title: Protective effect of vitamin C on oxidative stress: a randomized controlled trial.
abstract: BACKGROUND
  Although a number of reports regarding the role of reactive oxygen species (ROS) as the first step in cancer induction exist, few studies have investigated how vitamin C influences ROS in human plasma.
  
  
  OBJECTIVE
  Using the ROS assay system, a method recently established by one of the authors, we aimed to evaluate the effect of vitamin C supplementation on serum ROS among subjects diagnosed with chronic gastritis.
  
  
  METHODS
  A total of 244 Japanese subjects with atrophic gastritis were randomized to take 5-year supplementation of either 50 mg or 500 mg of vitamin C.
  
  
  RESULTS
  The adjusted difference in the changes of total ROS between baseline and after 5-year supplementation was statistically significant between the intervention groups: 2.70 decrease (corresponds to 1.26% decrease) in the high-dose group and 4.16 increase (corresponds to 3.79% increase) in the low-dose group, p for difference = 0.01.
  
  
  CONCLUSIONS
  Vitamin C was suggested to reduce oxidative stress among subjects with atrophic gastritis.
authors.affiliation: Epidemiology and Prevention Division, Research Center for Cancer Prevention and Screening National Cancer Center, 5-1-1 Tsukiji, Chuo-ku, Tokyo 104-0045, Japan. ssasazuk@gan2.res.ncc.go.jp
authors.forename: Shizuka
authors.initials: S
authors.lastname: Sasazuki
authors.forename: Tomonori
authors.initials: T
authors.lastname: Hayashi
authors.forename: Kei
authors.initials: K
authors.lastname: Nakachi
authors.forename: Satoshi
authors.initials: S
authors.lastname: Sasaki
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Tsubono
authors.forename: Shunji
authors.initials: S
authors.lastname: Okubo
authors.forename: Masato
authors.initials: M
authors.lastname: Hayashi
authors.forename: Shoichiro
authors.initials: S
authors.lastname: Tsugane
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D000975:Antioxidants / Q000378:metabolism / Q000627:therapeutic use*; D001205:Ascorbic Acid / Q000097:blood / Q000627:therapeutic use*; D002908:Chronic Disease; D019587:Dietary Supplements; D004305:Dose-Response Relationship, Drug; D005260:Female; D005757:Gastritis, Atrophic / Q000097:blood* / Q000382:microbiology; D016481:Helicobacter Infections / Q000097:blood / Q000382:microbiology; D016480:Helicobacter pylori; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress / Q000187:drug effects*; D017382:Reactive Oxygen Species / Q000097:blood
chemical_list: D000975:Antioxidants; D017382:Reactive Oxygen Species; D001205:Ascorbic Acid