Relationship of cigarette smoking, alcohol use, and dietary habits with Helicobacter pylori infection in Japanese men

Background: Little is known of factors determining infection with Helicobacter pylori. Methods: In a cross-sectional study of 566 men aged 50-55 years, who received a preretirement health examination at the Self Defense Forces Fukuoka Hospital between January 1993 and December 1994, we examined the association of smoking, alcohol use, and dietary habits with H. pylori infection. Results: The overall seropositivity as determined with IgG antibody was 79.3% (449 of 565). The rank was inversely associated with the infection (trend, P = 0.048). Neither smoking nor alcohol drinking was related to the infection. The prevalence adjusted for rank tended to be lower in men consuming raw vegetables (trend, P = 0.12) daily than those with less consumption. Unexpectedly, the consumption of tofu (soybean curd) was significantly, negatively related to the infection (trend, P = 0.013). The seropositivity was unrelated to the consumption of pickled vegetables, soy paste soup, green tea, or garlic. Conclusion: The findings suggest that fresh vegetables may be protective against H. pylori infection. The study does not support either an increased risk of the infection associated with salty foods or a protective effect of green tea or garlic.