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

Background: 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.

Methods: 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.

Results: 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).

Conclusions: 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.