Infant milk-feeding practices and childhood leukemia: a systematic review

Breastfeeding Duration Reduces the Risk of Childhood Leukemia and Modifies the Risk of Developing Functional Gastrointestinal Disorders

Objective: The aim of this study was to test the hypothesis that the duration of breastfeeding in infancy reduces the risk of childhood leukemia or lymphoma, and modifies the risk of developing functional gastrointestinal disorders (FGIDs). Subjects and Methods: This case-control study involved the recruitment of children with lymphoid malignancy and functional gastrointestinal symptoms with healthy children as controls. Focused questionnaires were used to collect data on breastfeeding history and other key risk factors. Univariate and multivariate analyses were undertaken. Results: Of the 334 children with lymphoid malignancy, 65% were male. The control group included 334 age- and sex-matched participants. Most (n = 189; 56.6%) of the children with leukemia were <10 years of age. Differences between cases and controls included the duration of breastfeeding (p < 0.0001), mean birthweight (p < 0.001), maternal age (p < 0.001), paternal age (p < 0.001), birth order (p < 0.001), mean number of children (p < 0.001), BMI percentile (p = 0.042), and maternal smoking (p = 0.012). Breastfeeding duration of up to 6 months' duration, when compared with feeding of longer than 6 months, was associated with increased odds ratios (OR) for acute lymphoblastic leukemia (OR = 3.43, 95% confidence interval [CI] 2.37-4.98; p < 0.001), Hodgkin's lymphoma (OR = 1.58, 95% CI: 0.88-2.84, p = 0.120), Non-Hodgkin's lymphoma (OR = 2.14, 95% CI: 1.25-3.65, p = 0.005), and overall (OR = 1.95, 95% CI: 1.40-2.71, p < 0.001). Cases also differed from controls with regard to FGIDs, such as stomach ache (p < 0.001), dyspepsia (p < 0.001), early satiety (p = 0.017), bowel satisfaction (p < 0.001), bloating (p < 0.001), nausea (p = 0.005), vomiting (p = 0.039), constipation (p = 0.003), diarrhea (p = 0.010), gastrointestinal canal congestion (p =0.039), muscle aches pains (p = 0.008), fecal incontinence (p = 0.021), and indigestion (p = 0.003). A multivariate stepwise regression analysis revealed that maternal smoking (p < 0.001), formula feeding (p < 0.001), duration of breastfeeding (p < 0.001), birth order (p = 0.002), mother's age (p = 0.004) and the child's birthweight (p = 0.009) were predictors for leukemia. Further analysis showed that dyspepsia (p < 0.001), gastrointestinal tract canal congestion (p < 0.001), constipation (p = 0.009), diarrhea (p = 0.013), bowel satisfaction (p = 0.021), bloating (p = 0.022), duration of breastfeeding (p < 0.001), and stomach ache (p = 0.025) were significant predictors for developing FGID symptoms after adjusting for age, gender, and other confounding variables. Conclusion: This study confirmed that breastfeeding has some effect on reducing possible risk of childhood lymphoma and leukemia and FGID symptoms compared with healthy control children.

Role of breastfeeding on maternal and childhood cancers: An umbrella review of meta-analyses

Background

Multiple studies and meta-analyses have claimed that breastfeeding is inversely correlated with maternal and childhood cancers. These results could either be causal or confounded by shared risk factors. By conducting an umbrella review, we aimed to consolidate the relationship between breastfeeding and maternal and childhood cancers.

Methods

We searched PubMed, Embase, Web of Science, Elsevier ScienceDirect, and Cochrane Library databases from inception to December 2022. Two reviewers independently extracted the data and assessed the quality of the studies using standardised forms. We considered two types of breastfeeding comparisons ("ever" vs "never" breastfeeding; and "longest" vs "shortest" duration). We estimated the pooled risk and 95% confidence interval (CI) for each meta-analysis.

