Long-chain polyunsaturated fatty acid supplementation in preterm infants

Modification of erythrocyte membrane phospholipid composition in preterm newborns with retinopathy of prematurity: The omegaROP study

N-3 polyunsaturated fatty acids (PUFAs) may prevent retinal vascular abnormalities observed in oxygen-induced retinopathy, a model of retinopathy of prematurity (ROP). In the OmegaROP prospective cohort study, we showed that preterm infants who will develop ROP accumulate the n-6 PUFA arachidonic acid (ARA) at the expense of the n-3 PUFA docosahexaenoic acid (DHA) in erythrocytes with advancing gestational age (GA). As mice lacking plasmalogens -That are specific phospholipids considered as reservoirs of n-6 and n-3 PUFAs- Display a ROP-like phenotype, the aim of this study was to determine whether plasmalogens are responsible for the changes observed in subjects from the OmegaROP study. Accordingly, preterm infants aged less than 29 weeks GA were recruited at birth in the Neonatal Intensive Care Unit of University Hospital Dijon, France. Blood was sampled very early after birth to avoid any nutritional influence on its lipid composition. The lipid composition of erythrocytes and the structure of phospholipids including plasmalogens were determined by global lipidomics using liquid chromatography coupled to high-resolution mass spectrometry (LC-HRMS). LC-HRMS data confirmed our previous observations by showing a negative association between the erythrocyte content in phospholipid esterified to n-6 PUFAs and GA in infants without ROP (rho = -0.485, p = 0.013 and rho = -0.477, p = 0.015 for ethanolamine and choline total phospholipids, respectively). Phosphatidylcholine (PtdCho) and phosphatidylethanolamine (PtdEtn) species with ARA, namely PtdCho16:0/20:4 (rho = -0.511, p < 0.01) and PtdEtn18:1/20:4 (rho = -0.479, p = 0.015), were the major contributors to the relationship observed. On the contrary, preterm infants developing ROP displayed negative association between PtdEtn species with n-3 PUFAs and GA (rho = -0.380, p = 0.034). They were also characterized by a positive association between GA and the ratio of ethanolamine plasmalogens (PlsEtn) with n-6 PUFA to PlsEtn with n-3 PUFAs (rho = 0.420, p = 0.029), as well as the ratio of PlsEtn with ARA to PlsEtn with DHA (rho = 0.843, p = 0.011). Altogether, these data confirm the potential accumulation of n-6 PUFAs with advancing GA in erythrocytes of infants developing ROP. These changes may be partly due to plasmalogens.

Protocol for assessing if behavioural functioning of infants born <29 weeks' gestation is improved by omega-3 long-chain polyunsaturated fatty acids: follow-up of a randomised controlled trial

INTRODUCTION

During the last trimester of pregnancy, the fetal brain undergoes a rapid growth spurt and accumulates essential nutrients including docosahexaenoic acid (DHA). This takes place ex-utero for infants born <29 weeks' gestation, without the in-utero provisions of DHA. Infants born <29 weeks' are more likely to experience behavioural and emotional difficulties than their term-born counterparts. It has been hypothesised that supplementing preterm infants with dietary DHA may alleviate insufficiency and subsequently prevent or minimise behavioural problems. This protocol describes a follow-up of infants born <29 weeks gestation who were enrolled in a randomised controlled trial (RCT) of DHA supplementation. We aim to determine whether DHA supplementation improves the behaviour, and general health of these infants.

METHODS AND ANALYSIS

Infants born <29 weeks' gestation were enrolled in a multicentre blinded RCT of enteral DHA supplementation. Infants were randomised to receive an enteral emulsion that provided 60 mg/kg/day of DHA or a control emulsion commenced within the first 3 days of enteral feeding, until 36 weeks' postmenstrual age or discharge home, whichever occurred first. Families of surviving children (excluding those who withdrew from the study) from the Australian sites (up to 955) will be invited to complete a survey. The survey will include questions regarding child behavioural and emotional functioning, executive functioning, respiratory health and general health. We hypothesise that the DHA intervention will have a benefit on the primary outcome, parent-rated behaviour and emotional status as measured using the Total Difficulties score of the Strengths and Difficulties Questionnaire. Detecting a 2-point difference between groups (small effect size of 0.25 SD) with 90% power will require follow-up of 676 participants.

ETHICS AND DISSEMINATION

The Women's and Children Health Network Human Research Ethics Committee reviewed and approved the study (HREC/16/WCHN/184). Results will be disseminated in peer-reviewed publications and conference presentations.

TRIAL REGISTRATION NUMBER

ACTRN12612000503820.

Early nutrition and white matter microstructure in children born very low birth weight

Infants born at very low birth weight (<1500 g) are vulnerable to nutritional deficits during their first postnatal month, which are associated with poor neurodevelopmental outcomes. Despite this knowledge, the impact of early postnatal nutrition on white matter microstructure in children born with very low birth weight has not been investigated. In this prospective cohort study, we employed a whole-brain approach to investigate associations between precise estimates of nutrient intake within the first postnatal month with white matter microstructure at 5 years of age. Detailed information about breastmilk, macronutrient and energy intakes during this period were prospectively recorded for all participants. Multi-shell diffusion and T1-weighted MRIs were acquired in 41 children (21 males; mean scan age: 5.75 ± 0.22 years; mean birth weight: 1028.6 ± 256.8 g). The diffusion tensor imaging and neurite orientation dispersion and density imaging models were used to obtain maps of fractional anisotropy, radial diffusivity, orientation dispersion and neurite density indices. Tract-based spatial statistics was used to test associations between metrics of white matter microstructure with breastmilk, macronutrient (protein, lipids and carbohydrate) and energy intake. Associations between white matter microstructure and cognitive outcomes were also examined. Compared to children who did not meet enteral feeding recommendations, those who achieved enteral protein, lipid and energy recommendations during the first postnatal month showed improved white matter maturation at 5 years. Among the macronutrients, greater protein intake contributed most to the beneficial effect of nutrition, showing widespread increases in fractional anisotropy and reductions in radial diffusivity. No significant associations were found between white matter metrics with breastmilk or carbohydrate intake. Voxel-wise analyses with cognitive outcomes revealed significant associations between higher fractional anisotropy and neurite density index with higher processing speed scores. Lower radial diffusivity and orientation dispersion index were also associated with improved processing speed. Our findings support the long-term impacts of early nutrition on white matter microstructure, which in turn is related to cognitive outcomes. These results provide strong support for early postnatal nutritional intervention as a promising strategy to improve long-term cognitive outcomes of infants born at very low birth weight.

The Influence of Omega-3 Long-Chain Polyunsaturated Fatty Acid, Docosahexaenoic Acid, on Child Behavioral Functioning: A Review of Randomized Controlled Trials of DHA Supplementation in Pregnancy, the Neonatal Period and Infancy

This is a review of randomized controlled trials using docosahexaenoic acid (DHA) interventions in the first 1000 days of life with assessments of behavioral functioning in childhood. Electronic databases were searched for trials with a DHA intervention (compared with a placebo group that received no or less DHA) at any time to either women or infants during the first 1000 days, with a subsequent assessment of child behavior. There were 25 trials involving 10,320 mother-child pairs, and 71 assessments of behavior in 6867 of the children (66.5% of those originally enrolled). From the 71 assessments administered, there were 401 comparisons between a DHA group and a control group, with most reporting a null effect. There were no findings of a positive effect of DHA, and 23 instances where the DHA group had worse scores compared with the control group. There was limited evidence that DHA supplementation had any effect on behavioral development, although two of the largest trials with behavioral measures detected adverse effects. Future trials, and future follow-ups of existing trials, should make an effort to evaluate the effect of DHA intervention on behavioral functioning.

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.

