Abstract PURPOSE: This study is to examine the role of dietary antioxidant intake on the severity of gastritis at the baseline in an intervention study, Chemoprevention of Gastric Dysplasia. METHODS: The Chemoprevention of Gastric Dysplasia is an intervention study conducted in the towns of Pasto and Tuquerres, Colombia. A 79-item food frequency questionnaire was administered to 1,219 subjects at baseline. Endoscopic screening for precancerous gastric lesions was performed in all subjects by biopsy and histologic diagnosis. Subjects without adequate diagnostic material (n = 18) and subjects identified as histologically normal (n = 12) or with gastric cancer (n = 4) were excluded from these analyses. Analysis of Variance on logarithm-transformed data was conducted on dietary antioxidants and the stages of gastritis (atrophic gastritis, intestinal metaplasia, and gastric dysplasia). RESULTS: After adjusting for age, body mass index, smoking status, year of education, total calorie intake, and H-pylori infection status, dietary vitamin C and vitamin E were found to be inversely associated with the severity of gastritis (p < 0.05). Decreased dietary α-carotene was found to be marginally associated with gastric dysplasia. Data were then stratified by town where subjects were recruited. The trends for the observed associations were apparent for dietary α-carotene, vitamin C and E. However, the association was significant only for vitamin C in Pasto. Compared to subjects with atrophic gastritis, subjects diagnosed with gastric dysplasia have an approximately 15% lower intake of vitamin C. CONCLUSIONS: This study confirmed the protective effect of specific dietary antioxidants on the severity of gastritis. Dietary vitamin C, and to a lesser extent, dietary vitamin E are potentially important for the prevention of gastric cancer.