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

Human milk polyunsaturated fatty acids are related to neurodevelopmental, anthropometric, and allergic outcomes in early life: a systematic review

Polyunsaturated fatty acids are critically important for newborn nutrition and in the trajectory of growth and developmental processes throughout early life. This systematic review (PROSPERO ID: CRD42023400059) critically analyzes literature pertaining to how omega-3 and omega-6 fatty acids in human milk are related to health outcomes in early life. Literature selected for the review were published between 2005 and 2020 and included assessments in healthy term children between 0 and 5 years of age. The studies reported the relation between human milk fatty acids docosahexaenoic acid (C22:6n-3, DHA), eicosapentaenoic acid (C20:5n-3, EPA), alpha-linolenic acid (C18:3n-3, ALA), arachidonic acid (C20:4n-6, AA), and linoleic acid (C18:2n-6, LA) with three domains of health outcomes: neurodevelopment, body composition, and allergy, skin & eczema. Results from the 21 studies consistently suggested better health outcomes across the three domains for infants consuming milk with higher concentrations of total n-3, DHA, EPA, and ALA. Negative health outcomes across the three domains were associated with higher levels of total n-6, AA, and LA in milk. N-3 and n-6 content of milk were related to neurodevelopmental, body composition, and allergy, skin & eczema outcomes with moderate certainty. Maternal diet impacting milk fatty acid content and fatty acid desaturase genotype modifying physiologic responses to fatty acid intake were prominent gaps identified in the review using the NIH Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies and GRADE approach. This research study can inform baby nutrition product development, and fatty acid intake recommendations or dietary interventions for mothers and children.

The Benefits of Breastfeeding on Child Intelligence, Behavior, and Executive Function: A Review of Recent Evidence

Background: The effects of breastfeeding on neurodevelopmental outcomes are unclear. Inconsistent findings have been reported and confounding factors make interpretation of studies difficult. The World Health Organization published a systematic review on breastfeeding and intelligence in 2013, demonstrating a positive association with improved performance on intelligence tests. The objective of this review is to explore published literature since 2013 to examine the association between breastfeeding, cognition, executive function, and behavior. Methods: Duplicate searches were carried out using Web of Science and OVID for publications between January 2012 and March 2022. Non-English articles and those not correcting for maternal IQ or home environment were excluded. Results: Twenty-three studies were included, examining the effects of breastfeeding on cognition (21), executive function (3), and behavior (6). Most studies showed a modest dose-dependent increase in cognitive scores in children who were breastfed, test score differences ranging from 0.19 to 0.96 points per month of breastfeeding comparing any breastfeeding, predominant and exclusive breastfeeding. Four out of six studies showed a positive correlation between breastfeeding and behavior. One out of three studies assessing breastfeeding and executive function showed a positive dose-dependent correlation. Discussion: Recent evidence demonstrates that breastfeeding has a small positive effect on IQ in later childhood. Evidence suggesting that breastfeeding is a protective factor in developing conduct disorders and achieving higher executive function is limited. Further research is required. Limitations include potential confounders and recall bias of breastfeeding.

Impact of feeding habits on the development of language-specific processing of phonemes in brain: An event-related potentials study

Introduction

Infancy is a stage characterized by multiple brain and cognitive changes. In a short time, infants must consolidate a new brain network and develop two important properties for speech comprehension: phonemic normalization and categorical perception. Recent studies have described diet as an essential factor in normal language development, reporting that breastfed infants show an earlier brain maturity and thus a faster cognitive development. Few studies have described a long-term effect of diet on phonological perception.

Methods

To explore that effect, we compared the event-related potentials (ERPs) collected during an oddball paradigm (frequent /pa/80%, deviant/ba/20%) of infants fed with breast milk (BF), cow-milk-based formula (MF), and soy-based formula (SF), which were assessed at 3, 6, 9, 12, and 24 months of age [Mean across all age groups: 127 BF infants, Mean (M) 39.6 gestation weeks; 121 MF infants, M = 39.16 gestation weeks; 116 SF infants, M = 39.16 gestation weeks].

Results

Behavioral differences between dietary groups in acoustic comprehension were observed at 24-months of age. The BF group displayed greater scores than the MF and SF groups. In phonological discrimination task, the ERPs analyses showed that SF group had an electrophysiological pattern associated with difficulties in phonological-stimulus awareness [mismatch negativity (MMN)-2 latency in frontal left regions of interest (ROI) and longer MMN-2 latency in temporal right ROI] and less brain maturity than BF and MF groups. The SF group displayed more right-lateralized brain recruitment in phonological processing at 12-months old.

