Dementia and Alzheimer's disease in community-dwelling elders taking vitamin C and/or vitamin E

BACKGROUND: Since increased oxidative stress may impair cognition and be a risk factor for dementia, there has been interest in determining whether use of antioxidants could protect against such events. OBJECTIVE: To determine whether supplement use of vitamins C and/or E in a community-based sample of older African American and white individuals delayed incident dementia or Alzheimer's disease (AD). METHODS: We selected a subgroup from the Duke Established Populations for Epidemiologic Studies of the Elderly, a longitudinal study of community-representative persons aged 65-105 years living in 5 adjacent counties in North Carolina, and followed them for dementia (1986-1987 through June 2000). Information gathered during in-home interviews included sociodemographic characteristics, health status, health service use, and vitamin use. Diagnosis of dementia and AD was based on evaluations using the clinical and neuropsychological batteries of the Consortium to Establish a Registry for Alzheimer's Disease, with final determination by consensus agreement of specialists using Diagnostic and Statistical Manual of Mental Disorders, third revision, and National Institute for Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and Related Disorders criteria. RESULTS: Of 616 persons initially dementia-free (mean age 73 y; 62% female; 62% African American), 141 developed dementia, of whom 93 developed AD. Increased age and mobility problems were risk factors for dementia (only age for AD), while an increased number of outpatient visits reduced the likelihood of developing dementia. Neither use of any vitamins C and/or E (used by 8% of subjects at baseline) nor high-dose use reduced the time to dementia or AD. CONCLUSIONS: In this community in the southeastern US where vitamin supplement use is low, use of vitamins C and/or E did not delay the incidence of dementia or AD.