Effects of prenatal fish-oil and 5-methyltetrahydrofolate supplementation on cognitive development of children at 6.5 y of age

Growth and adiposity in newborns study (GAINS): The influence of prenatal DHA supplementation protocol

BACKGROUND

Obesity and central fat mass (FM) accrual drive disease development and are related to greater morbidity and mortality. Excessive gestational weight gain (GWG) increases fetal fat accretion resulting in greater offspring FM across the lifespan. Studies associate greater maternal docosahexaenoic acid (DHA) levels with lower offspring FM and lower visceral adipose tissue during childhood, however, most U.S. pregnant women do not consume an adequate amount of DHA. We will determine if prenatal DHA supplementation is protective for body composition changes during infancy and toddlerhood in offspring exposed to excessive GWG.

METHODS AND DESIGN

Infants born to women who participated in the Assessment of DHA on Reducing Early Preterm Birth randomized controlled trial (ADORE; NCT02626299) will be invited to participate. Women were randomized to either a high 1000 mg or low 200 mg daily prenatal DHA supplement starting in the first trimester of pregnancy. Offspring body composition and adipose tissue distribution will be measured at 2 weeks, 6 months, 12 months, and 24 months using dual energy x-ray absorptiometry. Maternal GWG will be categorized as excessive or not excessive based on clinical guidelines.

DISCUSSION

Effective strategies to prevent obesity development are lacking. Exposures during the prenatal period are important in the establishment of the offspring phenotype. However, it is largely unknown which exposures can be successfully targeted to have a meaningful impact. This study will determine if prenatal DHA supplementation modifies the relationship between maternal weight gain and offspring FM and FM distribution at 24 months of age.

ETHICS AND DISSEMINATION

The University of Kansas Medical Center Institutional Review Board (IRB) approved the study protocol (STUDY00140895). The results of the trial will be disseminated at conferences and in peer reviewed publications.

TRIAL REGISTRATION

ClinicalTrials.gov ID: NCT03310983.

A Systematic Review of Omega-3 Fatty Acid Consumption and Cognitive Outcomes in Neurodevelopment

INTRODUCTION

This systematic review addresses the effects of n-3 long-chain polyunsaturated fatty acids consumption on human neurodevelopment. It evaluates articles published between 2000 and 2022 investigating the cognitive outcomes during the period of neurodevelopment: from fetal development to adolescence. For the purpose of this review the terms LC PUFA and omega-3 fatty acid will be used interchangeably.

METHOD

Data were sourced from several major databases including PubMed (MEDLINE), Web of Science, and ProQuest Central. Randomized controlled trials (RCTs), nonrandomized controlled trials, prospective or retrospective cohort studies, and observational studies investigating the effects of omega-3 fatty acid consumption from dietary supplements, multiple-nutrient supplement, or food questionnaire on neurodevelopment were considered. Study population was separated in three developmental phases: (1) in-utero, (2) lactation/infancy, and (3) childhood/adolescence. Each article was evaluated for several key factors such as study type, type/dosage of PUFAs, number of subjects, length of intervention, participant age range, population characteristics, outcome measure (both primary/cognitive and secondary/other), results, conclusion, and confounding variables/limitations.

RESULTS

A total of 88 articles were included in the review, 69 RCTs and 19 longitudinal or observational studies. The results indicate equivocal effect of intervention, with some short-term benefits observed in the areas of visual attention, working memory, executive function, and communication. Omega-3 supplement might have a short-term positive impact on neurodevelopment in all three phases. Supplementation is recommended throughout life, rather than only during the earliest developmental stage.

Prenatal folic acid supplement/dietary folate and cognitive development in 4-year-old offspring from the Japan Environment and Children's Study

We evaluated the association between maternal prenatal folic acid supplement use/dietary folate intake and cognitive development in 4-year-old offspring (N = 3445) using data from the Japan Environment and Children's Study. Cognitive development was evaluated using the Kyoto Scale of Psychological Development 2001. Multiple regression analysis revealed that offspring of mothers who started using folic acid supplements pre-conception had a significantly higher language-social developmental quotient (DQ) (partial regression coefficient 1.981, 95% confidence interval 0.091 to 3.872) than offspring of mothers who did not use such supplements at any time throughout their pregnancy (non-users). Offspring of mothers who started using folic acid supplements within 12 weeks of gestation had a significantly higher cognitive-adaptive (1.489, 0.312 to 2.667) and language-social (1.873, 0.586 to 3.159) DQ than offspring of non-users. Regarding daily dietary folate intake from preconception to early pregnancy, multiple regression analysis revealed that there was no significant association with any DQ area in the 200 to < 400 µg and the ≥ 400 µg groups compared with the < 200 µg group. Maternal prenatal folic acid supplementation starting within 12 weeks of gestation (but not adequate dietary folate intake from preconception to early pregnancy) is positively associated with cognitive development in 4-year-old offspring.

Paternal preconceptional diet enriched with n-3 polyunsaturated fatty acids affects offspring brain function in mice

Recent studies demonstrate that paternal nutrition prior to conception may determine offspring development and health through epigenetic modification. This study aims to investigate the effects of paternal supplementation of n-3 polyunsaturated fatty acids (n-3 PUFAs) on the brain development and function, and associated gene imprinting in the offspring. Three to four-week-old male C57BL/6J mice (founder) were fed with an n-3 PUFA-deficient diet (n-3 D), and two n-3 PUFA supplementation diets – a normal n-3 PUFA content diet (n-3 N) and a high n-3 PUFA content diet (n-3 H) for 12 weeks. Then they were mated to 10-week-old virgin female C57BL/6J mice to generate the offspring. The results showed that paternal n-3 PUFA supplementation in preconception reduced the anxiety- and depressive-like behavior, and improved sociability, learning and memory in the offspring, along with increased synaptic number, upregulated expressions of neuron specific enolase, myelin basic protein, glial fibrillary acidic protein, brain-derived neurotrophic factor in the hippocampus and cerebral cortex, and altered expressions of genes associated with mitochondria biogenesis, fusion, fission and autophagy. Furthermore, with paternal n-3 PUFA supplementation, the expression of imprinted gene Snrpn was downregulated both in testes of the founder mice and their offspring, but upregulated in the cerebral cortex and hippocampus, with altered DNA methylation in its differentially methylated region. The data suggest that higher paternal intake of n-3 PUFAs in preconception may help to maintain optimal brain development and function in the offspring, and further raise the possibility of paternal nutritional intervention for mental health issues in subsequent generations.

Maternal Fatty Acid Metabolism in Pregnancy and Its Consequences in the Feto-Placental Development

During pregnancy, maternal plasma fatty acids are critically required for cell growth and development, cell signaling, and the development of critical structural and functional aspects of the feto-placental unit. In addition, the fatty acids modulate the early stages of placental development by regulating angiogenesis in the first-trimester human placenta. Preferential transport of maternal plasma long-chain polyunsaturated fatty acids during the third trimester is critical for optimal fetal brain development. Maternal status such as obesity, diabetes, and dietary intakes may affect the functional changes in lipid metabolic processes in maternal-fetal lipid transport and metabolism. Fatty acids traverse the placental membranes via several plasma membrane fatty acid transport/binding proteins (FAT, FATP, p-FABPpm, and FFARs) and cytoplasmic fatty acid-binding proteins (FABPs). This review discusses the maternal metabolism of fatty acids and their effects on early placentation, placental fatty acid transport and metabolism, and their roles in feto-placental growth and development. The review also highlights how maternal fat metabolism modulates lipid processing, including transportation, esterification, and oxidation of fatty acids.

Fish Nutritional Value as an Approach to Children's Nutrition

Fish is a relatively cheap and accessible source of animal protein for human consumption even in rural communities. It is critical for global food and nutrition security, and its consumption continues to increase. As a highly nutritious food, fish consumption is highly recommended for children and expectant mothers for normal growth and development. The present paper explores the nutritional value of fish as approach to nutrition in children and its benefits. The findings reveal that fish is a valuable source of essential amino acids (EAA) and polyunsaturated fatty acids (PUFAs) that play important physiological functions for maintenance and development of fetuses, neonates, and infant brains. Therefore, it could be a valuable tool in the fight against food insecurity and malnutrition. However, fish and fish products are also highly susceptible to contamination by various organic and inorganic compounds that threaten public health. Particularly, heavy metals and biogenic amines (BAs) have shown adverse effects when contaminated fish is consumed, and the effects in children have been worse. Hence, while fish consumption is highly recommended for children's nutrition, the safety and quality of the product should always be checked to safeguard public health.

Omega-3 Fatty Acid Dietary Supplements Consumed During Pregnancy and Lactation and Child Neurodevelopment: A Systematic Review

BACKGROUND

Maternal nutrition during pregnancy and lactation has profound effects on the development and lifelong health of the child. Long-chain PUFAs are particularly important for myelination and the development of vision during the perinatal period.

OBJECTIVES

We conducted a systematic review to examine the relationship between supplementation with omega-3 fatty acids during pregnancy and/or lactation and neurodevelopment in children, to inform the Scientific Report of the 2020 Dietary Guidelines Advisory Committee.

METHODS

We identified articles on omega-3 fatty acid supplementation in pregnant and lactating women that included measures of neurodevelopment in their children (0-18 y) by searching PubMed, CENTRAL, Embase, and CINAHL Plus. After dual screening articles for inclusion, we qualitatively synthesized and graded the strength of evidence using pre-established criteria for assessing risk of bias, consistency, directness, precision, and generalizability.

RESULTS

We included 33 articles from 15 randomized controlled trials (RCTs) and 1 prospective cohort study. Of the 8 RCTs that delivered omega-3 fatty acid dietary supplements during pregnancy alone (200-2200 mg/d DHA and 0-1100 mg/d EPA for approximately 20 wk), 5 studies reported ≥1 finding that supplementation improved measures of cognitive development in the infant or child by 6%-11% (P < 0.05), but all 8 studies also reported ≥1 nonsignificant (P > 0.05) result. There was inconsistent or insufficient evidence for other outcomes (language, social-emotional, physical, motor, or visual development; academic performance; risks of attention deficit disorder, attention-deficit/hyperactivity disorder, autism spectrum disorder, anxiety, or depression) and for supplementation during lactation or both pregnancy and lactation. Populations with a lower socioeconomic status and adolescents were underrepresented and studies lacked racial and ethnic diversity.