Discussion

We conclude that using soy-based formula in a prolonged and frequent manner might trigger a language development different from that observed in the BF or MF groups. The soy-based formula's composition might affect frontal left-brain area development, which is a nodal brain region in phonological-stimuli awareness.

Searching for a Relationship between Early Breastfeeding and Cognitive Development of Attention and Working Memory Capacity

Previous research consistently reported that subjects that were exclusively breastfed (eBF) vs. not-exclusively breastfed (neBF) during infancy (0-6 months) showed increased scores of general intelligence measures (e.g., the intelligence quotient). However, the existent literature largely neglected whether breastfeeding also affects specific cognitive processes, such as attention and working memory (WM) capacity. We tested whether eBF vs. neBF subjects showed performance differences in relation to these two core cognitive functions. The Attention Network Test (ANT), to measure alerting, orienting, and conflict, and the Change Colour Task (CCT), to measure visuospatial WM capacity, were administered to 144 participants divided according to age (6-, 10-, and 18-year-old participants) and breastfeeding (eBF or neBF during 0-6 months of life). Importantly, the sub-groups were homogenous in terms of maternal education, a factor potentially affecting the relation between breastfeeding and cognition. While we found increased performance as a function of participants' age in both tasks, we failed to observe effects related to breastfeeding, as evidenced by Bayesian analyses. These findings highlight for the first time that the pattern of nutrition provided during early infancy does not appear to affect the development of attention and WM capacity, at least starting from the age considered in the present study.

To what extent does confounding explain the association between breastfeeding duration and cognitive development up to age 14? Findings from the UK Millennium Cohort Study

Background

Breastfeeding duration is associated with improved cognitive development in children, but it is unclear whether this is a causal relationship or due to confounding. This study evaluates whether the observed association is explained by socioeconomic position (SEP) and maternal cognitive ability.

Methods

Data from 7,855 singletons born in 2000–2002 and followed up to age 14 years within the UK Millennium Cohort Study were analysed. Mothers reported breastfeeding duration, and children’s cognitive abilities were assessed at 5, 7, 11, and 14 years using validated measures. Standardised verbal (age 5 to 14) and spatial (age 5 to 11) cognitive scores were compared across breastfeeding duration groups using multivariable linear mixed-effects models (repeated outcome measures).

Results

At all ages, longer breastfeeding durations were associated with higher cognitive scores after accounting for the child’s own characteristics. Adjustment for SEP approximately halved the effect sizes. Further adjustment for maternal cognitive scores removed the remaining associations at age 5, but not at ages 7, 11 and 14 (e.g.: verbal scores, age 14; breastfed ≥12 months vs never breastfed: 0.26 SD; 95%CI: 0.18, 0.34).

Conclusion

The associations between breastfeeding duration and cognitive scores persist after adjusting for SEP and maternal cognitive ability, however the effect was modest.

Unexpected content of kynurenine in mother's milk and infant formulas

Mother's milk is widely recommended as complete food for the offspring in earliest postnatal time. However, the knowledge about detailed composition and the physiological role of bioactive components of breast milk is incomplete. Therefore, the aim of our study was to determine the content of kynurenine (KYN) in human breast milk during lactation and to explore the effects exerted by intragastric KYN administration from birth to weaning on physical and psychomotor development of adult rats. We found that KYN is consistently present in human milk and its content gradually increased from day 4 to 28 after delivery and that it is present in commercial baby formulas in amounts noticeably exceeding its physiological range. Animal studies showed that KYN supplementation resulted in a marked elevation of absorptive surface of rat intestine and in enhanced expression of both, aryl hydrocarbon receptor and G protein-coupled receptor 35 in the intestinal tissue in rats. Moreover, we discovered that KYN administration from birth to weaning resulted in neurobehavioral changes in adult rats. Therefore, we postulate that further research is required to thoroughly understand the function of KYN in early developmental stages of mammals and to ensure the safety of its presence in baby food products.