Results

We included seventeen meta-analyses with 55 comparisons. There was an inverse correlation between breastfeeding and childhood leukaemia (pooled risk = 0.90, 95% CI = 0.81-0.99), neuroblastoma (pooled risk = 0.81, 95% CI = 0.71-0.93), maternal ovarian cancer (pooled risk = 0.76, CI = 0.71-0.81), breast cancer (pooled risk = 0.85, 95% CI = 0.82-0.88), and oesophageal cancer (pooled risk = 0.67, 95% CI = 0.54-0.81) for "ever" vs "never" breastfeeding; and with childhood leukaemia (pooled risk = 0.94, 95% CI = 0.89-0.98), and maternal ovarian cancer (pooled risk = 0.84, 95% CI = 0.78-0.90) and breast cancer (pooled risk = 0.92, 95% CI = 0.89-0.96) for "longest" vs "shortest" breastfeeding duration.

Conclusions

We found evidence that breastfeeding may reduce the risk of maternal breast cancer, ovarian cancers, and childhood leukaemia, suggesting positive implications for influencing women's decision in breastfeeding.

Registration

PROSPERO (CRD42021255608).

An equitable, community-engaged translational framework for science in human lactation and infant feeding-a report from "Breastmilk Ecology: Genesis of Infant Nutrition (BEGIN)" Working Group 5

Human milk is the ideal source of nutrition for most infants, but significant gaps remain in our understanding of human milk biology. As part of addressing these gaps, the Breastmilk Ecology: Genesis of Infant Nutrition (BEGIN) Project Working Groups 1-4 interrogated the state of knowledge regarding the infant-human milk-lactating parent triad. However, to optimize the impact of newly generated knowledge across all stages of human milk research, the need remained for a translational research framework specific to the field. Thus, with inspiration from the simplified environmental sciences framework of Kaufman and Curl, Working Group 5 of the BEGIN Project developed a translational framework for science in human lactation and infant feeding, which includes 5 nonlinear, interconnected translational stages, T1: Discovery; T2: Human health implications; T3: Clinical and public health implications; T4: Implementation; and T5: Impact. The framework is accompanied by 6 overarching principles: 1) Research spans the translational continuum in a nonlinear, nonhierarchical manner; 2) Projects engage interdisciplinary teams in continuous collaboration and cross talk; 3) Priorities and study designs incorporate a diverse range of contextual factors; 4) Research teams include community stakeholders from the outset through purposeful, ethical, and equitable engagement; 5) Research designs and conceptual models incorporate respectful care for the birthing parent and address implications for the lactating parent; 6) Research implications for real-world settings account for contextual factors surrounding the feeding of human milk, including exclusivity and mode of feeding. To demonstrate application of the presented translational research framework and its overarching principles, 6 case studies are included, each illustrating research gaps across all stages of the framework. Applying a translational framework approach to addressing gaps in the science of human milk feeding is an important step toward the aligned goals of optimizing infant feeding across diverse contexts as well as optimizing health for all.

Technical Report: Breastfeeding and the Use of Human Milk

Breastfeeding and human milk are the normative standards for infant feeding and nutrition. The short- and long-term medical and neurodevelopmental advantages of breastfeeding make breastfeeding or the provision of human milk a public health imperative. The American Academy of Pediatrics (AAP) recommends exclusive breastfeeding for approximately 6 months after birth. Furthermore, the AAP supports continued breastfeeding, along with appropriate complementary foods introduced at about 6 months, as long as mutually desired by mother and child for 2 years or beyond. These recommendations are consistent with those of the World Health Organization (WHO). Medical contraindications to breastfeeding are rare. The AAP recommends that birth hospitals or centers implement maternity care practices shown to improve breastfeeding initiation, duration, and exclusivity. The Centers for Disease Control and Prevention and The Joint Commission monitor breastfeeding practices in United States hospitals. Pediatricians play a critical role in hospitals, their practices, and communities as advocates of breastfeeding and, thus, need to be trained about the benefits of breastfeeding for mothers and children and in managing breastfeeding. Efforts to improve breastfeeding rates must acknowledge existing disparities and the impact of racism in promoting equity in breastfeeding education, support, and services.

