Volume of alcohol intake, heavy episodic drinking, and all-cause mortality in Spain: A longitudinal population-based study

•The impact of low quantities of alcohol consumption on health remains controversial.•Compared to infrequent occasional drinking, consuming low amounts of alcohol had no impact on mortality risk.•Never-drinkers, former drinkers, and those consuming > 20 g/day had higher risk.•Individuals with weekly heavy episodic drinking also experienced higher mortality risk. The impact of alcohol consumption on health, particularly in low quantities, remains controversial. Our objective was to assess the association between alcohol volume and heavy episodic drinking (HED) with all-cause mortality, while minimizing many of the known methodological issues. This longitudinal study used data from the 2011–2012 National Health Survey and the 2014 European Health Survey in Spain. Data from 43,071 participants aged ≥ 15 years were linked to mortality records as of December 2021. Alcohol consumption categories were defined based on intake volume and frequency: never-drinkers, former drinkers, infrequent occasional drinkers (≤once/month), frequent occasional drinkers ( once /month). Regular drinkers (≥once/week) were further classified by volume: >0–10 g/day, >10–20 g/day, >20–40 g/day, and > 40 g/day. Heavy Episodic Drinking (HED) was defined as ≥ 6 and ≥ 5 standard drinks (10 g) within 4–6 h for men and women, respectively. Hazard ratios (HR) were calculated using Cox regression, adjusting for sociodemographic variables, lifestyle factors, health status, and alcohol volume or HED. Compared to infrequent occasional drinkers, HRs for never-drinkers and former drinkers were 1.30 (95 %CI:1.14–1.47) and 1.32 (95 %CI:1.15–1.50), respectively. No differences in mortality risk were observed for intakes up to 20 g/day, but it increased for consumptions > 20–40 g/day and > 40 g/day (HR = 1.29; 95 %CI:1.05–1.58 and HR = 1.57; 95 %CI:1.14–2.17, respectively). The HR of weekly HED vs. never was 1.31 (95 %CI:0.98–1.75). Compared to infrequent occasional drinking, consuming low amounts of alcohol had no impact on mortality risk. However, never-drinkers, former drinkers, individuals with regular consumption > 20 g/day, and those engaging in weekly HED, experienced higher mortality risk.