Antioxidant vitamin supplement use and risk of dementia or Alzheimer's disease in older adults.J Am Geriatr Soc 2008; 56(2):291-5JA
To examine whether use of vitamins C or E alone or in combination was associated with lower incidence of dementia or Alzheimer's disease (AD).
Prospective cohort study.
Group Health Cooperative, Seattle, Washington.
Two thousand nine hundred sixty-nine participants aged 65 and older without cognitive impairment at baseline in the Adult Changes in Thought study.
Participants were followed biennially to identify incident dementia and AD diagnosed according to standard criteria. Participants were considered to be users of vitamins C or E if they self-reported use for at least 1 week during the month before baseline.
Over a mean follow-up+/-standard deviation of 5.5+/-2.7 years, 405 subjects developed dementia (289 developed AD). The use of vitamin E was not associated with dementia (adjusted hazard ratio (HR)=0.98, 95% confidence interval (CI)=0.77-1.25) or with AD (HR=1.04; 95% CI=0.78-1.39). No association was found between vitamin C alone (dementia: HR=0.90, 95% CI=0.71-1.13; AD: HR=0.95, 95% CI=0.72-1.25) or concurrent use of vitamin C and E (dementia: HR=0.93, 95% CI=0.72-1.20; AD: HR=1.00, 95% CI=0.73-1.35) and either outcome.
In this study, the use of supplemental vitamin E and C, alone or in combination, did not reduce risk of AD or overall dementia over 5.5 years of follow-up.