Allium vegetable intake and gastric cancer: A case–control study and meta-analysis




To provide new epidemiological data and summarize evidence on the association between allium vegetable intake and gastric cancer risk.

Methods and results

Data were from an Italian case–control study including 230 cases and 547 controls. Odds ratios were derived using multiple logistic regression. We combined results from all published studies using random-effect models. In our case–control study, the odds ratios were 0.59 (95% confidence interval, CI, 0.25–1.41) for ≥2 portions of onion per week, 0.69 (95% CI, 0.41–1.15) for high garlic intake, and 0.70 (95% CI, 0.39–1.28) for frequent use of both onion and garlic. Besides our study, 22 case–control and four cohort studies were included in the meta-analyses (>10 000 cases). The pooled relative risks for the highest versus lowest intake category were 0.78 (95% CI, 0.67–0.91) for allium vegetables (ten case–control and four cohort studies), 0.60 (95% CI, 0.47–0.76) for garlic (12 case–control studies), and 0.55 (95% CI, 0.41–0.73) for onion (13 case–control studies). The pooled relative risk for high allium vegetable intake from the four cohorts was 1.02 (95% CI, 0.88–1.18).


High allium vegetable consumption is likely to reduce gastric cancer risk. This evidence is derived mainly from case–control studies. Further data from large cohorts are desirable for conclusive confirmation.