Nutrition and the development of cognitive functions: interpretation of behavioral studies in animals and human infants

Infant formula supplemented with milk fat globule membrane compared with standard infant formula for the cognitive development of healthy term-born formula-fed infants: protocol for a randomised controlled trial

INTRODUCTION

Milk fat globule membrane (MFGM) is a complex lipid-protein structure in mammalian milk and human milk that is largely absent from breastmilk substitutes. The objective of this trial is to investigate whether providing infant formula enriched with MFGM versus standard infant formula improves cognitive development at 12 months of age in exclusively formula-fed full-term infants.

METHODS AND ANALYSIS

This is a randomised, controlled, clinician-blinded, researcher-blinded and participant-blinded trial of two parallel formula-fed groups and a breastfed reference group that were recruited in the suburban Adelaide (Australia) community by a single study centre (a medical research institute). Healthy, exclusively formula-fed, singleton, term-born infants under 8 weeks of age were randomised to either an MFGM-supplemented formula (intervention) or standard infant formula (control) from enrolment until 12 months of age. The reference group was not provided with formula. The primary outcome is the Cognitive Scale of the Bayley Scales of Infant Development, Fourth Edition (Bayley-IV) at 12 months. Secondary outcomes are the Bayley-IV Cognitive Scale at 24 months, other Bayley-IV domains (language, motor, emotional and behavioural development) at 12 and 24 months of age, infant attention at 4 and 9 months of age, parent-rated language at 12 and 24 months of age, parent-rated development at 6 and 18 months of age as well as growth, tolerance and safety of the study formula. To ensure at least 80% power to detect a 5-point difference in the mean Bayley-IV cognitive score, >200 infants were recruited in each group.

ETHICS AND DISSEMINATION

The Women's and Children Health Network Human Research Ethics Committee reviewed and approved the study (HREC/19/WCHN/140). Caregivers gave written informed consent prior to enrolling in the trial. Findings of this study will be disseminated through peer-reviewed publications and conference presentations.

TRIAL REGISTRATION NUMBER

ACTRN12620000552987; Australian and New Zealand Clinical Trial Registry: anzctr.org.au.

An expert panel on the adequacy of safety data and physiological roles of dietary bovine osteopontin in infancy

Human milk, due to its unique composition, is the optimal standard for infant nutrition. Osteopontin (OPN) is abundant in human milk but not bovine milk. The addition of bovine milk osteopontin (bmOPN) to formula may replicate OPN's concentration and function in human milk. To address safety concerns, we convened an expert panel to assess the adequacy of safety data and physiological roles of dietary bmOPN in infancy. The exposure of breastfed infants to human milk OPN (hmOPN) has been well-characterized and decreases markedly over the first 6 months of lactation. Dietary bmOPN is resistant to gastric and intestinal digestion, absorbed and cleared from circulation within 8-24 h, and represents a small portion (<5%) of total plasma OPN. Label studies on hmOPN suggest that after 3 h, intact or digested OPN is absorbed into carcass (62%), small intestine (23%), stomach (5%), and small intestinal perfusate (4%), with <2% each found in the cecum, liver, brain, heart, and spleen. Although the results are heterogenous with respect to bmOPN's physiologic impact, no adverse impacts have been reported across growth, gastrointestinal, immune, or brain-related outcomes. Recombinant bovine and human forms demonstrate similar absorption in plasma as bmOPN, as well as effects on cognition and immunity. The panel recommended prioritization of trials measuring a comprehensive set of clinically relevant outcomes on immunity and cognition to confirm the safety of bmOPN over that of further research on its absorption, distribution, metabolism, and excretion. This review offers expert consensus on the adequacy of data available to assess the safety of bmOPN for use in infant formula, aiding evidence-based decisions on the formulation of infant formula.

Gestational protein restriction alters early amygdala neurochemistry in male offspring

BACKGROUND

Gestational protein intake restriction-induced long-lasting harmful outcomes in the offspring's organs and systems. However, few studies have focused on this event's impact on the brain's structures and neurochemical compounds.

AIM

The present study investigated the effects on the amygdala neurochemical composition and neuronal structure in gestational protein-restricted male rats' offspring.

METHODS

Dams were maintained on isocaloric standard rodent laboratory chow with regular protein [NP, 17%] or low protein content [LP, 6%]. Total cells were quantified using the Isotropic fractionator method, Neuronal 3D reconstruction, and dendritic tree analysis using the Golgi-Cox technique. Western blot and high-performance liquid chromatography performed neurochemical studies.

RESULTS

The gestational low-protein feeding offspring showed a significant decrease in birth weight up to day 14, associated with unaltered brain weight in youth or adult progenies. The amygdala cell numbers were unchanged, and the dendrites length and dendritic ramifications 3D analysis in LP compared to age-matched NP progeny. However, the current study shows reduced amygdala content of norepinephrine, epinephrine, and dopamine in LP progeny. These offspring observed a significant reduction in the amygdala glucocorticoid (GR) and mineralocorticoid (MR) receptor protein levels. Also corticotrophin-releasing factor (CRF) amygdala protein content was reduced in 7 and 14-day-old LP rats.

CONCLUSION

The observed amygdala neurochemical changes may represent adaptation during embryonic development in response to elevated fetal exposure to maternal corticosteroid levels. In this way, gestational malnutrition stress can alter the amygdala's neurochemical content and may contribute to known behavioral changes induced by gestational protein restriction.

Severe Gestational Low-Protein Intake Impacts Hippocampal Cellularity, Tau, and Amyloid-β Levels, and Memory Performance in Male Adult Offspring: An Alzheimer-Simile Disease Model?

Background:

Maternal undernutrition has been associated with psychiatric and neurological disorders characterized by learning and memory impairment.

Objective:

Considering the lack of evidence, we aimed to analyze the effects of gestational protein restriction on learning and memory function associated with hippocampal cell numbers and neurodegenerative protein content later in life.

Methods:

Experiments were conducted in gestational low- (LP, 6% casein) or regular-protein (NP, 17% casein) diet intake offspring. Behavioral tests, isolated hippocampal isotropic fractionator cell studies, immunoblotting, and survival lifetime were observed.

Results:

The birthweight of LP males is significantly reduced relative to NP male progeny, and hippocampal mass increased in 88-week-old LP compared to age-matched NP offspring. The results showed an increased proximity measure in 87-week-old LP compared to NP offspring. Also, LP rats exhibited anxiety-like behaviors compared to NP rats at 48 and 86-wk of life. The estimated neuron number was unaltered in LP rats; however, non-neuron cell numbers increased compared to NP progeny. Here, we showed unprecedented hippocampal deposition of brain-derived neurotrophic factor, amyloid-β peptide (Aβ), and tau protein in 88-week-old LP relative to age-matched NP offspring.

Conclusion:

To date, no predicted studies showed changes in hippocampal morphological structure in maternal protein-restricted elderly offspring. The current data suggest that gestational protein restriction may accelerate hippocampal function loss, impacting learning/memory performance, and supposedly developing diseases similar to Alzheimer’s disease (AD) in elderly offspring. Thus, we propose that maternal protein restriction could be an elegant and novel method for constructing an AD-like model in adult male offspring.

Role of Vitamins in Neurodegenerative Diseases: A Review

BACKGROUND

Vitamins are the micronutrients required for boosting the immune system and managing any future infection. Vitamins are involved in neurogenesis, a defense mechanism working in neurons, metabolic reactions, neuronal survival, and neuronal transmission. Their deficiency leads to abnormal functions in the brain like oxidative stress, mitochondrial dysfunction, accumulation of proteins (synuclein, Aβ plaques), neurodegeneration, and excitotoxicity.

METHODS

In this review, we have compiled various reports collected from PubMed, Scholar Google, Research gate, and Science direct. The findings were evaluated, compiled, and represented in this manuscript.

