Vitamin E and Cognitive Decline in Older Persons
Martha Clare Morris, ScD; Denis A. Evans, MD; Julia L. Bienias, ScD; Christine C. Tangney, PhD; Robert S. Wilson, PhD
Source http://archneur.ama-assn.org
Background
Previous studies raise the possibility that antioxidants protect against neurodegenerative diseases.Objective
To examine whether intake of antioxidant nutrients, including vitamin E, vitamin C, and carotene, is associated with reduced cognitive decline with age.Design
Longitudinal population-based study conducted from September 17, 1993, to November 20, 2000, with an average follow-up of 3.2 years.Patients
The patients were 2889 community residents, aged 65 to 102 years, who completed a food frequency questionnaire, on average 18 months after baseline.Main Outcome Measure
Cognitive change as measured by 4 tests (the East Boston Memory Test, which tests immediate and delayed recall; the Mini-Mental State Examination; and the Symbol Digit Modalities Test) at baseline and 3 years for all participants, and at 6 months for 288 randomly selected participants.
Results
We used random-effects models to estimate nutrient effects on individual change in the average score of the 4 cognitive tests. The cognitive score declined on average by 5.0 10 -2 standardized units per year. There was a 36% reduction in the rate of decline among persons in the highest quintile of total vitamin E intake (-4.3 10 -2 standardized units per year) compared with those in the lowest quintile (-6.7 10 -2 standardized units per year) (P = .05), in a model adjusted for age, race, sex, educational level, current smoking, alcohol consumption, total calorie (energy) intake, and total intakes of vitamin C, carotene, and vitamin A. We also observed a reduced decline with higher vitamin E intake from foods (P = .03 for trend). There was little evidence of association with vitamin C or carotene intake.