Low levels of alcohol consumption and risk of intestinal metaplasia: A cohort study

Background: The impact of alcohol drinking on gastric precancerous lesions remains unclear. We investigated the relationship of alcohol intake with risk of atrophic gastritis (AG) and intestinal metaplasia (IM). Methods: This study included 202,675 Korean adults free from AG and IM on their initial endoscopy who were followed with repeated endoscopic examinations. A parametric proportional hazards model was used to estimate the adjusted HR (aHR) with 95% confidence interval (CI) for incident AG and IM based on endoscopic diagnosis. Results: During a mean follow-up of 4.7 years, 64,853 incident AG cases and 4,536 IM cases were identified. Alcohol consumption including drinking frequency, quantity, and binge drinking were consistently associated with increased risk of both AG and IM in a dose–response manner. After adjustment for confounders, the multivariable aHRs (95% CIs) for incident IM comparing average alcohol intake of <10, 10–<20, 20–<40, and ≥40 g/day with lifetime abstainers were 1.27 (1.02–1.56), 1.34 (1.07–1.66), 1.50 (1.20–1.86), and 1.54 (1.23–1.93), respectively. Former drinkers were also at a higher risk for AG and IM compared with lifetime abstainers. These associations were consistently observed in never smokers and in time-dependent analyses. Conclusions: In a large cohort of Korean individuals, alcohol intake even at low levels was independently associated with increased risk of developing endoscopic AG and IM, supporting a role of alcohol consumption in the pathogenesis of AG and IM, the precursor lesions of stomach cancer. Impact: Alcohol consumption from low-level drinking may contribute to gastric carcinogenesis.