The effect of Atlantic salmon consumption on the cognitive performance of preschool children - A randomized controlled trial

Nutritional Quality Implications: Exploring the Impact of a Fatty Acid-Rich Diet on Central Nervous System Development

Given the comprehensive examination of the role of fatty acid-rich diets in central nervous system development in children, this study bridges significant gaps in the understanding of dietary effects on neurodevelopment. It delves into the essential functions of fatty acids in neurodevelopment, including their contributions to neuronal membrane formation, neuroinflammatory modulation, neurogenesis, and synaptic plasticity. Despite the acknowledged importance of these nutrients, this review reveals a lack of comprehensive synthesis in current research, particularly regarding the broader spectrum of fatty acids and their optimal levels throughout childhood. By consolidating the existing knowledge and highlighting critical research gaps, such as the effects of fatty acid metabolism on neurodevelopmental disorders and the need for age-specific dietary guidelines, this study sets a foundation for future studies. This underscores the potential of nutritional strategies to significantly influence neurodevelopmental trajectories, advocating an enriched academic and clinical understanding that can inform dietary recommendations and interventions aimed at optimizing neurological health from infancy.

Gut-brain communication mediates the impact of dietary lipids on cognitive capacity

Cognitive impairment, as a prevalent symptom of nervous system disorders, poses one of the most challenging aspects in the management of brain diseases. Lipids present in the cell membranes of all neurons within the brain and dietary lipids can regulate the cognition and memory function. In recent years, the advancements in gut microbiome research have enabled the exploration of dietary lipids targeting the gut-brain axis as a strategy for regulating cognition. This present review provides an in-depth overview of how lipids modulate cognition via the gut-brain axis depending on metabolic, immune, neural and endocrine pathways. It also comprehensively analyzes the effects of diverse lipids on the gut microbiota and intestinal barrier function, thereby affecting the central nervous system and cognitive capacity. Moreover, comparative analysis of the positive and negative effects is presented between beneficial and detrimental lipids. The former encompass monounsaturated fatty acids, short-chain fatty acids, omega-3 polyunsaturated fatty acids, phospholipids, phytosterols, fungal sterols and bioactive lipid-soluble vitamins, as well as lipid-derived gut metabolites, whereas the latter (detrimental lipids) include medium- or long-chain fatty acids, excessive proportions of n-6 polyunsaturated fatty acids, industrial trans fatty acids, and zoosterols. To sum up, the focus of this review is on how gut-brain communication mediates the impact of dietary lipids on cognitive capacity, providing a novel theoretical foundation for promoting brain cognitive health and scientific lipid consumption patterns.

Hippocampal neurogenesis and Arc expression are enhanced in high-fat fed prepubertal female pigs by a diet including omega-3 fatty acids and Bifidobacterium breve CECT8242

PURPOSE

Obesity during childhood has become a pandemic disease, mainly caused by a diet rich in sugars and fatty acids. Among other negative effects, these diets can induce cognitive impairment and reduce neuroplasticity. It is well known that omega-3 and probiotics have a beneficial impact on health and cognition, and we have hypothesized that a diet enriched with Bifidobacterium breve and omega-3 could potentiate neuroplasticity in prepubertal pigs on a high-fat diet.

METHODS

Young female piglets were fed during 10 weeks with: standard diet (T1), high-fat (HF) diet (T2), HF diet including B. breve CECT8242 (T3) and HF diet including the probiotic and omega-3 fatty acids (T4). Using hippocampal sections, we analyzed by immunocytochemistry the levels of doublecortin (DCX) to study neurogenesis, and activity-regulated cytoskeleton-associated protein (Arc) as a synaptic plasticity related protein.

RESULTS

No effect of T2 or T3 was observed, whereas T4 increased both DCX+ cells and Arc expression. Therefore, a diet enriched with supplements of B. breve and omega-3 increases neurogenesis and synaptic plasticity in prepubertal females on a HF diet from nine weeks of age to sexual maturity. Furthermore, the analysis of serum cholesterol and HDL indicate that neurogenesis was related to lipidic demand in piglets fed with control or HF diets, but the neurogenic effect induced by the T4 diet was exerted by mechanisms independent of this lipidic demand.

CONCLUSION

Our results show that the T4 dietary treatment is effective in potentiating neural plasticity in the dorsal hippocampus of prepubertal females on a HF diet.

