Feeding in infancy and later ability and attainment: a longitudinal study

Association between breastfeeding duration and educational achievement in England: results from the Millennium Cohort Study

OBJECTIVE

To evaluate the association between breastfeeding duration and educational outcomes at the end of secondary education among children from the Millennium Cohort Study.

DESIGN

Cohort study comparing school results at age 16 according to breastfeeding duration.

SETTING

England.

PARTICIPANTS

Children born in 2000-2002 (nationally representative sample).

EXPOSURE

Self-reported breastfeeding duration (categorised).

MAIN OUTCOME MEASURES

Standardised school assessments taken at the end of secondary education (General Certificate of Secondary Education (GCSEs), marked 9-1) in English and Mathematics, categorised as: 'fail, marks <4', 'low pass, marks 4-6' and 'high pass, marks ≥7 (equivalent to A-A*)'. Additionally, overall achievement was measured using the 'attainment 8' score (adding the marks of eight GCSEs, English and Mathematics double weighted; 0-90).

RESULTS

Approximately 5000 children were included. Longer breastfeeding was associated with better educational outcomes. For example, after full adjustment for socioeconomic markers and maternal cognitive ability, in comparison with children who were never breastfed, those who were breastfed for longer were more likely to have a high pass in their English and Mathematics GCSEs, and less likely to fail the English GCSE (but not the Mathematics GCSE). Additionally, compared with those never breastfed, those breastfed for at least 4 months had, on average, a 2-3 point higher attainment 8 score (coefficients: 2.10, 95% CI 0.06 to 4.14 at 4-6 months; 2.56, 95% CI 0.65 to 4.47 at 6-12 months and 3.09, 95% CI 0.84 to 5.35 at ≥12 months).

CONCLUSIONS

A longer breastfeeding duration was associated with modest improvements in educational outcomes at age 16, after controlling for important confounders.

Milk fat globule membrane plus milk fat increase docosahexaenoic acid availability in infant formulas

PURPOSE

Milk fat globule membrane (MFGM) has components with emulsifier properties that could affect the provision of substrates to the brain. We evaluated the effects of MFGM plus milk fat addition to infant formulas on docosahexaenoic acid (DHA) availability and gut development.

METHODS

In Experiment 1, suckling piglets were divided into 3 groups: Group L1 (n = 8): fed with a vegetal fat formula with palm oil; L2 (n = 8): canola oil formula and L3 (n = 8): milk fat + canola oil + 1% Lacprodan (3% MFGM of total protein content). In Experiment 2, Group L4 (n = 7): fed with canola oil + 1% Lacprodan (3% MFGM) and Group L5 (n = 5): milk fat + canola oil + 2% Lacprodan (6% MFGM). All formulas contained 0.2% DHA and 0.2% arachidonic acid.

RESULTS

In Experiment 1, DHA was similar among the groups in both total fatty acids and plasma phospholipids (PL). However, 3% MFGM (L3) increased significantly the proportion of DHA and LC-PUFA n-3 in liver total fatty acids, jejunum, and also in jejunum PL respect to the other formulas. There were no changes in gut histology, cell proliferation, apoptosis, or brain DHA content. In Experiment 2, higher MFGM dose was used. Then, higher DHA was not only found in peripheral tissues of 6% MFGM (L5) piglets but also in plasma PL, while a similar trend was observed in cortex PL (p = 0.123).

CONCLUSION

In conclusion, MFGM plus milk fat may increase DHA availability of infant formulas which could contribute to their beneficial health effects.

The Importance of Marine Omega-3s for Brain Development and the Prevention and Treatment of Behavior, Mood, and Other Brain Disorders

Most of the global population is deficient in long-chain marine omega-3s. In particular, docosahexaenoic acid (DHA), a long-chain omega-3 fatty acid, is important for brain and eye development. Additionally, DHA plays a significant role in mental health throughout early childhood and even into adulthood. In the brain, DHA is important for cellular membrane fluidity, function and neurotransmitter release. Evidence indicates that a low intake of marine omega-3s increases the risk for numerous mental health issues, including Attention Deficit Hyperactivity Disorder (ADHD), autism, bipolar disorder, depression and suicidal ideation. Studies giving supplemental marine omega-3s have shown promise for improving numerous mental health conditions. This paper will review the evidence surrounding marine omega-3s and mental health conditions.

Breastfeeding Child Development

The literature reviewed in this article suggests that breastfeeding positively influences cognitive development. Studies comparing the effects of early feeding methods on cognition consistently show mental test score advantages for breastfed infants over bottlefed subjects. Also, breastfeeding may function as a buffer against adverse developmental outcomes from early traumatic events such as low birthweight or neurologic insults. It is recognized that breastmilk contains long-chain polyunsaturated fatty acids that are necessary for the normal development of the retina and cerebrum. Yet, breastfeeding may not always promote optimal development in children. Infants breastfed by mothers using alcohol or marijuana have lower scores on developmental tests. Thus, while breastfeeding has the potential for contributing to the healthy development of infants, it may also be capable of transferring toxic substances known to interfere with normal development.

Long chain polyunsaturated fatty acid supplementation in infants born at term

BACKGROUND

The long chain polyunsaturated fatty acids (LCPUFA) docosahexaenoic acid (DHA) and arachidonic acid (AA) are considered essential for maturation of the developing brain, retina and other organs in newborn infants. Standard infant milk formulae are not supplemented with LCPUFA; they contain only alpha-linolenic acid and linoleic acid, from which formula-fed infants must synthesise their own DHA and AA, respectively. Over the past few years, some manufacturers have added LCPUFA to formula milk and have marketed these products as providing an advantage for the overall development of full-term infants.

OBJECTIVES

To assess whether supplementation of formula milk with LCPUFA is both safe and beneficial for full-term infants, while focusing on effects on visual function, neurodevelopment and physical growth.