Epigenetic Effects of n-3 LCPUFAs: A Role in Pediatric Metabolic Syndrome

Childhood obesity represents an important public health issue worldwide and is strongly linked to metabolic alterations such as hypertension, insulin resistance, and dyslipidemia. The constellation of these conditions is commonly known as Metabolic Syndrome (MetS). Metabolic syndrome is not just a simple cluster of metabolic complications due to excess of adipose tissue, but is considered a risk factor for cardiovascular diseases. Evidence from several human and animal studies suggests that environmental and nutritional exposure during pregnancy may affect the newborn development and future health through epigenetic changes, playing a potential role in determining obesity and obesity-related complications. Understanding how nutritional epigenetic mechanisms contribute to the "transgenerational risk" for obesity and metabolic dysfunction is crucial in order to develop early prevention strategies for children's health. Nutrigenetics is the science that studies the role of nutrients in gene expression. Long Chain Polyunsaturated Fatty Acids (LCPUFAs) are known for their health benefits, especially in relation to their ability to modulate inflammation and improve some obesity-associated comorbidities, mainly by decreasing plasma triglycerides. Recent nutrigenetic research is focusing on the potential role of LCPUFAs in influencing epigenetic markers. In this review, we present the most recent updates about the possible interaction between n-3 LCPUFAs and epigenetic pathways in metabolic syndrome. Literature from MEDLINE® and the Cochrane database between May 2005 and December 2018 has been scanned.

Neurocognitive Functions in Infants with Malnutrition; Relation with Long-chain Polyunsaturated Fatty Acids, Micronutrients Levels and Magnetic Resonance Spectroscopy

PURPOSE

Malnutrition may influence neurocognitive development in children by directly affecting the brain structural development, or indirectly by affecting the children's cognition experience. Malnutrition alters the cell numbers, cell migration, synaptogenesis, and neurotransmission due to inadequate availability of necessary micronutrients to support cell growth. We aimed to analyze neurocognitive development in infants with malnutrition and its association with long chain polyunsaturated fatty acids (LC-PUFA), micronutrients levels and magnetic resonance spectroscopy (MRS) findings.

METHODS

The study included two groups; group 1, infants with malnutrition (n=24), group 2; healthy infants (n=21). Peripheral blood was obtained from the participants for studying micronutrients and LC-PUFA levels. The neurocognitive development was analyzed by the use of an Ankara Developmental Screening Inventory test. MRS were performed on all infants.

RESULTS

All parameters of neurocognitive development and serum calcium (9.6±0.9 mg/dL vs. 10.4±0.3 mg/dL, p<0.05) and magnesium (2.02±0.27 mg/dL vs. 2.2±0.14 mg/dL, p<0.05) levels were noted as being low in infants with marked malnutrition. No difference was found in LC-PUFA levels between healthy and malnourished infants. Thalamic choline/creatine levels were significantly high in infants with malnutrition (1.33±0.22 vs. 1.18±0.22, p<0.05). Total neurocognitive development in infants was positively correlated with serum calcium levels (p<0.05, r=0.381).

CONCLUSION

Calcium supplementation may improve neurocognitive development in malnourished infants.

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

INTRODUCTION

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

METHODS AND ANALYSIS

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

ETHICS AND DISSEMINATION

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

TRIAL REGISTRATION NUMBER

ACTRN12612000503820; Pre-results.

The effect of long chain polyunsaturated fatty acid supplementation on intelligence in low birth weight infant during lactation: A meta-analysis

Background

Low birth weight infant (LBWIs) are prone to mental and behavioural problems. As an important constituent of the brain and retina, long chain polyunsaturated fatty acids are essential for foetal infant mental and visual development. The effect of lactation supplemented with long chain polyunsaturated fatty acids (LCPUFA) on the improvement of intelligence in low birth weight children requires further validation.

Methods

In this study, a comprehensive search of multiple databases was performed to identify studies focused the association between intelligence and long chain polyunsaturated fatty acid supplementation in LBWIs. Studies that compared the Bayley Scales of Infant Development (BSID) or the Wechsler Abbreviated Scale of Intelligence for Children (WISC) scores between LBWIs who were supplemented and controls that were not supplemented with LCPUFA during lactation were selected for inclusion in the meta-analysis.

Results

The main outcome was the mean difference in the mental development index (MDI) and psychomotor development index (PDI) of the BSID and the full scale intelligence quotient (FSIQ), verbal intelligence quotient (VIQ) and performance intelligence quotient (PIQ) of the WISC between LBWIs and controls. Our findings indicated that the mean BSID or WISC scores in LBWIs did not differ between the supplemented groups and controls.

Conclusion

This meta-analysis does not reveal that LCPUFA supplementation has a significant impact on the level of intelligence in LBWIs.

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.

ω-3 and ω-6 Fatty Acid Supplementation May Reduce Autism Symptoms Based on Parent Report in Preterm Toddlers

Background

Children born preterm are at increased risk of autism spectrum disorder (ASD). n-3 (ω-3) Combined with n-6 (ω-6) fatty acids including γ-linolenic acid (GLA) may benefit children born preterm showing early signs of ASD. Previous trials have reported that docosahexaenoic acid (DHA) promotes cognitive development in preterm neonates and n-3 fatty acids combined with GLA improve attention-deficit-hyperactivity disorder.

Objectives

The objectives of the pilot Preemie Tots Trial were 1) to confirm the feasibility of a full-scale trial in toddlers born very preterm and exhibiting ASD symptoms and 2) to explore the effects of supplementation on parent-reported ASD symptoms and related behaviors.

Methods

This was a 90-d randomized, fully blinded, placebo-controlled trial in 31 children 18-38 mo of age who were born at ≤29 wk of gestation. One group was assigned to daily Omega-3-6-9 Junior (Nordic Naturals, Inc.) treatment (including 338 mg eicosapentaenoic acid, 225 mg DHA, and 83 mg GLA), and the other group received canola oil (124 mg palmitic acid, 39 mg stearic acid, 513 mg linoleic acid, 225 mg α-linolenic acid, and 1346 mg oleic acid). Mixed-effects regression analyses followed intent-to-treat analysis and explored effects on parent-reported ASD symptoms and related behaviors.

Results

Of 31 children randomly assigned, 28 had complete outcome data. After accounting for baseline scores, those assigned to treatment exhibited a greater reduction in ASD symptoms per the Brief Infant Toddler Social Emotional Assessment ASD scale than did those assigned to placebo (difference in change = - 2.1 points; 95% CI: - 4.1, - 0.2 points; standardized effect size = - 0.71). No other outcome measure reflected a similar magnitude or a significant effect.

Conclusions

This pilot trial confirmed adequate numbers of children enrolled and participated fully in the trial. No safety concerns were noted. It also found clinically-significant improvements in ASD symptoms for children randomly assigned to receive Omega-3-6-9 Junior, but effects were confined to one subscale. A future full-scale trial is warranted given the lack of effective treatments for this population. This trial was registered at www.clinicaltrials.gov as NCT01683565.

Nutrition after preterm birth and adult neurocognitive outcomes

BACKGROUND

Preterm birth (<37 gestational weeks) poses a risk of poorer neurocognitive functioning. Faster growth after preterm birth predicts better cognitive abilities and can be promoted through adequate nutrition, but it remains unknown whether variations in nutrient intakes translate into long-term benefits for neurodevelopment.

METHODS

In 86 participants of the Helsinki Study of Very Low Birth Weight Adults (birthweight <1500g), we examined if higher intakes of energy, macronutrients, and human milk during the first nine weeks after preterm birth predict performance in tests of cognitive ability at 25.1 years of age (SD = 2.1).

RESULTS

10 kcal/kg/day higher total energy intake at 3 to 6 weeks of age was associated with 0.21 SD higher adult IQ (95% Confidence Interval [CI] 0.07-0.35). Higher carbohydrate and fat intake at 3-6 weeks, and higher energy intake from human milk at 3-6 and at 6-9 weeks were also associated with higher adult IQ: these effect sizes ranged from 0.09 SD (95% CI 0.01-0.18) to 0.34 SD (0.14-0.54) higher IQ, per one gram/kg/day more carbohydrate and fat, and per 10 kcal/kg/day more energy from human milk. Adjustment for neonatal complications attenuated the associations: intraventricular hemorrhage, in particular, was associated with both poorer nutrition and poorer IQ.