Association between Elevated Iodine Intake and IQ among School Children in Portugal

The goal of this work was to examine whether elevated iodine intake was associated with adverse effects on IQ among school-age children in Portugal. In a representative sample of children from the north of the country, IQ percentiles by age (assessed with Raven’s Colored Progressive Matrices) were dichotomized to <50 (“below-average” IQs) and ≥50. Morning urine iodine concentrations, corrected for creatinine, were dichotomized to <250 µg/g and ≥250 µg/g, according to the European Commission/Scientific Committee on Food’s tolerable upper level of daily iodine intake for young children. Data were examined with Chi-square tests, logistic regression, and GLM univariate analysis. The sample (N = 1965) was classified as generally iodine-adequate (median urinary iodine concentration = 129 µg/L; median iodine-to-creatinine ratio = 126 µg/g) according to the WHO’s criteria. A greater proportion of children in the ≥250 µg/g group had below-average IQs, compared to children with less than 250 µg/g (p = 0.037), despite a sizable (though non-significant) proportion of children in the less-than-250 µg/g group also presenting below-average IQs, at the bottom of the iodine distribution (<50 µg/g). The proportion of below-average IQs increased with increasingly elevated iodine concentrations (p = 0.047). The association remained significant after the adjustment for confounders, with the elevated iodine group showing increased odds of having below-average IQs when compared with the non-elevated iodine group (OR 1.55; 95% CI 1.11−2.17; p = 0.011). Consistently, the former group presented a lower mean IQ than the latter (p = 0.006). High iodine intake was associated with lower IQs even in a population classified as iodine-adequate. These results bear on child cognition and on initiatives involving iodine supplementation.

The Effects of Nutritional Interventions on the Cognitive Development of Preschool-Age Children: A Systematic Review

The developing human brain requires all essential nutrients to form and to maintain its structure. Infant and child cognitive development is dependent on adequate nutrition. Children who do not receive sufficient nutrition are at high risk of exhibiting impaired cognitive skills. This systematic review aimed to examine the effects of nutritional interventions on cognitive outcomes of preschool-age children. PubMed, PsycInfo, Academic Search Complete, and Cochrane Library electronic databases were searched to identify Randomized Controlled Trials (RCTs) published after the year 2000. Studies assessing the effects of food-based, single, and multiple micronutrient interventions on the cognition of nourished and undernourished children aged 2-6 years were deemed eligible. A total of 12 trials were identified. Eight out of the twelve studies found significant positive effects on cognitive outcomes. Iron and multiple-micronutrients supplementation yield improvements in the cognitive abilities of undernourished preschool-age children. Increased fish consumption was found to have a beneficial effect in the cognitive outcomes of nourished children. On the other hand, B-vitamin, iodized salt, and guava powder interventions failed to display significant results. Findings of this review highlight the importance of adequate nutrition during preschool years, and the crucial role sufficient nutrition plays in cognitive development.

Twelve Weeks of Additional Fish Intake Improves the Cognition of Cognitively Intact, Resource-Limited Elderly People: A Randomized Control Trial

INTRODUCTION

Dietary omega 3 polyunsaturated fatty acids (PUFA) may reduce the risk of dementia. Many studies have investigated PUFA supplementation in high-income countries, yet food-based randomized control trials using omega 3 PUFA rich fish in lower to middle income countries, are lacking.

OBJECTIVE

To determine the effect on cognition of adding either fish or non-fish foods for twelve weeks to an enhanced diet of cognitively intact, independently living, resource-limited elderly people.

DESIGN

Randomized control trial (National Health Trial register: DOH-27-061-6026).

SETTING

Retirement center in urban South Africa.

PARTICIPANTS

Fifty-seven (74% female, mean age: 72±7 years) elderly participants with cognitive function exceeding 22 on the Mini Mental State Examination were randomized into an intervention (n=31) and control (n=26) group.

INTERVENTION

The usual diets of both groups were enhanced with context-appropriate foods to mimic elements of the Mediterranean-DASH Intervention for Neurodegenerative Delay (MIND) diet. The intervention group additionally received canned pilchards and fish spread every week amounting to an additional (theoretical) intake of 2.2g omega 3 PUFA daily. The control group received canned meatballs and texturized soya every week.

MEASUREMENTS

Cognition was measured twice before and once after the intervention phase using the Cognitive Abilities Screening Instrument (CASI). Adherence was assessed by a study-specific food frequency questionnaire and red blood cell (RBC) PUFA biomarkers. Data were analyzed using a non-parametric analysis of covariance (ANCOVA) with, and without, bootstrap imputation.

