A 10-year study led by Professor You Weicheng of Peking University School of Clinical Oncology has confirmed that eliminating Helicobacter pylori infection in the stomach can reduce the risk of precancerous lesions and gastric cancer by 40 percent. The study is the world’s largest and longest intervention trial for precancerous lesions in the stomach, and is systematic and original, the first of its kind in domestic and international cancer research. Recently, the research results won the second prize of Chinese Medical Science and Technology Award. Since 1995, the group has conducted a study on the relationship between precancerous lesions and gastric cancer, lesion transformation and influencing factors, and genetic susceptibility in 3,400 adults in a high incidence area of gastric cancer in Linqu County, Shandong Province, using a large sample and prospective study method, and conducted a randomized multifactorial intervention study including eradication of H. pylori infection for etiology. The results of the study showed that H. pylori infection is an important risk factor for gastric cancer, and the eradication of H. pylori infection can effectively reduce the incidence of precancerous lesions such as chronic atrophic gastritis, intestinal epithelial metaplasia, heterogeneous hyperplasia and gastric cancer. Compared with the placebo group, the risk of these precancerous lesions and gastric cancer was reduced by 40% in the H. pylori clearance group. The study also confirmed that high levels of serum VC can stop the progression of precancerous lesions and is a protective factor in reducing the risk of gastric cancer. Individuals with high levels of serum VC had an 80% lower risk of lesions progressing to heterogeneous hyperplasia or gastric cancer. This indicates that good dietary habits and the consumption of fresh vegetables and fruits are beneficial to the prevention of gastric cancer.