An 18-mo randomized, double-blind, placebo-controlled trial of DHA-rich fish oil to prevent age-related cognitive decline in cognitively normal older adults.

Background: Fish oil trials in cognitively healthy older adults have yielded inconsistent results. Supplementation may differentially affect the domains that underpin cognitive performance, and effects may differ across sex or genotype. Objective: The aim of this study was to test whether docosahexaenoic acid (DHA)-rich fish oil slows 18-mo cognitive decline in cognitively healthy elders. Design: In a double-blind, randomized, placebo-controlled, parallel-group trial, cognitively healthy Australian community-dwelling adults (aged 65-90 y) consumed either 1720 mg DHA and 600 mg eicosapentaenoic acid or low-polyphenolic olive oil daily, as capsules, for 18 mo. Groups were allocated by permuted-block randomization and stratified by age. Cognitive assessment was conducted at baseline and then every 6 mo. Primary analyses tested the difference between groups in the rate of 18-mo cognitive change via latent growth curve models on any of the following: reasoning, working memory, short-term memory, retrieval fluency, and cognitive speed-related constructs. Treatment interactions with sex and APOE-ε4 were tested. Secondary outcomes were self-reported changes in well-being and everyday functioning, blood pressure, biomarkers of n-3 (ω-3) long-chain polyunsaturated fatty acids (LC PUFAs), lipids, glucose metabolism, inflammation, oxidative stress, DNA damage, and Mini-Mental State Examination. Results: A total of 403 people were randomly assigned. Data from those who completed baseline were analyzed (n = 390; intervention n = 194, control n = 196). Daily supplementation with 2.3 g DHA-rich fish oil for 18 mo did not maintain or improve cognitive performance. A small negative main effect was found on psychomotor speed (intervention = -0.02, 95% CI: -0.04 to 0.00; d = 0.24, P = 0.03). Treatment effects differed according to sex on retrieval fluency and some speed-based domains, including psychomotor speed, and according to APOE-ε4 carrier status on reaction time and reasoning. For secondary outcomes, treatment was associated with increased perceived cognitive mistakes (d = 0.24; P = 0.003), increased oxidative stress, and expected changes in fatty acid metabolism. Conclusions: Findings do not support supplementing older adults with fish oil to prevent cognitive decline. Treatment interactions with sex and APOE-ε4 carrier status warrant further investigation. This trial was registered at the Australia and New Zealand Clinical Trials Register (ANZCTR) as ACTRN12607000278437.

Cognitive performance in older adults is inversely associated with fish consumption but not erythrocyte membrane n-3 fatty acids.

Higher n-3 (ω-3) polyunsaturated fatty acids (PUFAs) and fish intake may help maintain cognitive function in older age. However, evidence is inconsistent; few studies have examined the relation in cognitively healthy individuals across numerous cognitive domains, and none to our knowledge have considered lifetime fish intake. We examined associations between multiple domains of cognition and erythrocyte membrane n-3 PUFA proportions and historical and contemporary fish intake in 390 normal older adults, analyzing baseline data from the Older People, Omega-3, and Cognitive Health trial. We measured n-3 PUFA in erythrocyte membranes, and we assessed historical and contemporary fish intake by food-frequency questionnaires. We assessed cognitive performance on reasoning, working memory, short-term memory, retrieval fluency, perceptual speed, simple/choice reaction time, speed of memory-scanning, reasoning speed, inhibition, and psychomotor speed. Cognitive outcomes for each construct were factor scores from confirmatory factor analysis. Multiple linear regression models controlled for a number of potential confounding factors, including age, education, sex, apolipoprotein E-ε 4 allele, physical activity, smoking, alcohol intake, socioeconomic variables, and other health-related variables. Higher erythrocyte membrane eicosapaentonoic acid proportions predicted slower perceptual and reasoning speed in females, which was attenuated once current fish intake was controlled. No other associations were present between n-3 PUFA proportions and cognitive performance. Higher current fish consumption predicted worse performance on several cognitive speed constructs. Greater fish consumption in childhood predicted slower perceptual speed and simple/choice reaction time. We found no evidence to support the hypothesis that higher proportions of long-chain n-3 fatty acids or fish intake benefits cognitive performance in normal older adults.

Effect of a 12-mo micronutrient intervention on learning and memory in well-nourished and marginally nourished school-aged children: 2 parallel, randomized, placebo-controlled studies in Australia and Indonesia.