CONCLUSIONS

Limited evidence suggests that omega-3 fatty acid supplementation during pregnancy may result in favorable cognitive development in the child. There was insufficient evidence to evaluate the effects of omega-3 fatty acid supplementation during pregnancy and/or lactation on other developmental outcomes.

[Research advances in the effect of long-chain polyunsaturated fatty acids on neonates]

Adequate supply of long-chain polyunsaturated fatty acids (LCPUFAs) is of great importance for neonates, especially preterm infants. In particular, n-3 LCPUFAs and n-6 LCPUFAs play a key role in brain development, immune regulation, and disease prevention. Lack of LCPUFAs may lead to neurodevelopmental impairment, affect the development of neonatal immune system, and result in neonatal diseases. This article reviews related research advances in the physiological function of LCPUFAs and its effect on neonates, so as to provide reference for clinical application.

Impact of omega-3 fatty acid DHA and EPA supplementation in pregnant or breast-feeding women on cognitive performance of children: systematic review and meta-analysis

INTRODUCTION

The omega-3 long-chain polyunsaturated fatty acids docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) are important for brain development and cognitive performance. Because they are semi-essential fatty acids, they must be obtained from food. However, the dietary reference intakes of DHA and EPA have not yet been established. In women, a low DHA and/or EPA serum level during pregnancy or breastfeeding might negatively affect their children. For this study, we conducted a systematic review and meta-analysis of randomized control trials on the association between the consumption of fish oil supplements in pregnant and/or breastfeeding women and the cognitive performance of their children.

METHODS

The PubMed, Embase, and Central literature databases were systematically searched. We included and extracted relevant studies in duplicate and assessed study quality. Cognitive outcomes were grouped according to published criteria and according to time elapsed after the intervention. We performed fixed-effects meta-analyses for each cognitive outcome and for birth weight. We assessed potential confounding with meta-regressions and sensitivity analyses.

RESULTS

A total of 11 trials were included. No significant association was found between DHA/EPA supplementation and any of the assessed cognitive parameters or birth weight.

DISCUSSION

Our results confirm previous reviews on the studied topic. Reasons for inconclusive results may be small sample sizes for each assessed category, questionable quality of included studies, and the difficulty of reliably measuring cognitive performance in small children. Blood levels of omega-3 long-chain polyunsaturated fatty acids were mostly not comparable. Furthermore, the influence of genetic and environmental factors could not be assessed. Studies in this field should address such shortcomings.

Systematic Literature Review and Meta-Analysis of the Relationship Between Polyunsaturated and Trans Fatty Acids During Pregnancy and Offspring Weight Development

Eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), and trans fatty acids (TFAs) may have an impact on offspring weight development. We conducted a systematic review and meta-analysis according to PRISMA guidelines to evaluate whether levels of these fatty acids during pregnancy influenced offspring weight development. Randomized controlled trials (RCTs) with DHA and/or EPA supplementation or cohort studies, which examined levels of DHA, EPA, or TFAs in maternal or neonatal blood samples and recorded offspring weight, were included. Overall, 27 RCTs and 14 observational studies were identified. The results showed that DHA and/or EPA supplementation doses >650 mg/day resulted in slightly higher birth weight (MD 87.5 g, 95% CI 52.3-122.6, n = 3,831) and combined BMI and BMI z score at 5-10 years (SMD 0.11, 95% CI 0.04-0.18, n = 3,220). These results were rated as moderate quality. Results from the observational studies were generally inconsistent. High TFA levels during pregnancy seemed to be associated with lower birth weight. Finally, this review and meta-analysis supports a relationship between high maternal or neonatal DHA and/or EPA levels and higher offspring birth weight and weight in childhood. More high-quality long-term studies are still needed.

Fish Oil Supplementation in Pregnancy and Neurodevelopment in Childhood-A Randomized Clinical Trial

A double-blind randomized controlled trial of n-3 long-chain polyunsaturated fatty acid (n-3 LCPUFA) supplementation or matching placebo during third trimester of pregnancy was conducted within the COPSAC₂₀₁₀ mother-child cohort consisting of 736 women and their children. The objective was to determine if maternal n-3 LCPUFA pregnancy supplementation affects offspring neurodevelopment until 6 years. Neurodevelopment was evaluated in 654 children assessing age of motor milestone achievement, language development, cognitive development, general neurodevelopment, and emotional and behavioral problems. Maternal n-3 LCPUFA supplementation during pregnancy improved early language development and reduced the impact of emotional and behavioral problems. The n-3 LCPUFA supplementation was in boys associated with the earlier achievement of gross motor milestones, improved cognitive development, and a reduced impact of emotional and behavioral problems.

Long-Chain Polyunsaturated Fatty Acids, Homocysteine at Birth and Fatty Acid Desaturase Gene Cluster Polymorphisms are Associated with Children's Processing Speed up to Age 9 Years

Both pre- and early postnatal supplementation with docosahexaenoic acid (DHA), arachidonic acid (AA) and folate have been related to neural development, but their long-term effects on later neural function remain unclear. We evaluated the long-term effects of maternal prenatal supplementation with fish-oil (FO), 5-methyltetrahydrofolate (5-MTHF), placebo or FO + 5-MTHF, as well as the role of fatty acid desaturase (FADS) gene cluster polymorphisms, on their offspring’s processing speed at later school age. This study was conducted in NUHEAL children at 7.5 (n = 143) and 9 years of age (n = 127). Processing speed tasks were assessed using Symbol Digit Modalities Test (SDMT), Children Color Trails Test (CCTT) and Stroop Color and Word Test (SCWT). Long-chain polyunsaturated fatty acids, folate and total homocysteine (tHcy) levels were determined at delivery from maternal and cord blood samples. FADS and methylenetetrahydrofolate reductase (MTHFR) 677 C > T genetic polymorphisms were analyzed. Mixed models (linear and logistic) were performed. There were significant differences in processing speed performance among children at different ages (p < 0.001). The type of prenatal supplementation had no effect on processing speed in children up to 9 years. Secondary exploratory analyses indicated that children born to mothers with higher AA/DHA ratio at delivery (p < 0.001) and heterozygotes for FADS1 rs174556 (p < 0.05) showed better performance in processing speed at 9 years. Negative associations between processing speed scores and maternal tHcy levels at delivery were found. Our findings suggest speed processing development in children up to 9 years could be related to maternal factors, including AA/DHA and tHcy levels, and their genetic background, mainly FADS polymorphism. These considerations support that maternal prenatal supplementation should be quantitatively adequate and individualized to obtain better brain development and mental performance in the offspring.

Maternal Docosahexaenoic Acid Status during Pregnancy and Its Impact on Infant Neurodevelopment

Dietary components are essential for the structural and functional development of the brain. Among these, docosahexaenoic acid, 22:6n-3 (DHA), is critically necessary for the structure and development of the growing fetal brain in utero. DHA is the major n-3 long-chain polyunsaturated fatty acid in brain gray matter representing about 15% of all fatty acids in the human frontal cortex. DHA affects neurogenesis, neurotransmitter, synaptic plasticity and transmission, and signal transduction in the brain. Data from human and animal studies suggest that adequate levels of DHA in neural membranes are required for maturation of cortical astrocyte, neurovascular coupling, and glucose uptake and metabolism. Besides, some metabolites of DHA protect from oxidative tissue injury and stress in the brain. A low DHA level in the brain results in behavioral changes and is associated with learning difficulties and dementia. In humans, the third trimester-placental supply of maternal DHA to the growing fetus is critically important as the growing brain obligatory requires DHA during this window period. Besides, DHA is also involved in the early placentation process, essential for placental development. This underscores the importance of maternal intake of DHA for the structural and functional development of the brain. This review describes DHA’s multiple roles during gestation, lactation, and the consequences of its lower intake during pregnancy and postnatally on the 2019 brain development and function.

The Influence of DHA on Language Development: A Review of Randomized Controlled Trials of DHA Supplementation in Pregnancy, the Neonatal Period, and Infancy

This review summarizes randomized controlled trials (RCTs) assessing the effect of docosahexaenoic acid (DHA) supplementation in the first 1000 days on child language. Six databases were searched and RCTs were included if they involved supplementation with DHA during pregnancy, to preterm infants, or during the postpartum period, included a placebo group with less or no DHA, and reported a language outcome. We included 29 RCTs involving n = 10,405 participants from 49 publications. There was a total of 84 language measures at ages ranging from 3 months to 12 years. Of the 84 assessments, there were 4 instances where the DHA group had improved scores, and 2 instances where the DHA group had worse scores (with the majority of these significant effects found within one RCT). The remaining comparisons were null. A few RCTs that included subgroup analyses reported (inconsistent) effects. There was limited evidence that DHA supplementation had any effect on language development, although there were some rare instances of both possible positive and adverse effects, particularly within population subgroups. It is important that any subgroup effects are verified in future trials that are adequately powered to confirm such effects.

Effect of supplementary omega-3 fatty acids on pregnant women with complications and pregnancy outcomes: review from literature

Numerous benefits have been associated with omega-3 fatty acid consumption during pregnancy and the postpartum period, whether it is consumed in the diet with seafood or via supplements such as fish oil. This review primarily aimed to assess the current situation of the impact of omega-3 long-chain Poly Unsaturated Fatty Acid (PUFA) supplementation on the outcomes of pregnancy. The electronic search of Medline, PubMed, Public Library of Science (PLOS) and Google Scholar databases was carried out for papers from 01 February 1995 to 01 March 2017 using keywords such as "pregnancy," "supplement," "long-chain polyunsaturated fatty acids," "omega 3 fatty acids," and "clinical trials." Out of twenty-six studies, both observational and interventional, fourteen studies found the influence of omega 3 fatty acids during pregnancy or the early postpartum period on the duration of gestation and infant size at birth, preeclampsia, depression, and infant visual function and neurodevelopment have been reported. Omega 3 fatty acid intakes (both in terms of absolute amounts of docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) and the ratio of these 2 fatty acids) varied widely in these studies, however, and no clear consensus exists regarding the effects of omega 3 fatty acids on any of these outcomes. Because of the potential importance of these fatty acids for pregnant or lactating women, fetus, and newborn infants and the limited data from clinical trials assessing the effect of these fatty acids on pregnancy and infant outcomes, additional research is required to better define optimal intakes of specific omega 3 fatty acids during these critical periods.

