Insufficient Milk Supply and Breast Cancer Risk: A Systematic Review

Background

An association between insufficient milk supply, the inability of a mother''s breast milk to provide sufficiently for her infant, and breast cancer has been suggested by observations in animal models. To determine if an association has been reported in epidemiological studies of human breast cancer, a systematic review of the literature has been conducted. We also sought to identify the methodological limitations of existing studies to guide the design of any future prospective studies in this field.

Methodology/Principal Findings

PubMed, EMBASE, Web of Science, BIOSIS, and CAB abstracts were searched. We selected any study that (1) assessed breast cancer in association with breastfeeding history and (2) examined the relationship between insufficient milk supply with breast cancer. Seven relevant studies were identified that met both criteria. There was statistically significant heterogeneity among the results which likely reflects clinically significant differences in definitions of insufficient milk supply and reference groups that were used. Among premenopausal women who had experienced insufficient milk supply, odds ratios (ORs) for breast cancer risk ranged from 0.9 to 16.3. Among postmenopausal women, ORs ranged from 0.6 to 6.7. Based on the range of odds ratios obtained in the studies reported in this review, it remains unclear if there is a true association between insufficient milk supply and breast cancer.

Conclusions/Significance

Although some studies have shown a strong positive association, there is no consistent evidence for an effect of insufficient milk supply on breast cancer risk. Exposure definitions are in need of improvement in order to focus on primary insufficient milk supply. Reference groups consisting of women who have successfully breastfed may also introduce positive bias (inflation of the odds ratio) into study results because of the protective effect of prolonged breastfeeding in the control group.     

Docosahexaenoic acid and lactation

Docosahexaenoic acid (DHA) is an important component of membrane phospholipids in the retina and brain and accumulates rapidly in these tissues during early infancy. DHA is present in human milk, but the amount varies considerably and is largely dependent on maternal diet. This article reviews data addressing the impact of different DHA intakes by lactating women on infant and maternal outcomes to determine if available data are sufficient to estimate optimal breast milk DHA content and estimate dietary reference intakes (DRIs) for DHA by breast-feeding mothers. Results of published observational studies and interventional trials assessing the impact of maternal DHA intake (or breast milk DHA content) on infant visual function, neurodevelopment, and immunologic status were reviewed. Studies related to the potential impact of DHA intake on depression or cognitive function of lactating women also were reviewed. Although only a limited number of studies are available in the current medical literature, and study results have not been consistent, better infant neurodevelopment and/or visual function have been reported with higher vs. lower levels of breast milk DHA. The effect of DHA intake on the incidence or severity of depression in lactating women is not clear. Increasing breast milk DHA content above that typically found in the US, by increasing maternal DHA intake, may confer neurodevelopmental benefits to the recipient breast-fed infant. However, current data are insufficient to permit determination of specific DRIs during this period.     

Violations of the international code of marketing of breast milk substitutes: prevalence in four countries

Objective: To estimate the prevalence of violations of the international code of marketing of substitutes for breast milk in one city in each of Bangladesh, Poland, South Africa, and Thailand. Design: Multistage random sampling was used to select pregnant women and mothers of infants ⩽6 months old to interview at health facilities. Women were asked whether they had received free samples of substitutes for breast milk (including infant formula designed to meet the nutritional needs of infants from birth to 4 to 6 months of age, follow on formula designed to replace infant formula at the age of 4 to 6 months, and complementary foods for infants aged ⩽6 months), bottles, or teats. The source of the free sample and when it had been given to the women was also determined. 3 health workers were interviewed at each facility to assess whether the facility had received free samples, to determine how they had been used, and to determine whether gifts had been given to health workers by companies that manufactured or distributed breast milk substitutes. Compliance with the marketing code for information given to health workers was evaluated using a checklist. Setting: Health facilities in Dhaka, Bangladesh; Warsaw, Poland; Durban, South Africa; and Bangkok, Thailand. Subjects: 1468 pregnant women, 1582 mothers of infants aged ⩽6 months, and 466 health workers at 165 health facilities. Main outcome measures: Number of free samples received by pregnant women, mothers, and health workers; number of gifts given to health workers; and availability of information that violated the code in health facilities. Results: 97 out of 370 (26%) mothers in Bangkok reported receiving free samples of breast milk substitutes, infant formula, bottles, or teats compared with only 1 out of 385 mothers in Dhaka. Across the four cities from 3 out of 40 (8%) to 20 out of 40 (50%) health facilities had received free samples which were not being used for research or professional evaluation; from 2 out of 123 (2%) to 21 out of 119 (18%) health workers had received gifts from companies involved in the manufacturing or distribution of breast milk substitutes. From 6 out of 40 (15%) to 22 out of 39 (56%) health facilities information that violated the code had been provided by companies and was available to staff. Conclusion: Violations of the code were detected with a simple survey instrument in all of the four countries studied. Governmental and non-governmental agencies should monitor the prevalence of code violations using the simple methodology developed for this study.