CONCLUSION

The deficiency of vitamins in the body causes various neurological disorders like Alzheimer's disease, Parkinson's disease, Huntington's disease, and depression. We have discussed the role of vitamins in neurological disorders and the normal human body. Depression is linked to a deficiency of vitamin-C and vitamin B. In the case of Alzheimer's disease, there is a lack of vitamin-B1, B12, and vitamin-A, which results in Aβ-plaques. Similarly, in Parkinson's disease, vitamin-D deficiency leads to a decrease in the level of dopamine, and imbalance in vitamin D leads to accumulation of synuclein. In MS, Vitamin-C and Vitamin-D deficiency causes demyelination of neurons. In Huntington's disease, vitamin- C deficiency decreases the antioxidant level, enhances oxidative stress, and disrupts the glucose cycle. Vitamin B5 deficiency in Huntington's disease disrupts the synthesis of acetylcholine and hormones in the brain.

The Influence of Prenatal DHA Supplementation on Individual Domains of Behavioral Functioning in School-Aged Children: Follow-Up of a Randomized Controlled Trial

Docosahexaenoic acid (DHA) accumulates in the fetal brain during pregnancy and is thought to have a role in supporting neurodevelopment. We conducted a multicenter, double-blind, randomized controlled trial in women with a singleton pregnancy who were <21 weeks’ gestation at trial entry. Women were provided with 800 mg DHA/day or a placebo supplement from trial entry until birth. When children reached seven years of age, we invited parents to complete the Strengths and Difficulties Questionnaire (SDQ), the Behavior Rating Inventory of Executive Function (BRIEF), and the Conners 3rd Edition Attention-Deficit Hyperactivity Disorder (ADHD) Index to assess child behavior and behavioral manifestations of executive dysfunction. There were 543 parent–child pairs (85% of those eligible) that participated in the follow-up. Scores were worse in the DHA group than the placebo group for the BRIEF Global Executive, Behavioral Regulation and Metacognition Indexes, and the Shift, Inhibit, Monitor, Working Memory, and Organization of Materials scales, as well as for the Conners 3 ADHD index, and the SDQ Total Difficulties score, Hyperactivity/Inattention score, and Peer Relationship Problems score. In this healthy, largely term-born sample of children, prenatal DHA supplementation conferred no advantage to childhood behavior, and instead appeared to have an adverse effect on behavioral functioning, as assessed by standardized parental report scales.

A Systematic Review of the Dietary Choline Impact on Cognition from a Psychobiological Approach: Insights from Animal Studies

The influence of dietary choline availability on cognition is currently being suggested by animal and human studies which have focused mainly on the early developmental stages. The aim of this review is to systematically search through the available rodent (rats and mice) research published during the last two decades that has assessed the effect of dietary choline interventions on cognition and related attentional and emotional processes for the entire life span. The review has been conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement guidelines covering peer-reviewed studies included in PubMed and Scopus databases. After excluding duplicates and applying the inclusion/exclusion criteria we have reviewed a total of 44 articles published in 25 journals with the contribution of 146 authors. The results are analyzed based on the timing and duration of the dietary intervention and the behavioral tests applied, amongst other variables. Overall, the available results provide compelling support for the relevance of dietary choline in cognition. The beneficial effects of choline supplementation is more evident in recognition rather than in spatial memory tasks when assessing nonpathological samples whilst these effects extend to other relational memory tasks in neuropathological models. However, the limited number of studies that have evaluated other cognitive functions suggest a wider range of potential effects. More research is needed to draw conclusions about the critical variables and the nature of the impact on specific cognitive processes. The results are discussed on the terms of the theoretical framework underlying the relationship between the brain systems and cognition.

Prenatal dietary choline supplementation modulates long-term memory development in rat offspring

Background: Previous studies on preclinical models have shown that giving supplemental choline during the embryonic period improves performance on memory tasks during adulthood. However, the effects of an early intervention on the development of cognitive functions in the immature brain have not been widely studied. In addition, it has been well established that short-term memory in rats emerges at an earlier stage than long-term memory.Objective: The aim of this work was to examine the effect of prenatal dietary choline supplementation on long-term memory development in rats.Methods: In order to assess long-term memory, we used an object-recognition task, which evaluates the ability to recall a previously presented stimulus. Pregnant rats were fed with the diets AIN 76-A standard (1.1 g choline/Kg food) or supplemented (5 g choline/Kg food) between embryonic days (E) 12 and E18. On the first post-natal day (PN 0), male offspring of the rats fed with the supplemented and standard diet were cross-fostered to rat dams fed a standard diet during pregnancy and tested at the age of PN21-22 or PN29-31 applying 24-hour retention tests.Results: The supplemented animals spent less time exploring the familiar object after a 24-hour retention interval, an effect that was observed in both the group tested at PN21-22 days of age and that tested at PN29-31 days. The non-supplemented rats only showed this effect in the group tested at PN29-31 days.Conclusions: These results suggest that prenatal supplementation with choline accelerates the development of long-term memory in rats.

The influence of DHA supplementation during pregnancy on language development across childhood: Follow-up of a randomised controlled trial

Numerous randomised controlled trials have explored the effect of docosahexaenoic acid (DHA) supplementation in early life on neurodevelopment, with some suggested positive effects on language. Australian women with a singleton pregnancy <21 weeks' gestation were randomised to receive 800 mg DHA/day or a placebo until birth. A sample of 726 children (all n=96 born preterm, random sample of n=630 born at term) were invited to undergo assessments of language, academic, and language-based cognitive abilities at 1.5, four and seven years of age. No group differences were detected for any group comparison. Exploratory analyses for sex by treatment interactions revealed a possible adverse effect of DHA supplementation on the language of females at 1.5 years but no effects on outcomes at four or seven years. Taken as a whole, evidence of an effect of prenatal DHA supplementation on language abilities across childhood is negligible and could be a chance finding.

Effects of maternal stress and nutrient restriction during gestation on offspring neuroanatomy in humans

Cognitive and mental health are major determinants of quality of life, allowing integration into society at all ages. Human epidemiological and animal studies indicate that in addition to genetic factors and lifestyle, prenatal environmental influences may program neuropsychiatric disorders in later life. While several human studies have examined the effects of prenatal stress and nutrient restriction on brain function and mental health in later life, potentially mediating effects of prenatal stress and nutrient restriction on offspring neuroanatomy in humans have been studied only in recent years. Based on neuroimaging and anatomical data, we comprehensively review the studies in this emerging field. We relate prenatal environmental influences to neuroanatomical abnormalities in the offspring, measured in utero and throughout life. We also assess the relationship between neuroanatomical abnormalities and cognitive and mental disorders. Timing- and gender-specific effects are considered, if reported. Our review provides evidence for adverse effects of an unfavorable prenatal environment on structural brain development that may contribute to the risk for cognitive, behavioral and mental health problems throughout life.

DHA supplementation in infants born preterm and the effect on attention at 18 months' corrected age: follow-up of a subset of the N3RO randomised controlled trial

Infants born preterm miss out on the peak period of in utero DHA accretion to the brain during the last trimester of pregnancy which is hypothesised to contribute to the increased prevalence of neurodevelopmental deficits in this population. This study aimed to determine whether DHA supplementation in infants born preterm improves attention at 18 months' corrected age. This is a follow-up of a subset of infants who participated in the N3RO randomised controlled trial. Infants were randomised to receive an enteral emulsion of high-dose DHA (60 mg/kg per d) or no DHA (soya oil - control) from within the first days of birth until 36 weeks' post-menstrual age. The assessment of attention involved three tasks requiring the child to maintain attention on toy/s in either the presence or absence of competition or a distractor. The primary outcome was the child's latency of distractibility when attention was focused on a toy. The primary outcome was available for seventy-three of the 120 infants that were eligible to participate. There was no evidence of a difference between groups in the latency of distractibility (adjusted mean difference: 0·08 s, 95 % CI -0·81, 0·97; P = 0·86). Enteral DHA supplementation did not result in improved attention in infants born preterm at 18 months' corrected age.

Developmental assessments during the first 5 years of life in infants fed breast milk, cow's milk formula, or soy formula

OBJECTIVE

To investigate the effects of infant feeding mode on childhood cognition and language as the differential effects of infant feeding on development remain understudied.