Nutritional Factors in Fetal and Infant Brain Development

Fetal and infant brain development determine the trajectory of the organism across the lifespan. Optimal maternal and infant nutrition during the period of rapid brain development is vital to the integrity of the neural substrate for subsequent lifelong functions. The goal of this review is to educate the reader on the effects of fetal and infant nutrition on the developing human brain. A review of the literature reveals 6 nutrients that have been studied with respect to maternal nutrition and subsequent offspring brain development: folate, iodine, iron, vitamin D, choline, and docosahexaenoic acid (DHA; 22:6n-3). The research is discussed with a focus on the timing of nutrient needs (preconception, prenatally, and postnatally) as well as potential confounding and unobserved variables.

Early nutrition and gut microbiome: interrelationship between bacterial metabolism, immune system, brain structure, and neurodevelopment

Disturbances of diet during pregnancy and early postnatal life may impact colonization of gut microbiota during early life, which could influence infant health, leading to potential long-lasting consequences later in life. This is a nonsystematic review that explores the recent scientific literature to provide a general perspective of this broad topic. Several studies have shown that gut microbiota composition is related to changes in metabolism, energy balance, and immune system disturbances through interaction between microbiota metabolites and host receptors by the gut-brain axis. Moreover, recent clinical studies suggest that an intestinal dysbiosis in gut microbiota may result in cognitive disorders and behavioral problems. Furthermore, recent research in the field of brain imaging focused on the study of the relationship between gut microbial ecology and large-scale brain networks, which will help to decipher the influence of the microbiome on brain function and potentially will serve to identify multiple mediators of the gut-brain axis. Thus, knowledge about optimal nutrition by modulating gut microbiota-brain axis activity will allow a better understanding of the molecular mechanisms involved in the crosstalk between gut microbiota and the developing brain during critical windows. In addition, this knowledge will open new avenues for developing novel microbiota-modulating based diet interventions during pregnancy and early life to prevent metabolic disorders, as well as neurodevelopmental deficits and brain functional disorders.

Effect of omega-3 fatty acids on cognition: an updated systematic review of randomized clinical trials

Context

The increasing number of studies on the effects of n-3 long-chain polyunsaturated fatty acids (LC-PUFAs) on health, particularly cognition, in the last 5 years reflects the growing interest in this area of research.

Objective

The aim for this systematic review was to evaluate the scientific evidence published in the last 5 years (2012-2017) on the effects of n-3 LC-PUFA intake on cognition, cognitive development, and cognitive decline to determine whether n-3 LC-PUFAs support cognitive development and prevent cognitive decline.

Data Sources

The PubMed database was searched.

Study Selection

The 51 articles included in this systematic review reported on healthy individuals with mild or moderate cognitive impairment and patients with Alzheimer's disease. Risk of bias was assessed using Cochrane methodology.

Data Extraction

The number of study participants, the type of study, the type and dose of n-3 LC-PUFAs, and the key results are reported here.

Results

Current evidence indicates that n-3 LC-PUFAs administered during pregnancy or breastfeeding have no effect on the skills or cognitive development of children in later stages of development. Evidence regarding the improvement of cognitive function during childhood and youth or in attention deficit/hyperactivity disorder is inconclusive. Moreover, it is still unclear if n-3 LC-PUFAs can improve cognitive development or prevent cognitive decline in young or older adults.

Early nutrition in combination with polymorphisms in fatty acid desaturase gene cluster modulate fatty acid composition of cheek cells' glycerophospholipids in school-age children

Variants in the human genes of fatty acid (FA) desaturase 1 (FADS1), 2 (FADS2) and 3 (FADS3) are associated with PUFA blood levels. We explored if maternal prenatal supplementation and children's genetic variation in seventeen SNP of the FADS1, FADS2 and FADS3 gene cluster influence twenty-one of the most relevant cheek cells' derived FA in glycerophospholipids (GPL-FA). The study was conducted in 147 Spanish and German mother-children pairs participating in the Nutraceuticals for a Healthier Life (NUHEAL) study at 8, 9 and 9·5 years. Linear and mixed model longitudinal regression analyses were performed. Maternal fish-oil (FO) or FO+5-methyltetrahydrofolate (5-MTHF) supplementation during pregnancy was associated with a significant decrease of arachidonic acid (AA) concentrations in cheek cell GPL in the offspring, from 8 to 9·5 years; furthermore, maternal FO+5-MTHF supplementation was associated with higher n-6 docosapentaenoic acid concentrations in their children at age 8 years. FADS1 rs174556 polymorphism and different FADS2 genotypes were associated with higher concentrations of linoleic and α-linolenic acids in children; moreover, some FADS2 genotypes determined lower AA concentrations in children's cheek cells. It is suggested an interaction between type of prenatal supplementation and the offspring genetic background driving GPL-FA levels at school age. Prenatal FO supplementation, and/or with 5-MTHF, seems to stimulate n-3 and n-6 FA desaturation in the offspring, increasing long-chain PUFA concentrations at school age, but depending on children's FADS1 and FADS2 genotypes. These findings suggest potential early nutrition programming of FA metabolic pathways, but interacting with children's FADS polymorphisms.

The Importance of Maternal Folate Status for Brain Development and Function of Offspring

The importance of an adequate periconceptional maternal folate status to prevent fetal neural tube defects has been well demonstrated and resulted in the recommendation for women to use folic acid supplements during the periconception period. The importance of maternal folate status for offspring neurodevelopment and brain health is less well described. We reviewed the current evidence linking maternal folate status before conception and during pregnancy with neurodevelopment and cognition of the offspring. We discuss both animal and human studies. Preclinical research revealed the importance of maternal folate status for several key processes required for normal neurodevelopment and brain functioning in the offspring, including DNA synthesis, regulation of gene expression, synthesis of phospholipids and neurotransmitters, and maintenance of healthy plasma homocysteine concentrations. Human observational studies are inconclusive; about half have shown a positive association between maternal folate status and cognitive performance of offspring. Whereas some studies suggest a positive association between maternal folate intake and cognition of offspring during childhood, data from interventional studies are too limited to conclude that there is a direct effect. Future preclinical studies are needed to help us characterize the behavioral effects, understand the underlying mechanisms, and to establish an optimal dosage and time window of folate supplementation. Moreover, more conclusive data from well-designed human observational studies and randomized controlled trials are needed to determine whether current recommendations for folic acid supplementation during pregnancy cover the needs for normal cognitive development in the offspring.

Review and meta-analysis found that prenatal folic acid was associated with a 58% reduction in autism but had no effect on mental and motor development

AIM

The impact of prenatal folic acid on children's neurodevelopment and the risk of autism spectrum disorder (ASD) remain unclear and this review and meta-analysis aimed to quantify any associations.

METHODS

We systematically searched PubMed, Scopus and The Cochrane Library until June 2018 with no language restrictions. Standardised mean differences and odds ratio with 95% confidence intervals are used to describe any associations between folic acid and mental development, motor development and ASD.

RESULTS

The search strategy identified 647 papers and 16 were finally included in the meta-analysis after the application of the exclusion criteria. These provided a total cohort size of 756 365 children aged 11 months to 15 years from 10 countries. The main finding was that prenatal use of folic acid was associated with a 58% reduction in the risk of ASD in children. We were surprised that better scores for mental development were associated with low prenatal exposure to folic acid.

CONCLUSION

Although the results should be interpreted with caution, they showed that routine prenatal supplements of folic acid were associated with significantly lower levels of ASD. Further studies are needed to reach a firm conclusion, given the multifactorial aetiology of neurodevelopment.

An appraisal of folates as key factors in cognition and ageing-related diseases

Folic acid (FA) is often consumed as a food supplement and can be found in fortified staple foods in various western countries. Even though FA supplementation during pregnancy is known to prevent severe congenital anomalies in the developing child (e.g., neural tube defects), much less is known about its influence on cognition and neurological functioning. In this review, we address the advances in this field and situate how folate intake during pregnancy, postnatal life, adulthood and in the elderly affects cognition. In addition, an association between folate status and ageing, dementia and other neurodegenerative disorders such as Alzheimer's disease, Parkinson's disease and amyotrophic lateral sclerosis is discussed. While its role in the incidence and severity of these diseases is becoming apparent, the underlying action of folates and related metabolites remains elusive. Finally, the potential of FA as a nutraceutical has been proposed, although the efficacy will highly depend on the interplay with other micronutrients, the disease stage and the duration of supplementation. Hence, the lack of consistent data urges for more animal studies and (pre)clinical trials in humans to ascertain a potential beneficial role for folates in the treatment or amelioration of cognitive decline and ageing-related disorders.

Maternal folate nutrition and offspring health: evidence and current controversies

Periconceptional folic acid (FA) is known to have a protective effect in the prevention of neural tube defects (NTD), leading to global recommendations for FA supplementation before and in early pregnancy. Maternal folate throughout pregnancy may have other roles in offspring health, including neurodevelopment and cognitive performance in childhood. Folate is essential for C1 metabolism, a network of pathways involved in several biological processes including nucleotide synthesis, DNA repair and methylation reactions. The evidence reviewed here shows a conclusive role for offspring health of maternal folate nutrition in early pregnancy and probable benefits in later pregnancy. Folate-mediated epigenetic changes in genes related to brain development and function offer a plausible biological basis to link maternal folate with effects in offspring brain, albeit this research is in its infancy. Mandatory FA fortification of food has proven to be highly effective in decreasing NTD cases in populations where it has been implemented, but this policy is controversial owing to concerns related to potential adverse effects of over-exposure to FA. In the absence of population-wide fortification, and given the generally poor compliance with current FA recommendations, optimising folate status of mothers in very early pregnancy for protection against NTD remains challenging. Thus, current policy in the UK, Ireland and elsewhere in Europe for the prevention of NTD (based on periconceptional FA supplementation only), has proven to be largely ineffective. This review addresses the evidence and the controversies that surround this area, as well as identifying the challenges in translating policy into practice.

