Clinical practice: Breastfeeding and the prevention of allergy

Psychological factors affecting breastfeeding during the perinatal period in the UK: an observational longitudinal study

BACKGROUND

Identifying the behavioral determinants of breastfeeding is an important step toward increasing breastfeeding rates, but studies often adopt a limited measurement model. We aimed to identify, in a British population, which behavioral and psychological factors, assessed throughout the perinatal period, were most reliably associated with intent to breastfeed and breastfeeding at 1 and 6 months.

METHODS

This is an observational longitudinal study of a diverse (35.1% non-white) community sample of N = 222 pregnant women attending a maternity hospital in the UK. We assessed self-reported anxiety and depressive symptoms, stressful life events, and coping at 20-22, 28 and 36 weeks gestation and 1 and 6 months postnatally; intention to breastfeed was assessed at 20 weeks gestation. Breastfeeding was assessed at one and six months post-partum. We modelled the associations with logistic regressions, adjusting for socio-demographics.

RESULTS

Antenatal and post-partum depressive and anxiety symptoms were not reliably associated with breastfeeding behavior up to 6 months. In contrast, breastfeeding intention, which was not associated with affective symptoms, stress, and coping, was a reliable predictor of breastfeeding after adjusting for covariates. The association between intention to breastfeed and breastfeeding behavior was not moderated by behavioral/psychological factors (p > 0.5).

CONCLUSIONS

This study extends previous findings about the importance of intention to breastfeed to breastfeeding behaviour and suggests that suffering from affective symptoms does not inhibit breastfeeding. Antenatal intention to breastfeed can play a crucial role in shaping both maternal and child health outcomes.

Perinatal Risk Factors for Asthma and Allergic Rhinitis in Children and Adolescents

OBJECTIVES

In this study, we evaluated the associations between birth-related exposures, postnatal factors, and the risk of allergic rhinitis and asthma in children and adolescents.

METHODS

We performed a comprehensive search of five literature databases up to May 2023. To quantify the associations of birth-related exposures (birth weight, delivery mode, prematurity, sex, maternal age, and parental allergy history) and postnatal factors (birth order, number of siblings, breastfeeding exclusivity, and breastfeeding duration) with allergic disease, we calculated pooled odds ratios and 95% confidence intervals. We conducted subgroup analyses for allergic disease type, birth order, number of siblings, and parental allergy history. The methodological quality of the identified studies was evaluated using the Newcastle-Ottawa Scale.

RESULTS

This meta-analysis included 31 studies, encompassing 218,899 patients in total. The birth-related exposures of low birth weight, maternal age, and prematurity (less than 37 weeks gestation) were not significantly associated with the risk of asthma or allergic rhinitis during childhood or adolescence. Male sex, family history of allergy, and cesarean delivery were linked to an elevated risk of asthma or allergic rhinitis. Among postnatal factors, exclusive breastfeeding, breastfeeding for longer than 6 months, second or later birth order, and having siblings exhibited protective effects against allergic diseases in offspring.

CONCLUSION

The risks of allergic rhinitis and asthma were elevated in male patients, those delivered by cesarean section, and those with a family history of allergy. Conversely, exclusive breastfeeding, breastfeeding for longer than 6 months, and having siblings corresponded to a reduced risk of respiratory allergic diseases.

Directed acyclic graph for epidemiological studies in childhood food allergy: Construction, user's guide, and application

Understanding modifiable prenatal and early life causal determinants of food allergy is important for the prevention of the disease. Randomized clinical trials studying environmental and dietary determinants of food allergy may not always be feasible. Identifying risk/protective factors for early-life food allergy often relies on observational studies, which may be affected by confounding bias. The directed acyclic graph (DAG) is a causal diagram useful to guide causal inference from observational epidemiological research. To date, research on food allergy has made little use of this promising method. We performed a literature review of existing evidence with a systematic search, synthesized 32 known risk/protective factors, and constructed a comprehensive DAG for early-life food allergy development. We present an easy-to-use online tool for researchers to re-construct, amend, and modify the DAG along with a user's guide to minimize confounding bias. We estimated that adjustment strategies in 57% of previous observational studies on modifiable factors of childhood food allergy could be improved if the researchers determined their adjustment sets by DAG. Future researchers who are interested in the causal inference of food allergy development in early life can apply the DAG to identify covariates that should and should not be controlled in observational studies.

