Long-term behavioural consequences of infant feeding: the limits of observational studies

Mechanisms of Maternal Diet-Induced Obesity Affecting the Offspring Brain and Development of Affective Disorders

Depression and metabolic disease are common disorders that share a bidirectional relationship and continue to increase in prevalence. Maternal diet and maternal behaviour both profoundly influence the developmental trajectory of offspring during the perinatal period. At an epidemiological level, both maternal depression and obesity during pregnancy have been shown to increase the risk of neuropsychiatric disease in the subsequent generation. Considerable progress has been made to understand the mechanisms by which maternal obesity disrupts the developing offspring gut-brain axis, priming offspring for the development of affective disorders. This review outlines such mechanisms in detail, including altered maternal care, the maternal microbiome, inflammation, breast milk composition, and maternal and placental metabolites. Subsequently, offspring may be prone to developing gut-brain interaction disorders with concomitant changes to brain energy metabolism, neurotransmission, and behaviour, alongside gut dysbiosis. The gut microbiome may act as a key modifiable, and therefore treatable, feature of the relationship between maternal obesity and the offspring brain function. Further studies examining the relationship between maternal nutrition, the maternal microbiome and metabolites, and offspring neurodevelopment are warranted to identify novel therapeutic targets.

Association between duration of breastfeeding based on maternal reports and dorsal and ventral striatum and medial orbital gyrus volumes in early adolescence

Maternal breastfeeding has an impact on motor and emotional development in children of the next generation. Elucidating how breastfeeding during infancy affects brain regional structural development in early adolescence will be helpful for promoting healthy development. However, previous studies that have shown relationships between breastfeeding during infancy and cortical brain regions in adolescence are usually based on maternal retrospective recall of breastfeeding, and the accuracy of the data is unclear. In this study, we investigated the association between breastfeeding duration and brain regional volume in a population-neuroimaging study of early adolescents in Japan (N ​= ​207; 10.5-13.4 years) using voxel-based morphometry, which enabled us to analyze the whole brain. We evaluated breastfeeding duration as indexed by maternal and child health handbook records during infancy. The results showed a significant positive correlation between the duration of breastfeeding and gray matter volume in the dorsal and ventral striatum and the medial orbital gyrus. Post hoc exploratory analyses revealed that the duration of breastfeeding was significantly correlated with emotional behavior. Additionally, the volume in the medial orbital gyrus mediated an association between breastfeeding duration and emotional behavior. This is the first study to evaluate the effect of breastfeeding during infancy on regional brain volumes in early adolescence based on maternal and child health handbook records. Our findings shed light upon the importance of maternal breastfeeding for brain development related to emotional and motivational processing in early adolescence.

Nutritional and immunological factors in breast milk: A role in the intergenerational transmission from maternal psychopathology to child development

Perinatal psychopathologies affect more than 25% of women during and after their gestational period. These psychiatric disorders can potentially determine important biological variations in their organisms, affecting many different physiological and metabolic pathways. Of relevance, any of these changes occurring in the mother can alter the normal composition of breast milk, particularly the concentration of nutritional and inflammatory components, which play a role in child brain functioning and development. Indeed, there is evidence showing that changes in milk composition can contribute to cognitive impairments and alterations in mental abilities in children. This review aims to shed light on the unique intergenerational role played by breast milk composition, from maternal psychopathologies to child development.

Breastfeeding and offspring's compassion and empathy in adulthood: A study with an over 30-year follow-up

This study investigated whether breastfeeding predicts offspring's dispositional compassion and empathy from early adulthood to middle age. The parents of the participants (N = 1,394) of the Young Finns study answered questions about breastfeeding in 1983, and the participants' compassion and empathy were evaluated in 1997-2012 (participants were aged 20-50 years). Breastfeeding did not predict the course of compassion or empathy in adulthood at the age of 20-50 years. The associations remained non-significant, when adjusted for age, gender, socioeconomic factors, and a wide range of characteristics of the family environment (including mother's gestational age; premature birth; birth weight; number of other children at home; parental mental disorder; parental relationship status; parental postnatal smoking; parental postnatal alcohol use; parenting behavior; and child's externalizing behavior). In conclusion, breastfeeding seems not to predict offspring's compassion or empathy in adulthood. The findings may present a hopeful perspective for children growing up with non-breastfeeding caregivers.