The effect of maternal DHA supplementation on body fat mass in children at 7 years: follow-up of the DOMInO randomized controlled trial

BACKGROUND

Animal studies have suggested that an increased supply of omega-3 long chain polyunsaturated fatty acids (LCPUFA), in particular docosahexaenoic acid (DHA), during the perinatal period can prevent later excess body fat mass. However, previous human studies have produced inconsistent findings, and few have assessed potential effects beyond 6 years of age.

OBJECTIVE

To evaluate the effect of supplementing women in the second half of pregnancy with omega-3 LCPUFA, chiefly as DHA, on the percentage body fat of children at 7 years of age, as assessed by two methods: air displacement plethysmography (BOD POD) and bioelectrical impedance spectroscopy (BIS).

DESIGN

A time-restricted follow up at 7 years of age of children born to mothers enrolled in DOMInO (DHA to Optimise Maternal Infant Outcome) randomized controlled trial, in which women took either high-DHA tuna oil (800mg/day DHA) or placebo capsules from 20 weeks' gestation to delivery, at Adelaide-based centers. Primary outcomes were the percentage body fat at 7 years of age as assessed by both BOD POD and BIS. Weight, height, waist/hip circumferences and BMI were also recorded.

RESULTS

A total of 252 DOMInO children (n=135 males, n=117 females) completed the follow up study. There were no differences between the DHA and placebo groups in percentage body fat as assessed by either BOD POD [adjusted mean difference: -0.35, 95% CI: -1.46, 2.16; P=0.71] or BIS [adjusted mean difference: 0.64, 95% CI: -0.99, 2.27; P=0.44]. BMI z-scores were also similar between groups [adjusted mean difference: 0.18, 95% CI: -0.10, 0.45; P=0.21]. There were also no differences in height, weight or waist and hip circumference between the DHA and placebo groups at 7 years of age.

CONCLUSION

DHA supplementation in the second half of pregnancy has no effect on childhood growth or fat mass at 7 years of age, supporting findings from follow ups of the DOMInO children at 3 and 5 years.

Omega-3 fatty acid addition during pregnancy

BACKGROUND

Higher intakes of foods containing omega-3 long-chain polyunsaturated fatty acids (LCPUFA), such as fish, during pregnancy have been associated with longer gestations and improved perinatal outcomes. This is an update of a review that was first published in 2006.

OBJECTIVES

To assess the effects of omega-3 LCPUFA, as supplements or as dietary additions, during pregnancy on maternal, perinatal, and neonatal outcomes and longer-term outcomes for mother and child.

SEARCH METHODS

For this update, we searched Cochrane Pregnancy and Childbirth's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (16 August 2018), and reference lists of retrieved studies.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing omega-3 fatty acids (as supplements or as foods, stand-alone interventions, or with a co-intervention) during pregnancy with placebo or no omega-3, and studies or study arms directly comparing omega-3 LCPUFA doses or types. Trials published in abstract form were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed study eligibility, extracted data, assessed risk of bias in trials and assessed quality of evidence for prespecified birth/infant, maternal, child/adult and health service outcomes using the GRADE approach.

MAIN RESULTS

In this update, we included 70 RCTs (involving 19,927 women at low, mixed or high risk of poor pregnancy outcomes) which compared omega-3 LCPUFA interventions (supplements and food) compared with placebo or no omega-3. Overall study-level risk of bias was mixed, with selection and performance bias mostly at low risk, but there was high risk of attrition bias in some trials. Most trials were conducted in upper-middle or high-income countries; and nearly half the trials included women at increased/high risk for factors which might increase the risk of adverse maternal and birth outcomes.Preterm birth < 37 weeks (13.4% versus 11.9%; risk ratio (RR) 0.89, 95% confidence interval (CI) 0.81 to 0.97; 26 RCTs, 10,304 participants; high-quality evidence) and early preterm birth < 34 weeks (4.6% versus 2.7%; RR 0.58, 95% CI 0.44 to 0.77; 9 RCTs, 5204 participants; high-quality evidence) were both lower in women who received omega-3 LCPUFA compared with no omega-3. Prolonged gestation > 42 weeks was probably increased from 1.6% to 2.6% in women who received omega-3 LCPUFA compared with no omega-3 (RR 1.61 95% CI 1.11 to 2.33; 5141 participants; 6 RCTs; moderate-quality evidence).For infants, there was a possibly reduced risk of perinatal death (RR 0.75, 95% CI 0.54 to 1.03; 10 RCTs, 7416 participants; moderate-quality evidence: 62/3715 versus 83/3701 infants) and possibly fewer neonatal care admissions (RR 0.92, 95% CI 0.83 to 1.03; 9 RCTs, 6920 participants; moderate-quality evidence - 483/3475 infants versus 519/3445 infants). There was a reduced risk of low birthweight (LBW) babies (15.6% versus 14%; RR 0.90, 95% CI 0.82 to 0.99; 15 trials, 8449 participants; high-quality evidence); but a possible small increase in large-for-gestational age (LGA) babies (RR 1.15, 95% CI 0.97 to 1.36; 6 RCTs, 3722 participants; moderate-quality evidence, for omega-3 LCPUFA compared with no omega-3. Little or no difference in small-for-gestational age or intrauterine growth restriction (RR 1.01, 95% CI 0.90 to 1.13; 8 RCTs, 6907 participants; moderate-quality evidence) was seen.For the maternal outcomes, there is insufficient evidence to determine the effects of omega-3 on induction post-term (average RR 0.82, 95% CI 0.22 to 2.98; 3 trials, 2900 participants; low-quality evidence), maternal serious adverse events (RR 1.04, 95% CI 0.40 to 2.72; 2 trials, 2690 participants; low-quality evidence), maternal admission to intensive care (RR 0.56, 95% CI 0.12 to 2.63; 2 trials, 2458 participants; low-quality evidence), or postnatal depression (average RR 0.99, 95% CI 0.56 to 1.77; 2 trials, 2431 participants; low-quality evidence). Mean gestational length was greater in women who received omega-3 LCPUFA (mean difference (MD) 1.67 days, 95% CI 0.95 to 2.39; 41 trials, 12,517 participants; moderate-quality evidence), and pre-eclampsia may possibly be reduced with omega-3 LCPUFA (RR 0.84, 95% CI 0.69 to 1.01; 20 trials, 8306 participants; low-quality evidence).For the child/adult outcomes, very few differences between antenatal omega-3 LCPUFA supplementation and no omega-3 were observed in cognition, IQ, vision, other neurodevelopment and growth outcomes, language and behaviour (mostly low-quality to very low-quality evidence). The effect of omega-3 LCPUFA on body mass index at 19 years (MD 0, 95% CI -0.83 to 0.83; 1 trial, 243 participants; very low-quality evidence) was uncertain. No data were reported for development of diabetes in the children of study participants.

AUTHORS' CONCLUSIONS

In the overall analysis, preterm birth < 37 weeks and early preterm birth < 34 weeks were reduced in women receiving omega-3 LCPUFA compared with no omega-3. There was a possibly reduced risk of perinatal death and of neonatal care admission, a reduced risk of LBW babies; and possibly a small increased risk of LGA babies with omega-3 LCPUFA.For our GRADE quality assessments, we assessed most of the important perinatal outcomes as high-quality (e.g. preterm birth) or moderate-quality evidence (e.g. perinatal death). For the other outcome domains (maternal, child/adult and health service outcomes) GRADE ratings ranged from moderate to very low, with over half rated as low. Reasons for downgrading across the domain were mostly due to design limitations and imprecision.Omega-3 LCPUFA supplementation during pregnancy is an effective strategy for reducing the incidence of preterm birth, although it probably increases the incidence of post-term pregnancies. More studies comparing omega-3 LCPUFA and placebo (to establish causality in relation to preterm birth) are not needed at this stage. A further 23 ongoing trials are still to report on over 5000 women, so no more RCTs are needed that compare omega-3 LCPUFA against placebo or no intervention. However, further follow-up of completed trials is needed to assess longer-term outcomes for mother and child, to improve understanding of metabolic, growth and neurodevelopment pathways in particular, and to establish if, and how, outcomes vary by different types of omega-3 LCPUFA, timing and doses; or by characteristics of women.

Fish Intake in Pregnancy and Offspring Metabolic Parameters at Age 9⁻16-Does Gestational Diabetes Modify the Risk?

Oily fish, an important source of marine n-3 long-chain polyunsaturated fatty acids (LCPUFA), has shown to reduce cardiometabolic risk in adults. Whether maternal fish intake affects offspring metabolic health is less established, especially among high-risk pregnancies. We aimed to examine the association of fish intake in pregnancy with offspring metabolic health who were either exposed or unexposed to gestational diabetes mellitus (GDM). Our study included 1234 mother-offspring dyads (608 with a GDM index pregnancy and 626 control dyads) nested within the Danish National Birth Cohort, which is a prebirth cohort. Maternal seafood and marine n-3 LCPUFA consumption was quantified by a food frequency questionnaire (gestational week 25) and a sub-sample with interview data (weeks 12 and 30). The offspring were clinically examined at 9–16 years, including a Dual energy X-ray Absorptiometry (DXA) scan and a fasting blood sample. We calculated multivariable effect estimates and 95% confidence intervals (CI) for anthropometric, adiposity, and metabolic parameters. The median (IQR) intake of total seafood was 23(24) g/day. We found largely no association for total seafood and marine n-3 LCPUFA with offspring metabolic parameters in either group. Using interview data, GDM-exposed women reporting no fish in week 12 and 30 (versus intake >2 times/week) had offspring with a higher Body Mass Index (BMI) (ratio of geometric means (RGM): 1.28, 95% CI: 1.06, 1.55), waist circumference (RGM: 1.22, 95% CI: 1.05, 1.40), triglycerides (RGM: 1.77, 95% CI: 1.03, 3.03), and homeostatic model assessment of insulin resistance HOMA-IR (RGM: 2.16, 95% CI: 1.17, 3.97). We found no associations of n-3 LCPUFA and seafood intake with offspring metabolic outcomes. However, GDM-exposed women who consistently reported eating no fish had offspring with a poorer metabolic profile. Fish intake in pregnancy may mitigate some adverse effects of intrauterine hyperglycemia, however, these findings need replication in better powered studies.