SEARCH METHODS

Two review authors independently searched the Cochrane Central Register of Controlled Trials (CENTRAL; December 2016), MEDLINE (Ovid, 1966 to December 2016), Embase (Ovid, 1980 to December 2016), the Cumulative Index to Nursing and Allied Health Literature (CINAHL; 1980 to December 2016) and abstracts of the Pediatric Academic Societies (2000 to 2016). We applied no language restrictions.

SELECTION CRITERIA

We reviewed all randomised controlled trials (RCTs) evaluating effects of LCPUFA supplemented versus non-supplemented formula milk on visual function, neurodevelopment and physical growth. We did not include trials reporting only biochemical outcomes.

DATA COLLECTION AND ANALYSIS

Two review authors extracted data independently. We assessed risk of bias of included studies using the guidelines of the Cochrane Neonatal Review Group. When appropriate, we conducted meta-analysis to determine a pooled estimate of effect.

MAIN RESULTS

We identified 31 RCTs and included 15 of these in the review (N = 1889).Nine studies assessed visual acuity, six of which used visual evoked potentials (VEP), two Teller cards and one both. Four studies reported beneficial effects, and the remaining five did not. Meta-analysis of three RCTs showed significant benefit for sweep VEP acuity at 12 months (log of the minimum angle of resolution (logMAR)) (mean difference (MD) -0.15, 95% confidence interval (CI) -0.17 to -0.13; I² = 0; three trials; N = 244), but meta-analysis of three other RCTs showed no benefit for visual acuity measured with Teller cards at 12 months (cycles/degree) (MD -0.01, 95% CI -0.12 to 0.11; I² = 0; three trials; N = 256). GRADE analysis for the outcome of visual acuity indicated that the overall quality of evidence was low.Eleven studies measured neurodevelopmental outcomes at or before two years. Nine studies used Bayley Scales of Infant Development, version II (BSID-II), and only two of these studies reported beneficial effects. Meta-analysis revealed no significant differences between LCPUFA and placebo groups in BSID Mental Developmental Index (MDI) scores at 18 months (MD 0.06, 95% CI -2.01 to 2.14; I² = 75%; four trials; N = 661) and no significant differences in BSID Psychomotor Development Index (PDI) scores at 18 months (MD 0.69, 95% CI -0.78 to 2.16; I² = 61%; four trials; N = 661). Results showed no significant differences between the two groups in BSID-II scores at one year and two years of age. One study reported better novelty preference measured by the Fagan Infant Test at nine months. Another study reported better problem solving at 10 months. One study used the Brunet and Lezine test to assess the developmental quotient and found no beneficial effects. Follow-up of some infants in different studies at three, six and nine years of age revealed no beneficial effects of supplementation. GRADE analysis of these outcomes indicated that the overall quality of evidence was low.Thirteen studies measured physical growth; none found beneficial or harmful effects of supplementation. Meta-analysis of five RCTs showed that the supplemented group had lower weight (z scores) at one year of age (MD -0.23, 95% CI -0.40 to -0.06; I² = 83%; N = 521) and that the two groups showed no significant differences with respect to length and head circumference (z scores). Meta-analysis at 18 months and at two years revealed no significant differences between the two groups with respect to weight (kg), length (cm) and head circumference (cm). GRADE analysis of these outcomes indicated that the overall quality of evidence was low.

AUTHORS' CONCLUSIONS

Most of the included RCTs reported no beneficial effects or harms of LCPUFA supplementation on neurodevelopmental outcomes of formula-fed full-term infants and no consistent beneficial effects on visual acuity. Routine supplementation of full-term infant milk formula with LCPUFA cannot be recommended at this time.

Effects of Health and Nutrition on Cognitive and Behavioural Development in Children in the First Three Years of Life: Part 1: Low Birthweight, Breastfeeding, and Protein-Energy Malnutrition

The following paper and its accompanying paper (Grantham-McGregor SM, et al. Effects of health and nutrition on cognitive and behavioural development in children in the first three years of life. Part 2: Infections and micronutrient deficiencies: iodine, iron, and zinc. Food Nutr Bull 1999;20:76–99) review the literature on the conditions that are prevalent and considered to be likely to affect child development and are therefore of public health importance. the reviews are selective, and we have generally focused on recent work, particularly in areas that remain controversial. the reviews are restricted to nutritional and health insults that are important in the first three years of life. Where possible, we have discussed the better studies. This paper considers the effects of low birthweight (focusing on small-for-gestational-age babies) and early childhood protein-energy malnutrition on mental, motor, and behavioural development. We have also included a section on breastfeeding because of its importance to child health and nutrition programmes.

Long-term neurodevelopmental benefits of breastfeeding

PURPOSE OF REVIEW

The American Academy of Pediatrics recommends exclusive breastfeeding for the first 6 months of an infant#$#apos;s life, with continuation of breastfeeding for at least a year or as mutually desired by mother and child. A robust body of research literature documenting the short-term medical, developmental, and emotional benefits of breastfeeding for infants and toddlers supports this position. This article reviews the neurodevelopmental benefits of breastfeeding as it relates to preschool and school-age children, with particular emphasis on cognitive development, attention-deficit/hyperactivity disorder, and autism spectrum disorder.

RECENT FINDINGS

The majority of research studies examining breastfeeding and long-term neurodevelopmental outcomes suggest that children who breastfeed for longer than 6 months have better cognitive outcomes, lower risk of developing attention-deficit/hyperactivity disorder, and lower risk of being diagnosed with autism spectrum disorder.

SUMMARY

Pediatricians play a critical role in educating and counseling families about infant nutrition and feeding. Along with the many positive short-term medical effects that breastfeeding confers, physicians should be aware of the growing body of research suggesting that there are also significant long-term neurodevelopmental benefits of breastfeeding.