Breastfeeding and the Development of Socio-Emotional Competencies: A Systematic Review

Aim: To assess the current scientific evidence about the relationship between breastfeeding and the development of infant's socio-emotional competencies. Materials and Methods: A systematic review of literature was conducted through PubMed, LILACS (Literatura Latinoamericana y del Caribe en Ciencias de la Salud), and PsycINFO of population-based cohorts. Records were screened, data extracted, and a quality assessment performed by two authors independently. Results: Thirteen studies were included in the review with six finding a statistically significant association between breastfeeding and the development of socio-emotional competencies such as problem solving, agreeableness, and optimism. In five studies, no statistically significant association was found, and in three, a negative association existed. Regarding quality assessment, four studies had a strong global rating, four had a moderate rating, and five had a weak global rating. Conclusion: Almost half (6/13) of the studies found a positive association between breastfeeding and the development of social-emotional competencies in infants; however, a great heterogeneity was present in the quality of the included studies. There is a need for further and higher quality research into this field of study.

Breastfeeding and externalising problems: a quasi-experimental design with a national cohort

Evidence from correlational studies supporting the benefits of breastfeeding on children's externalising problems is mixed. Quasi-experimental approaches can help in better understanding possible 'effects'. We aimed to investigate the longitudinal impact of breastfeeding on externalising problems from childhood into adolescence. Participants included ~ 5000 full-term children, from the Growing Up in Ireland Child Cohort. Externalising problems (conduct problems and hyperactivity) were assessed using both the parent and teacher versions of the Strengths and Difficulties Questionnaire when children were age 9 and 13. Maternal reports were used to collect retrospective information on breastfeeding. Propensity score matching, and adjusting for multiple testing were used to compare the average treatment effects for children who were breastfed. Post matching results revealed statistically significant reductions in hyperactivity at age nine, using both maternal and teacher reports (difference score - 0.48, 95% CI - 0.85, - 0.11; and - 0.51, 95% CI - 0.90, - 0.12, respectively), for children who were breastfed between 6 and 12 months, but not thereafter. These effects were not maintained at age 13. Moreover, no effects of breastfeeding on conduct problems were found at any age, regardless of duration, using either maternal or teacher report. While some benefits of breastfeeding were found, compatible with a temporary modest reduction in hyperactivity, related to being breastfed for 26-50 weeks, these results must be viewed in the context of reliance of propensity score matching on observable characteristics. Additionally, our results are suggestive of a potential non-linear dose-response of breastfeeding on hyperactivity.

Breastfeeding and mental health in adulthood: A birth cohort study in Brazil

BACKGROUND

Breastfeeding is negatively associate with behavioral and internalization problems, psychological stress, and depressive/anxiety symptoms. However, studies evaluating specific mental health disorders are scarce. We aimed to assess the association between breastfeeding and mental health outcomes in young adults.

METHODS

In 1982, hospital deliveries in Pelotas (Southern Brazil) were identified; liveborns were examined and their mothers interviewed (n=5914). Information on breastfeeding was collected in early childhood. In 2012-13, at 30 years of age, we used the Mini International Neuropsychiatric Interview (MINI) for the diagnosis of major depression (MD), generalized anxiety disorder (GAD) and social anxiety disorder (SAD). In addition, we used the Beck Depression Inventory (BDI-II) and the Self-reported Questionnaire (SRQ-20), to evaluate depressive symptoms severity and common mental disorders (CMD), respectively. We used multivariable regression models to evaluate the association between breastfeeding and mental health outcomes.

RESULTS

We evaluated 3657 individuals. Prevalence of CMD, MD, GAD and SAD was 24.3%, 7.9%, 12.7% and 3.6%, respectively. In multivariable models the odds of having a more severe case of depression (BDI-II) was smaller among those breastfed for 6 or more months (OR=0.69 95%CI [0.53-0.89]). We observed a similar pattern for MD and CMD, however, confidence intervals included the reference.

LIMITATIONS

We had no information on home environment characteristics during childhood. Lack of power and a small effect size could explain why we did not detect an association between breastfeeding and MD.

CONCLUSION

Breastfeeding reduced the odds of having more severe depressive symptoms.