The effectiveness of ω-3 polyunsaturated fatty acid interventions during pregnancy on obesity measures in the offspring: an up-to-date systematic review and meta-analysis

BACKGROUND

The potential role of ω-3 long chain polyunsaturated fatty acid (LCPUFA) supplementation during pregnancy on subsequent risk of obesity outcomes in the offspring is not clear and there is a need to synthesise this evidence.

OBJECTIVE

A systematic review and meta-analysis of randomised controlled trials (RCTs), including the most recent studies, was conducted to assess the effectiveness of ω-3 LCPUFA interventions during pregnancy on obesity measures, e.g. BMI, body weight, fat mass in offspring.

METHODS

Included RCTs had a minimum of 1-month follow-up post-partum. The search included CENTRAL, MEDLINE, SCOPUS, WHO's International Clinical Trials Reg., E-theses and Web of Science databases. Study quality was evaluated using the Cochrane Collaboration's risk of bias tool.

RESULTS

Eleven RCTs, from ten unique trials, (3644 children) examined the effectiveness of ω-3 LCPUFA maternal supplementation during pregnancy on the development of obesity outcomes in offspring. There were heterogeneities between the trials in terms of their sample, type and duration of intervention and follow-up. Pooled estimates did not show an association between prenatal intake of fatty acids and obesity measures in offspring.

CONCLUSION

These results indicate that maternal supplementation with ω-3 LCPUFA during pregnancy does not have a beneficial effect on obesity risk. Due to the high heterogeneity between studies along with small sample sizes and high rates of attrition, the effects of ω-3 LCPUFA supplementation during pregnancy for prevention of childhood obesity in the long-term remains unclear. Large high-quality RCTs are needed that are designed specifically to examine the effect of prenatal intake of fatty acids for prevention of childhood obesity. There is also a need to determine specific sub-groups in the population that might get a greater benefit and whether different ω-3 LCPUFA, i.e. eicosapentaenoic (EPA) vs. docosahexanoic (DHA) acids might potentially have different effects.

Еffects of fortified milk on cognitive abilities in school-aged children: results from a randomized-controlled trial

BACKGROUND

Micronutrients such as vitamins and minerals and long-chain polyunsaturated omega-3 fatty acids (PUFAs) are essential for children's brain development and cognitive functions. The current study investigated whether milk fortified with micronutrients and PUFA can result in improved cognitive function in mainstream school children.

METHODS

One-hundred-and-nineteen children (age 8-14, 58 boys) were randomly allocated to a fortified milk group or a regular full milk control group. Participants consumed 0.6L/day of the milk for 5 months. We recorded relevant biochemical, anthropometric, and cognitive measures (working memory and processing speed) at the start of the study and at follow-up after 5 months.

RESULTS

The fortified milk significantly increased docosahexaenoic acid (DHA) (change from baseline of 28% [95% CI 17-39%] vs. -6% [95% CI - 13 to 0%] in the control group) and serum 25OH-vitamin D concentrations (41% [95% CI 30-52%] vs. 21% [95% CI 11-30%] in the control group). The fortified milk improved working memory on one of two tests (32% [95% CI 17-47%] vs. 13% [95% CI 6-19%] in the control group). The fortified milk also indirectly increased processing speed on one of two tests; this effect was small and completely mediated by increases in 25OH-vitamin D concentrations.

CONCLUSIONS

These results suggest that fortifying milk with micronutrients and PUFA could be an effective and practical way to aid children's cognitive development.

Prenatal n-3 long-chain fatty acid status and offspring metabolic health in early and mid-childhood: results from Project Viva

Higher maternal and biomarker levels of n-3 long-chain polyunsaturated fatty acids (LCPUFAs) have been associated with improved perinatal outcomes and may also influence offspring metabolic health. Past studies were not powered to examine metabolic outcomes and few have specifically targeted metabolically vulnerable populations. We examined the associations of prenatal n-3 LCPUFA status with markers of metabolic health in early and mid-childhood in the full population as well as stratified by maternal glucose tolerance. Our data consisted of 1418 mother-child dyads from Project Viva, a longitudinal, prospective pre-birth cohort enrolled in eastern Massachusetts. We assessed maternal dietary intake of fish and n-3 LCPUFA in mid-pregnancy using a validated food frequency questionnaire. N-3 LCPUFA levels were quantified in maternal second trimester and umbilical cord plasma using liquid-gas chromatography. We assessed offspring anthropometry, adiposity, and blood pressure at early (median age: 3.2 years) and mid-childhood (median age: 7.7 years); and assayed blood samples collected at these visits for metabolic biomarkers. We report here multivariable effect estimates and 95% CI. Early childhood BMI z-score was on average 0.46 (1.03) units and waist circumference 51.3 (3.7) cm. At mid-childhood these measures were 0.39 (1.00) units and 60.0 (8.3) cm, respectively. Higher cord plasma DHA levels were associated with lower BMI z-score ((Q)uartile 4 vs. Q1: -0.21, 95% CI: -0.38, -0.03), waist circumference (Q4 vs. Q1: -0.63, 95% CI: -1.27, 0.00 cm), and leptin levels (Q4 vs. Q1: -0.36, 95% CI: -0.77, 0.05 ng/mL) in early childhood. These associations were strongest and reached significance in offspring of women with isolated hyperglycemia vs. better or worse glycemic status. Higher maternal DHA + EPA (Q4 vs. Q1: -1.59, 95% CI: -2.80, -0.38 μg/mL) and fish (≥3 vs. 0 portions/week: -2.18, 95% CI: -3.90, -0.47 μg/mL) intake was related to lower adiponectin in early childhood. None of these associations persisted with mid-childhood outcomes. We did not find associations with any of the other outcomes. This study supports early and possibly transient effects of prenatal n-3 LCPUFA status on anthropometric measures and adipokine levels. It also raises the possibility that offspring of women with isolated hyperglycemia derive the most benefits from higher n-3 LCPUFA status.

Whole blood n-3 fatty acids are associated with executive function in 2-6-year-old Northern Ghanaian children

Several studies demonstrate the importance of essential fatty acids (EFAs), and the long chain polyunsaturated FA docosahexaenoic acid (DHA), on cognition and brain development. The objective of this study was to investigate the relationship between whole-blood FAs and executive function in children from Northern Ghana. A total of 307, 2-to-6-year-old children attempted the dimensional change card sort (DCCS) task to assess executive function, and dried blood spot samples were collected and analyzed for FA content. Significant differences in mean % total whole-blood fatty acids were observed between children who could not follow directions on the DCCS test (49.8% of the sample) and those who could (50.2% of the sample). Positive associations with DCCS performance were observed for DHA (β=0.25, P=.06), total n-3 (β=0.17, P=.06) and dihomo-gamma-linolenic acid (DGLA; β=0.60, P=.06). Children with the highest levels of total n-3 and DHA were three and four times, respectively, more likely to pass at least one condition of the DCCS test of executive function than those with the lowest DHA levels. The results of this study indicate an association between n-3 FAs and high-level cognitive processes in children two to six years of age, providing impetus for further studies into possible interventions to improve EFA status of children in developing countries.

n-3 Fatty Acid Supplementation in Mothers, Preterm Infants, and Term Infants and Childhood Psychomotor and Visual Development: A Systematic Review and Meta-Analysis

Background

Epidemiologic studies link maternal seafood and n-3 (ω-3) polyunsaturated fatty acid (PUFA) consumption with improved childhood cognitive development; trials show mixed results.

Objective

We investigated effects of n-3 PUFA supplementation on child cognitive and visual outcomes.

Methods

We systematically reviewed and meta-analyzed randomized controlled trials of n-3 PUFA supplementation in mothers or infants (age ≤2 y) and evaluated standardized measures of cognitive or visual development up to age 18 y. Of 6286 abstracts and 669 full-text articles, 38 trials with 53 intervention arms were included. Data were extracted independently in duplicate. Findings were pooled using random-effects meta-analysis across supplementation periods (maternal, preterm, term infant); we also explored subgroup analyses stratified by supplementation period. Heterogeneity was explored using I2, stratified analysis, and meta-regression. Cognitive development was assessed by Bayley Scales of Infant Development mental and psychomotor developmental indexes (MDI, PDI) and intelligence quotient (IQ); visual acuity was assessed by electrophysiological or behavioral measures.

Results

The 38 trials (mothers: n = 13; preterm infants: n = 7; term infants: n = 18) included 5541 participants. When we explored effects during different periods of supplementation, n-3 PUFA supplementation improved MDI in preterm infants (3.33; 95% CI: 0.72, 5.93), without statistically significant effects on PDI or IQ in different intervention period subgroups. Visual acuity [measured as the logarithm of the minimum angle of resolution (logMAR)] was improved by supplementation in preterm (-0.08 logMAR; 95% CI: -0.14, -0.01 logMAR) and term infants (-0.08 logMAR; 95% CI: -0.11, -0.05 logMAR), with a nonsignificant trend for maternal supplementation (-0.02 logMAR; 95% CI: -0.04, 0.00 logMAR). In main analyses pooling all supplementation periods, compared with placebo, n-3 PUFA supplementation improved MDI (n = 21 trials; 0.91; 95% CI: 0.005, 1.81; P = 0.049), PDI (n = 21 trials; 1.06 higher index; 95% CI: 0.10, 2.03; P = 0.031), and visual acuity (n = 24; -0.063 logMAR; 95% CI: -0.084, -0.041 logMAR; P < 0.001) but not IQ (n = 7; 0.20; 95% CI: -1.56, 1.96, P = 0.83), although few studies assessed this endpoint. Potential publication bias was identified for MDI (Eggers P = 0.005), but not other endpoints. Significant differences in findings were not identified by world region, race, maternal education, age at outcome assessment, supplementation duration, DHA or EPA dose, DHA:AA ratio, or study quality score (P-interaction > 0.05 each).

Conclusions

n-3 PUFA supplementation improves childhood psychomotor and visual development, without significant effects on global IQ later in childhood, although the latter conclusion is based on fewer studies.

