Authors
  Paleologos M.  Cumming RG.  Lazarus R.
Institution
  Department of Public Health and Community Medicine, Faculty of Medicine,
  University of Sydney, New South Wales, Australia.
Title
  Cohort study of vitamin C
  intake and cognitive impairment.
Source
  American Journal of Epidemiology.  148(1):45-50, 1998 Jul 1.
Abstract
  To test the hypothesis that vitamin C protects against
  cognitive impairment, the authors conducted a cohort
  study (n=117) in a retirement community in Sydney,
  Australia. Vitamin C intake was assessed at baseline (1991)
  with a semiquantitative food frequency questionnaire, and cognitive function
  was assessed 4 years later (1995). After adjustment for age, sex, smoking,
  education, total energy intake, and use of psychotropic medications,
  consumption of vitamin C supplements was associated with a
  lower prevalence of more severe cognitive impairment (based on scores on the
  Mini-Mental State Examination; adjusted odds ratio=0.39, 95% confidence
  interval 0.18-0.84). There were no associations between
  vitamin C intake and scores on tests of verbal and category
  fluency. This study suggests that vitamin C
  might protect against cognitive impairment.