Key messages

• A simple multistage random sampling procedure can be used to interview women and health professionals to assess whether violations of the international code of marketing of substitutes for breast milk are occurring
• 3050 women and 466 health professionals were interviewed at 165 health facilities in Bangladesh, Poland, South Africa, and Thailand
• 97 out of 370 mothers in Bangkok reported receiving free samples of breast milk substitutes, infant formula, bottles, or teats compared with only 1 out of 385 mothers in Dhaka. In Bangkok health workers reported that 20 out of 40 health facilities had also received free samples. Most free samples were distributed by health facilities
• In Warsaw 56% of facilities surveyed were found to have information available for health workers that had been provided by manufacturers or distributors of breast milk substitutes in contravention of the code; 18% of health workers in Warsaw had received free gifts from manufacturers

     

Choline status in newborns, infants, children, breast-feeding women, breast-fed infants and human breast milk

This study assessed the choline status in newborns, infants, children, breast-feeding women, breast milk, infant formula, breast-fed and formula-fed infants. The serum free choline level was 35.1+/-1.1 micromol/L at birth and decreased to 24.2+/-1.6, 18.1+/-0.8, 16.3+/-0.9, 14.3+/-0.8, 12.9+/-0.6 or 10.9+/-0.6 micromol/L at 22-28, 151-180, 331-365, 571-730, 731-1095 or 4016-4380 days after birth, respectively. The serum phospholipid-bound choline level was 1997+/-75 micromol/L at birth and increased gradually to 2315+/-190 or 2572 +/-100 micromol/L at 571-730 or 4016-4380 days after birth, respectively. In breast-feeding women, serum free and phospholipid-bound choline levels were doubled at 12-28 days after birth, they decreased toward the control values with time. Free choline, phosphocholine and glycerophosphocholine were major choline compounds in breast milk. Their concentrations in mature milk were much greater than in colostrum and serum. Choline contents of breast milk varied greatly between mothers, and milk free choline levels were correlated with serum free choline (r=.541; P<.001), phospholipid-bound choline (r=.527; P<.001) and glycerophosphocholine (r=.299; P<.01) concentrations and lactating days (r=.520; P<.001). In breast-fed infants, serum free choline concentrations were correlated with free choline (r=.47; P<.001), phosphocholine (r=.345; P<.002), glycerophosphocholine (r=.311; P<.01) and total choline (r=.306; P<.01) contents of breast milk. Serum free choline concentration in formula-fed infants was lower than breast-fed infants. These data show that (a) circulating choline status is elevated during infancy and lactation, (b) choline contents of breast milk vary between mothers and milk free choline contents are influenced by maternal circulating choline status, and (c) the choline contents of breast milk can influence infants' circulating choline status.     

Dissin' "the Standard": Ebonics as Guerrilla Warfare at Capital High

This article analyzes the discourse styles, including the linguistic practices, of a group of African American high school students and offers a twofold conclusion: (1) Ebonics or Black English is the norm against which all other speech practices are evaluated by the students at the research site and (2) "the standard"—that is, the standard English dialect—is constructed as a vernacular. As a vernacular, this discourse is not privileged; indeed, it is "dissed" (disrespected) and is only "leased" by the students on a daily basis from nine to three. This linguistic practice is centrally implicated in the postulated guerrilla warfare at the school. With data from a predominantly African American high school in Washington, D.C., the effects of this practice on African American academic achievement are documented. Several policy implications are also noted.     