How does high DHA fish oil affect health? A systematic review of evidence

The health benefits of fish oil, and its omega-3 long chain polyunsaturated fatty acid content, have attracted much scientific attention in the last four decades. Fish oils that contain higher amounts of eicosapentaenoic acid (EPA; 20:5n-3) than docosahexaenoic acid (DHA; 22:6n-3), in a distinctive ratio of 18/12, are typically the most abundantly available and are commonly studied. Although the two fatty acids have traditionally been considered together, as though they were one entity, different physiological effects of EPA and DHA have recently been reported. New oils containing a higher quantity of DHA compared with EPA, such as fractionated and concentrated fish oil, tuna oil, calamari oil and microalgae oil, are increasingly becoming available on the market, and other oils, including those extracted from genetically modified oilseed crops, soon to come. This systematic review focuses on the effects of high DHA fish oils on various human health conditions, such as the heart and cardiovascular system, the brain and visual function, inflammation and immune function and growth/Body Mass Index. Although inconclusive results were reported in several instances, and inconsistent outcomes observed in others, current data provides substantiated evidence in support of DHA being a beneficial bioactive compound for heart, cardiovascular and brain function, with different, and at times complementary, effects compared with EPA. DHA has also been reported to be effective in slowing the rate of cognitive decline, while its possible effects on depression disorders are still unclear. Interestingly, gender- and age- specific divergent roles for DHA have also been reported. This review provides a comprehensive collection of evidence and a critical summary of the documented physiological effects of high DHA fish oils for human health.

Associations between maternal long-chain polyunsaturated fatty acid concentrations and child cognition at 7 years of age: The MEFAB birth cohort

INTRODUCTION

Concentrations of the fish fatty acids EPA and DHA are low among Dutch women of reproductive age. As the human brain incorporates high concentrations of these fatty acids in utero, particularly during third trimester of gestation, these low EPA and DHA concentrations may have adverse consequences for fetal brain development and functioning.

METHODS

Analyses were conducted using longitudinal observational data of 292 mother-child pairs participating in the MEFAB cohort. Maternal AA, DHA, and EPA were determined in plasma phospholipids - obtained in three trimesters - by gas-liquid chromatography. Cognitive function was assessed at 7 years of age, using the Kaufman Assessment Battery for Children, resulting in three main outcome parameters: sequential processing (short-term memory), simultaneous processing (problem-solving skills), and the mental processing composite score. Spline regression and linear regression analyses were used to analyse the data, while adjusting for potential relevant covariates.

RESULTS

Only 2% of the children performed more than one SD below the mental processing composite norm score. Children with lower test scores (<25%) were more likely to have a younger mother with a higher pre-gestational BMI, less likely to be breastfed, and more likely to be born with a lower birth weight, compared to children with higher test scores (≥25%). Fully-adjusted linear regression models did not show associations of maternal AA, DHA, or EPA status during any of the pregnancy trimesters with childhood sequential and simultaneous processing.

CONCLUSION

Maternal fatty acid status during pregnancy was not associated with cognitive performance in Dutch children at age 7.

Docosahexaenoic acid (DHA), a fundamental fatty acid for the brain: New dietary sources

Docosahexaenoic acid (C22: 6n-3, DHA) is a long-chain polyunsaturated fatty acid of marine origin fundamental for the formation and function of the nervous system, particularly the brain and the retina of humans. It has been proposed a remarkable role of DHA during human evolution, mainly on the growth and development of the brain. Currently, DHA is considered a critical nutrient during pregnancy and breastfeeding due their active participation in the development of the nervous system in early life. DHA and specifically one of its derivatives known as neuroprotectin D-1 (NPD-1), has neuroprotective properties against brain aging, neurodegenerative diseases and injury caused after brain ischemia-reperfusion episodes. This paper discusses the importance of DHA in the human brain given its relevance in the development of the tissue and as neuroprotective agent. It is also included a critical view about the ways to supply this noble fatty acid to the population.

Effects of maternal omega-3 fatty acids supplementation during pregnancy/lactation on body composition of the offspring: A systematic review and meta-analysis

BACKGROUND & AIMS

The effect of maternal omega-3 fatty acids intake on the body composition of the offspring is unclear. The aim of this study was to conduct a systematic review and meta-analysis to confirm the effects of omega-3 fatty acids supplementation during pregnancy and/or lactation on body weight, body length, body mass index (BMI), waist circumference, fat mass and sum of skinfold thicknesses of offspring.

METHODS

Human intervention studies were selected by a systematic search of PubMed, Web of Science, the Cochrane Library and references of related reviews and studies. Randomized controlled trials of maternal omega-3 fatty acids intake during pregnancy or lactation for offspring's growth were included. The data were analyzed with RevMan 5.3 and Stata 12.0. Effect sizes were presented as weighted mean differences (WMD) or standardized mean difference (SMD) with 95% confidence intervals (95% CI).

RESULTS

Twenty-six studies comprising 10,970 participants were included. Significant increases were found in birth weight (WMD = 42.55 g, 95% CI: 21.25, 63.85) and waist circumference (WMD = 0.35 cm, 95% CI: 0.04, 0.67) in the omega-3 fatty acids group. There were no effects on birth length (WMD = 0.09 cm, 95% CI: -0.03, 0.21), postnatal length (WMD = 0.13 cm, 95% CI: -0.11, 0.36), postnatal weight (WMD = 0.04 kg, 95% CI: -0.07, 0.14), BMI (WMD = 0.09, 95% CI: -0.05, 0.23), the sum of skinfold thicknesses (WMD = 0.45 mm, 95% CI: -0.30, 1.20), fat mass (WMD = 0.05 kg, 95% CI: -0.01, 0.11) and the percentage of body fat (WMD = 0.04%, 95% CI: -0.38, 0.46).

CONCLUSIONS

This meta-analysis showed that maternal omega-3 fatty acids supplementation can increase offspring's birth weight and postnatal waist circumference. However, it did not appear to influence children's birth length, postnatal weight/length, BMI, sum of skinfold thicknesses, fat mass and the percentage of body fat during postnatal period. Larger, well-designed studies are recommended to confirm this conclusion.

The impact of folic acid supplementation on gestational and long term health: Critical temporal windows, benefits and risks

Highlights

Associations between FA supplementation in pregnancy and effects on offspring's NTDs, allergy/respiratory problems, cancer and behaviour problems as been studied.There is growing concern about the effects of excessive FA supplementation, whether in terms of doses or times of exposure.FA supplementation in the periconceptional period is protective against NTDs while in later periods it could be deleterious.A daily dose of 0.4 mg FA in the periconceptional period seems to be effective and safe.

Abstract

Maternal folic acid (FA) supplementation is one of the most popular nutritional interventions during pregnancy for its protective effect against neural tube defects (NTDs).The purposes of this review are: (a) to gather the current evidence regarding supplementation of maternal diet with FA and (b) to problematize the available literature in terms of dosages, critical temporal windows, and its potential benefits and risks.The expression (pregnancy OR fetus OR offspring OR mother) AND ("folic acid" AND supplementation) was searched on PubMed database, filtering for articles published from 2005 to 2014. Publications referring to FA supplementation during the periconceptional period or pregnancy in which there was a conclusion about the effects of isolated FA supplementation on pregnant woman, pregnancy or offspring were included. Of the initial 1182 papers, 109 fulfilled the inclusion criteria.The majority of the publications reported FA supplementation outcomes on offspring's health, with emphasis in NTDs, allergy/respiratory problems, cancer and behaviour problems. Some inconsistency is observed on the impact of FA supplementation on different outcomes, except for NTDs. It is also visible an increased concern about the impact of excessive supplementation, either in terms of doses or exposure's duration.In conclusion, there is a growing interest in FA supplementation issues. The protective effect of FA supplementation over NTDs has been confirmed, being the periconceptional period a critical window, and it is frequently suggested that allergy/respiratory outcomes arise from (excessive) FA supplementation particularly later in pregnancy. Further research on critical doses and time of exposure should be conducted.

Impact of the n-6:n-3 long-chain PUFA ratio during pregnancy and lactation on offspring neurodevelopment: 5-year follow-up of a randomized controlled trial

BACKGROUND/OBJECTIVES

Evidence regarding the effect of n-3 long-chain polyunsaturated fatty acid (LCPUFA) supplementation during pregnancy on offspring's neurodevelopment is not conclusive.

SUBJECTS/METHODS

In this analysis, the effect of a reduced n-6:n-3 LCPUFA ratio in the diet of pregnant/lactating women (1.2 g n-3 LCPUFA together with an arachidonic acid (AA)-balanced diet between 15th wk of gestation-4 months postpartum vs control diet) on child neurodevelopment at 4 and 5 years of age was assessed. A child development inventory (CDI) questionnaire and a hand movement test measuring mirror movements (MMs) were applied and the association with cord blood LCPUFA concentrations examined.

RESULTS

CDI questionnaire data, which categorizes children as 'normal', 'borderline' or 'delayed' in different areas of development, showed no significant evidence between study groups at 4 (n=119) and 5 years (n=130) except for the area 'letters' at 5 years of age (P=0.043). Similarly, the results did not strongly support the hypothesis that the intervention has a beneficial effect on MMs (for example, at 5 years: dominant hand, fast: adjusted mean difference, -0.08 (-0.43, 0.26); P=0.631). Children exposed to higher cord blood concentrations of docosahexaenoic acid, eicosapentaenoic acid and AA, as well as a lower ratio of n-6:n-3 fatty acids appeared to show beneficial effects on MMs, but these results were largely not statistically significant.

CONCLUSIONS

Our results do not show clear benefits or harms of a change in the n-6:n-3 LCPUFA ratio during pregnancy on offspring's neurodevelopment at preschool age. Findings on cord blood LCPUFAs point to a potential influence on offspring development.