BACKGROUND: Little is known about the combined effect of micronutrients and essential fatty acids on cognitive function in school-aged children. OBJECTIVE: We assessed the effect of micronutrients, long-chain n-3 fatty acids, or both on indicators of cognitive performance in well-nourished and marginally nourished school-aged children. DESIGN: Two 2-by-2 factorial randomized controlled double-blind trials were performed home-based in Adelaide, South Australia, and at 6 primary schools in Jakarta, Indonesia. A total of 396 children (aged 6-10 y) in Australia and 384 children in Indonesia were randomly allocated to receive a drink with a micronutrient mix (iron, zinc, folate, and vitamins A, B-6, B-12, and C), with docosahexanoic acid (DHA, 88 mg/d) and eicosapentaenoic acid (EPA, 22 mg/d), or with both or placebo 6 d/wk for 12 mo. Biochemical indicators were determined at baseline and 12 mo. Cognitive performance was measured at baseline, 6 mo, and 12 mo. RESULTS: The micronutrient treatment significantly improved plasma micronutrient concentrations in Australian and Indonesian children. DHA+EPA treatment increased plasma DHA and total plasma n-3 fatty acids in both countries. The micronutrient treatment resulted in significant increases in scores on tests representing verbal learning and memory in Australia (estimated effect size: 0.23; 95% CI: 0.01, 0.46). A similar effect was observed among Indonesian girls (estimated effect size: 0.32; 95% CI: -0.01, 0.64). No effects were found on tests measuring general intelligence or attention. No effects of DHA+EPA on the factors of cognitive tests were observed. CONCLUSION: In well-nourished school-aged children, fortification with multiple micronutrients can result in improvements in verbal learning and memory.

Nutrients for cognitive development in school-aged children.

This review considers the research to date on the role of nutrition in cognitive development in children, with a particular emphasis on the relatively neglected post-infancy period. Undernutrition and deficiencies of iodine, iron, and folate are all important for the development of the brain and the emergent cognitive functions, and there is some evidence to suggest that zinc, vitamin B12, and omega-3 polyunsaturated fatty acids may also be important. Considerations for future research include a focus on the interactions between micronutrients and macronutrients that might be influential in the optimization of cognitive development; investigation of the impact of nutritional factors in children after infancy, with particular emphasis on effects on the developing executive functions; and selection of populations that might benefit from nutritional interventions, for example, children with nutrient deficiencies or those suffering from attention deficit-hyperactivity disorder and dyslexia.

Symptom experience in Australian men and women in midlife.

OBJECTIVE: To compare the experience of vasomotor, psychological and somatic symptoms in Australian men and women in midlife, to investigate whether symptoms often attributed to endocrine changes in midlife are associated with health and psychological well-being, and to evaluate their relationship to menopausal status in women. METHODS: A cross-sectional, correlational, population-based study based on self-report questionnaires. Participants comprised 451 men and 766 women, aged between 39 and 65, from urban and rural South Australia, who responded to invitations to participate, or who volunteered to participate following media releases. Outcome measures used comprised a 47-item symptom checklist of current presence and severity of vasomotor, somatic and psychological symptoms experienced by men and women during midlife, and measures of health and psychological well-being. RESULTS: The majority of men and women reported that they were not 'bothered' by vasomotor, psychological and somatic symptoms. For those symptoms in which men and women differed significantly, women generally reported being more 'bothered' than men, although the pattern of association between symptoms and measures of health and psychological well-being was the same for both men and women. Items from all three symptom clusters were independently related to menopausal status. CONCLUSIONS: Health and psychological well-being play a role in the genesis of symptoms experienced by men and women in midlife. Both men and women experience similar symptoms, although women are more distressed by them signifying support for a menopausal syndrome in women. The finding of an independent relationship between menopausal status and psychological and somatic symptoms, in addition to the vasomotor symptoms, contradicts the narrow-estrogen hypothesis of climacteric symptoms.

Short-term folate, vitamin B-12 or vitamin B-6 supplementation slightly affects memory performance but not mood in women of various ages.

Based on research demonstrating associations between folate, B-12 and B-6 vitamins and cognition and mood, we investigated the effects of short-term supplementation in 211 healthy younger, middle-aged and older women who took either 750 microg of folate, 15 microg of vitamin B-12, 75 mg of vitamin B-6 or a placebo daily for 35 d. In addition, we examined associations between dietary intake of these vitamins and cognition and mood. Usual dietary intake status was estimated using a retrospective, self-report, quantified food frequency questionnaire. Participants completed alternate forms of standardized tests of cognitive processing resources, memory, executive function, verbal ability and self-report mood measures before and after supplementation. Supplementation had a significant positive effect on some measures of memory performance only, and no effect on mood. Dietary intake status was associated with speed of processing, recall and recognition and verbal ability.