METHODS

Breastfed [BF, 174], cow's milk-based formula-fed [MF, 169], or soy protein-based formula-fed [SF, 161] children were longitudinally tested from age 3 to 60 months for neurodevelopment. Data were analyzed using mixed models while adjusting for multiple covariates. Sex differences were also assessed.

RESULTS

Standard scores were within established norms for all groups. There were no differences in mental development to age 24 months, yet BF children had significantly higher motor development scores at age 3 months than SF children (99.1 versus. 97.2). BF children had significantly higher composite intelligence scores at 48 months than MF and SF children (113.4 versus. 109.6 and 108.4, respectively) and higher verbal intelligence scores than SF children at 48 (105.6 versus. 100.7) and 60 months (109.8 versus. 105.9). Greater total language scores at ages 36 and 48 months were found in BF children compared with children fed MF or SF (p < .001), with differences between sexes for auditory comprehension. Higher total language scores at age 60 months were found between BF and SF (105.0 versus. 100.1).

CONCLUSION

Breastfeeding was associated with small, statistically significant, differences between children ages 3 and 5 years in verbal intelligence, expressive communication, and auditory comprehension with the latter having potential sexual dimorphic effects. Yet, these differences remain small and may not be of clinical relevance. Overall, MF and SF did not significantly differ.

Critical and Sensitive Periods in Development and Nutrition

Critical or sensitive periods in the life of an organism during which certain experiences or conditions may exert disproportionate influence (either for harm or benefit) on long-term developmental outcomes have been the subject of investigation for over a century. This chapter reviews research in the context of the development of social preferences and sensory systems, with a summary of the criteria for defining such a period and the evidence necessary to establish its existence. The notion of nutritional programming, central to the Barker/Developmental Origins hypotheses of health and disease, represents a variant of the critical/sensitive period concept. It is implicit in these hypotheses that the fetal period is a time during which metabolic and physiological systems are malleable and thus susceptible to either insult or enhancement by nutrient intake. Evidence for critical/sensitive periods or nutritional programming requires a systematic manipulation of the age at which nutritional conditions or supplements are implemented. While common in research using animal models, the approach is difficult to establish in epidemiological studies and virtually nonexistent in human clinical trials. Future work seeking to establish definitive evidence for critical/sensitive periods or programming may be advanced by harmonized outcome measures in experimental trials across which the timing, duration, and dose of nutrients is varied.

Female finches prefer courtship signals indicating male vigor and neuromuscular ability

Female songbirds use male song to discriminate among individuals and evaluate their quality as potential mates. Previous behavioral experiments in many species, including the species studied here, have shown that females will solicit copulation in response to song even if no male is present. Those data demonstrate that female mate choice is closely tied to song features, but they leave open the question of which song parameters are most influential in female mate selection. We sought to identify features of male song that are salient for mate choice in female Bengalese finches. Using a novel experimental approach, we simultaneously tested the possible influence of specific notes or note transitions, the number of different note types in the male’s repertoire, the complexity of note content and note sequence, and the stereotypy of note content and note sequence. In additional experiments, we also tested the influence of the pitch and tempo of note production. Our results demonstrate that females generally preferred songs containing increased tempo in the context of species-typical frequency bandwidth, consistent with the idea that females prefer songs that are especially challenging to produce. Female preference for song features that pose a neuromuscular challenge has also been reported in other species. Our data extend those observations into a species that thrives in a laboratory setting and is commonly used in studies of the neural basis of behavior. These results provide an excellent new model system in which to study female preference and the neural mechanisms that underlie signal evaluation and mate choice.

Effectiveness of a home fortification programme with multiple micronutrients on infant and young child development: a cluster-randomised trial in rural Bihar, India

Research demonstrates the importance of nutrition for early brain development. Few studies have examined the effectiveness of multiple micronutrient powders (MNP) on child development. This study examined the impacts of home fortification with MNP on motor and mental development, executive function and memory of children living in Bihar. This two-arm cluster-randomised effectiveness trial selected seventy health sub-centres to receive either MNP and nutrition counselling (intervention) or nutrition counselling alone (control) for 12 months. Front-line health workers delivered the intervention to all households in study communities with a child aged 6-18 months. Data were collected using cross-sectional surveys at baseline and endline by selecting households from intervention (baseline, n 2184; endline, n 2170) and control (baseline, n 2176; endline, n 2122) communities using a two-stage cluster-randomised sampling strategy. Children in the intervention group had a significantly larger improvement from baseline to endline compared with those in the control group on scores for motor and mental development (Cohen's d, motor=0·12; 95 % CI 0·03, 0·22; mental=0·15; 95 % CI 0·06, 0·25). Greater impacts of MNP on motor and mental development were observed in children from households with higher stimulation scores at baseline compared with those with lower stimulation (Cohen's d, motor=0·20 v. 0·09; mental=0·22 v. 0·14; P interaction<0·05). No significant treatment differences were seen for executive function or memory. Home fortification with MNP through the existing health infrastructure in Bihar was effective in improving motor and mental development and should be considered in combination with other child development interventions such as stimulation.

Antenatal Vitamin D Status Is Not Associated with Standard Neurodevelopmental Assessments at Age 5 Years in a Well-Characterized Prospective Maternal-Infant Cohort

Background

Although animal studies show evidence for a role of vitamin D during brain development, data from human studies show conflicting signals.

Objective

We aimed to explore associations between maternal and neonatal vitamin D status with childhood neurodevelopmental outcomes.

Methods

Comprehensive clinical, demographic, and lifestyle data were collected prospectively in 734 maternal-infant dyads from the Cork BASELINE Birth Cohort Study. Serum 25-hydroxyvitamin D [25(OH)D] concentrations were quantified at 15 weeks of gestation and in umbilical cord sera at birth via a CDC-accredited liquid chromatography-tandem mass spectrometry method. Children were assessed at age 5 y through the use of the Kaufman Brief Intelligence Test (2nd Edition, KBIT-2) and the Child Behaviour Checklist (CBCL). Linear regression was used to explore associations between 25(OH)D and neurodevelopmental outcomes.

Results

25(OH)D concentrations were <30 nmol/L in 15% of maternal and 45% of umbilical cord sera and <50 nmol/L in 42% of mothers and 80% of cords. At age 5 y, the mean ± SD KBIT-2 intelligence quotient (IQ) composite score was 104.6 ± 8.6; scores were 107.2 ± 10.0 in verbal and 99.8 ± 8.8 in nonverbal tasks. Developmental delay (scores <85) was seen in <3% of children across all domains. The mean ± SD CBCL total problem score was 21.3 ± 17.5; scores in the abnormal/clinical range for internal, external, and total problem scales were present in 12%, 4%, and 6% of participants, respectively. KBIT-2 and CBCL subscale scores at 5 y were not different between children exposed to low antenatal vitamin D status, either at 30 or 50 nmol/L 25(OH)D thresholds. Neither maternal nor cord 25(OH)D (per 10 nmol/L) were associated with KBIT-2 IQ composite scores [adjusted β (95% CI): maternal -0.01 (-0.03, 0.02); cord 0.01 (-0.03, 0.04] or CBCL total problem scores [maternal 0.01 (-0.04, 0.05); cord 0.01 (-0.07, 0.09)].

Conclusion

In this well-characterized prospective maternal-infant cohort, we found no evidence that antenatal 25(OH)D concentrations are associated with neurodevelopmental outcomes at 5 y. The BASELINE Study was registered at www.clinicaltrials.gov as NCT01498965; the SCOPE Study was registered at http://www.anzctr.org.au as ACTRN12607000551493.

Assessing whether early attention of very preterm infants can be improved by an omega-3 long-chain polyunsaturated fatty acid intervention: a follow-up of a randomised controlled trial

INTRODUCTION

Docosahexaenoic acid (DHA) accumulates in the frontal lobes (responsible for higher-order cognitive skills) of the fetal brain during the last trimester of pregnancy. Infants born preterm miss some of this in utero provision of DHA, and have an increased risk of suboptimal neurodevelopment. It is thought that supplementing infants born preterm with DHA may improve developmental outcomes. The aim of this follow-up is to determine whether DHA supplementation in infants born preterm can improve areas of the brain associated with frontal lobe function, namely attention and distractibility.