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.

Early supplementation of phospholipids and gangliosides affects brain and cognitive development in neonatal piglets

BACKGROUND

Because human breast milk is a rich source of phospholipids and gangliosides and breastfed infants have improved learning compared with formula-fed infants, the importance of dietary phospholipids and gangliosides for brain development is of interest.

OBJECTIVE

We sought to determine the effects of phospholipids and gangliosides on brain and cognitive development.

METHODS

Male and female piglets from multiple litters were artificially reared and fed formula containing 0% (control), 0.8%, or 2.5% Lacprodan PL-20 (PL-20; Arla Foods Ingredients), a phospholipid/ganglioside supplement, from postnatal day (PD) 2 to PD28. Beginning on PD14, performance in a spatial T-maze task was assessed. At PD28, brain MRI data were acquired and piglets were killed to obtain hippocampal tissue for metabolic profiling.

RESULTS

Diet affected maze performance, with piglets that were fed 0.8% and 2.5% PL-20 making fewer errors than control piglets (80% vs. 75% correct on average; P < 0.05) and taking less time to make a choice (3 vs. 5 s/trial; P < 0.01). Mean brain weight was 5% higher for piglets fed 0.8% and 2.5% PL-20 (P < 0.05) than control piglets, and voxel-based morphometry revealed multiple brain areas with greater volumes and more gray and white matter in piglets fed 0.8% and 2.5% PL-20 than in control piglets. Metabolic profiling of hippocampal tissue revealed that multiple phosphatidylcholine-related metabolites were altered by diet.

CONCLUSION

In summary, dietary phospholipids and gangliosides improved spatial learning and affected brain growth and composition in neonatal piglets.

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

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

Breast milk and cognitive development--the role of confounders: a systematic review

OBJECTIVES

The association between breastfeeding and child cognitive development is conflicted by studies reporting positive and null effects. This relationship may be confounded by factors associated with breastfeeding, specifically maternal socioeconomic class and IQ.

DESIGN

Systematic review of the literature.

SETTING AND PARTICIPANTS

Any prospective or retrospective study, in any language, evaluating the association between breastfeeding and cognitive development using a validated method in healthy term infants, children or adults, was included.

PRIMARY AND SECONDARY OUTCOME MEASURES

Extracted data included the study design, target population and sample size, breastfeeding exposure, cognitive development assessment tool used and participants' age, summary of the results prior to, and following, adjustment for confounders, and all confounders adjusted for. Study quality was assessed as well.

RESULTS

84 studies met our inclusion criteria (34 rated as high quality, 26 moderate and 24 low quality). Critical assessment of accepted studies revealed the following associations: 21 null, 28 positive, 18 null after adjusting for confounders and 17 positive-diminished after adjusting for confounders. Directionality of effect did not correlate with study quality; however, studies showing a decreased effect after multivariate analysis were of superior quality compared with other study groupings (14/17 high quality, 82%). Further, studies that showed null or diminished effect after multivariate analysis corrected for significantly more confounders (7.7±3.4) as compared with those that found no change following adjustment (5.6±4.5, p=0.04). The majority of included studies were carried out during childhood (75%) and set in high-income countries (85.5%).

CONCLUSIONS

Much of the reported effect of breastfeeding on child neurodevelopment is due to confounding. It is unlikely that additional work will change the current synthesis. Future studies should attempt to rigorously control for all important confounders. Alternatively, study designs using sibling cohorts discordant for breastfeeding may yield more robust conclusions.

Coupling Mass Spectrometry-Based "Omic" Sciences with Bioguided Processing to Unravel Milk's Hidden Bioactivities

Many of milk's functional molecules could not be discovered until the right concordance of novel separation and analytical technologies were developed and applied. Many health-promoting components still await discovery due to technical challenges in their identification, isolation and testing. As new analytical technologies are assembled, new functional milk molecules will be discovered. Bovine milk is a source of a wide array of known bioactive compounds from a variety of molecular classes, including free glycans, lipids, glycolipids, peptides, proteins, glycoproteins, stem cells and microRNA. Because milk is such a complex mixture, when analyzed without fractionation or purification, many components mask the analytical signal of others, so some components cannot be detected. Modern analytics allow for the discovery and characterization of hundreds of novel milk compounds with high-resolution and high-accuracy. Liquid chromatography paired with electrospray ionization allows the separation of peptides, glycans and glycolipids for improved mass spectrometric detection. Target proteins and glycoproteins can now be purified from intact milk or other dairy streams by chromatography in order to better characterize these proteins for new bioactivities. The combination of advanced analytics with the new engineering capabilities will allow for high molecular resolution and separation techniques that can be scaled-up to semi-industrial and industrial scale for translation of lab-based discoveries. Bioguided analysis and design of dairy processing side streams will result in the transformation of waste into isolated functional ingredients to add value to dietary products.

A Household Study of Self-Regulation in Children

Delay of gratification (DoG) and delay discounting (DD) are behavioral measures of self-regulation and impulsivity. Whereas DoG refers to the postponement of gratification, DD involves the devaluation of a reward over time. Previous studies have demonstrated associations between paternal self-control, paternal personality traits, parenting styles, maternal intelligence, and children’s self-regulation. The present study explored intergenerational links between mothers’ and child’s self-regulation and maternal antecedents of children’s DoG. We analyzed 267 mother-child dyads in the German Socio-Economic Panel (SOEP) Children’s Study. Measures included an experiment using gummy bears as rewards to assess DoG in children and monetary choice procedures to assess DD in mothers. Additionally, cognitive abilities and personality traits of mothers and children were assessed. The main result was that the children’s age and breastfeeding were significant predictors of DoG in children, even when we controlled for other influences such as maternal cognitive abilities and personality traits. We explain the result in the context of previous findings concerning attachment security, bonding, maternal sensitivity, children’s self-regulation of energy intake, neuroscientific evidence, and breastfeeding. Further studies should use equivalent measures of DoG in children and parents to further explore this link between breastfeeding and DoG in a genetically sensitive design.

