title: High alcohol consumption in middle-aged adults is associated with poorer cognitive performance only in the low socio-economic group. Results from the GAZEL cohort study.
abstract: OBJECTIVE
  To examine the association of alcohol consumption over 10 years with cognitive performance in different socio-economic groups.
  
  
  METHODS
  Prospective cohort study, the French GAZEL study.
  
  
  METHODS
  France.
  
  
  METHODS
  Employees of France's national electricity and gas company.
  
  
  METHODS
  Alcohol intake was assessed annually, beginning in 1992, using questions on frequency and quantity of alcoholic beverages consumed in a week; used to define mean consumption and trajectory of alcohol intake over 10 years. Cognitive performance among participants aged ≥ 55 years (n = 4073) was assessed in 2002-04 using the Digit Symbol Substitution Test (DSST), a measure of psychomotor speed, attention and reasoning. Occupational position at age 35 and education were used as the markers of socio-economic position.
  
  
  RESULTS
  All analyses were stratified by socio-economic position. In the low occupational group, participants consuming a mean of more than 21 drinks per week had 2.1 points lower (95% CI: -3.9, -0.3) DSST score compared to those consuming four to 14 drinks per week. In participants with primary school education, the corresponding difference was 3.6 points (95% CI: -7.1, -0.0). No association between alcohol consumption and cognitive performance was observed in the intermediate and high socio-economic groups, defined using either occupation or education. Analysis of trajectories of alcohol consumption showed that in the low socio-economic groups large increase or decrease in alcohol consumption was associated with lower cognitive scores compared to stable consumption.
  
  
  CONCLUSIONS
  Our results suggest that high alcohol consumption is associated with poorer cognitive performance only in the low socio-economic group, due possibly to greater cognitive reserve in the higher socio-economic groups.
authors.affiliation: Centre for Research in Epidemiology and Population Health, Hôpital Paul Brousse, Villejuif, France. Severine.Sabia@inserm.fr
authors.forename: Séverine
authors.initials: S
authors.lastname: Sabia
authors.forename: Alice
authors.initials: A
authors.lastname: Guéguen
authors.forename: Claudine
authors.initials: C
authors.lastname: Berr
authors.forename: Lisa
authors.initials: L
authors.lastname: Berkman
authors.forename: Joël
authors.initials: J
authors.lastname: Ankri
authors.forename: Marcel
authors.initials: M
authors.lastname: Goldberg
authors.forename: Marie
authors.initials: M
authors.lastname: Zins
authors.forename: Archana
authors.initials: A
authors.lastname: Singh-Manoux
mesh_terms: D000328:Adult; D000367:Age Factors; D000428:Alcohol Drinking / Q000453:epidemiology*; D000434:Alcoholic Beverages / Q000706:statistics & numerical data*; D003072:Cognition Disorders / Q000453:epidemiology*; D015331:Cohort Studies; D015987:Effect Modifier, Epidemiologic; D005260:Female; D005602:France / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D011597:Psychomotor Performance / Q000187:drug effects; D012959:Socioeconomic Factors