Association between maternal breastfeeding and risk of systemic neoplasms of offspring

Background

Breastfeeding might prevent childhood cancer by stimulating the immune system.

Methods

The following databases, including PubMed, Embase, and Cochrane Library, were searched from inception to January 10, 2021.

Results

In dose-dependent manner, there was a statistically significant inverse association between any breastfeeding and the incidence of childhood cancer. There was no evidence that breastfeeding was inversely related to childhood cancer of the skeletal, reproductive, or sensory systems. However, breastfeeding was inversely associated with the incidence of hematological malignancies and cancers of the nervous and urinary systems. Among hematological malignancies, the relationship was significant for acute lymphocytic leukemia (ALL) and acute myeloid leukemia (AML), but not for acute non-lymphocytic leukemia (ANLL), Hodgkin’s lymphoma (HL), or non-HL.

Conclusions

The evidences demonstrated that breastfeeding have a potential protective role in preventing selective childhood cancer growth, especially for ALL, AML, cancer of nervous and urinary systems. This study recommended that breastfeeding be extended for as long as possible or maintained for at least 6 months to prevent selective childhood cancer growth.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13052-022-01292-9.

Infant Feeding Practices And Childhood Acute Leukemia: Findings From The Childhood Cancer & Leukemia International Consortium

Increasing evidence suggests that breastfeeding may protect from childhood acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML). However, most studies have limited their analyses to any breastfeeding, and only a few data have examined exclusive breastfeeding, or other exposures such as formula milk. We performed pooled analyses and individual participant data meta-analyses of data from sixteen studies (N=17,189 controls; N=10,782 ALL and N=1,690 AML cases) from the Childhood Leukemia International Consortium (CLIC) to characterize the associations of breastfeeding duration with ALL and AML, as well as exclusive breastfeeding duration and age at introduction to formula with ALL. In unconditional multivariable logistic regression analyses of pooled data, we observed decreased odds of ALL among children breastfed 4-6 months (0.88, 95% CI 0.81-0.96) or 7-12 months (OR 0.85, 0.79-0.92). We observed a similar inverse association between breastfeeding ≥4 months and AML (0.82, 95% CI 0.71-0.95). Odds of ALL were reduced among children exclusively breastfed 4-6 months (OR 0.73, 95% CI 0.63-0.85) or 7-12 months (OR 0.70, 95% CI 0.53-0.92). Random effects meta-analyses produced similar estimates, and findings were unchanged in sensitivity analyses adjusted for race/ethnicity or mode of delivery, restricted to children diagnosed ≥1 year of age, or diagnosed with B-ALL. Our pooled analyses indicate that longer breastfeeding is associated with decreased odds of ALL and AML. Few risk factors for ALL and AML have been described, therefore our findings highlight the need to promote breastfeeding for leukemia prevention.

Article: "Too Old" and "Too Cold": Discomfort Towards Photographs of Breastfeeding Beyond Infancy and Public Breastfeeding in Nova Scotia, Canada

BACKGROUND

Social norms and public perception of breastfeeding are well-established predictors of breastfeeding outcomes; however, little is known about perceptions of breastfeeding beyond infancy or public breastfeeding among the public in Nova Scotia, Canada.

RESEARCH AIM

To explore public opinion about breastfeeding beyond infancy and public breastfeeding.

METHODS

In this cross-sectional study participants were recruited from public spaces in Nova Scotia, Canada. Using photo elicitation methods, participants (N = 229) viewed six photographs of breastfeeding children aged 2 weeks, 13 months, and 2.5 years, one photograph captured at home, and the other in a public space (a café, a store, or outdoors). Participants were asked to score their self-rated comfort with each photograph on a 10.0 cm visual analog scale and asked to share their feelings about each photograph (open-ended responses).