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.

Maternal prolactin inhibition at the end of lactation affects learning/memory and anxiety-like behaviors but not novelty-seeking in adult rat progeny

Maternal hypoprolactinemia at the end of lactation in rats reduces milk production and is associated with offspring's malnutrition. Since malnutrition during development is also known to have long lasting effects on cognition and emotion, in the present study we tested the hypothesis that maternal hypoprolactinemia, induced by bromocriptine treatment, at the end of the lactating period affects memory/learning, novelty-seeking and anxiety-like behaviors in adult male Wistar rats using, respectively, the radial arm water maze (RAWM), the hole board (HB) arena and the elevated plus-maze (EPM). We also analyzed serum corticosterone and thyroid hormone levels at postnatal day (PN) 21. Lactating dams were treated with bromocriptine (BRO, 1mg twice a day, inhibiting prolactin) or saline from PN19 to 21 (the last 3 days of lactation). BRO offspring had hypercorticosteronemia and hypothyroidism at PN21. In the RAWM, reductions in latency observed in CON rats were initially more accentuated than in BRO ones. By the end of the testing period, latencies became similar between groups. No difference was observed between groups regarding the number of nose-pokes in the HB. In the EPM, BRO rats stayed less time in and had fewer entries into the open-arms than CON ones. This pattern of results indicates that maternal bromocriptine treatment at the end of the lactating period results in poorer memory/learning performance and in higher levels of anxiety-like behavior in the adult offspring, demonstrating that even a relatively short period of malnutrition during development can have long lasting detrimental effects regarding cognition and emotion.

Propensity scores: From naïve enthusiasm to intuitive understanding

Estimation of the effect of a binary exposure on an outcome in the presence of confounding is often carried out via outcome regression modelling. An alternative approach is to use propensity score methodology. The propensity score is the conditional probability of receiving the exposure given the observed covariates and can be used, under the assumption of no unmeasured confounders, to estimate the causal effect of the exposure. In this article, we provide a non-technical and intuitive discussion of propensity score methodology, motivating the use of the propensity score approach by analogy with randomised studies, and describe the four main ways in which this methodology can be implemented. We carefully describe the population parameters being estimated — an issue that is frequently overlooked in the medical literature. We illustrate these four methods using data from a study investigating the association between maternal choice to provide breast milk and the infant's subsequent neurodevelopment. We outline useful extensions of propensity score methodology and discuss directions for future research. Propensity score methods remain controversial and there is no consensus as to when, if ever, they should be used in place of traditional outcome regression models. We therefore end with a discussion of the relative advantages and disadvantages of each.

Cognitive function in adolescence: testing for interactions between breast-feeding and FADS2 polymorphisms

OBJECTIVES

Breast-fed C-allele carriers of the rs174575 single nucleotide polymorphism in the fatty acyl desaturase 2 (FADS2) gene have been reported to show a 6.4 to 7 IQ point advantage over formula-fed C-allele carriers, with no effect of breast-feeding in GG carriers. An Australian sample was examined to determine if an interaction between breast-feeding and the rs174575 single nucleotide polymorphism had any effect on IQ.

METHOD

This hypothesis was tested in more than 700 families of adolescent twins assessed for IQ and breast-feeding, birth weight, and FADS2 polymorphisms, and parental socioeconomic status and education, and maternal FADS2 status.

RESULTS

No significant evidence for a moderating effect on IQ of rs174575 C-carrier status and breast-feeding was found, and there no effects of maternal FADS2 status on offspring IQ. In addition, no main effects of any FADS2 polymorphisms on IQ were found when the genotype was kept as two-homozygote and one-heterozygote categories and indeed no evidence for effects of breast-feeding on IQ scores after controlling for parental socioeconomic status and education. The investigation was extended to two additional FADS2 polymorphisms (rs1535 and rs174583), but again, although these polymorphisms code alleles affecting fatty acid metabolism, no main or interaction effects were found on IQ.

CONCLUSION

These results support the view that apparent effects of breast-feeding on IQ reflect differential likelihood of breast-feeding as a function of parental education and did not support the predicted interaction effect of FADS2 and breast-feeding on IQ.

Breastfeeding duration and academic achievement at 10 years

INTRODUCTION

The aim of this study was to examine the relationship between duration of breastfeeding and educational outcomes. We hypothesized that longer periods of breastfeeding would predict better educational outcomes in middle childhood.

METHODS

The Western Australian Pregnancy Cohort (Raine) Study used a cohort of 2900 women who were enrolled at 18 weeks' gestation; with 2868 live-born children were followed prospectively. At ∼10 years of age, data from 1038 children were linked to standardized mathematics, reading, writing, and spelling scores. Associations between breastfeeding duration and educational outcomes were estimated by using linear models with adjustment for gender, family income, maternal factors, and early stimulation at home through reading.

RESULTS

Ten-year-old children who were predominantly breastfed for 6 months or longer in infancy had higher academic scores than children who were breastfed for less than 6 months. The effect of breastfeeding on educational outcomes differed according to gender; boys were particularly responsive (in mathematics, spelling, reading, and writing) to a longer duration of breastfeeding.

CONCLUSIONS

Predominant breastfeeding for 6 months or longer was positively associated with academic achievement in children at 10 years of age. However, the effectiveness of breastfeeding differed according to gender; the benefits were only evident for boys.

