Fighting the free radicals for improved cognition

Vitamin E and C supplements may have a positive effect on cognitive function in older women due to their antioxidative effects, suggest Harvard researchers.

The researchers cited experimental data that suggests oxygen free radicals are probably involved in the deterioration of cognitive processes. The study, led by Francine Godstein at the Harvard Medical School in the US, aimed to investigate the relation of high-dose antioxidant supplements such as vitamins E and C in cognition.

Information on the use of specific supplements containing vitamins E and C was collected biennially beginning in 1980 from nearly 15,000 women who participated in the Nurses' Health Study. From 1995 to 2000, researchers used telephone tests, including delayed recall of a ten-word list, immediate and delayed recall of a short paragraph and a verbal fluency test, to assess cognition in the women, aged 70-79 years old at that time.

The study confirmed that long-term, current users of vitamin E with vitamin C had significantly better mean performance on the test (judged by a global score that combined individual test results), than did women who had never taken vitamin E or C. There was also a trend for increasingly higher mean scores with increasing durations of use.

These associations were found to be strongest among women with low dietary intakes of vitamin E (alpha-tocopherol). Benefits were less consistent for women taking vitamin E alone, with no evidence of higher scores with longer durations of use. Vitamin C supplements alone had little relation to performance on the cognitive tests, report the researchers.

The scientists concluded that the use of specific vitamin E supplements, but not specific vitamin C supplements, may be related to modest cognitive benefits in older women. Vitamin E and C taken together has the most significant impact on healthy cognition.

Full details of the study can be found in the April 2003 edition of the American Journal of Clinical Nutrition​