RESULTS

Participants in the intervention group had a significantly higher post intervention (P=0.036) CASI score than the control group, when the model was fitted with imputation and controlled for baseline scores. Participants in the intervention group also had a significantly higher intake of calculated dietary omega 3 PUFA and higher levels of RBC eicosapentaenoic acid and docosapentaenoic acid content than the control group (P < 0.05).

CONCLUSION

Twelve weeks of fish intake in the context of a modified MIND diet may improve the cognition of cognitively intact, resource-limited elderly people.

Locally-Procured Fish Is Essential in School Feeding Programmes in Sub-Saharan Africa

Fish make an important contribution to micronutrient intake, long-chained polyunsaturated omega-3 fatty acids (n-3 LC-PUFAS), and animal protein, as well as ensuring food and nutrition security and livelihoods for fishing communities. Micronutrient deficiencies are persistent in sub-Saharan Africa (SSA), contributing to public health issues not only in the first 1000 days but throughout adolescence and into adulthood. School feeding programs (SFPs) and home-grown school feeding programs (HGSF), which source foods from local producers, particularly fisherfolk, offer an entry point for encouraging healthy diets and delivering essential macro- and micronutrients to schoolchildren, which are important for the continued cognitive development of children and adolescents and can contribute to the realization of sustainable development goals (SDGs) 1, 2, 3, 5, and 14. The importance of HGSF for poverty alleviation (SDG1) and zero hunger (SDG 2) have been recognized by the United Nations Hunger Task Force and the African Union Development Agency-New Partnership for African Development (AUDA-NEPAD), which formulated a strategy for HGSF to improve nutrition for the growing youth population across Africa. A scoping review was conducted to understand the lessons learned from SFPs, which included fish and fish products from small-scale producers, identifying the challenges and best practices for the inclusion of fish, opportunities for improvements across the supply chain, and gaps in nutritional requirements for schoolchildren which could be improved through the inclusion of fish. Challenges to the inclusion fish in SFPs include food safety, supply and access to raw materials, organizational capacity, and cost, while good practices include the engagement of various stakeholders in creating and testing fish products, and repurposing fisheries by-products or using underutilized species to ensure cost-effective solutions. This study builds evidence of the inclusion of nutritious fish and fish products in SFPs, highlighting the need to replicate and scale good practices to ensure sustainable, community-centred, and demand-driven solutions for alleviating poverty, malnutrition, and contributing to greater health and wellbeing in adolescence.

Biomarkers and Fatty Fish Intake: A Randomized Controlled Trial in Norwegian Preschool Children

BACKGROUND

Biomarkers such as omega-3 (n-3) PUFAs, urinary iodine concentration (UIC), 1-methylhistidine (1-MH), and trimethylamine N-oxide (TMAO) have been associated with fish intake in observational studies, but data from children in randomized controlled trials are limited.

OBJECTIVES

The objective of this exploratory analysis was to investigate the effects of fatty fish intake compared with meat intake on various biomarkers in preschool children.

METHODS

We randomly allocated (1:1) 232 children, aged 4 to 6 y, from 13 kindergartens. The children received lunch meals of either fatty fish (herring/mackerel) or meat (chicken/lamb/beef) 3 times a week for 16 wk. We analyzed 86 biomarkers in plasma (n = 207), serum (n = 195), RBCs (n = 211), urine (n = 200), and hair samples (n = 210). We measured the effects of the intervention on the normalized biomarker concentrations in linear mixed-effect regression models taking the clustering within the kindergartens into account. The results are presented as standardized effect sizes.

RESULTS

We found significant effects of the intervention on the following biomarkers: RBC EPA (20:5n-3), 0.61 (95% CI: 0.36, 0.86); DHA (22:6n-3), 0.43 (95% CI: 0.21, 0.66); total n-3 PUFAs, 0.41 (95% CI: 0.20, 0.64); n-3/n-6 ratio, 0.48 (95% CI: 0.24, 0.71); adrenic acid (22:4n-6, -0.65 (95% CI: -0.91, -0.40), arachidonic acid (20:4n-6), -0.54 (95% CI: -0.79, -0.28); total n-6 PUFAs, -0.31 (95% CI: -0.56, -0.06); UIC, 0.32 (95% CI: 0.052, 0.59); hair mercury, 0.83 (95% CI: 0.05, 1.05); and plasma 1-MH, -0.35 (95% CI: -0.61, -0.094).

