Allium vegetables to keep gastric cancer at bay…

▶ Zhou Y, Zhuang W, Hu W, et al. Consumption of large amounts of allium vegetables reduces risk for gastric cancer in a meta-analysis. Gastroenterology. Published Online First: 4 April 2011. doi:10.1053/j.gastro.2011.03.057.

Despite a declining incidence, gastric cancer remains the second most common cause of cancer death worldwide. The causative role of Helicobacter pylori in the disease is widely accepted, although, as yet, no country has instituted population screening and treatment as a prevention strategy. Some investigators have reported that the incidence of gastric cancer is lower in regions where the consumption of allium vegetables (onions, leeks, scallions, chives and garlic) is high. This meta-analysis of observational studies has attempted to synthesise all available published evidence examining this issue.

The authors identified 21 studies that included in excess of 500 000 individuals. When the occurrence of gastric cancer was compared between the highest and lowest categories of allium vegetable consumption, the odds of gastric cancer were significantly reduced (OR 0.54; 95% CI 0.43 to 0.65). There was statistically significant heterogeneity between individual study results, but no evidence of publication bias. Summary ORs were similar when subgroup analyses were conducted according to type of study and geographical region. When each allium vegetable was studied individually, there was a significant effect for all types, with the exception of onion …