Effects of Soy-Based Infant Formula on Weight Gain and Neurodevelopment in an Autism Mouse Model

Mice fed soy-based diets exhibit increased weight gain compared to mice fed casein-based diets, and the effects are more pronounced in a model of fragile X syndrome (FXS; Fmr1KO). FXS is a neurodevelopmental disability characterized by intellectual impairment, seizures, autistic behavior, anxiety, and obesity. Here, we analyzed body weight as a function of mouse age, diet, and genotype to determine the effect of diet (soy, casein, and grain-based) on weight gain. We also assessed plasma protein biomarker expression and behavior in response to diet. Juvenile Fmr1KO mice fed a soy protein-based rodent chow throughout gestation and postnatal development exhibit increased weight gain compared to mice fed a casein-based purified ingredient diet or grain-based, low phytoestrogen chow. Adolescent and adult Fmr1KO mice fed a soy-based infant formula diet exhibited increased weight gain compared to reference diets. Increased body mass was due to increased lean mass. Wild-type male mice fed soy-based infant formula exhibited increased learning in a passive avoidance paradigm, and Fmr1KO male mice had a deficit in nest building. Thus, at the systems level, consumption of soy-based diets increases weight gain and affects behavior. At the molecular level, a soy-based infant formula diet was associated with altered expression of numerous plasma proteins, including the adipose hormone leptin and the β-amyloid degrading enzyme neprilysin. In conclusion, single-source, soy-based diets may contribute to the development of obesity and the exacerbation of neurological phenotypes in developmental disabilities, such as FXS.

Investigating changes of proteome in the bovine milk serum after retort processing using proteomics techniques

The objective of this study was to investigate the changes of the proteins in bovine milk serum after retort processing by label-free quantification proteomics techniques. A total of 96 and 106 proteins were quantified in control group (CG) and retort group (RG), respectively. Hierarchical clustering analysis of the identified milk serum proteins showed a decrease in the abundance of most proteins, such as serum albumin, lactoperoxidase, lactotransferrin, and complement C3, and an increase in the abundance of other proteins such as κ-casein, lipocalin 2, and Perilipin. Student's t-test showed 21 proteins significantly differential abundance between CG and RG (p < .05), of which intensity-based absolute quantification (iBAQ) of five proteins decreased and iBAQ of 16 proteins increased. Bioinformatics analysis demonstrated that retort processing increased the digestibility of proteins, but this improvement was offset by a decrease in the digestibility of proteins caused by protein modification. Our results provide insight into the proteome of retort sterilized milk for the first time. Given the extremely high security of retort sterilized milk, the proteome of bovine milk serum changes after retort sterilization exposed in this study will contribute to the formula design of retort sterilized milk products.

The prevalence and clinical relevance of hyperhomocysteinemia suggesting vitamin B12 deficiency in presumed healthy infants

BACKGROUND

Previous studies have demonstrated a high prevalence of biochemical vitamin B12 deficiency in infants in Norway. Increased total homocysteine (tHcy) is the most important marker of B12 deficiency in infants. There is a need to evaluate its clinical relevance.

AIMS

To investigate the prevalence of hyperhomocysteinemia (S-tHcy > 8 μmol/L) suggestive of suboptimal B12 status and the prevalence of clinically relevant hyperhomocysteinemia in presumed healthy infants in Norway. Further, to evaluate risk factors, presence of symptoms and psychomotor development in these children.

METHODS

In a prospective study we clinically examined 252 infants aged 3-7 months using standardized neurological and psychomotor tests prior to analyzing biochemical B12 deficiency markers in 250 infants.

RESULTS

Twenty-five of 250 (10%) infants had hyperhomocysteinemia combined with clinically relevant symptoms suggestive of B12 deficiency. Hyperhomocysteinemia was associated with tremor, excessive sleep, and sub-normal scores in the fine motor section of the Ages and Stages Questionnaire. One-hundred and fourteen of 250 (46%) infants had hyperhomocysteinemia. Multiple regression analysis showed months of infant formula use as the strongest negative predictor for hyperhomocysteinemia.

CONCLUSION

We have demonstrated associations between symptoms suggestive of infant B12 deficiency and increased levels of tHcy in presumed healthy infants The combination of hyperhomocysteinemia and associated relevant symptoms suggestive of B12 deficiency was a common finding, albeit most infants with hyperhomocysteinemia did not show symptoms.

Neurodevelopmental Outcomes in Infants Fed with Soy Formula: A Retrospective, National Population-Based Observational Cohort Study

BACKGROUND

Soy-based infant formulas are increasingly popular, but data regarding their effects on neurodevelopmental outcomes during early childhood is scanty.

OBJECTIVE

This study investigated the effect of consuming soy-based infant formula at 9-12 mo after birth on the subsequent development of epilepsy, neurodevelopmental disorders, and developmental status.

METHODS

This nationwide retrospective administrative study used health screening examinations and linked insurance claims data of children born in Korea during 2008 and 2009. Infants who received soy formula were compared with those who received cow's milk formula using propensity score matching that considered birth history, economic status, clinical conditions, and drug prescription records. Exposure was defined as soy formula feeding determined from questionnaires completed by the parents when children were 9-12 mo old. Outcomes were epilepsy, attention-deficit hyperactivity disorder (ADHD), autism spectrum disorder (ASD), and developmental status. Children were followed until 31 December, 2017.