Long-term health outcomes and mechanisms associated with breastfeeding

Breastfeeding is superior to formula feeding because it has factors that have long term consequences for early metabolism and disease later in life. In this paper, the scientific evidence in support of why breast milk is beneficial for infants is summarized and the mechanisms in which breastfeeding impacts on disease are explored. Human milk may show a reduced occurrence of disease because mammalian evolution promotes survival, and because of specific factors in milk that promote active stimulation of the infant's immune system and gastrointestinal mucosal maturation decrease the incidence of infection and alter the gut microflora. Bioactive factors, including: hormones, growth factors, colony-stimulating factors and specific nutrients, may have such far-reaching effects on the infant's immune response that normal development depends heavily on its provision. All mothers should be encouraged and supported to continue breastfeeding for 6 months and beyond in order to promote the good health of their infants.

Effect of breastfeeding and sociodemographic factors on visual outcome in childhood and adolescence

BACKGROUND

It has been suggested that early life factors, including breastfeeding and birth weight, program childhood myopia.

OBJECTIVE

We examined the relation of reduced unaided vision (indicative of myopia) in childhood and adolescence with infant feeding, parental education, maternal age at birth, birth weight, sex, birth order, and socioeconomic status.

DESIGN

Three British cohorts recruited infants born in 1946 (n = 5362), 1958 (n = 18,558), and 1970 (n = 16,567). Adjusted odds ratios (ORs) for unaided vision of 6/12 or worse at ages 10-11 and 15-16 y from each cohort were pooled by using fixed-effects meta-analyses.

RESULTS

The prevalence of reduced vision ranged from 4.4% to 6.5% at 10-11 y and from 9.4% to 11.4% at 16 y, with marginally higher levels in later cohorts. Breastfeeding declined across successive cohorts (65%, 43%, and 22% in those breastfed for >1 mo, respectively). Pooled ORs showed no associations between infant feeding and vision after adjustment at either age. Parental education (OR: 1.48, high versus low education; 95% CI: 1.23, 1.79), maternal age (OR: 1.10, per 5-y increase; 95% CI: 1.04, 1.17), birth weight (OR: 0.85, per 1-kg rise; 95% CI: 0.76, 0.95), number of older siblings (OR: 0.89, per older sibling; 95% CI: 0.83, 0.94), and sex (OR: 1.10, girls versus boys; 95% CI: 0.98, 1.23) were related to adverse visual outcome in childhood. Stronger associations were observed in adolescence, except that the association with birth weight was null.

CONCLUSIONS

Infant feeding does not appear to influence visual development. Consistent associations of reduced vision with parental education, sex, maternal age, and birth order suggest that other environmental factors are important for visual development and myopia in early life.

Duration of Breast Feeding and Cognitive Function: Population Based Cohort Study

Some evidence suggests that breast feeding is weakly but positively associated with cognitive function. This association has been robust to adjustment for various confounders. The aim of this paper is to determine if duration of breast feeding is associated with cognitive function in late childhood. Data was abstracted from the 1970 British Cohort Study. 11004 liveborn white singletons born during 5-11 April 1970 in the United Kingdom were followed from birth to 10 years. Cognitive function at 10 years is the dependent variable, a latent construct composed of one ability test and three performance measures. Estimates derived from multiple linear regression and structural equation modeling were compared. Effect sizes were estimated using standardized coefficients (SC). Differences in cognitive function according to breast feeding duration were estimated to be small by multiple linear regression (SC = 0.07) and much smaller and non-significant as estimated by structural equation modeling (SC = 0.02) after adjusting for parental socioeconomic status (SES), birth weight, parity, gestational age, maternal age and maternal smoking. Differences in cognitive function according to duration of breast feeding appear to be small and of little clinical importance as estimated by structural equation modeling.

Breastfeeding during infancy may protect against bed-wetting during childhood

OBJECTIVE

Our goal was to test the hypothesis that children who exhibit bed-wetting during childhood were less likely to be breastfed during infancy compared with normal controls.

METHODS

A case-control study was conducted in a pediatric continence center and a general pediatric practice. Cases (n = 55) were recruited from the continence center and defined as children 5 to 13 years of age who experienced lifetime involuntary voiding of urine during nighttime sleep at least 2 times a week in the absence of defects of the central nervous system or urinary tract. Age- and gender-matched controls (n = 117) who did not exhibit bed-wetting were enrolled from a general pediatric practice. Infant feeding practices were measured as breastfeeding (yes/no) and, for those who were breastfeed, by the duration of breastfeeding and the time of formula supplementation.

RESULTS

Among the case subjects, 45.5% were breastfed, whereas among the controls 81.2% were breastfed. The controls reported higher household incomes than the case subjects, and their mean family size (number of children) was slightly lower. After adjusting for race, income, and family size, the odds ratio was 0.283, indicating that case subjects were significantly less likely than controls to be breastfeed. Among all the study subjects who were breastfed, controls were breastfed for a significantly longer period than case subjects (an average of 3 months longer). Although breastfed controls were less likely to be supplemented with formula than breastfed case subjects, this difference was not statistically significant.

CONCLUSIONS

Breastfeeding longer than 3 months may protect against bed-wetting during childhood. Breast milk supplemented with formula did not make a difference in the rate of enuresis.

Childhood cognitive ability and age at menopause: evidence from two cohort studies

OBJECTIVE

To investigate whether poorer cognitive ability in childhood is associated with an earlier menopause.

DESIGN

Two cohorts were included: a nationally representative British birth cohort study of 1,350 women born in March 1946 and followed up to age 54 years, and an Aberdeen cohort study of 3,465 women born in Aberdeen from 1950 to 1956 and followed up to age 44 to 50 years. Both cohorts had prospective information on childhood cognitive ability at age 7 or 8 years.

