adjusted hazard ratio for every one gram/day increase 1.02; 95% CI 1.01-1.02). No evidence of a threshold effect was found. Importantly, a clear trend pointed towards an increased risk of severe liver disease in men who consumed less than 30 grams of alcohol per day.

Conclusion: Alcohol consumption in young men is associated with an increased risk of severe liver disease, up to 39 years later in life. The risk was dose-dependent, with no sign of a threshold effect. Current guidelines for safe alcohol intake in men might have to be revised.

Lay summary: We investigated more than 43,000 Swedish men in their late teens enlisted for conscription in 1969–1970. After almost 40 years of follow-up, we found that alcohol consumption was a significant risk factor for developing severe liver disease, independent of confounders. This risk was dose-dependent, and was most pronounced in men consuming two drinks per day or more.