title: Reducing carcinogenic acetaldehyde exposure in the achlorhydric stomach with cysteine.
abstract: BACKGROUND
  Acetaldehyde, associated with alcohol consumption, has recently been classified as a group 1 carcinogen in humans. Achlorhydric atrophic gastritis is a well-known risk factor for gastric cancer. Achlorhydria leads to microbial colonization of the stomach. Several of these microbes are able to produce significant amounts of acetaldehyde by oxidation from alcohol. Acetaldehyde can be eliminated from saliva after alcohol intake and during smoking with a semi-essential amino acid, L-cysteine. The aim of this study was to determine whether cysteine can be used to bind acetaldehyde in the achlorhydric stomach after ethanol ingestion.
  
  
  METHODS
  Seven volunteers with achlorhydric atrophic gastritis were given either slow-release L-cysteine or placebo capsules in a double-blinded randomized trial. Volunteers served as their own controls. A naso-gastric tube was inserted to each volunteer. The volunteers ingested placebo or 200 mg of L-cysteine capsules, and ethanol 0.3 g/kg body weight (15 vol%) was infused intragastrically through a naso-gastric tube. Five-milliliter samples of gastric contents were aspirated at 5-minute intervals.
  
  
  RESULTS
  During the follow-up period, the mean acetaldehyde level of gastric juice was 2.6 times higher with placebo than with L-cysteine (13 vs. 4.7 μM, p < 0.05, n = 7).
  
  
  CONCLUSIONS
  L-cysteine can be used to decrease acetaldehyde concentration in the achlorhydric stomach during alcohol exposure. Intervention studies with L-cysteine are needed on reducing acetaldehyde exposure in this important risk group for gastric cancer.
authors.affiliation: Research Unit on Acetaldehyde and Cancer, Faculty of Medicine, Biomedicum Helsinki, University of Helsinki, Finland.
authors.forename: Klas
authors.initials: K
authors.lastname: Linderborg
authors.forename: Tuuli
authors.initials: T
authors.lastname: Marvola
authors.forename: Martti
authors.initials: M
authors.lastname: Marvola
authors.forename: Mikko
authors.initials: M
authors.lastname: Salaspuro
authors.forename: Martti
authors.initials: M
authors.lastname: Färkkilä
authors.forename: Satu
authors.initials: S
authors.lastname: Väkeväinen
mesh_terms: D000079:Acetaldehyde / Q000378:metabolism*; D000126:Achlorhydria / Q000188:drug therapy* / Q000378:metabolism*; D002273:Carcinogens / Q000378:metabolism*; D003545:Cysteine / Q000008:administration & dosage* / Q000378:metabolism; D003692:Delayed-Action Preparations; D004311:Double-Blind Method; D005260:Female; D005500:Follow-Up Studies; D005750:Gastric Juice / Q000187:drug effects / Q000378:metabolism; D005753:Gastric Mucosa / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D013270:Stomach / Q000187:drug effects
chemical_list: D002273:Carcinogens; D003692:Delayed-Action Preparations; D000079:Acetaldehyde; D003545:Cysteine