RESULTS

In both cohorts, women with lower cognitive scores in childhood reached menopause earlier than women with higher scores. With follow-up of menopause to 49 years, the hazard ratio (HR) for one standard deviation of the cognitive score was 0.80 (95% CI, 0.72-0.90) in the Aberdeen cohort and 0.84 (95% CI, 0.73-0.97) in the older 1946 birth cohort. The effect was still evident in the 1946 birth cohort with follow-up of menopause to 53 years (HR = 0.87; 95% CI, 0.79-0.95). These ratios were weakly attenuated by adjustment for potential confounding effects of lifetime socioeconomic circumstances, parity, and smoking.

CONCLUSIONS

The association between early cognitive ability and timing of menopause only partially reflects common risk factors, although residual confounding remains a possibility. Alternatively, early environmental or genetic programming may explain this association, perhaps through setting lifelong patterns of hormone release or causing transient hormonal changes at sensitive periods of development. These findings have implications for the interpretation of studies investigating an association between age at menopause and adult cognitive function.

Polyunsaturated fatty acids: biochemical, nutritional and epigenetic properties

Dietary polyunsaturated fatty acids (PUFA) have effects on diverse physiological processes impacting normal health and chronic diseases, such as the regulation of plasma lipid levels, cardiovascular and immune function, insulin action and neuronal development and visual function. Ingestion of PUFA will lead to their distribution to virtually every cell in the body with effects on membrane composition and function, eicosanoid synthesis, cellular signaling and regulation of gene expression. Cell specific lipid metabolism, as well as the expression of fatty acid-regulated transcription factors, likely play an important role in determining how cells respond to changes in PUFA composition. This review will focus on recent advances on the essentiality of these molecules and on their interplay in cell physiology, leading to new perspective in different therapeutic fields.

Nutrients for cognitive development in school-aged children

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

Influence of breast-feeding and parental intelligence on cognitive development in the 24-month-old child

This study was designed to analyze the relationship between breast-feeding and mental development at 24 months of age, independently of the influence of other factors. A total of 238 babies born between October 1995 and February 1998 were enrolled in an observational prospective cohort study. Cognitive development was assessed using the Bayley Infant Development Scale. The results of multiple linear regression analysis showed that infants breast-fed for longer than 4 months scored 4.3 points higher on the mental development scale than those breast-fed for less time. No differences were found in psychomotor development as a function of feeding regimen or duration. The positive linear correlation observed between parental IQ and mental development scores at 24 months was also statistically significant (mother: r = 0.39; p < 0.001; father: r = 0.43; p < 0.001). It may be concluded that breast-feeding for longer than 4 months has a positive effect on the child's mental development at 24 months of age. Parental intelligence also appears to influence cognitive development.

The role and potential of sialic acid in human nutrition

Sialic acids are a family of nine-carbon acidic monosaccharides that occur naturally at the end of sugar chains attached to the surfaces of cells and soluble proteins. In the human body, the highest concentration of sialic acid (as N-acetylneuraminic acid) occurs in the brain where it participates as an integral part of ganglioside structure in synaptogenesis and neural transmission. Human milk also contains a high concentration of sialic acid attached to the terminal end of free oligosaccharides, but its metabolic fate and biological role are currently unknown. An important question is whether the sialic acid in human milk is a conditional nutrient and confers developmental advantages on breast-fed infants compared to those fed infant formula. In this review, we critically discuss the current state of knowledge of the biology and role of sialic acid in human milk and nervous tissue, and the link between sialic acid, breastfeeding and learning behaviour.

Breast feeding and cognitive development in childhood: a prospective birth cohort study

The aim of this study was to examine prospectively the relation between duration of breast feeding and cognitive outcomes. A cohort study of 2860 children enrolled before birth provided data from 2393 term infants of English-speaking mothers. Of these, complete infant feeding data in the first year of life and verbal cognitive IQ (Peabody Picture Vocabulary Test - PPVT-R) were available for 1450 children at 6 years, and a performance subtest (Perceptual organisation WISC - Block Design) for 1375 children at 8 years. Full breast feeding was categorised as none,> 0 to < 4 months, 4-6 months and> 6 months. Associations between breast-feeding duration and PPVT-R at 6 years and Block Design at 8 years were estimated before and after adjustment for gender, gestational age, maternal age, maternal education, parental smoking and the presence of older siblings. The early cessation of full breast feeding was associated with reduced verbal IQ and the performance subtest. In unadjusted analysis, mean standardised PPVT-R scores were 6.44 points greater (P < 0.0001) in children fully breast fed for> 6 months compared with those never breast fed. After adjustment, mean PPVT-R scores were 3.56 points higher in children fully breast fed for> 6 months compared with those children never breast fed (P = 0.003). Similarly, Block Design scores were higher in those fully breast fed for> 6 months compared with those never breast fed in unadjusted (P = 0.001) but not adjusted analyses (P = 0.223). Interactions between maternal education (four levels) and breast feeding demonstrated a positive association of maternal education on verbal IQ (F = 2.64; P = 0.005) in children breast fed for longer but not on performance (F = 0.74; P = 0.67). The early introduction of milk other than breast milk was associated with reduced verbal IQ after adjustment for social and perinatal confounders. Although these effects were interacting with maternal education, they may act through undefined mechanisms in human milk.

Long-term effects of breast-feeding in a national birth cohort: educational attainment and midlife cognitive function

OBJECTIVE

A recent meta-analysis showed that breast-feeding confers a 3.2 point increment in cognitive function through adolescence. Little is known, however, about possible longer-term effects of breast-feeding. We investigated the effect of breast-feeding on educational attainment, and on a range of cognitive skills in midlife, in the British 1946 birth cohort.