RESULTS

A total of 153,841 eligible participants were enrolled; 11,535 (7.5%) children received soy formula, while 142,864 (92.5%) received cow's milk formula. The incidence rate of epilepsy during the follow-up period was 29.8 per 100,000 person-years (95% CI: 19.48, 41.65) in the soy formula group and 22.6 per 100,000 person-years (95% CI: 31.97, 59.07) in the cow's milk formula group, with no significant difference (aHR: 1.318; 95% CI: 0.825, 2.106). The 2 groups also had no difference based on prespecified analysis using different definitions of epilepsy. Likewise, no significant associations of soy formula with ADHD (aHR: 1.26; 95% CI: 1.00, 1.60) or ASD (aHR: 0.99; 95% CI: 0.54, 1.83), or delays of developmental stages were observed.

CONCLUSIONS

Feeding with soy formula rather than cow's milk formula had no apparent association with increased risks of epilepsy, ADHD, ASD, and developmental status, according to this cohort composed of a general pediatric population.

Early Environmental and Biological Influences on Preschool Motor Skills: Implications for Early Childhood Care and Education

Early motor skills underpin the more complex and specialized movements required for physical activity. Therefore, the design of interventions that enhance higher levels of early motor skills may encourage subsequent participation in physical activity. To do so, it is necessary to determine the influence of certain factors (some of which appear very early) on early motor skills. The objective of this study was to examine the influence of some very early environmental variables (delivery mode, feeding type during the first 4 months of life) and some biological variables (sex and age in months) on preschool motor skills, considered both globally and specifically. The sample was composed by 43 preschool students aged 5-6 years. The participant's parents completed an ad hoc questionnaire, reporting on delivery mode, feeding type, sex, and age in months. The children's motor skills were assessed using observational methodology in the school setting, while the children participated in their regular motor skills sessions. A Nomothetic/Punctual/Multidimensional observational design was used. Results revealed that certain preschool motor skills were specifically influenced by delivery mode, feeding type, sex, and age. Children born by vaginal delivery showed higher scores than children born via C-section in throwing (p = 0.000; d = 0.63); total control of objects (p = 0.004; d = 0.97); total gross motor skills (p = 0.005; d = 0.95); and total motor skills (p = 0.002; d = 1.04). Children who were exclusively breastfed outperformed those who were formula-fed in throwing (p = 0.016; d = 0.75); visual-motor integration (p = 0.005; d = 0.94); total control of objects (p = 0.002; d = 1.02); total gross motor skills (p = 0.023; d = 0.82); and total motor skills (p = 0.042; d = 0.74). Boys outperformed girls in throwing (p = 0.041; d = 0.74) and total control of objects (p = 0.024; d = 0.63); while the opposite occurred in static balance (p = 0.000; d = 1.2); visual-motor coordination (p = 0.020; d = 0.79); and total fine motor skills (p = 0.032; d = 0.72). Older children (aged 69-74 months) obtained higher scores than younger ones (aged 63-68 months) in dynamic balance (p = 0.030; d = 0.66); visual-motor integration (p = 0.034; d = 0.63); and total balance (p = 0.013; d = 0.75). Implications for early childhood care and education are discussed since this is a critical period for motor skill development and learning.

Effect of Food Endotoxin on Infant Health

Endotoxin is a complex molecule derived from the outer membrane of Gram-negative bacteria, and it has strong thermal stability. The processing of infant food can kill pathogenic bacteria but cannot remove endotoxin. Because the intestinal structure of infants is not fully developed, residual endotoxin poses a threat to their health by damaging the intestinal flora and inducing intestinal inflammation, obesity, and sepsis, among others. This paper discusses the sources and contents of endotoxin in infant food and methods for preventing endotoxin from harming infants. However, there is no clear evidence that endotoxin levels in infant food cause significant immune symptoms or even diseases in infants. However, in order to improve the safety level of infant food and reduce the endotoxin content, this issue should not be ignored. The purpose of this review is to provide a theoretical basis for manufacturers and consumers to understand the possible harm of endotoxin content in infant formula milk powder and to explore how to reduce its level in infant formula milk powder. Generally, producers should focus on cleaning the milk source, securing the cold chain, avoiding long-distance transportation, and shortening the storage time of raw milk to reduce the level of bacteria and endotoxin. After production and processing, the endotoxin content should be measured as an important index to test the quality of infant formula milk powder so as to provide high-quality infant products for the healthy growth of newborns.