Less than one-fifth of the mothers practised exclusive breastfeeding in the emerging regions of Ethiopia: a multilevel analysis of the 2016 Ethiopian demographic and health survey

BACKGROUND

The burden of low coverage of exclusive breastfeeding (EBF) has a significant impact on the health of a newborn and also on the family and social economy in the long term. Even though the prevalence of EBF practices in Ethiopia is low, the practices in the pastoral communities, in particular, are significantly low and affected by individual and community-level factors. Besides, its adverse outcomes are mostly unrecognised. Therefore, this study aimed to assess the individual and community-level factors of low coverage of EBF practices in the emerging regions of Ethiopia.

METHODS

In this analysis, data from 2016 Ethiopian Demographic and Health Survey (EDHS) were used. A two-stage stratified sampling technique was used to identify 1406 children aged 0 to 23 months in the emerging regions of Ethiopia. A multilevel mixed-effect binary logistic regression analysis was used to determine the individual and community level factors associated with exclusive breastfeeding practices. In the final model, variables with a p-value of < 0.05 and Adjusted Odds Ratio (AOR) with 95% Confidence Interval (CI) were found to be statistically significant factors that affect exclusive breastfeeding practices.

RESULTS

Overall, 17.6% (95% CI: 15.6-19.6) of the children aged 0 to 23 months have received exclusive breastfeeding. Employed mothers (AOR: 0.33, 95% CI: 0.21-0.53), richer household wealth status (AOR: 0.39, 95% CI: 0.16-0.96), mothers undecided to have more children (AOR: 2.29, 95% CI: 1.21-4.29), a child with a history of diarrhoea (AOR: 0.31, 95% CI: 0.16-0.61) were the individual-level factors, whereas Benishangul region (AOR: 2.63, 95% CI: 1.44-4.82) was the community-level factors associated with the exclusive breastfeeding practices.

CONCLUSIONS

Less than one-fifth of the mothers have practised exclusive breastfeeding in the emerging regions of Ethiopia. The individual-level factors such as mother's employment status, household wealth status, desire for more children, presence of diarrhoea and community-level factors such as region have contributed to the low coverage of exclusive breastfeeding. Therefore, the federal and regional health bureaus and other implementers should emphasise to those emerging regions by creating awareness and strengthening the existing community-based health extension program to enhance exclusive breastfeeding practices.

Exclusive breastfeeding for the first 3 months of life may reduce the risk of respiratory allergies and some asthma in children at the age of 6 years

AIM

We examined the associations between breastfeeding and respiratory allergies and types of asthma in American children.

METHODS

This longitudinal study used data from mother-infant pairs who took part in the Infant Feeding Practices Study II in 2005-2007 and the Year 6 Follow-Up Study in 2012. The mothers reported breastfeeding practices on a monthly basis for the first year of life, childhood asthma and allergies at age 6 years, and associated factors. Generalised linear models were used in statistical analyses.

RESULTS

Overall, 1177 mother-infant pairs were included in the sample. A third (32.9%) of the children were exclusively breastfed until the age of 3 months and by the age of 6 years 20.8% had been diagnosed with respiratory allergies and 11.3% with asthma. In the multivariable analyses, exclusive breastfeeding for 3 months was associated with a reduced relative risk of respiratory allergies of 0.77 at the age of 6 years. It also reduced the relative risk of asthma to 0.66, but only if the children did not have a family history of asthma.

CONCLUSION

This longitudinal study provided evidence that exclusive breastfeeding for the first 3 months may reduce the risk of respiratory allergies and asthma in children 6 years of age, but concerning asthma, statistical significance was reached only in children without a family predisposition to asthma.

Diet and asthma in Lebanese schoolchildren: A cross-sectional study

OBJECTIVES

The causes of the global increase in asthma in children are unknown. It has been hypothesized that diet is an important factor that may play a role in the pathogenesis of the disease. The objective was to evaluate the association between diet and current asthma among Lebanese children.

METHODS

A cross-sectional study was conducted on 1000 children recruited from public and private schools in Lebanon. Of the total enrolled participants, 107 children were diagnosed with current asthma and were analyzed. The food frequency questionnaire was used to assess participants' dietary habits.