DESIGN

Regression analyses were used to test the association between breast-feeding, likelihood of obtaining advanced educational qualifications by age 26 years, and three cognitive test scores at age 53 years: i.e. reading ability (NART), timed visual search and verbal memory. These associations were then adjusted for social confounding variables and for cognitive ability at age 15 years.

SETTING AND SUBJECTS

One thousand seven hundred and thirty-nine male and female participants in the MRC National Survey of Health and Development, also known as the British 1946 birth cohort, distributed throughout England, Wales and Scotland.

RESULTS

Breast-feeding was significantly and positively associated with educational attainment, an effect that was independent of early social background, but largely accounted for by cognitive ability at age 15 years. Breast-feeding was significantly and positively associated with the NART at 53 years, an effect that was independent of early social background, educational attainment and adult social class, but, again, largely accounted for by cognitive ability at 15 years. There was no independent effect of breast-feeding on timed visual search or verbal memory at 53 years.

CONCLUSION

The benefit of breast-feeding has long-term potential impact across the life course through its influence on childhood cognition and educational attainment.

How good is the evidence linking breastfeeding and intelligence?

BACKGROUND

We conducted a critical review of the many studies that have tried to determine whether breastfeeding has a beneficial effect on intellect.

DESIGN/METHODS

By searching Medline and the references of selected articles, we identified publications that evaluated the association between breastfeeding and cognitive outcomes. We then appraised and described each study according to 8 principles of clinical epidemiology: 1) study design, 2) target population: whether full-term infants were studied, 3) sample size, 4) collection of feeding data: whether studies met 4 standards of quality- suitable definition and duration of breastfeeding, and appropriate timing and source of feeding data, 5) control of susceptibility bias: whether studies controlled for socioeconomic status and stimulation of the child, 6) blinding: whether observers of the outcome were blind to feeding status, 7) outcome: whether a standardized individual test of general intelligence at an age older than 2 years was used, and 8) format of results: whether studies reported an effect size or some other strategy to interpret the clinical impact of results.

RESULTS

We identified 40 pertinent publications from 1929 to February 2001. Twenty-seven (68%) concluded that breastfeeding promotes intelligence. Many studies, however, had methodological flaws. Only 2 papers studied full-term infants and met all 4 standards of high-quality feeding data, controlled for 2 critical confounders, reported blinding, used an appropriate test, and allowed the reader to interpret the clinical significance of the findings with an effect size. Of these 2, 1 study concluded that the effect of breastfeeding on intellect was significant, and the other did not.

CONCLUSION

Although the majority of studies concluded that breastfeeding promotes intelligence, the evidence from higher quality studies is less persuasive.

Relationship between omega3 long-chain polyunsaturated fatty acid status during early infancy and neurodevelopmental status at 1 year of age

OBJECTIVE

To determine the influence of alpha-linolenic acid (ALA; 18 : 3omega3) intake and, hence, the influence of plasma and/or erythrocyte phospholipid content of docosahexaenoic acid (DHA; 22 : 6omega3) during early infancy on neurodevelopmental outcome of term infants.

METHODS

The Bayley Scales of Infant Development (second edition), the Clinical Adaptive Test/Clinical Linguistic and Auditory Milestone Scale (CAT/CLAMS) and the Gross Motor Scale of the Revised Gesell Developmental Inventory were administered at a mean age of 12.26 +/- 0.94 months to 44 normal term infants enrolled in a study evaluating the effects of infant formulas differing only in ALA content (0.4, 1.0, 1.7 and 3.2% of total fatty acids).

RESULTS

As reported previously [Jensen et al., Lipids 13 (1996) 107; J. Pediatr. 131 (1997) 200], the group fed the formula with the lowest ALA content had the lowest mean plasma and erythrocyte phospholipid DHA contents at 4 months of age. This group also had the lowest mean score on every neurodevelopmental measure. The difference in mean gross motor developmental quotient of this group versus the group fed the formula with 1.0% ALA but not of the other groups was statistically significant (P < 0.05). Across the groups, motor indices correlated positively with each other and with the plasma phospholipid DHA content at 4 months of age (P=0.02-0.03). The CLAMS developmental quotient correlated with the erythrocyte phospholipid content of 20 : 5omega3 (P < 0.01) but not with DHA.

CONCLUSIONS

These statistically significant correlations suggest that the omega3 fatty acid status during early infancy may be important with respect to neurodevelopmental status at 1 year of age and highlight the need for further studies of this possibility.

Breast feeding and cognitive development at age 1 and 5 years

AIM

To examine whether duration of breast feeding has any effect on a child's cognitive or motor development in a population with favourable environmental conditions and a high prevalence of breast feeding.

METHODS

In 345 Scandinavian children, data on breast feeding were prospectively recorded during the first year of life, and neuromotor development was assessed at 1 and 5 years of age. Main outcome measures were Bayley's Scales of Infant Development at age 13 months (Mental Index, MDI; Psychomotor Index, PDI), Wechsler Preschool and Primary Scales of Intelligence (WPPSI-R), and Peabody Developmental Scales at age 5.

RESULTS

Children breast fed for less than 3 months had an increased risk, compared to children breast fed for at least 6 months, of a test score below the median value of MDI at 13 months and of WPPSI-R at 5 years. Maternal age, maternal intelligence (Raven score), maternal education, and smoking in pregnancy were significant confounders, but the increased risk of lower MDI and total IQ scores persisted after adjustment for each of these factors. We found no clear association between duration of breast feeding and motor development at 13 months or 5 years of age.

CONCLUSION

Our data suggest that a longer duration of breast feeding benefits cognitive development.