METHODS AND ANALYSIS

We will assess a subset of children from the N-3 (omega-3) Fatty Acids for Improvement in Respiratory Outcomes (N3RO) multicentre double-blind randomised controlled trial of DHA supplementation. Infants born <29 weeks' completed gestation were randomised to receive an enteral emulsion containing 60 mg/kg/day of DHA or a control emulsion from within the first 3 days of enteral feeding until 36 weeks' postmenstrual age.Children will undergo multiple measures of attention at 18 months' corrected age. The primary outcome is the average time to be distracted when attention is focused on a toy. Secondary outcomes are other aspects of attention, and (where possible) an assessment of cognition, language and motor development with the Bayley Scales of Infant and Toddler Development, Third Edition.A minimum of 72 children will be assessed to ensure 85% power to detect an effect on the primary outcome. Families, and research personnel are blinded to group assignment. All analyses will be conducted according to the intention-to-treat principal.

ETHICS AND DISSEMINATION

All procedures were approved by the relevant institutional ethics committees prior to commencement of the study. Results will be disseminated in peer-reviewed journal publications and academic presentations.

TRIAL REGISTRATION NUMBER

ACTRN12612000503820; Pre-results.

Effects of Nutritional Interventions during Pregnancy on Infant and Child Cognitive Outcomes: A Systematic Review and Meta-Analysis

BACKGROUND

Epidemiological studies have demonstrated that folate, iodine and iron intake during pregnancy impacts on foetal brain development and cognitive function. However, in human studies, the relationship with other dietary nutrients is less clear.

OBJECTIVE

This systematic review aims to critically appraise the current literature and meta-analyses results from nutritional interventions during pregnancy that aimed to optimise infant and child cognitive outcomes.

DESIGN

Ten electronic databases were searched for articles published up to August 2017. The search was limited to articles published in English. Randomised controlled trials (RCTs) testing the impact of any nutritional intervention (dietary counselling, education, nutrient supplementation, fortified foods and/or foods) during pregnancy on cognitive outcomes of children (<10 years old). Two independent reviewers assessed study eligibility and quality using the American Dietetic Association quality criteria checklist for primary research. Standardised mean differences were used for nine cognitive domains to measure effects for meta-analyses.

RESULTS

A total of 34 RCTs were included (21 studies included children aged less than 35 months, 10 studies included children aged 36-60 months and 3 studies included children aged 61-119 months). The types of nutritional interventions included nutrient supplements, whole foods, fortified foods and nutrition education. The following nine cognition outcomes: attention, behaviour, crystallised intelligence, fluid intelligence, global cognition, memory, motor skills, visual processing, and problem solving were not significantly impacted by nutritional interventions, although 65% of studies conducted post-hoc data analyses and were likely to be underpowered. Although, long chain polyunsaturated fatty acids (LCPUFA) supplementation was associated with a marginal increase in crystallised intelligence (Effect size (ES): 0.25; 95% confidence interval (95% CI): -0.04, 0.53), the effect was not statistically significant (p = 0.09), with significant study heterogeneity (p = 0.00).

CONCLUSIONS

LCPUFA supplementation may be associated with an improvement in child crystallised intelligence, however further research is warranted. The remaining eight cognition domains were not significantly impacted by maternal nutritional interventions.

Impact of diet-derived signaling molecules on human cognition: exploring the food-brain axis

The processes that define mammalian physiology evolved millions of years ago in response to ancient signaling molecules, most of which were acquired by ingestion and digestion. In this way, evolution inextricably linked diet to all major physiological systems including the nervous system. The importance of diet in neurological development is well documented, although the mechanisms by which diet-derived signaling molecules (DSMs) affect cognition are poorly understood. Studies on the positive impact of nutritive and non-nutritive bioactive molecules on brain function are encouraging but lack the statistical power needed to demonstrate strong positive associations. Establishing associations between DSMs and cognitive functions like mood, memory and learning are made even more difficult by the lack of robust phenotypic markers that can be used to accurately and reproducibly measure the effects of DSMs. Lastly, it is now apparent that processes like neurogenesis and neuroplasticity are embedded within layers of interlocked signaling pathways and gene regulatory networks. Within these interdependent pathways and networks, the various transducers of DSMs are used combinatorially to produce those emergent adaptive gene expression responses needed for stimulus-induced neurogenesis and neuroplasticity. Taken together, it appears that cognition is encoded genomically and modified by epigenetics and epitranscriptomics to produce complex transcriptional programs that are exquisitely sensitive to signaling molecules from the environment. Models for how DSMs mediate the interplay between the environment and various neuronal processes are discussed in the context of the food–brain axis.

Microcytosis is associated with low cognitive outcomes in healthy 2-year-olds in a high-resource setting

Fe deficiency in early childhood is associated with long-term consequences for cognitive, motor and behavioural development; however explorations in healthy children from low risk, high-resource settings have been limited. We aimed to explore associations between Fe status and neurodevelopmental outcomes in low risk, healthy 2-year-olds. This study was a secondary analysis of a nested case–control subgroup from the prospective, maternal-infant Cork Babies after Screening for Pregnancy Endpoints: Evaluating the Longitudinal Impact using Neurological and Nutritional Endpoints (BASELINE) Birth Cohort Study. At 2 years, serum ferritin, Hb and mean corpuscular volume (MCV) were measured and neurodevelopment was assessed using the Bayley Scales of Infant and Toddler Development (n 87). Five children had Fe deficiency (ferritin <12 µg/l) and no child had Fe deficiency anaemia (Hb<110 g/l+ferritin<12 µg/l). Children with microcytosis (MCV<74 fl, n 13) had significantly lower mean cognitive composite scores (88·5 (sd 13·3) v. 97·0 (sd 7·8), P=0·04, Cohen’s d effect size=0·8) than those without microcytosis. The ferritin concentration which best predicted microcytosis was calculated as 18·4 µg/l (AUC=0·87 (95% CI 0·75, 0·98), P<0·0001, sensitivity 92 %, specificity 75 %). Using 18·5 µg/l as a threshold, children with concentrations <18·5 µg/l had significantly lower mean cognitive composite scores (92·3 (sd 10·5) v. 97·8 (sd 8·1), P=0·012, Cohen’s d effect size=0·6) compared with those with ferritin ≥18·5 µg/l. All associations were robust after adjustment for potential confounding factors. Despite a low prevalence of Fe deficiency using current diagnostic criteria in this healthy cohort, microcytosis was associated with lower cognitive outcomes at 2 years. This exploratory study emphasises the need for re-evaluation of the diagnostic criteria for Fe deficiency in young children, with further research in adequately powered studies warranted.

Premature Brain Aging in Baboons Resulting from Moderate Fetal Undernutrition

Contrary to the known benefits from a moderate dietary reduction during adulthood on life span and health, maternal nutrient reduction during pregnancy is supposed to affect the developing brain, probably resulting in impaired brain structure and function throughout life. Decreased fetal nutrition delivery is widespread in both developing and developed countries, caused by poverty and natural disasters, but also due to maternal dieting, teenage pregnancy, pregnancy in women over 35 years of age, placental insufficiency, or multiples. Compromised development of fetal cerebral structures was already shown in our baboon model of moderate maternal nutrient reduction. The present study was designed to follow-up and evaluate the effects of moderate maternal nutrient reduction on individual brain aging in the baboon during young adulthood (4–7 years; human equivalent 14–24 years), applying a novel, non-invasive neuroimaging aging biomarker. The study reveals premature brain aging of +2.7 years (p < 0.01) in the female baboon exposed to fetal undernutrition. The effects of moderate maternal nutrient reduction on individual brain aging occurred in the absence of fetal growth restriction or marked maternal weight reduction at birth, which stresses the significance of early nutritional conditions in life-long developmental programming. This non-invasive MRI biomarker allows further longitudinal in vivo tracking of individual brain aging trajectories to assess the life-long effects of developmental and environmental influences in programming paradigms, aiding preventive and curative treatments on cerebral atrophy in experimental animal models and humans.