RESULTS

The consumption of sweets ≥3 times weekly (ORa = 5.42), white bread ≥3 times weekly (ORa = 26.38), and olive oil daily (ORa = 9.80) were associated with higher odds of current asthma. Drinking carbonated beverages occasionally (ORa = 0.25) and ≥3 times per week (ORa = 0.03) was significantly associated with lower odds of current asthma. Adhering to Mediterranean diet (occasional, >3 times weekly and daily) was significantly associated with lower odds of current asthma compared to never consuming Mediterranean diet (ORa = 0.23 and ORa = 0.22, respectively). The occasional consumption of bread was significantly associated with higher odds of current asthma (ORa = 8.2), whereas daily consumption was significantly associated with lower odds (ORa = 0.336). Moreover, the occasional, ≥3 times weekly and daily consumption of meat were significantly associated with higher odds of current asthma (ORa = 9.6; ORa = 5.1 and ORa = 4.5), respectively. An occasional consumption of junk food was significantly associated with lower odds of current asthma (ORa = 0.044), whereas a daily consumption was associated with higher odds.

CONCLUSION

Adhering to certain diets might be associated with higher odds of current asthma.

Economic value of using partially hydrolysed infant formula for risk reduction of atopic dermatitis in high-risk, not exclusively breastfed infants in Singapore

INTRODUCTION

Previous trials have demonstrated reductions in atopic dermatitis (AD) incidence when healthy, high-risk, non-exclusively breastfed infants were fed until four months of age with 100% whey-based partially hydrolysed formula (PHF-W) versus standard cow's milk formula (CMF). We assessed the cost-effectiveness of this intervention in Singapore.

METHODS

Modelling techniques were used to simulate, from birth to Month 30, the incidence and clinical/economic burden of AD in high-risk, non-exclusively breastfed infants fed with PHF-W or CMF for up to four months. Epidemiologic and clinical data were from a local comparative trial. Expert opinion informed AD treatment patterns and outcomes. Outcomes included reduction in AD risk, time spent with AD, days without AD flare, quality-adjusted life years (QALYs) and direct/indirect costs. Multivariate probabilistic sensitivity analysis was used to assess model parameter uncertainty.

RESULTS

Over 30 months, with the use of PHF-W instead of CMF, the proportion of children who developed AD and the time spent with AD decreased by 16.0% (28.3% vs. 44.3%) and 6.4 months, respectively, while time without AD flare and QALYs increased by 14.9 days and 0.021 QALYs per patient, respectively. Estimated AD-related discounted costs per child for PHF-W and CMF were SGD 771 and SGD 1,309, respectively (net savings: SGD 538). PHF-W was less expensive and more effective than CMF for 73%, and cost less than SGD 50,000 per QALY for 87% of all multivariate simulations.

CONCLUSION

Early short-term nutritional intervention with PHF-W instead of CMF may reduce AD incidence and costs for healthy, high-risk, non-exclusively breastfed infants in Singapore.

Maternal smoking in pregnancy and its influence on childhood asthma

Maternal smoking in pregnancy (MSP) is a large modifiable risk factor for pregnancy related mortality and morbidity and also the most important known modifiable risk factor for asthma. This review summarises the effects of MSP throughout infancy, childhood and adolescence with regards to asthma (development and severity). Firstly, the direct damage caused by nicotine on fetal lung development, fetal growth and neuronal differentiation is discussed, as well as the indirect effects of nicotine on placental functioning. Secondly, the effects of MSP on later immune functioning resulting in increased infection rate are summarised and details are given on the effects of MSP modulating airway hyperreactivity, reducing lung function and therefore increasing asthma morbidity. Furthermore, epigenetic effects are increasingly being recognised. These can also result in transgenerational detrimental effects induced by cigarette smoke. In summary, the causal relationship between MSP and asthma development is well documented and presents a major health problem for generations to come. The high prevalence of MSP is alarming and epigenetic effects of nicotine on immune functioning potentiate this danger. A considerable part of the increase in asthma prevalence worldwide is due to MSP.

Factors affecting breast milk composition and potential consequences for development of the allergic phenotype

There is conflicting evidence on the protective role of breastfeeding in relation to allergic sensitization and disease. The factors in breast milk which influence these processes are still unclear and under investigation. We know that colostrum and breast milk contain a variety of molecules which can influence immune responses in the gut-associated lymphoid tissue of a neonate. This review summarizes the evidence that variations in colostrum and breast milk composition can influence allergic outcomes in the infant, and the evidence that maternal and environmental factors can modify milk composition. Taken together, the data presented support the possibility that maternal dietary interventions may be an effective way to promote infant health through modification of breast milk composition.

Is the Relationship Between Breastfeeding and Childhood Risk of Asthma and Obesity Mediated by Infant Antibiotic Treatment?

