Antioxidants improve cognition in elderly women - Geriatric Nutrition - Author Abstract

Nutrition Research Newsletter, May, 2003

As the population ages, there is a significant public health interest in determining ways to maintain cognitive functioning throughout later life. Experimental data has shown that it is likely that oxygen free radicals are involved in the deterioration of cognitive processes. Recently, observational studies have suggested that antioxidant intake may decrease the risk of developing Alzheimer disease. Additionally, randomized clinical trials of Alzheimer's patients have shown that very high doses of vitamin E resulted in a longer time living freely, without being institutionalized.

Recently, Boston investigators investigated the relation of specific vitamin E and vitamin C supplements, including the dose and duration, to performance on cognitive tests in older women. The Nurses' Health Study cohort, a group of female nurses longitudinally studied in regards to lifestyle and medical history beginning in 1976, was used in the present investigation. Collection of dietary information regarding vitamin supplements began in 1980. All Nurses' health Study participants who were free of diagnosed stroke, greater than 70 years of age and who had answered the most recent mailed questionnaire were eligible to participate in the study of cognitive function. A total of 22,213 women completed the interview.

The initial assessment consisted of the Telephone Interview for Cognitive Status (TICS), which is modeled on the Mini-Mental State Examination. After determining a high degree of acceptance to telephone interviews, researchers gradually included additional tests: immediate and delayed recall of the East Boston Memory Test (EBMT), delayed recall of the TICS 10-word list, a test of verbal fluency, and a digit span backwards test.

On each subsequent biennial questionnaire following 1980, subjects were asked about their specific use, including dose and duration, of specific vitamin E and vitamin C supplements. For each vitamin, investigators calculated duration on the basis of reported years of use from the 1980 questionnaires and then added time according to the women's responses to subsequent questionnaires.

Results revealed that long-term, current users of vitamin E with vitamin C had significantly better mean performances, as judged by a global score that combined the individual cognitive test scores, than did women who had never used vitamin E or C (P = 0.03). There was a trend for increasingly higher mean scores with increasing durations of use (P = 0.04). These associations were found to be strongest among women with low dietary intakes of alpha-tocopherol. The benefits were less consistent for women taking vitamin E alone, with no evidence of higher scores with longer durations of use. Additionally, use of vitamin C supplements alone had little relation to performance on the cognitive tests.

It appears that the use of specific vitamin E supplements, especially when combined with vitamin C supplements, may be beneficial in maintaining cognitive function during later adult years.

F. Grodstein, J. Cehn, W. Willett. High-dose antioxidant supplements and cognitive function in community-dwelling elderly women. Am J Clin Nutr;77:975-984 (April, 2003). [Correspondence: F Grodstein, Channing Laboratory, 181 Longwood Avenue, Boston, MA 02115. E-mail: fran.grodstein@channing.harvard.edu].