CONCLUSIONS

Of the 86 biomarkers, the strongest effect of fatty fish intake was on n-3 PUFAs, UIC, hair mercury, and plasma 1-MH. We observed no or limited effects on biomarkers related to micronutrient status, inflammation, or essential amino acid, choline oxidation, and tryptophan pathways.The trial was registered at clinicaltrials.gov (NCT02331667).

Effects of oily fish intake on cognitive and socioemotional function in healthy 8-9-year-old children: the FiSK Junior randomized trial

BACKGROUND

Long-chain n-3 PUFAs (n-3 LCPUFAs) accrete in the brain during childhood and affect brain development. Randomized trials in children show inconsistent effects of n-3 LCPUFAs on cognitive and socioemotional function, and few have investigated effects of fish per se.

OBJECTIVES

We aimed to investigate the effects of oily fish consumption on overall and domain-specific cognitive and socioemotional scores and explore sex differences.

METHODS

Healthy 8-9-y-old children (n = 199) were randomly allocated to receive ∼300 g/wk oily fish or poultry (control) for 12 ± 2 wk. At baseline and endpoint, we assessed attention, processing speed, executive functions, memory, emotions, and behavior with a large battery of tests and questionnaires and analyzed erythrocyte fatty acid composition.

RESULTS

One hundred and ninety-seven (99%) children completed the trial. Children in the fish group consumed 375 (25th-75th percentile: 325-426) g/wk oily fish resulting in 2.3 (95% CI: 1.9, 2.6) fatty acid percentage points higher erythrocyte n-3 LCPUFA than in the poultry group. The overall cognitive performance score tended to improve by 0.17 (95% CI: -0.01, 0.35) points in children who received fish compared with poultry, supported by n-3 LCPUFA dose dependency. This was driven mainly by fewer errors [-1.9 (95% CI: -3.4, -0.3)] in an attention task and improved cognitive flexibility measured as faster reaction time [-51 ms (95% CI: -94, -7 ms)] in a complex relative to a simple task ("mixing cost"). The fish intervention furthermore reduced parent-rated Strength and Difficulties Questionnaire total difficulties by -0.89 (95% CI: -1.60, -0.18) points mainly due to a -0.63 (95% CI: -1.11, -0.16) points reduction in internalizing problems that was reflected in tendency to a decrease in the overall socioemotional problems score of -0.13 (95% CI: -0.26, 0.01) points. The overall effects were similar in boys and girls.

CONCLUSIONS

Oily fish dose-dependently improved cognitive function, especially attention and cognitive flexibility, and reduced socioemotional problems. The results support the importance of n-3 LCPUFAs for optimal brain function and fish intake recommendations in children.The trial was registered at www.clinicaltrials.gov as NCT02809508.

Is high oily fish intake achievable and how does it affect nutrient status in 8-9-year-old children?: the FiSK Junior trial

PURPOSE

Most children do not meet dietary guidelines for fish intake. Fish is the main source of EPA (20:5n-3), DHA (22:6n-3) and vitamin D, but may replace better iron sources such as meat. We investigated if intake of 300 g/week oily fish was achievable in children and how it affected their nutrient status. Additionally, we validated a fish food frequency questionnaire (FFQ) by correlations against EPA + DHA in red blood cells (RBC).

METHODS

In a randomised 12-week trial, 199 children (8-9 years) received oily fish or poultry (control) to be eaten five times/week. We measured dietary intake and analysed fasting RBC EPA + DHA, serum 25-hydroxyvitamin D (25(OH)D), blood haemoglobin and plasma ferritin.

RESULTS

197 (99%) children completed the study. The median (25th-75th percentile) intake was 375 (325-426) and 400 (359-452) g/week oily fish and poultry, respectively. The fish group increased their intake of EPA + DHA by 749 (593-891) mg/day and vitamin D by 3.1 (1.6-3.8) µg/day. Endpoint RBC EPA + DHA was 2.3 (95% CI 1.9; 2.6) fatty acid %-point higher than the poultry group (P < 0.001). The fish group avoided the expected 25(OH)D winter decline (P < 0.001) and had 23%-point less vitamin D insufficiency (winter subgroup, n = 82). Haemoglobin and ferritin decreased slightly in both groups (P < 0.05), but the number of children with low values did not change (P > 0.14). FFQ estimates moderately reflected habitual intake (r = 0.28-0.35) and sufficiently captured intervention-introduced changes in intake (r > 0.65).

CONCLUSION

Oily fish intake of 300 g/week was achievable and improved children's EPA + DHA and 25(OH)D status, without markedly compromising iron status. These results justify public health initiatives focusing on children's fish intake.