BACKGROUND

Studies of the protective effect of breastfeeding on asthma have not brought unequivocal results, and thus this issue remains controversial. Antibiotic use, known to increase asthma risk, may be involved in this relationship. The objective of this study was to assess the influence of breastfeeding duration on obesity and asthma risk in childhood and to test a mediating role of antibiotic use in infancy.

SUBJECTS AND METHODS

A cross-sectional anthropometric and questionnaire study was conducted on 1,277 schoolchildren 8 years of age. Data on weight status, asthma, breastfeeding duration, antibiotic administration in infancy, socioeconomic status, and lifestyle were analyzed. Multivariate standard and logistic regression and mediation analyses, controlling for confounders, were applied.

RESULTS

Total duration of breastfeeding was negatively related to the child's body mass index (p=0.038), fat percentage (p=0.030), and obesity risk (p=0.032). Dropping the variable of antibiotic use from the model made the breastfeeding duration a significant predictor of low asthma risk (p=0.027). Antibiotic treatment mediated the relationship between breastfeeding duration and asthma risk (Sobel's z=-2.61, p=0.009).

CONCLUSIONS

Our findings support protective effects of longer duration of breastfeeding against obesity and asthma. We propose a new mechanism for a relationship between breastfeeding and asthma: shorter breastfeeding compromises infant health and thereby leads to antibiotic treatment, which in turn increases the risk of asthma.

Breastfeeding duration and asthma in Puerto Rican children

RATIONALE

Little is known about breastfeeding and asthma in Puerto Ricans, the ethnic group most affected by this disease in the US. We examined the relation between the currently recommended duration of breastfeeding and asthma in school-aged Puerto Rican children.

METHODS

Case-control study of 1,127 Puerto Rican children aged 6-14 years living in Hartford, Connecticut (n = 449) and San Juan, Puerto Rico (n = 678). Parental recall of breastfeeding was categorized based on duration and according to current guidelines (i.e., none, 0-6 months, and >6 months). Asthma was defined as parental report of physician-diagnosed asthma and wheeze in the previous year. We used logistic regression for the multivariate analysis, which was conducted separately for each study site and for the combined cohort. All multivariate models were adjusted for age, gender, household income, atopy, maternal asthma, body mass index, early-life exposure to environmental tobacco smoke, and (for the combined cohort) study site.

RESULTS

After adjustment for covariates, children who were breastfed for up to 6 months had 30% lower odds of asthma (95% CI = 0.5-1.0, P = 0.04) than those who were not breastfed. In this analysis, breastfeeding for longer than 6 months was not significantly associated with asthma (OR = 1.5, 95% CI = 1.0-2.4, P = 0.06).

CONCLUSIONS

Our results suggest that breastfeeding for up to 6 months (as assessed by parental recall) is associated with decreased odds of asthma in Puerto Rican children, and that there is no additional beneficial effect of breastfeeding for over 6 months. These results support current recommendations on the duration of breastfeeding in an ethnic group at risk for asthma.

Pre- and postnatal risk factors in relation to allergic rhinitis in school-aged children in China

Objective

The objective of this study was to investigate the relationship between prenatal and postnatal risk factors and the prevalence of allergic rhinitis (AR) in Chinese children of specific ages.

Study Design

This study was a cross-sectional survey. Students from 8 metropolitan cities in China were studied in November and December, 2005. There were 20,803 elementary-school Chinese children (49.6% boys, mean age, 9.19 years) enrolled. Questions from the standard questionnaire of the International Study of Asthma and Allergies in Children were completed to enable us to examine the pattern of current AR. The potential confounders and pre-and postnatal risk factors were analyzed using logistic regression.

Results

The overall prevalence of AR was found in this study to be 9.8%. After adjusting for several likely confounders, there was a higher likelihood of AR in school-aged children who were not exclusively breastfed in the first 4 months of their lives (odds ratio [OR]: 1.28; 95% confidence interval [CI]: 1.16–1.41), children who were born post-term (OR: 1.34; 95% CI: 1.12–1.60), children delivered by cesarean section (OR: 1.07; 95% CI: 1.00–1.19), or children born to mothers who experienced depressive symptoms during the pre- and postnatal periods (OR: 1.28; 95% CI: 1.15–1.42).

Conclusions

AR in school-aged children was found to be associated with pre- and postnatal events. These findings indicate that strategies to reduce exposure to risk factors during pre- and postnatal periods for childhood allergies might be warranted.