Vitamin B-12 and Cognition in Children

Vitamin B-12 is essential for brain development, neural myelination, and cognitive function. Inadequate vitamin B-12 status during pregnancy and early childhood has been associated with adverse child health outcomes, including impaired cognitive development. However, the underlying mechanisms have not been elucidated. This review was conducted to examine the evidence that links vitamin B-12 and cognition in children. The search strategy resulted in 17 studies: 3 cross-sectional, 1 case-control, and 12 cohort studies, and 1 randomized trial. Cognitive processes assessed included attention, memory, and perception. Developmental outcomes, academic performance, and intelligence quotient were also considered. Despite the high prevalence of vitamin B-12 insufficiency and associated risk of adverse cognitive outcomes in children, to our knowledge, no studies to date have been conducted to examine the effects of vitamin B-12 supplementation on cognition in children. The role of vitamin B-12 in the etiology of child cognitive outcomes needs to be elucidated to inform public health interventions.

Assessing infant cognitive development after prenatal iodine supplementation

Little information is available on infant behavioral development outcomes of prenatal iodine supplementation in regions of mild to moderate iodine deficiency. Studies performed to date, all of which relied on global developmental assessments, have yielded inconsistent findings with regard to psychomotor development, negative findings with regard to mental development, and no information as to the development of specific cognitive functions. Our review of these studies leads us to suspect that the use of global developmental assessments might partially explain the negative and inconsistent findings. To identify cognitive processes that might be sensitive to prenatal iodine supplementation, we examined the timing of thyroid hormone action on specific brain systems. The development of infant visual attention is sensitive to thyroid hormone during the early prenatal period, when the fetus is entirely dependent on maternal thyroid hormone. For this reason, infant visual attention has the potential to be a sensitive measure of infant outcomes in prenatal iodine supplementation studies. We suggest the assessment of infant visual attention, with follow-up examination of childhood executive functions, as a means of capturing the effects of maternal iodine deficiency and prenatal iodine supplementation on specific cognitive processes. In particular, we propose comparison of infant performance on global developmental tests and specialized tests of visual attention in pilot trials of prenatal iodine supplementation in regions of mild to moderate iodine deficiency. Only by comparing the 2 types of tests side by side will it be possible to establish whether the use of a sensitive measure of infant visual attention will increase the reliability of such supplementation studies. Recognizing that exposure misclassification may also provide a partial explanation for the inconsistent neurodevelopmental outcomes in previous studies, we suggest that urinary iodine concentration or creatinine-corrected iodine excretion be monitored regularly in such trials throughout the prenatal period.

Rearing Temperature Influences Adult Response to Changes in Mating Status

Rearing environment can have an impact on adult behavior, but it is less clear how rearing environment influences adult behavior plasticity. Here we explore the effect of rearing temperature on adult mating behavior plasticity in the butterfly Bicyclus anynana, a species that has evolved two seasonal forms in response to seasonal changes in temperature. These seasonal forms differ in both morphology and behavior. Females are the choosy sex in cohorts reared at warm temperatures (WS butterflies), and males are the choosy sex in cohorts reared at cooler temperatures (DS butterflies). Rearing temperature also influences mating benefits and costs. In DS butterflies, mated females live longer than virgin females, and mated males live shorter than virgin males. No such benefits or costs to mating are present in WS butterflies. Given that choosiness and mating costs are rearing temperature dependent in B. anynana, we hypothesized that temperature may also impact male and female incentives to remate in the event that benefits and costs of second matings are similar to those of first matings. We first examined whether lifespan was affected by number of matings. We found that two matings did not significantly increase lifespan for either WS or DS butterflies relative to single matings. However, both sexes of WS but not DS butterflies experienced decreased longevity when mated to a non-virgin relative to a virgin. We next observed pairs of WS and DS butterflies and documented changes in mating behavior in response to changes in the mating status of their partner. WS but not DS butterflies changed their mating behavior in response to the mating status of their partner. These results suggest that rearing temperature influences adult mating behavior plasticity in B. anynana. This developmentally controlled behavioral plasticity may be adaptive, as lifespan depends on the partner’s mating status in one seasonal form, but not in the other.

Global health and development in early childhood

Health and nutritional risks co-occur in the lives of children under the age of 2 years who live in developing countries. We review evidence showing how these risks, in addition to inadequate psychosocial stimulation, prevent children from developing expected cognitive and language abilities. A systematic review and meta-analysis of 21 interventions aimed at enhancing stimulation and 18 interventions that provided better nutrition--all conducted since 2000--revealed that stimulation had a medium effect size of 0.42 and 0.47 on cognitive and language development, respectively, whereas nutrition by itself had a small effect size of 0.09. The implementation processes of these interventions are described and compared. A number of unresolved issues are outlined and discussed, including ways to maximize parental health behavior change, assess mediators that account for intervention effects, and expand the assessment of young children's brain functions that underlie language and cognition and are affected by nutrition and stimulation.

Zinc supplementation sustained normative neurodevelopment in a randomized, controlled trial of Peruvian infants aged 6-18 months

A double-blind, randomized clinical trial was conducted to determine the effects of prevention of zinc deficiency on cognitive and sensorimotor development during infancy. At 6 mo of age, infants were randomly assigned to be administered a daily liquid supplement containing 10 mg/d of zinc (zinc sulfate), 10 mg/d of iron (ferrous sulfate), and 0.5 mg/d of copper (copper oxide), or an identical daily liquid supplement containing only 10 mg/d of iron and 0.5 mg/d of copper. Various controls were implemented to ensure adherence to the supplement protocol. A battery of developmental assessments was administered from 6 to 18 mo of age that included a visual habituation/recognition memory task augmented with heart rate at 6, 9, and 12 mo of age; the Bayley Scales of Infant Development, 2nd edition (BSID2) at 6, 12, and 18 mo; the A-not-B error task at 9 and 12 mo; and free-play attention tasks at 12 and 18 mo. Only infants supplemented with zinc had the normative decline in look duration from 6 to 12 mo during habituation and a normative decline in shifting between objects on free-play multiple-object attention tasks from 12 to 18 mo of age. The 2 groups did not differ on any of the psychophysiologic indices, the BSID2, or the A-not-B error task. The findings are consistent with zinc supplementation supporting a profile of normative information processing and active attentional profiles during the first 2 y of life. This trial was registered at clinicaltrials.gov as NCT00589264.

Randomized controlled trial of maternal omega-3 long-chain PUFA supplementation during pregnancy and early childhood development of attention, working memory, and inhibitory control

BACKGROUND

Docosahexaenoic acid (DHA) accumulates in the hippocampus and frontal lobes of the fetal brain during the last trimester of pregnancy. These areas of the brain contribute to attention and working memory and inhibitory control (WMIC).

OBJECTIVE

We evaluated the effect of maternal omega-3 (n-3) long-chain polyunsaturated fatty acid supplementation in pregnancy on child attention and WMIC.

DESIGN

A total of 185 term-born children of mothers who were randomly allocated to consume 800 mg DHA/d (treatment) or a placebo (control) from ∼20 wk of gestation until birth were assessed with multiple measures of attention and WMIC at a mean (± SD) of 27 ± 2 mo. Primary outcomes were the average time it took to be distracted when playing with a toy (distractibility) and the accuracy of remembering a new hiding location while inhibiting a learned response to search in the previous location (WMIC).

RESULTS

Assessments were completed by 81 children in the treatment group (mean ± SD age: 835 ± 50.4 d) and 77 children in the control group (839 ± 65.6 d). There was no effect of supplementation on primary outcomes [distractibility mean difference: -0.2 s (95% CI: -0.7, 0.4 s); WMIC mean difference: 8.9 mm (95% CI: -10.6, 28.3 mm)]. There was no difference between DHA-supplemented and control groups except that treatment-group children looked away from the toys fewer times than controls when presented with multiple toys competing for attention but less accurately remembered a repeated hiding location. These secondary effects were not consistent with any other outcomes and may have been a result of chance. Cord plasma DHA was not consistently associated with attention and WMIC.