Breastfeeding and brain development

Although biochemical evidence seems to support the fact that more DHA is incorporated into the brain of breastfed infants compared with formula-fed infants, whether the levels of DHA in the brain are clinically significant is unclear. Because randomized trials cannot be done, this issue is difficult to study. The effects of breastfeeding on developmental outcome in term infants seems to be small or insignificant. For otherwise healthy children the potential differences are not clinically relevant; however, these small differences distributed over an entire population might have a significant effect on society. Although significant methodologic concerns exist, the effects of breastfeeding on preterm infants may be greater than those for term infants. Extremely low birth weight, premature infants (< 750-1000 g) have been found to have IQs that are 13 points lower than term controls and a 50% to 60% risk for requiring special-education services when they are in school. In these infants, small improvements in IQ and neurologic function could have a much greater effect. Further study of neurodevelopmental outcome in premature infants fed breast milk compared with those fed preterm formula are indicated. This information should not change the practice of encouraging breastfeeding of term and preterm infants because other advantages to breastfeeding exist.

Breast milk feeding and cognitive ability at 7-8 years

OBJECTIVE

To examine the association between duration of breast milk feeding and cognitive ability at 7-8 years in a birth cohort of very low birthweight infants.

DESIGN

280 survivors from a national birth cohort of 413 New Zealand very low birthweight infants born in 1986 were assessed at age 7-8 years on measures of verbal and performance intelligence quotient (IQ) using the WISC-R. At the same time mothers were questioned as to whether they had elected to provide expressed breast milk at birth and the total duration of breast milk feeding.

RESULTS

Some 73% of mothers provided expressed breast milk and 37% breast fed for four months or longer. Increasing duration of breast milk feeding was associated with increases in both verbal IQ (p < 0.001) and performance IQ (p < 0.05): children breast fed for eight months or longer had mean (SD) verbal IQ scores that were 10.2 (0.56) points higher and performance IQ scores that were 6.2 (0.35) points higher than children who did not receive breast milk. These differences were substantially reduced after control for selection factors associated with receipt of breast milk. Nevertheless, even after control for confounding, there remained a significant (p < 0.05) association between duration of breast milk feeding and verbal IQ: children breast fed for eight months or longer had adjusted mean (SD) verbal IQ scores that were 6 (0.36) points higher than the scores of those who did not receive breast milk.

CONCLUSIONS

These findings add to a growing body of evidence to suggest that breast milk feeding may have small long term benefits for child cognitive development.

Dietary fats and cholesterol in italian infants and children

The fat intake of Italian infants has peculiar characteristics that begin quite early because their mothers' milk has a monounsaturated fat content (45%) at the upper limit of the values found in Europe. Comparison studies in breast-fed and formula-fed infants were conducted to evaluate growth and developmental correlates and differences in fat intakes in the early months of life. Breast-fed infants have higher blood lipid concentrations at 4 mo of age than do formula-fed infants. The addition of long-chain polyunsaturated fatty acids (LCPUFAs) and cholesterol to formulas for term infants may affect concentrations of circulating blood lipids as well as the LCPUFA composition of the lipids during the breast-feeding period. The addition of LCPUFAs does not seem to affect the growth rate of formula-fed infants. Although an initial benefit of LCPUFA feeding on eye-hand coordination was observed, this effect was not sustained; by 24 mo, different feeding groups had similar developmental scores. Other peculiarities of the Italian experience are presented, including body weights from infancy to early childhood in 147 children, the nutrient densities of different diets in Italian schoolchildren, and the effects of nutritional education on dietary intakes. The diets of these children were high in animal protein and supplied approximately 30-35% of energy from fats throughout childhood. Both the dietary protein intakes at 1 y of age and parental body mass indexes were associated with 5-y body mass index values. Classroom education may be useful to lower the plasma lipid concentrations in healthy, primary school-age children. It is not known whether this early modification can be maintained and whether it influences the later development of cardiovascular disorders.

A critical evaluation of the evidence on the association between type of infant feeding and cognitive development

This paper presents a critical evaluation of 24 studies on the association between type of infant feeding and cognitive development published over the past 20 years. Validity and generalisability of study findings were assessed according to three methodological standards: clearly defined outcome, specification of partial vs. exclusive breast feeding and control of confounding. Only six of the 24 investigations met all three standards. The most frequent study flaw was failure to distinguish between partial and exclusive breast feeding. Studies which made this distinction found larger IQ advantages to breast-fed infants than studies that did not. Four of the six studies meeting all three standards found an advantage in cognitive development to breast-fed infants of the order of two to five IQ points for term infants and eight points for low birthweight infants. We conclude that the question of whether breast feeding and formula feeding have differential effects on cognitive development has not yet been comprehensively answered. Research to date provides only an indication of the effect of relatively brief durations of partial breast feeding and even briefer durations of exclusive breast feeding. Future studies should measure breast feeding as a continuous dose-type variable, examine longer durations of breast feeding and control for a full range of confounders using techniques that deal appropriately with multicollinearity.

The role of long-chain polyunsaturated fatty acids in infant cognitive development

Dietary long-chain polyunsaturated fatty acids (LCPUFA) in infancy are necessary for normal brain growth and development, and may play an important role in the development of infant cognition. Several randomized, controlled studies have evaluated the effects of feeding both term and preterm infants formula containing LCPUFA or no LCPUFA on a variety of measures of cognitive behaviour. Studies of the relation of LCPUFA to performance on tests of psychomotor development have produced inconsistent results, with supplemented infants demonstrating either higher scores or no differences in comparison to controls. This pattern suggests that global tests of development may be insufficiently sensitive for detecting the effects of LCPUFA on infant cognitive function. In contrast, studies assessing the influence of LCPUFA on development of specific cognitive behaviours have shown a significant advantage for supplemented infants on measures of visual attention and problem solving. These results suggest that LCPUFA may enhance more efficient information processing or attention regulation in infants. Whether there are any long-term effects of dietary LCPUFA in infancy on childhood cognition is not known.