CONCLUSION

In preterm neonates with very low birth weight, higher energy and human milk intake predict better neurocognitive abilities in adulthood. To understand the determinants of these infants' neurocognitive outcome, it seems important to take into account the role of postnatal nutrition, not just as an isolated exposure, but as a potential mediator between neonatal illness and long-term neurodevelopment.

Optimizing Nutrition in Preterm Low Birth Weight Infants-Consensus Summary

Preterm birth survivors are at a higher risk of growth and developmental disabilities compared to their term counterparts. Development of strategies to lower the complications of preterm birth forms the rising need of the hour. Appropriate nutrition is essential for the growth and development of preterm infants. Early administration of optimal nutrition to preterm birth survivors lowers the risk of adverse health outcomes and improves cognition in adulthood. A group of neonatologists, pediatricians, and nutrition experts convened to discuss and frame evidence-based recommendations for optimizing nutrition in preterm low birth weight (LBW) infants. The following were the primary recommendations of the panel: (1) enteral feeding is safe and may be preferred to parenteral nutrition due to the complications associated with the latter; however, parenteral nutrition may be a useful adjunct to enteral feeding in some critical cases; (2) early, fast, or continuous enteral feeding yields better outcomes compared to late, slow, or intermittent feeding, respectively; (3) routine use of nasogastric tubes is not advisable; (4) preterm infants can be fed while on ventilator or continuous positive airway pressure; (5) routine evaluation of gastric residuals and abdominal girth should be avoided; (6) expressed breast milk (EBM) is the first choice for feeding preterm infants due to its beneficial effects on cardiovascular, neurological, bone health, and growth outcomes; the second choice is donor pasteurized human milk; (7) EBM or donor milk may be fortified with human milk fortifiers, without increasing the osmolality of the milk, to meet the high protein requirements of preterm infants; (8) standard fortification is effective and safe but does not fulfill the high protein needs; (9) use of targeted and adjustable fortification, where possible, helps provide optimal nutrition; (10) optimizing weight gain in preterm infants prevents long-term cardiovascular complications; (11) checking for optimal weight and sucking/swallowing ability is essential prior to discharge of preterm infants; and (12) appropriate counseling and regular follow-up and monitoring after discharge will help achieve better long-term health outcomes. This consensus summary serves as a useful guide to clinicians in addressing the challenges and providing optimal nutrition to preterm LBW infants.

Emerging Clinical Benefits of New-Generation Fat Emulsions in Preterm Neonates

Soybean oil-based intravenous fat emulsions (IVFEs) have been the predominant parenteral nutrition IVFE used in the United States for neonates over the past 45 years. Even though this emulsion has proven useful in supplying infants with energy for growth and essential fatty acids, there have been concerns over its composition in the development of several morbidities, ranging from sepsis to liver disease, bronchopulmonary dysplasia, and impaired neurodevelopment and growth. The exact mechanisms that drive these morbidities in preterm infants are multifactorial, but potential contributors include high ω-6 (n-6) fatty acid composition, low docosahexaenoic acid and antioxidant supplementation, and the presence of potentially harmful nonnutritive components (eg, phytosterols). To address these issues, new-generation IVFEs with various types and amounts of fat have been developed containing greater amounts of the medium-chain fatty acids, long-chain polyunsaturated fatty acid, docosahexaenoic acid, lower concentrations of ω-6 polyunsaturated fatty acids, supplemental vitamin E, and low or negligible amounts of phytosterols. This review examines the clinical outcomes associated with different morbidities of parenteral nutrition in neonates who have received either soybean oil-based or new-generation IVFEs and addresses whether the proposed benefits of new-generation IVFEs have improved outcomes in the neonatal population.

Longchain polyunsaturated fatty acid supplementation in preterm infants

BACKGROUND

Controversy exists over whether longchain polyunsaturated fatty acids (LCPUFA) are essential nutrients for preterm infants because they may not be able to synthesise sufficient amounts of LCPUFA to meet the needs of the developing brain and retina.

OBJECTIVES

To assess whether supplementation of formula milk with LCPUFA is safe and of benefit to preterm infants. The main areas of interest were the effects of supplementation on the visual function, development and growth of preterm infants.

SEARCH METHODS

Trials were identified by searching the Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 2) in the Cochrane Library (searched 28 February 2016), MEDLINE Ovid (1966 to 28 February 2016), Embase Ovid (1980 to 28 February 2016), CINAHL EBSCO (Cumulative Index to Nursing and Allied Health Literature; 1980 to 28 February 2016), MEDLINE In Process & Other Non-indexed Citations (1966 to 28 February 2016) and by checking reference lists of articles and conference proceedings. We also searched ClinicalTrials.gov (13 April 2016). No language restrictions were applied.

SELECTION CRITERIA

All randomised trials evaluating the effect of LCPUFA-supplemented formula in enterally-fed preterm infants (compared with standard formula) on visual development, neurodevelopment and physical growth. Trials reporting only biochemical outcomes were not included.

DATA COLLECTION AND ANALYSIS

All authors assessed eligibility and trial quality, two authors extracted data separately. Study authors were contacted for additional information.

MAIN RESULTS

Seventeen trials involving 2260 preterm infants were included in the review. The risk of bias varied across the included trials with 10 studies having low risk of bias in a majority of the domains. The median gestational age (GA) in the included trials was 30 weeks and median birth weight (BW) was 1300 g. The median concentration of docosahexaenoic acid (DHA) was 0.33% (range: 0.15% to 1%) and arachidonic acid (AA) 0.37% (range: 0.02% to 0.84%). Visual acuity Visual acuity over the first year was measured by Teller or Lea acuity cards in eight studies, by visual evoked potential (VEP) in six studies and by electroretinogram (ERG) in two studies. Most studies found no significant differences in visual acuity between supplemented and control infants. The form of data presentation and the varying assessment methods precluded the use of meta-analysis. A GRADE analysis for this outcome indicated that the overall quality of evidence was low. Neurodevelopment Three out of seven studies reported some benefit of LCPUFA on neurodevelopment at different postnatal ages. Meta-analysis of four studies evaluating Bayley Scales of Infant Development at 12 months (N = 364) showed no significant effect of supplementation (Mental Development Index (MDI): MD 0.96, 95% CI -1.42 to 3.34; P = 0.43; I² = 71% - Psychomotor DeveIopment Index (PDI): MD 0.23, 95% CI -2.77 to 3.22; P = 0.88; I² = 81%). Furthermore, three studies at 18 months (N = 494) also revealed no significant effect of LCPUFA on neurodevelopment (MDI: MD 2.40, 95% CI -0.33 to 5.12; P = 0.08; I² = 0% - PDI: MD 0.74, 95% CI -1.90 to 3.37; P = 0.58; I² = 54%). A GRADE analysis for these outcomes indicated that the overall quality of evidence was low. Physical growth Four out of 15 studies reported benefits of LCPUFA on growth of supplemented infants at different postmenstrual ages (PMAs), whereas two trials suggested that LCPUFA-supplemented infants grow less well. One trial reported mild reductions in length and weight z scores at 18 months. Meta-analysis of five studies (N = 297) showed increased weight and length at two months post-term in supplemented infants (Weight: MD 0.21, 95% CI 0.08 to 0.33; P = 0.0010; I² = 69% - Length: MD 0.47, 95% CI 0.00 to 0.94; P = 0.05; I² = 0%). Meta-analysis of four studies at a corrected age of 12 months (N = 271) showed no significant effect of supplementation on growth outcomes (Weight: MD -0.10, 95% CI -0.31 to 0.12; P = 0.34; I² = 65% - Length: MD 0.25; 95% CI -0.33 to 0.84; P = 0.40; I² = 71% - Head circumference: MD -0.15, 95% CI -0.53 to 0.23; P = 0.45; I² = 0%). No significant effect of LCPUFA on weight, length or head circumference was observed on meta-analysis of two studies (n = 396 infants) at 18 months (Weight: MD -0.14, 95% CI -0.39 to 0.10; P = 0.26; I² = 66% - Length: MD -0.28, 95% CI -0.91 to 0.35; P = 0.38; I² = 90% - Head circumference: MD -0.18, 95% CI -0.53 to 0.18; P = 0.32; I² = 0%). A GRADE analysis for this outcome indicated that the overall quality of evidence was low.

