title: Coffee and oxidative stress: a human intervention study.
abstract: OBJECTIVE
  Coffee is known to contain phytochemicals with antioxidant potential. The aim of this study was to investigate possible antioxidant effects of coffee in healthy human volunteers.
  
  
  METHODS
  A placebo-controlled intervention trial was carried out on 160 healthy human subjects, randomised into three groups, receiving 3 or 5 cups of study coffee or water per day, for 8 weeks. Blood samples were taken before, during, and after the intervention. Serum was used for analysis of blood lipids and standard clinical chemistry analytes. Peripheral blood mononuclear cells were isolated, and DNA damage (strand breaks and oxidised bases) was measured with the comet assay. The lipid oxidation product isoprostane 8-iso-PGF2α was assayed in urine samples by LC-MS/MS.
  
  
  RESULTS
  There was no significant effect of coffee consumption on the markers of oxidation of DNA and lipids. Creatinine (in serum) increased by a few per cent in all groups, and the liver enzyme γ-glutamyl transaminase was significantly elevated in serum in the 5 cups/day group. Other clinical markers (including glucose and insulin), cholesterol, triacylglycerides, and inflammatory markers were unchanged. There was no effect of coffee on blood pressure.
  
  
  CONCLUSIONS
  In a carefully controlled clinical trial with healthy subjects, up to 5 cups of coffee per day had no detectable effect, either beneficial or harmful, on human health.
authors.affiliation: NorGenoTech AS, Totenvegen 2049, 2848, Skreia, Norway. sas@norgenotech.no.|Department of Nutrition, Faculty of Medicine, University of Oslo, PB 1046 Blindern, 0316, Oslo, Norway. sas@norgenotech.no.
authors.forename: Sergey
authors.initials: S
authors.lastname: Shaposhnikov
authors.affiliation: Kraft Foods R & D Inc., Zweigniederlassung München, PB 830550, 81705, Munich, Germany.|, Johann-Straub-Weg 8, 81927, Muenchen, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Hatzold
authors.affiliation: Department of Nutrition, Faculty of Medicine, University of Oslo, PB 1046 Blindern, 0316, Oslo, Norway.
authors.forename: Naouale El
authors.initials: NE
authors.lastname: Yamani
authors.affiliation: Kraft Foods R & D Inc., Zweigniederlassung München, PB 830550, 81705, Munich, Germany.|Bunge North America, St. Louis, MO, USA.
authors.forename: Philip Mark
authors.initials: PM
authors.lastname: Stavro
authors.affiliation: NorGenoTech AS, Totenvegen 2049, 2848, Skreia, Norway.|Department of Nutrition, Faculty of Medicine, University of Oslo, PB 1046 Blindern, 0316, Oslo, Norway.
authors.forename: Yolanda
authors.initials: Y
authors.lastname: Lorenzo
authors.affiliation: Department of Environmental Chemistry, Norwegian Institute for Air Research, PB 100, 2027, Kjeller, Norway.
authors.forename: Maria
authors.initials: M
authors.lastname: Dusinska
authors.affiliation: TNO Triskelion, Zeist, The Netherlands.
authors.forename: Astrid
authors.initials: A
authors.lastname: Reus
authors.affiliation: TNO, Zeist, The Netherlands.
authors.forename: Wilrike
authors.initials: W
authors.lastname: Pasman
authors.affiliation: NorGenoTech AS, Totenvegen 2049, 2848, Skreia, Norway.|Department of Nutrition, Faculty of Medicine, University of Oslo, PB 1046 Blindern, 0316, Oslo, Norway.|Comet BioTech AS, Instituttveien 18, 2007, Kjeller, Norway.
authors.forename: Andrew
authors.initials: A
authors.lastname: Collins
mesh_terms: D000328:Adult; D000975:Antioxidants / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D015415:Biomarkers / Q000097:blood; D003069:Coffee / Q000009:adverse effects; D020552:Comet Assay; D003404:Creatinine / Q000097:blood; D015930:Diet Records; D000072001:Diet, Healthy; D005260:Female; D006801:Humans; D006949:Hyperlipidemias / Q000453:epidemiology / Q000209:etiology / Q000378:metabolism / Q000517:prevention & control*; D007963:Leukocytes, Mononuclear / Q000276:immunology; D008055:Lipids / Q000097:blood / Q000652:urine; D059012:Lost to Follow-Up; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000453:epidemiology / Q000209:etiology / Q000378:metabolism / Q000517:prevention & control*; D009426:Netherlands / Q000453:epidemiology; D018384:Oxidative Stress; D010349:Patient Compliance; D010352:Patient Dropouts; D012306:Risk
chemical_list: D000975:Antioxidants; D015415:Biomarkers; D003069:Coffee; D008055:Lipids; D003404:Creatinine
keywords: Coffee; DNA oxidation; Human intervention trial; Lipid oxidation