Prenatal fish oil supplementation and early childhood development in the Upstate KIDS Study

Fish oil contains omega-3 fatty acids, which play a vital role in fetal growth and development. In utero exposure to omega-3 fatty acids is exclusively dependent on maternal nutrition. Previous studies have suggested that prenatal fish oil supplementation has positive impacts on child neurodevelopment later in life. This study examines the associations between fish oil supplementation both before pregnancy and throughout pregnancy and subsequent child development. Mother-child pairs from the Upstate KIDS Study, a birth cohort consisting of children born between 2008 and 2010, were included. Self-reported prenatal fish oil supplementation data were available for 5845 children (3807 singletons and 2038 twins). At multiple time points, from 4 months to 3 years of age, child development was reported by the parents on the Ages and Stages Questionnaire (ASQ). Five developmental domains were assessed: fine motor, gross motor, communication, personal-social functioning and problem solving. Generalized linear mixed models were used to estimate odds ratios (OR) while adjusting for covariates. Primary analyses showed that the risk of failing the ASQ problem-solving domain was significantly lower among children of women who took fish oil before pregnancy (OR 0.40, 95% confidence intervals (CI) 0.18-0.89) and during pregnancy (OR 0.43, 95% CI 0.22-0.83). Gender interaction was not statistically significant, although stratified results indicated stronger associations among girls. Similarly, associations were primarily among singletons. Prenatal fish oil supplementation may be beneficial in regards to neurodevelopment. Specifically, it is associated with a lower risk of failing the problem-solving domain up to 3 years of age.

On the relationship between head circumference, brain size, prenatal long-chain PUFA/5-methyltetrahydrofolate supplementation and cognitive abilities during childhood

Head circumference in infants has been reported to predict brain size, total grey matter volume (GMV) and neurocognitive development. However, it is unknown whether it has predictive value on regional and subcortical brain volumes. We aimed to explore the relationship between several head circumference measurements since birth and distributions of GMV and subcortical volumes at later childhood. We examined seventy-four, Caucasian, singleton, term-born infants born to mothers randomised to receive fish oil and/or 5-methyltetrahydrofolate or placebo prenatal supplementation. We assessed head circumference at birth and at 4 and 10 years of age and cognitive abilities at 7 years of age. We obtained brain MRI at 10 years of age, on which we performed voxel-based morphometry, cortical surface extraction and subcortical segmentation. Analyses were controlled for sex, age, height, weight, family status, laterality and total intracranial volume. Prenatal supplementation did not affect head circumference at any age, cognitive abilities or total brain volumes. Head circumference at 4 years presented the highest correlation with total GMV, white matter volume and brain surface area, and was also strongly associated with GMV of frontal, temporal and occipital areas, as well as with caudate nucleus, globus pallidus, putamen and thalamus volumes. As relationships between brain volumes in childhood and several outcomes extend into adulthood, we have found that ages between 0 and 4 years as the optimal time for brain growth; postnatal factors might have the most relevant impact on structural maturation of certain cortical areas and subcortical nuclei, independent of prenatal supplementation.

Physical fitness and shapes of subcortical brain structures in children

A few studies have recently reported that higher cardiorespiratory fitness is associated with higher volumes of subcortical brain structures in children. It is, however, unknown how different fitness measures relate to shapes of subcortical brain nuclei. We aimed to examine the association of the main health-related physical fitness components with shapes of subcortical brain structures in a sample of forty-four Spanish children aged 9·7 (sd 0·2) years from the NUtraceuticals for a HEALthier life project. Cardiorespiratory fitness, muscular strength and speed agility were assessed using valid and reliable tests (ALPHA-fitness test battery). Shape of the subcortical brain structures was assessed by MRI, and its relationship with fitness was examined after controlling for a set of potential confounders using a partial correlation permutation approach. Our results showed that all physical fitness components studied were significantly related to the shapes of subcortical brain nuclei. These associations were both positive and negative, indicating that a higher level of fitness in childhood is related to both expansions and contractions in certain regions of the accumbens, amygdala, caudate, hippocampus, pallidum, putamen and thalamus. Cardiorespiratory fitness was mainly associated with expansions, whereas handgrip was mostly associated with contractions in the structures studied. Future randomised-controlled trials will confirm or contrast our findings, demonstrating whether changes in fitness modify the shapes of brain structures and the extent to which those changes influence cognitive function.

New Perspective on Impact of Folic Acid Supplementation during Pregnancy on Neurodevelopment/Autism in the Offspring Children - A Systematic Review

It has been conclusively established that folic acid supplementation prior to and during early pregnancy (up to 12 weeks of gestation) can prevent neural tube defects (NTDs). We hypothesized that folate effects may extend from neuro-structural defects to alterations in neuro-behavioural and emotional skills including autism spectrum disorders (ASDs) and other developmental disorders. The objective of this review was to comprehensively evaluate evidence on the impact of folic acid on neurodevelopment other than NTDs. We conducted an online search of relevant literature compiled by the National Library of Medicine from Medline and EMBASE (searched on Dec 31, 2014: http://www.ncbi.nlm.nih.gov/entrez/query/fcgi and http://www.elsevier.com/online-tools/embase). We first created 3 files (search restricted to English literature) using the following key words: 1) folate or folic acid (171322 papers identified by this search); 2) maternal or pregnancy or pregnant or gestation or gestational or prenatal or antenatal or periconception or periconceptional (1349219 papers identified by this search); and 3) autism or autism spectrum disorders or developmental delay or development or neurodevelopment or mental or cognitive or language or personal-social or gross motor or fine motor or behaviour or intellectual or intelligence or Bayley Scale (8268145 papers identified by this search). We then merged the 3 files and reviewed the papers that addressed these three issues simultaneously. A total of 22 original papers that examined the association between folic acid supplementation in human pregnancy and neurodevelopment/autism were identified after the screening, with 15 studies showing a beneficial effect of folic acid supplementation on neurodevelopment/autism, 6 studies showed no statistically significant difference, while one study showed a harmful effect in > 5 mg folic acid supplementation/day during pregnancy. Folic acid supplementation in pregnancy may have beneficial effects on the neurodevelopment of children beyond its proven effect on NTDs.

Cow's milk allergy: towards an update of DRACMA guidelines

BACKGROUND

In 2010, the diagnosis and treatment of IgE-mediated CMA were systematized in a GRADE guideline.

OBJECTIVES & METHODS

After 6 years, the state of the knowledge in diagnosis and treatment of CMA has largely evolved. We summarize here the main advances, and exemplify indicating some specific points: studies aimed at better knowledge of the effects of breastfeeding and the production of new special formulae intended for the treatment of CMA. The literature (PubMed/MEDLINE) was searched using the following algorithms: (1) [milk allergy] AND diagnosis; (2) [milk allergy] AND [formul*] OR [breast*], setting the search engine [6-years] time and [human] limits. The authors drew on their collective clinical experience to restrict retrieved studies to those of relevance to a pediatric allergy practice.

RESULTS

Several clinical studies did address the possibility to diagnose CMA using new tools in vitro and in vivo, or to diagnose it without any evaluation of sensitization. Some studies also addressed the clinical role of formulae based on milk hydrolysates, soy, or rice hydrolysates in the treatment of CMA. Many studies have elucidated the effects of selective nutrients in breastfed infants on their immunologic and neurologic characteristics.

CONCLUSIONS

Evidence-based diagnostic criteria should be identified for non-IgE-mediated CMA. Debate is ongoing about the best substitute for infants with CMA. In particular, Hydrolyzed Rice Formulae have been widely assessed in the last six years. In the substitute choice, clinicians should be aware of recent studies that can modify the interpretation of the current recommendations. New systematic reviews and metanalyses are needed to confirm or modify the current DRACMA recommendations.

Association between maternal nutritional status in pregnancy and offspring cognitive function during childhood and adolescence; a systematic review

Background

The mother is the only source of nutrition for fetal growth including brain development. Maternal nutritional status (anthropometry, macro- and micro-nutrients) before and/or during pregnancy is therefore a potential predictor of offspring cognitive function. The relationship of maternal nutrition to offspring cognitive function is unclear. This review aims to assess existing evidence linking maternal nutritional status with offspring cognitive function.

Methods

Exposures considered were maternal BMI, height and weight, micronutrient status (vitamins D, B12, folate and iron) and macronutrient intakes (carbohydrate, protein and fat). The outcome was any measure of cognitive function in children aged <18 years. We considered observational studies and trials with allocation groups that differed by single nutrients. We searched Medline/PubMed and the Cochrane Library databases and reference lists of retrieved literature. Two reviewers independently extracted data from relevant articles. We used methods recommended by the Centre for Reviews and Dissemination, University of York and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement.

Results

Of 16,143 articles identified, 38 met inclusion criteria. Most studies were observational, and from high-income settings. There were few randomized controlled trials. There was consistent evidence linking maternal obesity with lower cognitive function in children; low maternal BMI has been inadequately studied. Among three studies of maternal vitamin D status, two showed lower cognitive function in children of deficient mothers. One trial of folic acid supplementation showed no effects on the children’s cognitive function and evidence from 13 observational studies was mixed. Among seven studies of maternal vitamin B12 status, most showed no association, though two studies in highly deficient populations suggested a possible effect. Four out of six observational studies and two trials (including one in an Iron deficient population) found no association of maternal iron status with offspring cognitive function. One trial of maternal carbohydrate/protein supplementation showed no effects on offspring cognitive function.

Conclusions

Current evidence that maternal nutritional status during pregnancy as defined by BMI, single micronutrient studies, or macronutrient intakes influences offspring cognitive function is inconclusive. There is a need for more trials especially in populations with high rates of maternal undernutrition.

Systematic review registration

Registered in PROSPERO CRD42013005702.

Electronic supplementary material

The online version of this article (doi:10.1186/s12884-016-1011-z) contains supplementary material, which is available to authorized users.

Reduced DHA transfer in diabetic pregnancies: mechanistic basis and long-term neurodevelopmental implications

Infants born to diabetic mothers have a higher frequency of impaired neurodevelopment. The omega-3 or n-3 fatty acid docosahexaenoic acid (DHA) is an important structural component of neural tissue and is critical for fetal brain development. Maternal DHA supplementation during pregnancy is linked to better infant neurodevelopment; however, maternal-fetal transfer of DHA is reduced in women with diabetes. Evidence of mechanisms explaining altered maternal-fetal DHA transfer in this population is limited. This review explores existing evidence underpinning reduced maternal-fetal DHA transfer in maternal fuel metabolism in this population. Further research is necessary to evaluate the role of peroxisome proliferator-activated receptors in modulating placental fatty acid binding and maternal-fetal DHA transfer. Considerations for clinical practice include a diet high in DHA and/or provision of supplemental DHA to obstetric diabetic patients within minimum guidelines.