AUTHORS' CONCLUSIONS

Infants enrolled in the trials were relatively mature and healthy preterm infants. Assessment schedule and methodology, dose and source of supplementation and fatty acid composition of the control formula varied between trials. On pooling of results, no clear long-term benefits or harms were demonstrated for preterm infants receiving LCPUFA-supplemented formula.

Fatty acid composition in breastfeeding and school performance in children aged 12 years

PURPOSE

Breastfeeding has been associated with improved cognition. It remains unclear whether long-chain polyunsaturated fatty acids (LC-PUFAs) play a role in this association. We assessed the association between LC-PUFA concentrations in infant feeding and school performance at age 12.

METHODS

Within a population-based birth cohort, we compared school performance of 277 non-breastfed children and 157 children who had fatty acid composition of their mothers' breast milk measured. Two indicators of school performance were: (1) the score on a standardized achievement test and (2) the teacher's advice regarding a child's potential performance level in secondary education. Linear regression and multinomial logistic regression analyses were performed to assess the independent association between LC-PUFA content of breast milk and school performance.

RESULTS

Girls, who received breast milk with a relative high content (above the median) of docosahexaenoic acid (DHA), had a higher Cito-test score (β = 2.96 points, 95 % CI 0.24; 5.69) than non-breastfed girls. Among the breastfed girls, each percentage point of higher content of total n-3 LC-PUFA (β = 4.55, 95 % CI 0.43; 8.66) and DHA (β = 7.09, 95 % CI 0.9; 13.3) was associated with a higher Cito-test score. The association between LC-PUFA content and teacher school advice showed a similar pattern. There was no association between LC-PUFA content and school performance in boys.

CONCLUSION

Although a large part of the association between infant milk feeding and cognition seems to be explained by sociodemographic and lifestyle-related factors, a relative high content of n-3 PUFAs, especially DHA, in breast milk is associated with better school performance in 12-year-old girls but not in boys.

Growth, metabolic markers, and cognition in 8-year old children born prematurely, follow-up of a randomized controlled trial with essential fatty acids

The study is a follow-up of a randomized, double-blinded, placebo-controlled trial of supplementation with docosahexaenoic acid (DHA) and arachidonic acid (AA) to 129 very low birth weight (VLBW; birth weight <1500 g) infants fed human milk. The main hypothesis was that supplementation would affect growth, metabolic markers, and cognitive function. The secondary aim was to describe predictors of metabolic markers and cognitive status at follow-up. Ninety-eight children met for 8-year follow-up with anthropometric measures, blood biomarkers, and cognitive testing. The intervention group had significantly lower insulin-like growth factor-1 (IGF-1) at 8 years, whereas no differences in growth or intelligence quotient (IQ) were found. For the total cohort, weight gain during first year of life was neither associated with BMI, metabolic markers, nor IQ at follow-up. Blood DHA at 8 years was positively associated with IQ.

CONCLUSIONS

The study is the first long-term follow-up of a randomized controlled trial with essential fatty acids investigating growth, metabolic factors, and IQ. IGF-1 levels were significantly lower in the intervention group at 8 years. First-year growth was not associated with BMI, metabolic markers, or IQ at follow-up. Current DHA status was a significant predictor of higher IQ at follow-up.

WHAT IS KNOWN

• Preterm children have increased risk of lower intelligence quotient (IQ), reduced growth, and abnormal metabolic status. • Early intake of docosahexaenoic acid (DHA) and arachidonic acid (AA), as well as early growth pattern, may influence both IQ and metabolic status. What is New: • Early intervention with DHA and AA led to reduced insulin-like growth factor-1 in blood at 8 years of age. • Weight gain during first year of life was neither associated with impaired metabolic markers nor improved IQ at follow-up. • Current DHA status was a significant predictor of higher IQ at 8 years, also when maternal education and birth weight were included in the model.

Long-chain polyunsaturated fatty acids and the preterm infant: a case study in developmentally sensitive nutrient needs in the United States

The vast majority of infant formulas in the United States contain the long-chain polyunsaturated fatty acids (PUFAs) docosahexaenoic acid (22:6n-3) and arachidonic acid (20:4n-6), which were first permitted by the US Food and Drug Administration in 2001. As a scientific case study, preclinical animal studies of these nutrients definitively influenced the design and interpretation of human clinical studies. Early studies were tied to the availability of test substances, and in hindsight suggest re-evaluation of the essential fatty acid concept in light of the totality of available evidence. Research in the 1950s established the essentiality of n-6 PUFAs for skin integrity; however, widespread recognition of the essentiality of n-3 PUFAs came decades later despite compelling evidence of their significance. Barriers to an understanding of the essentiality of n-3 PUFAs were as follows: 1) their role is in neural function, which is measured only with difficulty compared with skin lesions and growth faltering that are apparent for n-6 PUFAs; 2) the experimental use of vegetable oils as PUFA sources that contain the inefficiently used C18 PUFAs rather than the operative C20 and C22 PUFAs; 3) the shift from reliance on high-quality animal studies to define mechanisms that established the required nutrients in the first part of the 20th century to inherently challenging human studies. Advances in nutrition of premature infants require the best practices and opinions available, taking into account the totality of preclinical and clinical evidence.

Synergistic Effects of Human Milk Nutrients in the Support of Infant Recognition Memory: An Observational Study

The aim was to explore the relation of human milk lutein; choline; and docosahexaenoic acid (DHA) with recognition memory abilities of six-month-olds. Milk samples obtained three to four months postpartum were analyzed for fatty acids, lutein, and choline. At six months, participants were invited to an electrophysiology session. Recognition memory was tested with a 70-30 oddball paradigm in a high-density 128-lead event-related potential (ERP) paradigm. Complete data were available for 55 participants. Data were averaged at six groupings (Frontal Right; Frontal Central; Frontal Left; Central; Midline; and Parietal) for latency to peak, peak amplitude, and mean amplitude. Difference scores were calculated as familiar minus novel. Final regression models revealed the lutein X free choline interaction was significant for the difference in latency scores at frontal and central areas (p < 0.05 and p < 0.001; respectively). Higher choline levels with higher lutein levels were related to better recognition memory. The DHA X free choline interaction was also significant for the difference in latency scores at frontal, central, and midline areas (p < 0.01; p < 0.001; p < 0.05 respectively). Higher choline with higher DHA was related to better recognition memory. Interactions between human milk nutrients appear important in predicting infant cognition, and there may be a benefit to specific nutrient combinations.

Supplementation with long chain polyunsaturated fatty acids (LCPUFA) to breastfeeding mothers for improving child growth and development

BACKGROUND

Long chain polyunsaturated fatty acids (LCPUFA), especially docosahexaenoic acid (DHA), are the most abundant fatty acids in the brain and are necessary for growth and maturation of an infant's brain and retina. LCPUFAs are named "essential" because they cannot be synthesised efficiently by the human body and come from maternal diet. It remains controversial whether LCPUFA supplementation to breastfeeding mothers is beneficial for the development of their infants.

OBJECTIVES

To assess the effectiveness and safety of supplementation with LCPUFA in breastfeeding mothers in the cognitive and physical development of their infants as well as safety for the mother and infant.

SEARCH METHODS

We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (6 August 2014), CENTRAL (Cochrane Library 2014, Issue 8), PubMed (1966 to August 2014), EMBASE (1974 to August 2014), LILACS (1982 to August 2014), Google Scholar (August 2014) and reference lists of published narrative and systematic reviews.

