Association Between Lifestyle Factors, Vitamin and Garlic Supplementation, and Gastric Cancer Outcomes

Key Points Question Are lifestyle factors associated with increased risk of gastric cancer (GC), and are they associated with changes in the long-term effects of vitamin and garlic supplementation on GC prevention in high-risk populations in China? Findings In this secondary analysis of a randomized clinical trial with 3365 participants, smoking, but not alcohol intake, was associated with increased risk of GC incidence and mortality; the beneficial effect of garlic supplementation on GC prevention was stronger for individuals who did not drink alcohol. Meaning The findings of this study provide evidence on the association of lifestyle factors with GC in high-risk populations and suggest that mass GC prevention strategies should be tailored to specific population subgroups to maximize potential beneficial effects.