RESULTS

Mean (SD) visual analog scale comfort scores for photographs differed by location (private, 7.9 [2.2]; public, 7.3 [2.6]; p < .05) and child age (2 weeks, 8.5 [2.0]; 13 months, 7.5 [2.6]; 2.5 years, 6.9 [3.0]; p < .05). Participants who identified as women and parents self-reported significantly higher comfort with all photographs, while younger participants and urban dwellers were generally less comfortable. Open-ended responses varied considerably, but a higher proportion of negative comments were reported for older children feeding in public spaces (e.g., 2.5-year-old in public: "Inappropriate. Indecent. Abnormal.").

CONCLUSION

Given the importance of social norms in supporting breastfeeding, future public health campaigns should strive to normalize breastfeeding beyond infancy, and in public spaces.

Breastmilk Feeding during the First 4 to 6 Months of Age and Childhood Disease Burden until 10 Years of Age

BACKGROUND

Breastfeeding is recommended due to its beneficial effects on human health. However, the effect of breastfeeding on health differs, resulting in various childhood diseases.

OBJECTIVE

Our purpose was to investigate the association between breastfeeding at least in the first 4 months and the subsequent development of 15 certainly defined childhood diseases until 10 years of age, the all-cause hospitalization rate and growth at 6-7 years of age.

METHODS

Participants included propensity-score matched 188,052 children born between January 2008 and December 2009, who were followed up till 10 years of age. Data were taken from the National Investigation of birth Cohort in Korea study 2008 database. Risk ratios were obtained using a modified Poisson regression and weighted risk differences using binomial regression.

RESULTS

Compared to formula feeding, breastfeeding was associated with decreased risks of febrile convulsion, attention deficit hyperactivity disorder and autism spectrum disorder, pneumonia, acute bronchiolitis, hypertrophic pyloric stenosis, asthma, all-cause hospitalization, overweight/obesity and short stature. Exclusive breastfeeding at 4 to 6 months of age had similar results to exclusive breastfeeding over 6 months of age.

CONCLUSIONS

Breastfeeding in early infancy reduces the risk for various childhood diseases, all-cause hospitalization rate, obesity, and short stature during childhood.

More than Nutrition: Therapeutic Potential of Breast Milk-Derived Exosomes in Cancer

Human breast milk (HBM) is an irreplaceable source of nutrition for early infant growth and development. Breast-fed children are known to have a low prevalence and reduced risk of various diseases, such as necrotizing enterocolitis, gastroenteritis, acute lymphocytic leukemia, and acute myeloid leukemia. In recent years, HBM has been found to contain a microbiome, extracellular vesicles or exosomes, and microRNAs, as well as nutritional components and non-nutritional proteins, including immunoregulatory proteins, hormones, and growth factors. Especially, the milk-derived exosomes exert various physiological and therapeutic function in cell proliferation, inflammation, immunomodulation, and cancer, which are mainly attributed to their cargo molecules such as proteins and microRNAs. The exosomal miRNAs are protected from enzymatic digestion and acidic conditions, and play a critical role in immune regulation and cancer. In addition, the milk-derived exosomes are developed as drug carriers for delivering small molecules and siRNA to tumor sites. In this review, we examined the various components of HBM and their therapeutic potential, in particular of exosomes and microRNAs, towards cancer.

Systematic review methods for the Pregnancy and Birth to 24 Months Project

The USDA's Nutrition Evidence Systematic Review (NESR) team specializes in conducting systematic reviews (SRs) to inform federal nutrition policy and programs. The NESR's dedicated staff collaborate with leading scientists to answer important food- and nutrition-related public health questions by objectively reviewing, evaluating, and synthesizing research using state-of-the-art methodology. NESR uses a rigorous, protocol-driven methodology that is designed to minimize bias; to ensure availability of SRs that are relevant, timely, and high quality; and to ensure transparency and reproducibility of findings. This article describes the methods used by NESR to conduct a series of SRs on diet and health in infants, toddlers, and women who are pregnant as part of the Pregnancy and Birth to 24 Months Project.