SELECTION CRITERIA

Randomised controlled trials or cluster-randomised controlled trials evaluating the effects of LCPUFA supplementation on breastfeeding mothers (including the pregnancy period) and their infants.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed eligibility and trial quality, performed data extraction and evaluated data accuracy.

MAIN RESULTS

We included eight randomised controlled trials involving 1567 women. All the studies were performed in high-income countries. The longest follow-up was seven years.We report the results from the longest follow-up time point from included studies. Overall, there was moderate quality evidence as assessed using the GRADE approach from these studies for the following outcomes measured beyond 24 months age of children: language development and child weight. There was low-quality evidence for the outcomes: Intelligence or solving problems ability, psychomotor development, child attention, and child visual acuity.We found no significant difference in children's neurodevelopment at long-term follow-up beyond 24 months: language development (standardised mean difference (SMD) -0.27, 95% confidence interval (CI) -0.56 to 0.02; two trials, 187 participants); intelligence or problem-solving ability (three trials, 238 participants; SMD 0.00, 95% CI -0.36 to 0.36); psychomotor development (SMD -0.11, 95% CI -0.48 to 0.26; one trial, 113 participants); motor development (SMD -0.23, 95% CI -0.60 to 0.14; one trial, 115 participants), or in general movements (risk ratio, RR, 1.12, 95% CI 0.58 to 2.14; one trial, 77 participants; at 12 weeks of life). However, child attention scores were better at five years of age in the group of children whose mothers had received supplementation with fatty acids (mean difference (MD) 4.70, 95% CI 1.30 to 8.10; one study, 110 participants)). In working memory and inhibitory control, we found no significant difference (MD -0.02 95% CI -0.07 to 0.03 one trial, 63 participants); the neurological optimality score did not present any difference (P value: 0.55).For child visual acuity, there was no significant difference (SMD 0.33, 95% CI -0.04 to 0.71; one trial, 111 participants).For growth, there were no significant differences in length (MD -0.39 cm, 95% CI -1.37 to 0.60; four trials, 441 participants), weight (MD 0.13 kg, 95% CI -0.49 to 0.74; four trials, 441 participants), and head circumference (MD 0.15 cm, 95% CI -0.27 to 0.58; three trials, 298 participants). Child fat mass and fat mass distribution did not differ between the intervention and control group (MD 2.10, 95% CI -0.48 to 4.68; one trial, 115 participants, MD -0.50, 95% CI -1.69 to 0.69; one trial, 165 participants, respectively).One study (117 infants) reported a significant difference in infant allergy at short-term follow-up (risk ratio (RR) 0.13, 95% CI 0.02 to 0.95), but not at medium-term follow-up (RR 0.52, 95% CI 0.17 to 1.59).We found no significant difference in two trials evaluating postpartum depression. Data were not possible to be pooled due to differences in the describing of the outcome. One study (89 women) did not find any significant difference between the LCPUFA supplementation and the control group at four weeks postpartum (MD 1.00, 95%CI -1.72 to 3.72).No adverse effects were reported.

AUTHORS' CONCLUSIONS

Based on the available evidence, LCPUFA supplementation did not appear to improve children's neurodevelopment, visual acuity or growth. In child attention at five years of age, weak evidence was found (one study) favouring the supplementation. Currently, there is inconclusive evidence to support or refute the practice of giving LCPUFA supplementation to breastfeeding mothers in order to improve neurodevelopment or visual acuity.

The association between linoleic acid levels in colostrum and child cognition at 2 and 3 y in the EDEN cohort

BACKGROUND

Breastfeeding has been associated with improved cognitive development. This may be explained by polyunsaturated fatty acid (PUFA) content of breast milk, especially long-chain (LC) PUFA that are needed for postnatal brain growth.

METHODS

Using data from the French EDEN cohort, we aimed to study whether the PUFA content of colostrum may explain observed associations between breastfeeding duration and cognitive scores at 2 and 3 y. A total of 709 breastfed children with available data on PUFA composition of milk were assessed using parent-reported questionnaires for motor and language at 2 y of age, or global cognition at 3 y. Multiple linear regressions were used to examine associations between PUFA levels and child cognitive scores, after controlling for many confounders.

RESULTS

We found no association between LCPUFA levels in colostrum and child development. However, levels of linoleic acid (LA) were negatively associated with motor and cognitive scores, independently of breastfeeding duration. Children breastfed with the highest levels of LA tended to score closer to the never breastfed children than children breastfed with the lowest levels of LA.

CONCLUSION

Our findings suggest that too high levels of LA in colostrum are associated with poorer child development at 2 and 3 y.

The Relationship between Nutrition in Infancy and Cognitive Performance during Adolescence

OBJECTIVES

In this study, we aimed to investigate the long-term associations between breastfeeding duration during infancy, diet quality as measured by a diet score at 1 year of age, and cognitive performance during adolescence.

METHODS

Participants (n = 717) were recruited from the West Australian Pregnancy Cohort (Raine) Study, a prospective longitudinal study of 2868 children and their families based in Perth, WA, Australia. Breastfeeding duration and an early diet score at age 1 year were used as the main predictor variables, while a computerized cognitive battery (CogState) was used to assess adolescents' cognitive performance at 17 years. The diet score, which has seven food group components, was based on a 24-h recall questionnaire completed by the mother at 1 year of age. A higher diet score represents a better, more nutritious eating pattern. Associations between breastfeeding duration, diet score, and cognitive performance were assessed in multivariable regression models.

RESULTS

Higher diet scores at 1 year representing better diet quality were significantly associated with faster reaction times in cognitive performance at 17 years [Detection Task (DET): β = -0.004, 95% CI: -0.008; 0.000, p = 0.036; Identification Task (IDN): β = -0.004, 95% CI: -0.008; 0.000, p = 0.027]. Breastfeeding duration (≥4 months) was also significantly associated with a shorter reaction time, but only for males (DET: β = -0.026, 95% CI: -0.046; -0.006, p = 0.010).

CONCLUSION

Nutrition in early childhood may have a long-term association with fundamental cognitive processing speed, which is likely to be related to enhanced brain development in the first year of life.

Impact of nutrition on brain development and its neuroprotective implications following preterm birth

The impact of nutrition on brain development in preterm infants has been increasingly appreciated. Early postnatal growth and nutrient intake have been demonstrated to influence brain growth and maturation with subsequent effects on neurodevelopment that persist into childhood and adolescence. Nutrition could also potentially protect against injury. Inflammation and perinatal infection play a crucial role in the pathogenesis of white matter injury, the most common pattern of brain injury in preterm infants. Therefore, nutritional components with immunomodulatory and/or anti-inflammatory effects may serve as neuroprotective agents. Moreover, growing evidence supports the existence of a microbiome-gut-brain axis. The microbiome is thought to interact with the brain through immunological, endocrine, and neural pathways. Consequently, nutritional components that may influence gut microbiota may also exert beneficial effects on the developing brain. Based on these properties, probiotics, prebiotic oligosaccharides, and certain amino acids are potential candidates for neuroprotection. In addition, the amino acid glutamine has been associated with a decrease in infectious morbidity in preterm infants. In conclusion, early postnatal nutrition is of major importance for brain growth and maturation. Additionally, certain nutritional components might play a neuroprotective role against white matter injury, through modulation of inflammation and infection, and may influence the microbiome-gut-brain axis.

Enhanced nutrient supply to very low birth weight infants is associated with improved white matter maturation and head growth

BACKGROUND

Extrauterine growth restriction is common among very low birth weight infants (VLBW, BW <1,500 g). Optimal postnatal nutrient supply is essential to limit growth restriction and ensure adequate growth and neurodevelopment.

OBJECTIVES

We compared an enhanced postnatal nutrient supply to a standard supply and evaluated the effects on growth velocity, head circumference growth and cerebral maturation - the latter by magnetic resonance diffusion tensor imaging (DTI). We hypothesized increased growth velocity, head circumference growth and decreased mean diffusivity (MD) in cerebral white matter (WM) areas, suggesting improved cerebral maturation among infants on the enhanced nutrient supply.