CONCLUSION

Maternal DHA supplementation during pregnancy does not enhance attention or WMIC in term-born preschoolers. The DHA for Maternal and Infant Outcomes trial was registered at www.anzctr.org.au as ACTRN1260500056906.

Oral zinc supplementation may improve cognitive function in schoolchildren

Zinc is an important micronutrient for humans, and zinc deficiency among schoolchildren is deleterious to growth and development, immune competence, and cognitive function. However, the effect of zinc supplementation on cognitive function remains poorly understood. The purpose of our study was to evaluate the effect of oral zinc supplementation (5 mg Zn/day for 3 months) on the Full Scale Intelligence Quotient (FSIQ), Verbal Intelligence Quotient (VIQ), and Performance Intelligence Quotient (PIQ) using a Wechsler Intelligence Scale for Children (WISC-III). We studied 36 schoolchildren aged 6 to 9 years (7.8 ± 1.1) using a nonprobability sampling method. The baseline serum zinc concentrations increased significantly after zinc supplementation (p < 0.0001), with no difference between sexes. Tests were administered under basal conditions before and after zinc supplementation, and there was no difference in FSIQ according to gender or age. The results demonstrated that zinc improved the VIQ only in the Information Subtest (p = 0.009), although the supplementation effects were more significant in relation to the PIQ, as these scores improved for the Picture Completion, Picture Arrangement, Block Design, and Object Assembly Subtests (p = 0.0001, for all subtests). In conclusion, zinc supplementation improved specific cognitive abilities, thereby positively influencing the academic performance of schoolchildren, even those without marginal zinc deficiency.

Fish oil-supplementation from 9 to 12 months of age affects infant attention in a free-play test and is related to change in blood pressure

INTRODUCTION

This intervention examined whether fish-oil-supplementation in late infancy modifies free-play test scores and if this is related to blood pressure (BP) and mean RR interval.

PATIENTS AND METHODS

83 Danish 9-month-old infants were randomized to ±fish oil (FO) (3.4±1.1mL/d) for 3months and 61 of these completed the free-play-test before and after the intervention.

RESULTS

Most of the free-play scores changed during the intervention, but the intervention affected only the number of looks away from the toy, which was increased in +FO and decreased in -FO (p=0.037). The increased numbers of looks away were associated with an increase in erythrocyte eicosapentaenoic acid (r=0.401, p=0.017, n=35) and were also associated with a decrease in systolic-BP (r=-0.511, p<0.001, n=52).

CONCLUSIONS

The results indicate that n-3 fatty acid intake also in late infancy can influence brain development and that the cognitive and cardiovascular effects may be related.

The role of gangliosides in brain development and the potential benefits of perinatal supplementation

The maternal diet provides critical nutrients that can influence fetal and infant brain development and function. This review highlights the potential benefits of maternal dietary ganglioside supplementation on fetal and infant brain development. English-language systematic reviews, preclinical studies, and clinical studies were obtained through searches on PubMed. Reports were selected if they included benefits and harms of maternal ganglioside supplementation during pregnancy or ganglioside-supplemented formula after pregnancy. The potential benefits of ganglioside supplementation were explored by investigating the following: (1) their role in neural development, (2) their therapeutic use in neural injury and disease, (3) their presence in human breast milk, and (4) their use as a dietary supplement during or after pregnancy. Preclinical studies indicate that ganglioside supplementation at high doses (1% of total dietary intake) can significantly increase cognitive development and body weight when given prenatally. However, lower ganglioside supplementation doses have no beneficial cognitive effects, even when given throughout pregnancy and lactation. In human clinical trials, infants given formula supplemented with gangliosides showed increased cognitive development and an increase in ganglioside content. Ganglioside supplementation may promote brain development and function in offspring when administered at the optimum dosage. We propose that prenatal maternal dietary supplementation with gangliosides throughout pregnancy may promote greater long-term effects on brain development and function. Before this concept can be encouraged in preconception clinics, future research and clinical trials are needed to confirm the ability of dietary gangliosides to improve cognitive development, but available results already encourage this area of research.

Long-term effects of LCPUFA supplementation on childhood cognitive outcomes

BACKGROUND

The effect of long-chain polyunsaturated fatty acid (LCPUFA) intake on cognitive development is controversial. Most randomized trials have assessed cognition at 18 mo, although significant development of cognitive abilities (early executive function) emerge later.

OBJECTIVE

The objective was to evaluate cognition beyond 18 mo and longitudinal cognitive change from 18 mo to 6 y in children who were fed variable amounts of docosahexaenoic acid (0.32%, 0.64%, and 0.96% of total fatty acids) and arachidonic acid (ARA; 0.64%) compared with children who were not fed LCPUFA as infants.

DESIGN

Eighty-one children (19 placebo, 62 LCPUFA) who participated in a double-blind, randomized trial of LCPUFA supplementation as infants were re-enrolled at 18 mo and tested every 6 mo until 6 y on age-appropriate standardized and specific cognitive tests.

RESULTS

LCPUFA supplementation did not influence performance on standardized tests of language and performance at 18 mo; however, significant positive effects were observed from 3 to 5 y on rule-learning and inhibition tasks, the Peabody Picture Vocabulary Test at 5 y, and the Weschler Primary Preschool Scales of Intelligence at 6 y. Effects of LCPUFAs were not found on tasks of spatial memory, simple inhibition, or advanced problem solving.

CONCLUSIONS

The data from this relatively small trial suggest that, although the effects of LCPUFAs may not always be evident on standardized developmental tasks at 18 mo, significant effects may emerge later on more specific or fine-grained tasks. The results imply that studies of nutrition and cognitive development should be powered to continue through early childhood. This parent trial was registered at clinicaltrials.gov as NCT00266825.

The effects of prenatal and early postnatal tocotrienol-rich fraction supplementation on cognitive function development in male offspring rats

BACKGROUND

Recent findings suggest that the intake of specific nutrients during the critical period in early life influence cognitive and behavioural development profoundly. Antioxidants such as vitamin E have been postulated to be pivotal in this process, as vitamin E is able to protect the growing brain from oxidative stress. Currently tocotrienols are gaining much attention due to their potent antioxidant and neuroprotective properties. It is thus compelling to look at the effects of prenatal and early postnatal tocotrienols supplementation, on cognition and behavioural development among offsprings of individual supplemented with tocotrienols. Therefore, this study is aimed to investigate potential prenatal and early postnatal influence of Tocotrienol-Rich Fraction (TRF) supplementation on cognitive function development in male offspring rats. Eight-week-old adult female Sprague Dawley (SD) rats were randomly assigned into five groups of two animals each. The animals were fed either with the base diet as control (CTRL), base diet plus vehicle (VHCL), base diet plus docosahexanoic acid (DHA), base diet plus Tocotrienol-Rich fraction (TRF), and base diet plus both docosahexaenoic acid, and tocotrienol rich fraction (DTRF) diets for 2 weeks prior to mating. The females (F0 generation) were maintained on their respective treatment diets throughout the gestation and lactation periods. Pups (F1 generation) derived from these dams were raised with their dams from birth till four weeks post natal. The male pups were weaned at 8 weeks postnatal, after which they were grouped into five groups of 10 animals each, and fed with the same diets as their dams for another eight weeks. Learning and behavioural experiments were conducted only in male off-spring rats using the Morris water maze. Eight-week-old adult female Sprague Dawley (SD) rats were randomly assigned into five groups of two animals each. The animals were fed either with the base diet as control (CTRL), base diet plus vehicle (VHCL), base diet plus docosahexanoic acid (DHA), base diet plus Tocotrienol-Rich fraction (TRF), and base diet plus both docosahexaenoic acid, and tocotrienol rich fraction (DTRF) diets for 2 weeks prior to mating. The females (F0 generation) were maintained on their respective treatment diets throughout the gestation and lactation periods. Pups (F1 generation) derived from these dams were raised with their dams from birth till four weeks post natal. The male pups were weaned at 8 weeks postnatal, after which they were grouped into five groups of 10 animals each, and fed with the same diets as their dams for another eight weeks. Learning and behavioural experiments were conducted only in male off-spring rats using the Morris water maze.

