title: Induction of CYP1A2 by heavy coffee consumption in Serbs and Swedes.
abstract: OBJECTIVE
  To investigate the influence of coffee consumption on CYP1A2 enzyme activity controlling for the effects of smoking and oral contraceptive (OC) use among Serbs and Swedes and to compare CYP1A2 activity between the two populations.
  
  
  METHODS
  Data on oral contraceptive use, habitual coffee consumption and smoking habits were obtained from 100 Serbian and 149 Swedish healthy volunteers using a detailed questionnaire. CYP1A2 activity was estimated by plasma paraxanthine/caffeine (17X/137X) ratio analysed by reversed-phase HPLC after oral administration of 100 mg caffeine.
  
  
  RESULTS
  Daily consumption of at least three cups of coffee significantly increased CYP1A2 enzyme activity in both Serbs (P=0.0002) and Swedes (P<0.0001). Among non-smokers and non-OC users, heavy coffee consumption significantly increased CYP1A2 activity in Serbs (mean difference 0.11; 95% CI of the mean difference 0.04, 0.18; P=0.003) and Swedes (mean difference 0.07; 95% CI of the mean difference 0.01, 0.12; P=0.02). Significantly higher 17X/137X ratio was detected in Serbian smokers compared to non-smokers. There was no significant gender difference in CYP1A2 activity in Serbs. Controlling for the effect of smoking, heavy coffee consumption habit and oral contraceptive use, significantly lower 17X/137X ratio was observed in Serbs than in Swedes (P=0.0003).
  
  
  CONCLUSIONS
  Habitual heavy coffee consumption increases CYP1A2 activity. Polycyclic aromatic hydrocarbons formed during roasting of coffee beans might partly be responsible for this effect. The reason for the observed lower CYP1A2 activity in Serbs as compared to Swedes remains to be investigated.
authors.affiliation: Division of Clinical Pharmacology, Department of Laboratory Medicine, Karolinska Institutet, Karolinska University Hospital, Huddinge, C1: 68, SE-14186, Stockholm, Sweden.
authors.forename: Natasa
authors.initials: N
authors.lastname: Djordjevic
authors.forename: Roza
authors.initials: R
authors.lastname: Ghotbi
authors.forename: Leif
authors.initials: L
authors.lastname: Bertilsson
authors.forename: Slobodan
authors.initials: S
authors.lastname: Jankovic
authors.forename: Eleni
authors.initials: E
authors.lastname: Aklillu
mesh_terms: D000293:Adolescent; D000328:Adult; D003069:Coffee / Q000009:adverse effects*; D019388:Cytochrome P-450 CYP1A2 / Q000096:biosynthesis*; D004790:Enzyme Induction / Q000187:drug effects; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D012907:Smoking / Q000378:metabolism; D013548:Sweden; D015022:Yugoslavia
chemical_list: D003069:Coffee; C504573:CYP1A2 protein, human; D019388:Cytochrome P-450 CYP1A2