METHODS

In this randomized controlled trial, infants on the enhanced nutrient supply received increased amounts of energy, protein, fat, essential fatty acids and vitamin A until discharge. DTI was performed close to term equivalent age. Outcomes were growth velocity, head circumference growth and WM mean diffusivity.

RESULTS

Among the 50 included infants, 14 in the intervention group and 11 controls underwent a successful DTI. Infants on the enhanced diet achieved improved growth velocity (16.5 vs. 13.8 g/kg/day, p = 0.01) and increased head circumference (Δz score: 0.24 vs. -0.12, p = 0.15). A significantly lower MD was seen in a large WM area such as the superior longitudinal fasciculi (1.19 × 10(-3) vs. 1.24 × 10(-3) mm(2)/s, p = 0.04, adjusted for age when scanned).

CONCLUSIONS

Enhanced nutrient supply to VLBW infants is associated with improved growth velocity, increased head circumference growth and decreased regional WM mean diffusivity, suggesting improved maturation of cerebral connective tracts.

Current information and Asian perspectives on long-chain polyunsaturated fatty acids in pregnancy, lactation, and infancy: systematic review and practice recommendations from an early nutrition academy workshop

The Early Nutrition Academy supported a systematic review of human studies on the roles of pre- and postnatal long-chain polyunsaturated fatty acids (LC-PUFA) published from 2008 to 2013 and an expert workshop that reviewed the information and developed recommendations, considering particularly Asian populations. An increased supply of n-3 LC-PUFA during pregnancy reduces the risk of preterm birth before 34 weeks of gestation. Pregnant women should achieve an additional supply ≥200 mg docosahexaenic acid (DHA)/day, usually achieving a total intake ≥300 mg DHA/day. Higher intakes (600-800 mg DHA/day) may provide greater protection against early preterm birth. Some studies indicate beneficial effects of pre- and postnatal DHA supply on child neurodevelopment and allergy risk. Breast-feeding is the best choice for infants. Breast-feeding women should get ≥200 mg DHA/day to achieve a human milk DHA content of ∼0.3% fatty acids. Infant formula for term infants should contain DHA and arachidonic acid (AA) to provide 100 mg DHA/day and 140 mg AA/day. A supply of 100 mg DHA/day should continue during the second half of infancy. We do not provide quantitative advice on AA levels in follow-on formula fed after the introduction of complimentary feeding due to a lack of sufficient data and considerable variation in the AA amounts provided by complimentary foods. Reasonable intakes for very-low-birth weight infants are 18-60 mg/kg/day DHA and 18-45 mg/kg/day AA, while higher intakes (55-60 mg/kg/day DHA, ∼1% fatty acids; 35-45 mg/kg/day AA, ∼0.6-0.75%) appear preferable. Research on the requirements and effects of LC-PUFA during pregnancy, lactation, and early childhood should continue. © 2014 S. Karger AG, Basel.

LCPUFAs as conditionally essential nutrients for very low birth weight and low birth weight infants: metabolic, functional, and clinical outcomes-how much is enough?

Preterm infants are denied the rapid accumulation of docosahexaenoic acid (DHA) occurring during the third trimester in utero. The potential benefit of long-chain polyunsaturated fatty acids (LCPUFAs) has generated interest over the last 3 decades. Early intervention trials assessed the effects of supplementing infant formulas lacking DHA with concentrations equivalent to LCPUFA in milk of women from Westernized societies, leading to the inclusion of LCPUFA by the year 2000. Recently attention has been on determining the optimal dose of DHA and on whether there is in advantage in matching the higher doses of late pregnancy.

Fatty acid requirements in preterm infants and their role in health and disease

Challenges remain in optimizing the delivery of fatty acids to attain their nutritional and therapeutic benefits in neonatal health. In this review, knowledge about placental transfer of fatty acids to the developing fetus is summarized, the potential role and mechanisms of fatty acids in enhancing neonatal health and minimizing morbidities is outlined, the unique considerations for fatty acid delivery in the preterm population are defined, and the research questions are proposed that need to be addressed before new standards of care are adopted at the bedside for the provision of critical fatty acids to preterm infants.

The challenge of understanding cerebral white matter injury in the premature infant

White matter injury in the premature infant leads to motor and more commonly behavioral and cognitive problems that are a tremendous burden to society. While there has been much progress in understanding unique vulnerabilities of developing oligodendrocytes over the past 30years, there remain no proven therapies for the premature infant beyond supportive care. The lack of translational progress may be partially explained by the challenge of developing relevant animal models when the etiology remains unclear, as is the case in this disorder. There has been an emphasis on hypoxia-ischemia and infection/inflammation as upstream etiologies, but less consideration of other contributory factors. This review highlights the evolution of white matter pathology in the premature infant, discusses the prevailing proposed etiologies, critically analyzes a sampling of common animal models and provides detailed support for our hypothesis that nutritional and hormonal deprivation may be additional factors playing critical and overlooked roles in white matter pathology in the premature infant.

Does docosahexaenoic acid supplementation in term infants enhance neurocognitive functioning in infancy?

The proposal that dietary docosahexaenoic acid (DHA) enhances neurocognitive functioning in term infants is controversial. Theoretical evidence, laboratory research and human epidemiological studies have convincingly demonstrated that DHA deficiency can negatively impact neurocognitive development. However, the results from randomized controlled trials (RCTs) of DHA supplementation in human term-born infants have been inconsistent. This article will (i) discuss the role of DHA in the human diet, (ii) explore the physiological mechanisms by which DHA plausibly influences neurocognitive capacity, and (iii) seek to characterize the optimal intake of DHA during infancy for neurocognitive functioning, based on existing research that has been undertaken in developed countries (specifically, within Australia). The major observational studies and RCTs that have examined dietary DHA in human infants and animals are presented, and we consider suggestions that DHA requirements vary across individuals according to genetic profile. It is important that the current evidence concerning DHA supplementation is carefully evaluated so that appropriate recommendations can be made and future directions of research can be strategically planned.

Treatment of parenteral nutrition-associated liver disease: the role of lipid emulsions

Parenteral nutrition is a life-saving therapy for infants with intestinal failure. However, long-term parenteral nutrition carries the risk of progressive liver disease. Substantial data has implicated components of parenteral soybean oil in the pathogenesis of parenteral nutrition-associated liver disease (PNALD). Elevated serum concentrations of phytosterols, an abundance of omega-6 polyunsaturated fatty acids, and a relative paucity of α-tocopherol have been associated with the risk of cholestasis and hepatic injury observed in PNALD. Currently available treatment strategies include the reduction of the dose of administered parenteral soybean oil and/or the replacement of parenteral soybean oil with alternative parenteral lipid emulsions. The purpose of this review is to provide an overview of the pathogenetic mechanisms associated with the development of PNALD and the data evaluating currently available treatment strategies.

Long-chain omega-3 fatty acids: time to establish a dietary reference intake

The beneficial effects of consuming omega-3 polyunsaturated fatty acids (n-3 PUFAs), specifically eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), on cardiovascular health have been studied extensively. To date, there is no dietary reference intake (DRI) for EPA and DHA, although many international authorities and expert groups have issued dietary recommendations for them. Given the substantial new evidence published since the last Institute of Medicine (IOM) report on energy and macronutrients, released in 2002, there is a pressing need to establish a DRI for EPA and DHA. In order to set a DRI, however, more information is needed to define the intakes of EPA and DHA required to reduce the burden of chronic disease. Information about potential gender- or race-based differences in requirements is also needed. Given the many health benefits of EPA and DHA that have been described since the 2002 IOM report, there is now a strong justification for establishing a DRI for these fatty acids.

Nervonic acid is much lower in donor milk than in milk from mothers delivering premature infants--of neglected importance?