RESULTS

Results showed that prenatal and postnatal TRF supplementation increased the brain (4-6 fold increase) and plasma α-tocotrienol (0.8 fold increase) levels in male off-springs. There is also notably better cognitive performance based on the Morris water maze test among these male off-springs.

CONCLUSION

Based on these results, it is concluded that prenatal and postnatal TRF supplementation improved cognitive function development in male progeny rats.

Potential trade-off between vocal ornamentation and spatial ability in a songbird

Bird song is hypothesized to be a reliable indicator of cognition because it depends on brain structure and function. Song features have been found to correlate positively with measures of cognition, but the relationship between song and cognition is complicated because not all cognitive abilities are themselves positively correlated. If cognition is not a unitary trait, developmental constraints on brain growth could generate trade-offs between some aspects of cognition and song. To further clarify the relationship between song and cognition in song sparrows (Melospiza melodia), we examined repertoire size and performance on a spatial task. We found an inverse relationship between repertoire size and speed of spatial learning and suggest that a developmental trade-off between the hippocampus and song control nuclei could be responsible for this relationship. By attending to male song, females may learn about a suite of cognitive abilities; this study suggests that females may glean information about a male's cognitive weaknesses as well as his strengths.

Cognitive and motor skills in school-aged children following maternal vitamin A supplementation during pregnancy in rural Nepal: a follow-up of a placebo-controlled, randomised cohort

OBJECTIVE

To determine the effects of maternal vitamin A supplementation from preconception through postpartum on cognitive and motor development of children at 10-13 years of age in rural Nepal.

DESIGN

Follow-up assessment of children born to women randomly assigned by a village to receive either supplemental vitamin A (7000 µg retinol equivalents) or placebo weekly during a continuous 3.5-year period from 1994-1997. The participants came from 12 wards, a subset of 270 wards in the original trial. Trained staff tested children for cognition by the Universal Nonverbal Intelligence Test (UNIT) and motor ability using four subtests from the Movement Assessment Battery for Children (MABC). Data on schooling, home environment and nutritional and socioeconomic status were also collected.

SETTING

Southern plains district of Sarlahi, Nepal.

PARTICIPANTS

390 Nepalese children 10-13 years of age.

MAIN OUTCOME MEASURES

Raw scores on UNIT and square-root transformed scores on an abridged version of the MABC tests, expressed as cluster-summarised (mean±SD) values to account for the design of the original trial.

RESULTS

There were no differences in UNIT (79.61±5.99 vs 80.69±6.71) or MABC (2.64±0.07 vs 2.49±0.09) test scores in children whose mothers were exposed to vitamin A vs placebo (mean differences: -1.07, 95% CI -7.10 to 9.26, p=0.78; 0.15, 95% CI 0.43 to -0.08, p=0.15), respectively. More children in the placebo group had repeated a grade in school (28% of placebo vs 16.7% of vitamin A, p=0.01).

CONCLUSIONS

Preconceptional to postpartum maternal vitamin A supplementation, in an undernourished setting, does not improve cognition or motor development at ages 10-13 years.

The effect of maternal omega-3 (n-3) LCPUFA supplementation during pregnancy on early childhood cognitive and visual development: a systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Maternal fish consumption during pregnancy has been positively associated with cognitive and visual abilities in the offspring, leading to the hypothesis that maternal omega-3 (n-3) long-chain PUFA (LCPUFA) supplementation improves children's neurologic and visual development.

OBJECTIVE

The objective was to evaluate the effect of maternal omega-3 LCPUFA supplementation in pregnancy on neurologic and visual development in the offspring.

DESIGN

Five electronic databases were searched. Human randomized controlled trials that supplemented the maternal diet with omega-3 LCPUFAs during pregnancy, or pregnancy and lactation, and that assessed either neurologic or visual development of the offspring were included. Trial quality was assessed, and the results of eligible trials were compared in meta-analyses.

RESULTS

Eleven RCTs involving 5272 participants were included in the review. Most trials had methodologic limitations. No differences in standardized psychometric test scores for cognitive, language, or motor development were observed between the LCPUFA-supplemented and control groups, except for cognitive scores in 2-5-y-old children, in whom supplementation resulted in higher Developmental Standard Scores (mean difference: 3.92; 95% CI: 0.77, 7.08; n = 156; P = 0.01). However, this effect was from 2 trials with a high risk of bias. Because of the variety of visual assessments and age ranges, it was not possible to combine studies with visual outcomes in a meta-analysis, although 6 of the 8 assessments in 5 trials reported no difference between the supplemented and control groups.

CONCLUSION

The evidence does not conclusively support or refute that omega-3 LCPUFA supplementation in pregnancy improves cognitive or visual development.

The pilot study: sphingomyelin-fortified milk has a positive association with the neurobehavioural development of very low birth weight infants during infancy, randomized control trial

AIM

This study was a randomised control trial to examine the effects of sphingomyelin (SM), on the mental, motor and behavioural development of premature infants.

PATIENTS AND METHODS

Randomised, double-blind controlled trial, enroling infants born with a birth weight of less than 1500 g between January 2004 and October 2007 at Juntendo University Hospital, with follow-up to 18 months. Twenty-four preterm babies were randomly assigned; 12 were assigned to a test group and fed SM-fortified milk (SM 20% of all phospholipids in milk) and 12 were assigned to a control group (SM 13% of all phospholipids in milk). We analysed the composition of the plasma phospholipids and red-cell-membrane fatty acids, after which VEP, Fagan, BSID-II, attention and memory tests were performed.

RESULTS

The percentage of SM in the total phospholipids was significantly higher in the trial group than in the control group at 4, 6 and 8 weeks. The Behaviour Rating Scale of the BSID-II, the Fagan test scores, the latency of VEP, and sustained attention test scores at 18 months were all significantly better in the trial group than in the control group.

CONCLUSION

This study is the first to report that nutritional intervention via administration of SM-fortified milk has a positive association with the neurobehavioural development of low-birth-weight infants. However, detailed studies on the effects of SM on longer-term development are required.

Gestational protein restriction induces CA3 dendritic atrophy in dorsal hippocampal neurons but does not alter learning and memory performance in adult offspring

Studies have demonstrated that nutrient deficiency during pregnancy or in early postnatal life results in structural abnormalities in the offspring hippocampus and in cognitive impairment. In an attempt to analyze whether gestational protein restriction might induce learning and memory impairments associated with structural changes in the hippocampus, we carried out a detailed morphometric analysis of the hippocampus of male adult rats together with the behavioral characterization of these animals in the Morris water maze (MWM). Our results demonstrate that gestational protein restriction leads to a decrease in total basal dendritic length and in the number of intersections of CA3 pyramidal neurons whereas the cytoarchitecture of CA1 and dentate gyrus remained unchanged. Despite presenting significant structural rearrangements, we did not observe impairments in the MWM test. Considering the clear dissociation between the behavioral profile and the hippocampus neuronal changes, the functional significance of dendritic remodeling in fetal processing remains undisclosed.

Effects of maternal worm infections and anthelminthic treatment during pregnancy on infant motor and neurocognitive functioning

We tested the hypothesis that maternal worm infections in pregnancy affect infant motor and neurocognitive development, and that anthelminthic treatment during pregnancy can reverse these effects. We used measures which examine infant motor, cognitive and executive function, including inhibition. We assessed 983 Ugandan infants aged 15 months, using locally appropriate measures within the Entebbe Mother and Baby Study, a trial of anthelminthic treatment during pregnancy. Key exposures were maternal worm infections and anthelminthic treatment during pregnancy. Effects of other health and social factors were controlled for statistically. Of the five major worm species found in the pregnant women, two had influences on the developmental measures: Maternal Mansonella perstans and Strongyloides stercoralis infections showed negative associations with the A-not B-task, and Language, respectively. Performance on other psychomotor and cognitive measures was associated with illnesses during infancy and infants' behavior during assessment, but not with maternal worm infections. There were no positive effects of maternal anthelminthic treatment on infant abilities. Mansonella perstans and Strongyloides stercoralis infection during pregnancy seem associated with impaired early executive function and language, respectively, but single-dose anthelminthic treatment during pregnancy was not beneficial. The biological mechanisms that could underlie these neurocognitive effects are discussed.