Breastfeeding and introduction of complementary foods during infancy in relation to the risk of asthma and atopic diseases up to 10 years

BACKGROUND

It has been hypothesized that changes in diet during early life may have contributed to the increase in childhood asthma and atopy. The long-term effect of the timing and content of infant feeding on the incidence of asthma and atopic diseases in children is unclear.

OBJECTIVE

To investigate the associations between duration of breastfeeding and the timing of introduction of complementary foods during the first 6 months and parental-reported asthma, wheeze and atopic eczema up to 10 years of age.

METHODS

Infant feeding practices (breastfeeding and introduction of complementary foods) of 1924 singleton children participating in the Study of Eczema and Asthma To Observe the influence of Nutrition (SEATON) birth cohort were prospectively collected up to 6 months with outcomes (wheeze, atopic eczema and asthma) being assessed at 1, 2, 5 and 10 years. Data were analysed using generalized estimating equations and discrete hazards models with adjustment for confounders.

RESULTS

By 6 months, 59% and 35% of mothers had stopped exclusive and total breastfeeding, respectively. Although formula feeding was adversely associated with wheeze in the past 12 months (adjusted OR for no formula feeding: 070, 95% CI 0.50-0.97), and the introduction of biscuits/bread after 5 months of age adversely associated with atopic eczema (adjusted OR 1.34, 95% CI 1.06-1.69), these results lost their statistical significance after adjustment for multiple testing. Stratification of the results by the presence of eczema by 6 months of age and family atopic history did not substantially differ from the results of the whole study population.

CONCLUSION AND CLINICAL RELEVANCE

Our results suggest that the nature of infant feeding during the first 6 months seems not to substantially influence the long-term risk of asthma and atopic diseases in children, nor in children at high risk of atopic disease because of a family history of atopic disease.

Diet and allergic diseases among population aged 0 to 18 years: myth or reality?

Allergic diseases are an important health problem. However, epidemiological studies concerning childhood diet-related allergic diseases are scarce. This review examines published articles dealing with diet, dietary patterns and nutrition in relation with allergic diseases among population aged 0 to 18 years. Studies and trials were identified using MEDLINE/PubMed and Cochrane Database of Systematic Reviews and were limited to those published in English or French from 1992 until 2012. This manuscript also reviews the evidence for maternal diet during pregnancy and diet during early childhood and their association with childhood atopic diseases, taking into account the methodology used to evaluate dietary patterns. The evidence reviewed is derived from large epidemiological studies exploring the effects of different food categories on asthma, atopic dermatitis, and allergic rhinitis in children. Overall, maternal diet during pregnancy and a childhood diet rich in antioxidants and omega-3 fatty acids are considered as healthy diets that could be protective for allergic diseases in childhood.

Effect of non-human neutral and acidic oligosaccharides on allergic and infectious diseases in preterm infants

Short-term supplementation of non-human neutral and acidic oligosaccharides during the first postnatal weeks may enhance the maturation of the immune response in preterm infants and may lead to less allergic and infectious diseases during the first year of life. In a randomized controlled trial, 113 preterm infants (gestational age <32 weeks and/or birth weight <1500 g) were allocated to receive enteral neutral and acidic oligosaccharide supplementation or placebo between days 3 and 30 of life. The median age at follow-up was not different in both groups: 12 months corrected age (interquartile range [IQR], 11-15) in the prebiotic mixture group and 12 months corrected age in the placebo group (IQR, 10-19), respectively. In addition, baseline patient, maternal, and environmental characteristics were not different between the prebiotic mixture (n = 48) and placebo (n = 46) group. Incidence of allergic and infectious diseases was assessed by validated questionnaires. In total, 94/98 (96 %) of the eligible, surviving infants participated in this follow-up study. The incidence of atopic dermatitis (odds ratio [OR], 0.80; 95 % confidence interval [CI], 0.24-2.67), bronchial hyper-reactivity (OR, 1.04; 95 % CI, 0.38-2.87) and infections of the upper respiratory (OR, 0.95; 95 % CI, 0.37-2.44), lower respiratory (OR, 1.03; 95 % CI, 0.37-2.88), and gastrointestinal (OR, 1.77; 95 % CI, 0.55-5.73) tract was not different between the groups. Adjustment for potential confounding factors did not change the results of the primary analysis.

CONCLUSION

Short-term enteral supplementation of non-human neutral and acidic oligosaccharides during the neonatal period in preterm infants does not decrease the incidence of allergic and infectious diseases during the first year of life.