Nervonic acid is important for white matter development and its incorporation increases rapidly in the last trimester, but few studies focus on this fatty acid. Other mother's milk, usually after term delivery, is often used for premature infants, whose mothers cannot breastfeed. The fatty acid (FA) concentrations were analyzed by gas chromatography in 12 samples of donor human milk (DHM) from five mothers, and compared to milk from 42 mothers delivering preterm infants. Fat, lactose and protein contents were compared. Nervonic acid showed sevenfold higher concentrations and LCPUFA 90% higher concentrations in premature milk compared to DHM. Linoleic acid was found in 43% higher concentrations in DHM than in premature milk. The fat and protein contents were lower in DHM. Our results suggest that studies are warranted to investigate if DHM given to premature infants may require supplementation of nervonic acid, and not only LCPUFA, protein and minerals.

Neuroimaging, a new tool for investigating the effects of early diet on cognitive and brain development

Nutrition is crucial to the initial development of the central nervous system (CNS), and then to its maintenance, because both depend on dietary intake to supply the elements required to develop and fuel the system. Diet in early life is often seen in the context of "programming" where a stimulus occurring during a vulnerable period can have long-lasting or even lifetime effects on some aspect of the organism's structure or function. Nutrition was first shown to be a programming stimulus for growth, and then for cognitive behavior, in animal studies that were able to employ methods that allowed the demonstration of neural effects of early nutrition. Such research raised the question of whether nutrition could also programme cognition/brain structure in humans. Initial studies of cognitive effects were observational, usually conducted in developing countries where the presence of confounding factors made it difficult to interpret the role of nutrition in the cognitive deficits that were seen. Attributing causality to nutrition required randomized controlled trials (RCTs) and these, often in developed countries, started to appear around 30 years ago. Most demonstrated convincingly that early nutrition could affect subsequent cognition. Until the advent of neuroimaging techniques that allowed in vivo examination of the brain, however, we could determine very little about the neural effects of early diet in humans. The combination of well-designed trials with neuroimaging tools means that we are now able to pose and answer questions that would have seemed impossible only recently. This review discusses various neuroimaging methods that are suitable for use in nutrition studies, while pointing out some of the limitations that they may have. The existing literature is small, but examples of studies that have used these methods are presented. Finally, some considerations that have arisen from previous studies, as well as suggestions for future research, are discussed.

Long-term effects of LCPUFA supplementation on childhood cognitive outcomes

BACKGROUND

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

OBJECTIVE

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

DESIGN

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

RESULTS

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

CONCLUSIONS

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

Nutrition and neurodevelopment in children: focus on NUTRIMENTHE project

There is growing evidence that early nutrition affects later cognitive performance. The idea that the diet of mothers, infants, and children could affect later mental performance has major implications for public health practice and policy development and for our understanding of human biology as well as for food product development, economic progress, and future wealth creation. To date, however, much of the evidence is from animal, retrospective studies and short-term nutritional intervention studies in humans. The positive effect of micronutrients on health, especially of pregnant women eating well to maximise their child's cognitive and behavioural outcomes, is commonly acknowledged. The current evidence of an association between gestational nutrition and brain development in healthy children is more credible for folate, n-3 fatty acids, and iron. Recent findings highlight the fact that single-nutrient supplementation is less adequate than supplementation with more complex formulae. However, the optimal content of micronutrient supplementation and whether there is a long-term impact on child's neurodevelopment needs to be investigated further. Moreover, it is also evident that future studies should take into account genetic heterogeneity when evaluating nutritional effects and also nutritional recommendations. The objective of the present review is to provide a background and update on the current knowledge linking nutrition to cognition and behaviour in children, and to show how the large collaborative European Project NUTRIMENTHE is working towards this aim.

DHA supplementation: current implications in pregnancy and childhood

Dietary supplementation with ω-3 long chain fatty acids including docosahexaenoic acid (DHA) has increased in popularity in recent years and adequate DHA supplementation during pregnancy and early childhood is of clinical importance. Some evidence has been built for the neuro-cognitive benefits of supplementation with long chain polyunsaturated fatty acids (LCPUFA) such as DHA during pregnancy; however, recent data indicate that the anti-inflammatory properties may be of at least equal significance. Adequate DHA availability in the fetus/infant optimizes brain and retinal maturation in part by influencing neurotransmitter pathways. The anti-inflammatory properties of LCPUFA are largely mediated through modulation of signaling either directly through binding to receptors or through changes in lipid raft formation and receptor presentation. Our goal is to review the current findings on DHA supplementation, specifically in pregnancy and infant neurodevelopment, as a pharmacologic agent with both preventative and therapeutic value. Given the overall benefits of DHA, maternal and infant supplementation may improve neurological outcomes especially in vulernable populations. However, optimal composition of the supplement and dosing and treatment strategies still need to be determined to lend support for routine supplementation.

The role of nutrition in children's neurocognitive development, from pregnancy through childhood

This review examines the current evidence for a possible connection between nutritional intake (including micronutrients and whole diet) and neurocognitive development in childhood. Earlier studies which have investigated the association between nutrition and cognitive development have focused on individual micronutrients, including omega-3 fatty acids, vitamin B12, folic acid, choline, iron, iodine, and zinc, and single aspects of diet. The research evidence from observational studies suggests that micronutrients may play an important role in the cognitive development of children. However, the results of intervention trials utilizing single micronutrients are inconclusive. More generally, there is evidence that malnutrition can impair cognitive development, whilst breastfeeding appears to be beneficial for cognition. Eating breakfast is also beneficial for cognition. In contrast, there is currently inconclusive evidence regarding the association between obesity and cognition. Since individuals consume combinations of foods, more recently researchers have become interested in the cognitive impact of diet as a composite measure. Only a few studies to date have investigated the associations between dietary patterns and cognitive development. In future research, more well designed intervention trials are needed, with special consideration given to the interactive effects of nutrients.

Meta-analysis of LCPUFA supplementation of infant formula and visual acuity

BACKGROUND AND OBJECTIVE

Long-chain polyunsaturated fatty acids (LCPUFAs) are hypothesized to affect visual acuity development in infants. Randomized controlled trials (RCTs) have been conducted to assess whether supplementation of LCPUFAs of infant formulas affects infant visual acuity. This meta-analysis was conducted to evaluate whether LCPUFA supplementation of infant formulas improves infants' visual acuity.

METHODS

PubMed and PsycInfo were searched for RCTs assessing the efficacy of LCPUFA supplementation of infant formulas on infant visual acuity. RCTs assessing the effects of LCPUFA supplementation on visual acuity (by using either visual evoked potential or behavioral methods) in the first year of life were included in this meta-analysis. Our primary outcome was the mean difference in visual resolution acuity (measured in logarithm of minimum angle of resolution [logMAR]) between supplemented and unsupplemented infants. We also conducted secondary subgroup analyses and meta-regression examining the effects of LCPUFA dose and timing, preterm versus term birth status, and trial methodologic quality.

RESULTS

Nineteen studies involving 1949 infants were included. We demonstrated a significant benefit of LCPUFA supplementation on infants' visual acuity at 2, 4, and 12 months of age when visual acuity was assessed by using visual evoked potential and at 2 months of age by using behavioral methods. There was significant heterogeneity between trials but no evidence of publication bias. Secondary analysis failed to show any moderating effects on the association between LCPUFA supplementation and visual acuity.

CONCLUSIONS

Current evidence suggests that LCPUFA supplementation of infant formulas improves infants' visual acuity up to 12 months of age.