The Association Between Breastfeeding Duration and Attachment: A Genetically Informed Analysis

INTRODUCTION

A growing body of research explores whether breastfeeding during infancy influences the development of attachment security in offspring. Studies to date have generally yielded inconsistent results, with some studies detecting an association between breastfeeding and attachment security, and others failing to do so. The purpose of this study is to empirically consider whether (1) any association between breastfeeding and offspring attachment security is robust to both familial and genetic confounding and (2) whether the breastfeeding-attachment relationship is significant for both male and female offspring.

MATERIALS AND METHODS

The present study uses data from the Early Childhood Longitudinal Study: Birth Cohort (ECLS-B) to examine whether twins who differ in their extent of exposure to breastfeeding exhibit different attachment patterns by the time they reach toddlerhood.

RESULTS

The results suggest that, independent of genetic and shared environmental influences, breastfeeding duration increases the security of attachment in offspring, but only among females.

CONCLUSIONS

A longer duration of breastfeeding may help to facilitate a secure attachment among female offspring.

Weighing the Evidence of Common Beliefs in Obesity Research

Obesity is a topic on which many views are strongly held in the absence of scientific evidence to support those views, and some views are strongly held despite evidence to contradict those views. We refer to the former as "presumptions" and the latter as "myths." Here, we present nine myths and 10 presumptions surrounding the effects of rapid weight loss; setting realistic goals in weight loss therapy; stage of change or readiness to lose weight; physical education classes; breastfeeding; daily self-weighing; genetic contribution to obesity; the "Freshman 15"; food deserts; regularly eating (versus skipping) breakfast; eating close to bedtime; eating more fruits and vegetables; weight cycling (i.e., yo-yo dieting); snacking; built environment; reducing screen time in childhood obesity; portion size; participation in family mealtime; and drinking water as a means of weight loss. For each of these, we describe the belief and present evidence that the belief is widely held or stated, reasons to support the conjecture that the belief might be true, evidence to directly support or refute the belief, and findings from randomized controlled trials, if available. We conclude with a discussion of the implications of these determinations, conjecture on why so many myths and presumptions exist, and suggestions for limiting the spread of these and other unsubstantiated beliefs about the obesity domain.

Breastfeeding and later psychosocial development of children at 6 years of age

OBJECTIVE

To examine the association of breastfeeding duration with psychosocial development at 6 years of age.

METHODS

We analyzed data from the 2005-2007 Infant Feeding Practices Study II and its 2012 Year 6 Follow-Up (N = 1442). Our breastfeeding duration variable combined overall and exclusive breastfeeding reported during infancy (never breastfed, breastfed <6 months, breastfed ≥6 months + exclusive breastfeeding <3 months, and breastfed ≥6 months + exclusive breastfeeding ≥3 months). Maternal responses to the Strengths and Difficulties Questionnaire were used to create our child psychosocial outcome domains (emotional symptoms, conduct problems, hyperactivity, peer problems, prosocial behavior, and total difficulties). Separate multivariable logistic regression models controlling for maternal sociodemographic characteristics, maternal mental health, and child characteristics were used to assess the likelihood of having difficulties on the 6 domains based on breastfeeding duration.

RESULTS

Compared with children who were never breastfed, those who were breastfed for ≥6 months and exclusively breastfed for ≥3 months had decreased odds of difficulties with emotional symptoms (odds ratio [OR]: 0.52; 95% confidence interval [CI]: 0.27-0.99), conduct problems (OR: 0.24; 95% CI: 0.10-0.54), and total difficulties (OR: 0.39; 95% CI: 0.18-0.85) before adjustment. These associations were no longer significant after adjustment.

CONCLUSIONS

Although in our unadjusted analyses we observed significant associations between breastfeeding duration and later psychosocial development, including decreased odds of emotional, conduct, and total difficulties at 6 years of age, these findings were no longer detectable after adjusting for the many potential confounding factors that play a role in psychosocial development.

Breastfeeding and behavioral development: a nationwide longitudinal survey in Japan

OBJECTIVE

To prospectively examine the prolonged effect of breastfeeding on behavioral development.

STUDY DESIGN

We used a large, nationwide Japanese population-based longitudinal survey that began in 2001. We restricted participants to term singletons with birth weight >2500 g (n = 41 188). Infant feeding practice was queried at age 6-7 months. Responses to survey questions about age-appropriate behaviors at age 2.5 and 5.5 years were used as indicators of behavioral development. We conducted logistic regression analyses, controlling for potential child and parental confounding factors, with formula feeding as the reference group.

