title: Progressive commercial cigarette yield reduction: biochemical exposure and behavioral assessment.
abstract: BACKGROUND
  Mandated reduction of exposure to nicotine and other cigarette toxins has been proposed as a possible national regulatory strategy. However, tapering using lower yield commercial cigarettes may not be effective in reducing nicotine or tar exposure due to compensatory smoking behavior. We examined the effects of gradual reduction of nicotine yield in commercial cigarettes on smoking behavior, with an assessment of nicotine intake and exposure to tobacco smoke toxins.
  
  
  METHODS
  This 10-week longitudinal study of 20 smokers involved smoking the usual brand followed by different brands with progressively lower machine-determined yields, ranging from 0.9 to 0.1 mg nicotine, each smoked for 1 week. Subjects were followed for 4 weeks after returning to smoking the usual brand (or quitting). Smoking behaviors, biomarkers of tobacco smoke exposure, and cardiovascular effects were measured.
  
  
  RESULTS
  Cotinine and other biomarkers of smoke exposure remained unchanged comparing the usual brand with the 0.4 mg nicotine brands. A 30% to 40% decrease in nicotine, carbon monoxide, and carcinogen exposure comparing 0.1 mg nicotine cigarettes with baseline was observed. Self-efficacy was significantly increased and dependence decreased after tapering.
  
  
  CONCLUSIONS
  We confirm prior cross-sectional population and experimental studies showing complete compensation for cigarettes down to the 0.4 mg nicotine range. Nicotine and tobacco toxin exposure were substantially reduced while smoking 0.1 mg nicotine cigarettes. Our data suggest that the degree of nicotine dependence of smokers may be lowered with progressive yield tapering. Gradual tapering of smokers from regular to ultralow nicotine yield commercial cigarettes might facilitate smoking cessation and warrants future research.
authors.affiliation: Medical Service, San Francisco General Hospital Medical Center, and Department of Medicine, University of California at San Francisco, San Francisco, CA 94143-1220, USA. NBenowitz@MedSFGH.ucsf.edu
authors.forename: Neal L
authors.initials: NL
authors.lastname: Benowitz
authors.forename: Katherine M
authors.initials: KM
authors.lastname: Dains
authors.forename: Sharon M
authors.initials: SM
authors.lastname: Hall
authors.forename: Susan
authors.initials: S
authors.lastname: Stewart
authors.forename: Margaret
authors.initials: M
authors.lastname: Wilson
authors.forename: Delia
authors.initials: D
authors.lastname: Dempsey
authors.forename: Peyton
authors.initials: P
authors.lastname: Jacob
mesh_terms: D000293:Adolescent; D000328:Adult; D016739:Behavior, Addictive; D015415:Biomarkers / Q000378:metabolism*; D002319:Cardiovascular System; D002849:Chromatography, Gas; D002853:Chromatography, Liquid; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009538:Nicotine / Q000008:administration & dosage* / Q000378:metabolism*; D012907:Smoking / Q000453:epidemiology* / Q000378:metabolism*; D011795:Surveys and Questionnaires; D053719:Tandem Mass Spectrometry; D014029:Tobacco Use Disorder / Q000517:prevention & control*; D014026:Nicotiana
chemical_list: D015415:Biomarkers; D009538:Nicotine