Infant formulas for preterm infants: in-hospital and post-discharge

The availability and composition of preterm and post-discharge formulas (PDFs) have undergone considerable changes over the last decade. Human milk, supplemented with multi-component fortifier, is the preferred feed for very preterm infants as it has beneficial effects for both short- and long-term outcomes compared with formula. If supply of mother's milk or donor milk is inadequate, a breast milk substitute specifically designed for premature infants is the next option. Preterm formula is intended to provide nutrient intakes to match intrauterine growth and nutrient accretion rates and is enriched with energy, macronutrients, minerals, vitamins, and trace elements compared with term infant formulas. Post-natal longitudinal growth failure has been reported almost universally in extremely preterm infants. Since 2009, a nutritionally enriched PDF specifically designed for preterm infants post hospital discharge with faltering growth has been available in Australia and New Zealand. This formula is an intermediary between preterm and term formulas and contains more energy (73 kcal/100 mL), protein (1.9 g/100 mL), minerals, vitamins, and trace elements than term formulas. Although the use of a PDF is based on sound nutritional knowledge, the 2012 Cochrane Systematic Review of 10 trials comparing feeding preterm infants with PDF and term formula did not demonstrate any short- or long-term benefits. Health professionals need to make individual decisions on whether and how to use PDF.

Polyunsaturated fatty acids (PUFA) for attention deficit hyperactivity disorder (ADHD) in children and adolescents

BACKGROUND

Attention deficit hyperactivity disorder (ADHD) is a major problem in children and adolescents, characterised by age-inappropriate levels of inattention, hyperactivity and impulsivity, and is associated with long-term social, academic and mental health problems. The stimulant medications methylphenidate and amphetamine are the most frequently used treatments for ADHD, but these are not always effective and can be associated with side effects. Clinical and biochemical evidence suggests that deficiencies of polyunsaturated fatty acids (PUFA) could be related to ADHD. Children and adolescents with ADHD have been shown to have significantly lower plasma and blood concentrations of PUFA and, in particular, lower levels of omega-3 PUFA. These findings suggest that PUFA supplementation may reduce the attention and behaviour problems associated with ADHD.

OBJECTIVES

To compare the efficacy of PUFA to other forms of treatment or placebo in treating the symptoms of ADHD in children and adolescents.

SEARCH METHODS

We searched the following databases in August 2011: CENTRAL (The Cochrane Library 2011, Issue 2), MEDLINE (1948 to July Week 3, 2011), EMBASE (1980 to 2011 Week 29), PsycINFO (1806 to current), CINAHL (1937 to current), BIOSIS (1969 to 30 July 2011), Science Citation Index (1970 to 30 July 2011), Social Science Citation Index (1970 to 30 July 2011), Conference Proceedings Citation Index - Science (1990 to 30 July 2011), Conference Proceedings Citation Index - Social Science and Humanities (1990 to 30 July 2011), Cochrane Database of Systematic Reviews (2011, Issue 7), DARE (2011 Issue 2), Dissertation Abstracts (via Dissertation Express) and the metaRegister of Controlled Trials (mRCT). In addition, we searched the following repositories for theses on 2 August 2011: DART, NTLTD and TROVE. We also checked reference lists of relevant studies and reviews for additional references.

SELECTION CRITERIA

Two review authors independently assessed the results of the database searches. We resolved any disagreements regarding the selection of studies through consensus or, if necessary, by consultation with a third member of the review team.

DATA COLLECTION AND ANALYSIS

Two members of the review team independently extracted details of participants and setting, interventions, methodology and outcome data. If differences were identified, we resolved them by consensus or referral to a third member of the team. We made all reasonable attempts to contact the authors where further clarification or missing data were needed.

MAIN RESULTS

We included 13 trials with 1011 participants in the review. After screening 366 references, we considered 23 relevant and obtained the full text for consideration. We excluded five papers and included 18 papers describing the 13 trials. Eight of the included trials had a parallel design: five compared an omega-3 PUFA supplement to placebo; two compared a combined omega-3 and omega-6 supplement to placebo, and one compared an omega-3 PUFA to a dietary supplement. Five of the included trials had a cross-over design: two compared combined omega-3/6 PUFA to placebo; two compared omega-6 PUFA with placebo; one compared omega-3 to omega-6 PUFA, and one compared omega-6 PUFA to dexamphetamine. Supplements were given for a period of between four and 16 weeks.There was a significantly higher likelihood of improvement in the group receiving omega-3/6 PUFA compared to placebo (two trials, 97 participants; risk ratio (RR) 2.19, 95% confidence interval (CI) 1.04 to 4.62). However, there were no statistically significant differences in parent-rated ADHD symptoms (five trials, 413 participants; standardised mean difference (SMD) -0.17, 95% CI -0.38 to 0.03); inattention (six trials, 469 participants; SMD -0.04, 95% CI -0.29 to 0.21) or hyperactivity/impulsivity (five trials, 416 participants; SMD -0.04, 95% CI -0.25 to 0.16) when all participants receiving PUFA supplements were compared to those receiving placebo.There were no statistically significant differences in teacher ratings of overall ADHD symptoms (four trials, 324 participants; SMD 0.05, 95% CI -0.18 to 0.27); inattention (three trials, 260 participants; SMD 0.26, 95% CI -0.22 to 0.74) or hyperactivity/impulsivity (three trials, 259 participants; SMD 0.10, 95% CI -0.16 to 0.35).There were also no differences between groups in behaviour, side effects or loss to follow-up.Overall, there were no other differences between groups for any other comparison.

AUTHORS' CONCLUSIONS

Overall, there is little evidence that PUFA supplementation provides any benefit for the symptoms of ADHD in children and adolescents. The majority of data showed no benefit of PUFA supplementation, although there were some limited data that did show an improvement with combined omega-3 and omega-6 supplementation.It is important that future research addresses current weaknesses in this area, which include small sample sizes, variability of selection criteria, variability of the type and dosage of supplementation, short follow-up times and other methodological weaknesses.

Meta-analysis of long-chain polyunsaturated fatty acid supplementation of formula and infant cognition

BACKGROUND AND OBJECTIVE

Infant formula is supplemented with long-chain polyunsaturated fatty acids (LCPUFAs) because they are hypothesized to improve cognition. Several randomized controlled clinical trials have examined the effect of LCPUFA supplementation of infant formula on cognitive development. We conducted this meta-analysis to examine the efficacy of LCPUFA supplementation of infant formula on early cognitive development.

METHODS

Two authors searched PubMed, PsychInfo, and Scopus for randomized controlled clinical trials assessing the efficacy of LCPUFA supplementation of infant formulas on cognition. Our analysis was restricted to randomized controlled clinical trials that examined the effect of LCPUFA supplementation on infant cognition using Bayley Scales of Infant Development. Our primary outcome was the weighted mean difference in Bayley Scales of Infant Development score between infants fed formula supplemented with LCPUFA compared with unsupplemented formula. We conducted secondary subgroup analyses and meta-regression to examine the effects of study sample, LCPUFA dose, and trial methodologic quality on measured efficacy of supplementation.

RESULTS

Twelve trials involving 1802 infants met our inclusion criteria. Our meta-analysis demonstrated no significant effect of LCPUFA supplementation of formula on infant cognition. There was no significant heterogeneity or publication bias between trials. Secondary analysis failed to show any significant effect of LCPUFA dosing or prematurity status on supplementation efficacy.

CONCLUSIONS

LCPUFA supplementation of infant formulas failed to show any significant effect on improving early infant cognition. Further research is needed to determine if LCPUFA supplementation of infant formula has benefits for later cognitive development or other measures of neurodevelopment.

Motor, mental and behavioral developments in infancy are associated with fatty acid pattern in breast milk and plasma of premature infants

The objective of this study was to investigate any association between infants' early development and PUFA concentrations in early breast milk and infants' plasma phospholipids at 44 weeks gestational age. Fifty-one premature infants were included. The quality of general movement was assessed at 3 months, and motor, mental and behavioral development at 3, 6, 10 and 18 months corrected age using Bayley's Scales of Infant Development (BSID-II). Linoleic acid, the major n-6/n-3 FA ratios, Mead acid and the EFA deficiency index in early breast milk were negatively associated with development up to 18 months of age. DHA and AA, respectively, in infants' plasma phospholipids was positively, but the AA/DHA ratio negatively, associated with development from 6 to 18 months of age. Our data suggest that the commonly found high n-6 concentration in breast milk is associated with less favorable motor, mental and behavioral development up to 18 months of age.