RESULTS

We observed a dose-response relationship between breastfeeding status and an inability to perform age-appropriate behaviors at both ages. With a single exception, all ORs for outcomes for exclusive breastfeeding were smaller than those for partial feeding of various durations. The protective associations did not change after adjustment for an extensive list of confounders or in the sensitivity analyses.

CONCLUSION

We observed prolonged protective effects of breastfeeding on developmental behavior skills surveyed at age 2.5 and 5.5 years. Beneficial effects were most likely in children who were breastfed exclusively, but whether a biological ingredient in breast milk or extensive interactions through breastfeeding, or both, is beneficial is unclear.

Effect of early limited formula on duration and exclusivity of breastfeeding in at-risk infants: an RCT

BACKGROUND AND OBJECTIVES

Recent public health efforts focus on reducing formula use for breastfed infants during the birth hospitalization. No previous randomized trials report the effects of brief early formula use. The objective of the study was to determine if small formula volumes before the onset of mature milk production might reduce formula use at 1 week and improve breastfeeding at 3 months for newborns at risk for breastfeeding problems.

METHODS

We randomly assigned 40 exclusively breastfeeding term infants, 24 to 48 hours old, who had lost ≥5% birth weight to early limited formula (ELF) intervention (10 mL formula by syringe after each breastfeeding and discontinued when mature milk production began) or control (continued exclusive breastfeeding). Our outcomes were breastfeeding and formula use at 1 week and 1, 2, and 3 months.

RESULTS

Among infants randomly assigned to ELF during the birth hospitalization, 2 (10%) of 20 used formula at 1 week of age, compared with 9 (47%) of 19 control infants assigned during the birth hospitalization to continue exclusive breastfeeding (P = .01). At 3 months, 15 (79%) of 19 infants assigned to ELF during the birth hospitalization were breastfeeding exclusively, compared with 8 (42%) of 19 controls (P = .02).

CONCLUSIONS

Early limited formula may reduce longer-term formula use at 1 week and increase breastfeeding at 3 months for some infants. ELF may be a successful temporary coping strategy for mothers to support breastfeeding newborns with early weight loss. ELF has the potential for increasing rates of longer-term breastfeeding without supplementation based on findings from this RCT.

Cohort profile: The promotion of breastfeeding intervention trial (PROBIT)

The PROmotion of Breastfeeding Intervention Trial (PROBIT) is a multicentre, cluster-randomized controlled trial conducted in the Republic of Belarus, in which the experimental intervention was the promotion of increased breastfeeding duration and exclusivity, modelled on the Baby-friendly hospital initiative. Between June 1996 and December 1997, 17,046 mother-infant pairs were recruited during their postpartum hospital stay from 31 maternity hospitals, of which 16 hospitals and their affiliated polyclinics had been randomly assigned to the arm of PROBIT investigating the promotion of breastfeeding and 15 had been assigned to the control arm, in which breastfeeding practices and policies in effect at the time of randomization was continued. Of the mother-infant pairs originally recruited for the study, 16,492 (96.7%) were followed at regular intervals until the infants were 12 months of age (PROBIT I) for the outcomes of breastfeeding duration and exclusivity; gastrointestinal and respiratory infections; and atopic eczema. Subsequently, 13,889 (81.5%) of the children from these mother-infant pairs were followed-up at age 6.5 years (PROBIT II) for anthropometry, blood pressure (BP), behaviour, dental health, cognitive function, asthma and atopy outcomes, and 13,879 (81.4%) children were followed to the age of 11.5 years (PROBIT III) for anthropometry, body composition, BP, and the measurement of fasted glucose, insulin, adiponectin, insulin-like growth factor-I, and apolipoproteins. The trial registration number for Current Controlled Trials is ISRCTN37687716 and that for ClinicalTrials.gov is NCT01561612. Proposals for collaboration are welcome, and enquires about PROBIT should be made to an executive group of the study steering committee (M.S.K., R.M.M., and E.O.). More information, including information about how to access the trial data, data collection documents, and bibliography, is available at the trial website (http://www.bristol.ac.uk/social-community-medicine/projects/probit/).