Vitamin E and cognitive decline in older persons

Abstract

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 x 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 x 10(-2) standardized units per year) compared with those in the lowest quintile (-6.7 x 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.

Conclusion: Vitamin E intake, from foods or supplements, is associated with less cognitive decline with age.