Associations between dietary intake of folate and vitamins B-12 and B-6 and self-reported cognitive function and psychological well-being in Australian men and women in midlife.

OBJECTIVES: To assess dietary intake status of folate and vitamins B-12 and B-6 in 1183 middle-aged men and women, and to examine associations between dietary intake of these vitamins and self-reported cognitive function and psychological well-being. METHODS: A population-based sample of urban and rural South Australians completed questionnaires assessing demographics, background, health, and self-reported cognitive and memory functioning and psychological well-being. Usual dietary intake status was estimated using a retrospective, self-report, quantified food frequency questionnaire. RESULTS: About 20% of both men and women had intakes of folate that were below the Recommended Daily Intake for Australia. Vitamins B-12 and B-6 were positively related to memory functioning in men, and moderate dietary intake of folate and B-6 was associated with better memory functioning in women. CONCLUSIONS: Vitamin B-12 and B-6 intakes may be positively related to the memory performance of middle-aged men and intakes at around the RDI are associated with better memory functioning for women. The investigation of the dose-response effects of B vitamin supplementation on cognition and mood in middle-aged men and women using objective measures of cognition and accounting for the influence of confounding factors such age and education would be informative.

B vitamins, cognition, and aging: a review.

Recent research has highlighted the potential impact of nutritional factors and individual micronutrients on the brain and on cognitive performance, especially in older adults. The B vitamins, folate, B12, and B6, are of particular interest because even subclinical deficiencies in these vitamins are thought to be relatively common in the general population and in older adults in particular. Recent cross-sectional and longitudinal studies have provided evidence for an association between these B vitamins and many aspects of cognitive performance and have raised the possibility that even subclinical differences in nutritional status may have a subtle influence on aspects of cognitive performance, especially in older adults and in clinical populations. Preliminary evidence also indicates the effectiveness of supplementation in enhancing cognitive performance in older adults. Important considerations for future research include the use of placebo-controlled intervention studies, sensitive outcome measures of cognitive performance, and exploration of bioavailability and dose-response relationships.