Helicobacter pylori infection, garlic intake and precancerous lesions in aChinese population at low risk of gastric cancer

Background Cangshan County of Shandong Province has one of the lowest rates of gastric cancer (GC) in China. While intestinal metaplasia (IM) and dysp lasia (DYS) are less common in Cangshan than in areas of Shandong at high r isk of GC, these precursor lesions nevertheless affect about 20% of adults age greater than or equal to 55. Subjects and Setting In order to evaluate determinants of IM and DYS in Can gshan County, a low risk area of GC a survey was conducted among 214 adults who participated in a gastroscopic screening survey in Cangshan County in 1994. Method A dietary interview and measurement of serum Helicobacter pylori ant ibodies were performed. Reults The prevalence of H. pylori was lowest (19%) among those with normal gastric mucosa, rising steadily to 35% for superficial gastritis (SG), 56% for chronic atrophic gastritis (CAG), 80% for LM, and 100% for DYS. The pr evalence odds of precancerous lesions were compared with the odds of normal histology or SG. The odds ratio (OR) or CAG associated with H. pylori posi tivity was 4.2 (95% confidence interval [CI] : 1.7-10.0), while the OR of I M/DYS associated with H. pylori positivity was 31.5 (95% CI : 5.2-187). Aft er adjusting for H. pylori infection, drinking alcohol was a risk factor fo r CAG (OR = 3.2, 95% CI: 1.1-9.2) and IM/DYS (OR = 7.8, 95% CT:1.3-47.7). O n the other hand, consumption of garlic showed non-significant protective e ffects and an inverse association with H. pylori infection. Conclusions The findings of this study suggest that infection with H. pylor i is a risk factor and garlic may be protective, in the development and pro gression of advanced precancerous gastric lesions in an area of China at re latively low risk of GC.