Association between prenatal and current exposure to selected LCPUFAs and school performance at age 7

INTRODUCTION

Long-chain polyunsaturated fatty acids (LCPUFAs) are important for brain functioning and might, thus, influence cognition and school performance. However, research investigating LCPUFAs relationships with school performance is limited. The objective of this study was to determine the association between levels of the LCPUFAs docosahexaenoic acid (DHA), arachidonic acid (AA), eicosapentaenoic acid (EPA) and n-6 docosapentaenoic acid (Osbond acid, ObA) at study entry, 22 weeks of pregnancy, 32 weeks of pregnancy, at partus, in umbilical cord plasma and child's plasma at age 7 and school performance scores at age 7.

METHODS

Data from the Maastricht Essential Fatty Acid Birth cohort (MEFAB) were used for this study. Fatty acid levels of plasma phospholipids were measured in maternal blood plasma at study entry, 22 weeks of pregnancy, 32 weeks of pregnancy and partus. Childs fatty acid levels of plasma phospholipids were measured a in umbilical cord blood plasma, and in blood plasma of the child at age 7. Scores on national standardised tests for spelling, reading and arithmetic at age 7 were obtained via the school (scores were available for 149, 159 and 155 children, respectively). Associations between LCPUFA levels and school performance scores were analysed with categorical regression analyses with correction for covariates (smoking, maternal education, sex, breastfeeding, maternal intelligence, birth weight and BMI at age 7).

RESULTS

Significant (p<0.001) associations between DHA level at age 7 and both reading (β=0.158) and spelling (β=0.146) were found. Consistent significant negative associations were observed between all maternal DHA plasma levels and arithmetic scores at age 7 (all p<0.001, all β<-0.019). Additional significant negative associations were observed between maternal LCPUFA plasma levels at study entry and both reading and spelling scores at age 7; these associations were less consistent.

CONCLUSION

Plasma DHA levels at age 7 were positively associated with reading and spelling scores at age 7. Consistent significant negative associations between maternal plasma DHA levels and arithmetic scores of the child at age 7 were found. Although this is an observational study, which cannot proof causality, the consistent negative associations observed between maternal plasma DHA levels and the arithmetic scores of the children at age 7 calls upon prudence when considering DHA supplementation during pregnancy.

Folate and long-chain polyunsaturated fatty acid supplementation during pregnancy has long-term effects on the attention system of 8.5-y-old offspring: a randomized controlled trial

BACKGROUND

During fetal and perinatal periods, many nutrients, such as long-chain polyunsaturated fatty acids [contained in fish oil (FO)] and folate, are important in achieving normal brain development. Several studies have shown the benefits of early nutrition on children's neurocognitive development. However, the evidence with regard to the attention system is scarce.

OBJECTIVES

The aim of this study was to analyze the long-term effects of FO, 5-methyltetrahydrofolate (5-MTHF), or FO+5-MTHF prenatal supplementation on attention networks.

DESIGN

Participants were 136 children born to mothers from the NUHEAL (Nutraceuticals for a Healthy Life) project (randomly assigned to receive FO and/or 5-MTHF or placebo prenatal supplementation) who were recalled for a new examination 8.5 y later. The response conflict-resolution ability (using congruent and incongruent conditions)), alerting, and spatial orienting of attention were evaluated with behavioral measures (Attention Network Test), electroencephalography/event-related potentials (ERPs), and standardized low-resolution brain electromagnetic tomography (sLORETA).

RESULTS

Children born to mothers supplemented with 5-MTHF alone solved the response conflict more quickly than did the placebo and the FO+5-MTHF groups (all P < 0.05). Differences between ERP amplitudes for the conflict conditions were also observed. sLORETA analysis showed higher activation of the right midcingulate cortex for the incongruent condition. In addition, a significant slowing down of response speed depending on the warning cue in the 5-MTHF and FO groups was observed.

CONCLUSIONS

Folate supplementation during pregnancy, rather than FO or FO+5-MTHF supplementation, improves children's ability to solve response conflicts. This advantage seems to be based on the higher activation of the midcingulate cortex, indicating that early nutrition influences the functionality of specific brain areas involved in executive functions. This trial was registered at clinicaltrials.gov as NCT01180933.

Maternal prenatal and/or postnatal n-3 long chain polyunsaturated fatty acids (LCPUFA) supplementation for preventing allergies in early childhood

BACKGROUND

Allergies have become more prevalent globally over the last 20 years. Dietary consumption of n-3 (or omega 3) long chain polyunsaturated fatty acids (LCPUFA) has declined over the same period of time. This, together with the known role of n-3 LCPUFA in inhibiting inflammation, has resulted in speculation that n-3 LCPUFA may prevent allergy development. Dietary n-3 fatty acids supplements may change the developing immune system of the newborn before allergic responses are established, particularly for those with a genetic predisposition to the production of the immunoglobulin E (IgE) antibody. Individuals with IgE-mediated allergies have both the signs and symptoms of the allergic disease and a positive skin prick test (SPT) to the allergen.

OBJECTIVES

To assess the effect of n-3 LCPUFA supplementation in pregnant and/or breastfeeding women on allergy outcomes (food allergy, atopic dermatitis (eczema), allergic rhinitis (hay fever) and asthma/wheeze) in their children.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (6 August 2014), PubMed (1966 to 01 August 2014), CINAHL via EBSCOhost (1984 to 01 August 2014), Scopus (1995 to 01 August 2014), Web of Knowledge (1864 to 01 August 2014) and ClinicalTrials.gov (01 August 2014) and reference lists of retrieved studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) evaluating the effect of n-3 LCPUFA supplementation of pregnant and/or lactating women (compared with placebo or no treatment) on allergy outcomes of the infants or children. Trials using a cross-over design and trials examining biochemical outcomes only were not eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed eligibility and trial quality and performed data extraction. Where the review authors were also investigators on trials selected, an independent reviewer assessed trial quality and performed data extraction.

MAIN RESULTS

Eight trials involving 3366 women and their 3175 children were included in the review. In these trials, women were supplemented with n-3 LCPUFA during pregnancy (five trials), lactation (two trials) or both pregnancy and lactation (one trial). All trials randomly allocated women to either a n-3 LCPUFA supplement or a control group. The risk of bias varied across the eight included trials in this review with only two trials with a low risk of selection, performance and attrition bias.N-3 LCPUFA supplementation showed a clear reduction in the primary outcome of any allergy (medically diagnosed IgE mediated) in children aged 12 to 36 months (risk ratio (RR) 0.66, 95% confidence interval (CI) 0.44 to 0.98; two RCTs; 823 children), but not beyond 36 months (RR 0.86, 95% CI 0.61 to 1.20; one RCT, 706 children). For any allergy (medically diagnosed IgE mediated and/or parental report), no clear differences were seen in children either at 12 to 36 months (RR 0.89, 95% CI 0.71 to 1.11; two RCTs, 823 children) or beyond 36 months of age (RR 0.96, 95% CI 0.84 to 1.09; three RCTs, 1765 children).For the secondary outcomes of specific allergies there were no clear differences for food allergies at 12 to 36 months and beyond 36 months, but a clear reduction was seen for children in their first 12 months with n-3 LCPUFA (both for medically diagnosed IgE mediated and medically diagnosed IgE mediated and/or parental report). There was a clear reduction in medically diagnosed IgE-mediated eczema with n-3 LCPUFA for children 12 to 36 months of age, but not at any other time point for both medically diagnosed IgE mediated and medically diagnosed IgE mediated and/or parental report. No clear differences for allergic rhinitis or asthma/wheeze were seen at any time point for both medically diagnosed IgE mediated, and medically diagnosed IgE mediated and/or parental report.There was a clear reduction in children's sensitisation to egg and sensitisation to any allergen between 12 to 36 months of age when mothers were supplemented with n-3 LCPUFA.In terms of safety for the mother and child, n-3 LCPUFA supplementation during pregnancy did not show increased risk of postpartum haemorrhage or early childhood infections.

AUTHORS' CONCLUSIONS

Overall, there is limited evidence to support maternal n-3 LCPUFA supplementation during pregnancy and/or lactation for reducing allergic disease in children. Few differences in childhood allergic disease were seen between women who were supplemented with n-3 LCPUFA and those who were not.

Vitamin B-12 Deficiency in Children Is Associated with Grade Repetition and School Absenteeism, Independent of Folate, Iron, Zinc, or Vitamin A Status Biomarkers

BACKGROUND

Micronutrients are essential to neurocognitive development; yet their role in educational outcomes is unclear.

OBJECTIVE

We examined the associations of micronutrient status biomarkers with the risk of grade repetition and rates of school absenteeism in a cohort of school children.

METHODS

We recruited 3156 children aged 5-12 y from public schools in Bogota, Colombia. Circulating ferritin, hemoglobin, zinc, vitamin A, and vitamin B-12; erythrocyte folate; and mean corpuscular volume (MCV) were measured in blood samples obtained at the beginning of the year. Absenteeism was recorded weekly during the school year, and grade repetition was determined the next year. Risk ratios for grade repetition and rate ratios for absenteeism were estimated by categories of micronutrient status indicators with use of Poisson regression, adjusting for potential confounders.

RESULTS

The risk of grade repetition was 4.9%, and the absenteeism rate was 3.8 d per child-year of observation. Vitamin B-12 deficiency (<148 pmol/L) was associated with an adjusted 2.36-fold greater risk of grade repetition (95% CI: 1.03, 5.41; P = 0.04) compared with plasma concentrations ≥148 pmol/L. Other micronutrients were not related to grade repetition. Vitamin B-12 deficiency was also associated with school absenteeism rates. Compared with children with plasma vitamin B-12 concentrations ≥148 pmol/L, vitamin B-12-deficient children had a 1.89-times higher adjusted rate (95% CI: 1.53, 2.34; P < 0.0001). Anemia was related to a 72% higher rate (95% CI: 48%, 99%; P < 0.0001), whereas every 5-fL difference in MCV was associated with a 7% lower adjusted rate (95% CI: 4%, 10%; P < 0.0001).

CONCLUSIONS

Vitamin B-12 deficiency was associated with risk of grade repetition and school absenteeism rates in school children from Bogota, Colombia. The effects of correcting vitamin B-12 deficiency on educational outcomes and neurocognitive development of school children need to be determined in intervention studies.