Fruits, vegetables, and antioxidants and risk of gastric cancer among male smokers

Abstract

The effect of consumption of fruits, vegetables, and antioxidants on the incidence of gastric cancer is inconclusive. In this prospective cohort study, we report the association of dietary intake of fruits, vegetables, antioxidants, and baseline serum levels of antioxidants with subsequent incidence of gastric cardia cancer (GCC) and gastric noncardia cancer (GNCC). Participants of this study were 29,133 male smokers recruited into the alpha-Tocopherol, beta-Carotene Cancer Prevention study between 1985 and 1988. At baseline, a self-administered food use questionnaire with 276 food items was used to assess dietary intake. Baseline serum samples were stored at -70 degrees C. During a median follow-up of 12 years, 243 incident gastric adenocarcinomas (64 GCC and 179 GNCC) were diagnosed in this cohort, of whom 220 (57 GCC and 163 GNCC) had complete dietary information. For GCC, high dietary intake of retinol was protective [hazard ratio (HR), 0.46; 95% confidence interval (95% CI), 0.27-0.78], but high intake of alpha-tocopherol (HR, 2.06; 95% CI, 1.20-3.54) and gamma-tocopherol (HR, 1.94; 95% CI, 1.13-3.34) increased risk. For GNCC, higher intakes of fruits (HR, 0.51; 95% CI, 0.37-0.71), vitamin C (HR, 0.60; 95% CI, 0.41-0.86), alpha-tocopherol (HR, 0.78; 95% CI, 0.55-1.10), gamma-tocopherol (HR, 0.69; 95% CI, 0.49-0.96), and lycopene (HR, 0.67; 95% CI, 0.47-0.95) were protective. Our results suggest a difference in the effect of some of these exposures on GCC and GNCC. Tocopherols were associated with higher risk of GCC, whereas dietary intake of fruits, vitamin C, tocopherols, and lycopene seemed protective for GNCC.