Developmental status of 1-year-old infants fed breast milk, cow's milk formula, or soy formula

BACKGROUND AND OBJECTIVE

Although soy formula has been reported to support normal development, concerns exist regarding potential adverse developmental effects of phytochemicals associated with soy protein. This study characterized developmental status (mental, motor, and language) of breastfed (BF), milk-based formula-fed (MF), or soy protein-based formula-fed (SF) infants during the first year of life.

METHODS

Healthy infants (N = 391) were assessed longitudinally at ages 3, 6, 9, and 12 months. Development was evaluated by using the Bayley Scales of Infant Development and the Preschool Language Scale-3. Mixed effects models were used while adjusting for socioeconomic status, mother's age and IQ, gestational age, gender, birth weight, head circumference, race, age, and diet history.

RESULTS

No differences were found between formula-fed infants (MF versus SF). BF infants scored slightly higher than formula-fed infants on the Mental Developmental Index (MDI) score at ages 6 and 12 months (P < .05). Infants who were breastfed also had higher Psychomotor Development Index scores than SF infants at age 6 months and slightly higher Preschool Language Scale-3 scores than MF infants at ages 3 and 6 months (P < .05). In addition, BF infants had a lower probability to score within the lower MDI quartile compared with MF infants and a higher likelihood to score within the upper quartile for the MDI and Psychomotor Development Index compared with SF infants.

CONCLUSIONS

This unique study showed that all scores on developmental testing were within established normal ranges and that MF and SF groups did not differ significantly. Furthermore, this study demonstrated a slight advantage of BF infants on cognitive development compared with formula-fed infants.

Nutritional status and cognitive performance of mother-child pairs in Sidama, Southern Ethiopia

The purpose of this study was to assess the nutritional status and cognitive performance of women and their 5-year-old children using a cross-sectional design. Cognitive performance of mothers and children was assessed with Raven's Colored Progressive Matrices (CPM) and Kaufman Assessment Battery for Children-II (KABC-II). Demographic characteristics, food consumption patterns and anthropometry were also measured. Four rural districts in Sidama, southern Ethiopia served as the setting for this study. Subjects were one hundred women and their 5-year-old children. Mean ± standard deviation age of the mothers was 29 ± 6 years and family size was 7.0 ± 2.6. Maternal body mass index (BMI) ranged from 15.3 to 29.0 with 14% of the mothers having BMI < 18.5. Anthropometric assessment of children revealed 29% to be stunted (height-for-age z-score < -2) and 12% to be underweight (weight-for-age z-score < -2). Mothers' education significantly contributed to prediction of both mothers' and children's cognitive test scores. There were significant differences in mean cognitive test scores between stunted and non-stunted, and between underweight and normal-weight children. Height-for-age z-scores were correlated with scores for short-term memory (r = 0.42, P < 0.001), and visual processing (r = 0.42, P < 0.001) indices and weight-for-age z-scores were also correlated with scores of short-term memory (r = 0.41, P < 0.001) and visual processing (r = 0.43, P < 0.001) indices. Malnutrition in the community likely contributed to the cognitive performance of the subjects. Performance on memory and visual processing tasks was significantly lower in children with growth deficits suggesting that efficient and cost effective methods to alleviate malnutrition and food insecurity would impact not only child health but also cognitive function.

Assessing learning and memory in pigs

In recent years, there has been a surge of interest in (mini) pigs (Sus scrofa) as species for cognitive research. A major reason for this is their physiological and anatomical similarity with humans. For example, pigs possess a well-developed, large brain. Assessment of the learning and memory functions of pigs is not only relevant to human research but also to animal welfare, given the nature of current farming practices and the demands they make on animal health and behavior. In this article, we review studies of pig cognition, focusing on the underlying processes and mechanisms, with a view to identifying. Our goal is to aid the selection of appropriate cognitive tasks for research into pig cognition. To this end, we formulated several basic criteria for pig cognition tests and then applied these criteria and knowledge about pig-specific sensorimotor abilities and behavior to evaluate the merits, drawbacks, and limitations of the different types of tests used to date. While behavioral studies using (mini) pigs have shown that this species can perform learning and memory tasks, and much has been learned about pig cognition, results have not been replicated or proven replicable because of the lack of validated, translational behavioral paradigms that are specially suited to tap specific aspects of pig cognition. We identified several promising types of tasks for use in studies of pig cognition, such as versatile spatial free-choice type tasks that allow the simultaneous measurement of several behavioral domains. The use of appropriate tasks will facilitate the collection of reliable and valid data on pig cognition.

Cortical responses to speech sounds in 3- and 6-month-old infants fed breast milk, milk formula, or soy formula

Controversy exists about the safety of soy formula, with the main concern relating to potential estrogenic effects of soy protein. Since estrogens influence early brain development, we compared behavioral development and cortical responses (event-related potentials; ERPs) to speech sounds in infants fed either breast milk or formula (milk- or soy-based). Across-groups ERP measures were generally similar and behavioral measures were within normal ranges, suggesting no important influences of soy formula on behavioral development and brain function during the study period. Analyses relating ERP and behavioral measures revealed diet- and gender-specific emphases that may reflect differences in developmental trajectories of brain-behavior relationships.

The pig as a model animal for studying cognition and neurobehavioral disorders

In experimental animal research, a short phylogenetic distance, i.e., high resemblance between the model species and the species to be modeled is expected to increase the relevance and generalizability of results obtained in the model species. The (mini)pig shows multiple advantageous characteristics that have led to an increase in the use of this species in studies modeling human medical issues, including neurobehavioral (dys)functions. For example, the cerebral cortex of pigs, unlike that of mice or rats, has cerebral convolutions (gyri and sulci) similar to the human neocortex. We expect that appropriately chosen pig models will yield results of high translational value. However, this claim still needs to be substantiated by research, and the area of pig research is still in its infancy. This chapter provides an overview of the pig as a model species for studying cognitive dysfunctions and neurobehavioral disorders and their treatment, along with a discussion of the pros and cons of various tests, as an aid to researchers considering the use of pigs as model animal species in biomedical research.

Maternal DHA levels and toddler free-play attention

We investigated the relationship between maternal docosahexaenoic acid (DHA) levels at birth and toddler free-play attention in the second year. Toddler free-play attention was assessed at 12 and 18 months, and maternal erythrocyte (red-blood cell; RBC) phospholipid DHA (percentage of total fatty acids) was measured from mothers at delivery. Overall, higher maternal DHA status at birth was associated with enhanced attentional functioning during the second year. Toddlers whose mothers had high DHA at birth exhibited more total looking and fewer episodes of inattention during free-play than did toddlers whose mothers had low DHA at birth. Analyses also provided further information on changes in attention during toddlerhood. These findings are consistent with evidence suggesting a link between DHA and cognitive development in infancy and early childhood.

Is there convincing biological or behavioral evidence linking vitamin D deficiency to brain dysfunction?

Vitamin D insufficiency is common in the United States; the elderly and African-Americans are at particularly high risk of deficiency. This review, written for a broad scientific readership, presents a critical overview of scientific evidence relevant to a possible causal relationship between vitamin D deficiency and adverse cognitive or behavioral effects. Topics discussed are 1) biological functions of vitamin D relevant to cognition and behavior; 2) studies in humans and rodents that directly examine effects of vitamin D inadequacy on cognition or behavior; and 3) immunomodulatory activity of vitamin D relative to the proinflammatory cytokine theory of cognitive/behavioral dysfunction. We conclude there is ample biological evidence to suggest an important role for vitamin D in brain development and function. However, direct effects of vitamin D inadequacy on cognition/behavior in human or rodent systems appear to be subtle, and in our opinion, the current experimental evidence base does not yet fully satisfy causal criteria. Possible explanations for the apparent inconsistency between results of biological and cognitive/behavioral experiments, as well as suggested areas for further research are discussed. Despite residual uncertainty, recommendations for vitamin D supplementation of at-risk groups, including nursing infants, the elderly, and African-Americans appear warranted to ensure adequacy.

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.