title: Effect of dietary vitamin C on gastric cancer risk in the Korean population.
abstract: OBJECTIVE
  To investigate the effects of dietary vitamin C and foods containing vitamin C on gastric cancer risk.
  
  
  METHODS
  Our study included 830 control subjects and 415 patients. Data regarding demographics, medical history, and lifestyle, including dietary and nutrient intake, were collected using reliable self-administered questionnaires. Dietary intake information was collected from the participants using a food frequency questionnaire that has been previously reported as reliable and valid. A rapid urease test and a histological evaluation were used to determine the presence of Helicobacter pylori (H. pylori) infection. Twenty-three vitamin C-contributing foods were selected, representing over 80% of the cumulative vitamin C contribution.
  
  
  RESULTS
  In analyses adjusted for first-degree family history of gastric cancer, education level, job, household income, smoking status, and regular exercise, an inverse association between vitamin C intake and gastric cancer risk was observed for the highest (≥ 120.67 mg/d) vs the lowest (< 80.14 mg/d) intake category [OR (95%CI): 0.64 (0.46-0.88)], with a significant trend across the three intake categories (P = 0.007). No protective effect of vitamin C was detected after stratification by gender. No effect of vitamin C intake on the gastric cancer incidence was found in either men or women infected with H. pylori. Vitamin C-contributing foods, including cabbage [0.45 (0.32-0.63), 0.50 (0.34-0.75), 0.45 (0.25-0.81)], strawberries [0.56 (0.40-0.78), 0.49 (0.32-0.74), 0.52 (0.29-0.93)], and bananas [0.40 (0.29-0.57), 0.41 (0.27-0.62), 0.34 (0.19-0.63)], were protective factors against the risk of gastric cancer based on the results of the overall adjusted analyses and the results for men and women, respectively.
  
  
  CONCLUSIONS
  A protective effect of vitamin C and vitamin C-contributing foods against gastric cancer was observed. Further studies using larger sample sizes are required to replicate our results.
authors.affiliation: Bach Viet Hoang, Young-Woo Kim, Jeongseon Kim, Department of Cancer Control and Policy, Graduate School of Cancer Science and Policy, National Cancer Center, Goyang-si, Gyeonggi-do 10408, South Korea.
authors.forename: Bach Viet
authors.initials: BV
authors.lastname: Hoang
authors.affiliation: Bach Viet Hoang, Young-Woo Kim, Jeongseon Kim, Department of Cancer Control and Policy, Graduate School of Cancer Science and Policy, National Cancer Center, Goyang-si, Gyeonggi-do 10408, South Korea.
authors.forename: Jeonghee
authors.initials: J
authors.lastname: Lee
authors.affiliation: Bach Viet Hoang, Young-Woo Kim, Jeongseon Kim, Department of Cancer Control and Policy, Graduate School of Cancer Science and Policy, National Cancer Center, Goyang-si, Gyeonggi-do 10408, South Korea.
authors.forename: Il Ju
authors.initials: IJ
authors.lastname: Choi
authors.affiliation: Bach Viet Hoang, Young-Woo Kim, Jeongseon Kim, Department of Cancer Control and Policy, Graduate School of Cancer Science and Policy, National Cancer Center, Goyang-si, Gyeonggi-do 10408, South Korea.
authors.forename: Young-Woo
authors.initials: YW
authors.lastname: Kim
authors.affiliation: Bach Viet Hoang, Young-Woo Kim, Jeongseon Kim, Department of Cancer Control and Policy, Graduate School of Cancer Science and Policy, National Cancer Center, Goyang-si, Gyeonggi-do 10408, South Korea.
authors.forename: Keun Won
authors.initials: KW
authors.lastname: Ryu
authors.affiliation: Bach Viet Hoang, Young-Woo Kim, Jeongseon Kim, Department of Cancer Control and Policy, Graduate School of Cancer Science and Policy, National Cancer Center, Goyang-si, Gyeonggi-do 10408, South Korea.
authors.forename: Jeongseon
authors.initials: J
authors.lastname: Kim
mesh_terms: D000328:Adult; D001205:Ascorbic Acid; D002277:Carcinoma / Q000453:epidemiology*; D016022:Case-Control Studies; D004032:Diet / Q000706:statistics & numerical data*; D004040:Dietary Carbohydrates; D002149:Energy Intake; D005260:Female; D005638:Fruit; D016481:Helicobacter Infections / Q000453:epidemiology; D016480:Helicobacter pylori; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D065840:Protective Factors; D056910:Republic of Korea / Q000453:epidemiology; D012307:Risk Factors; D011198:Solanum tuberosum; D013274:Stomach Neoplasms / Q000453:epidemiology*; D011795:Surveys and Questionnaires
chemical_list: D004040:Dietary Carbohydrates; D001205:Ascorbic Acid
keywords: Gastric cancer; Helicobacter pylori; Korean population; Vitamin C; Vitamin C-contributing foods