Neonatal hypernatremic dehydration associated with breast-feeding malnutrition: a retrospective survey

BACKGROUND: Hypernatremic dehydration in neonates is a potentially devastating condition. Recent reports have identified breast-feeding malnutrition as a key factor in its pathophysiology. METHODS: Using a theoretical framework for breast-feeding kinetics, a retrospective chart review of all neonates less than 28 days of age who were seen at either British Columbia''s Children''s Hospital or the Vancouver Breastfeeding Centre between 1991-1994 was conducted to identify and classify possible causes of breast-feeding malnutrition among neonates who developed hypernatremic dehydration. RESULTS: Twenty-one cases hypernatremic dehydration were identified. Infant weight loss ranged from 8% to 30% of birth weight, and serum sodium levels ranged from 146 mmol/L to 207 mmol/L. In each case, maternal or infant factors (e.g., poor breast-feeding technique, lactation failure following postpartum hemorrhage and infant suckling disorders associated with cleft palate or ankyloglossia) that could interfere with either lactation or breast-feeding dynamics and account for insufficient breast milk intake were identified. INTERPRETATION: Prenatal and in-hospital screening for maternal and infant risk factors for breast-feeding malnutrition combined with early postpartum follow-up to detect excessive infant weight loss are important for the prevention of neonatal hypernatremic dehydration.     

A biocultural investigation of the weanling's dilemma in Kathmandu, Nepal: do universal recommendations for weaning practices make sense?

The primary objective of this report is to use data from a study of infant growth and weaning practices in Kathmandu, Nepal, to investigate universal recommendations about exclusive breast-feeding up to 6 months postpartum. A secondary objective is to demonstrate the complexity of the biocultural nature of infant feeding practices. A sample of 283 children under 5 years of age and their 228 mothers living in a peri-urban district of Kathmandu participated in this study. The children's height/length and weight were measured three times over 9 months. At each session, a demographic, child health and infant feeding survey was administered; between sessions, in-depth interviews were conducted with mothers regarding infant feeding practices. While a few of the infants under 2 months were receiving non-breast milk foods, at 3 months of age half of the sample had been introduced to non-breast milk foods and by 7 months all infants were eating non-breast milk foods. A comparison of growth indices and velocities between exclusively and partially breast-fed infants from birth to 7 months of age shows no evidence for a difference in nutritional status between the two groups. Although there are cultural rules about breast-feeding that vary by ethnic group, all mothers followed a feeding method that depended on their assessment of whether the child was getting enough breast milk. The conclusion is that exclusive breast-feeding up to 6 months may not be appropriate for all infants. In this sample, breast-feeding duration is not shortened by the early introduction of non-breast milk foods, as the median age of breast-feeding cessation is 36 months. One of the main reasons for severance was the onset of another pregnancy. Investigation of infant feeding practices must be contextualized in the local ecology of the population. While cultural beliefs about breast-feeding are relevant, mothers' individual assessments of their children's nutritional needs and demographic events in parents' lives must also be considered.     

Colostrum feeding behaviour and initiation of breast-feeding in rural Bangladesh

Human breast milk is primarily colostrum immediately following birth. Colostrum gradually changes to mature milk over the next several days. The role of colostrum in fighting infections and promoting growth and development of the newborn is widely acknowledged. This role is mediated by differences across cultures in the acceptability of colostrum and the prevalence of colostrum feeding. This study examined the prevalence of colostrum feeding and time to initiation of breast-feeding in 143 rural Bangladeshi women in Matlab thana. Structured interviews were collected during a 9-month prospective study conducted in 1993. Women were usually interviewed within 4 days of giving birth and were asked about whether or not they fed their child colostrum and the number of hours until they began breast-feeding the baby. Ninety per cent of the mothers reported feeding their newborn colostrum. A logistic regression found no effect on the prevalence of colostrum feeding from the following covariates: mother's age, parity, history of pregnancy loss, child's sex, mother's self-report of delivery complications, and the time from birth to interview. Fifty-nine per cent of mothers initiated breast-feeding within 4 h, and 88% within 12 h of parturition. Survival analysis was used to estimate the effects of covariates on the time from delivery to initial breast-feeding. Time to initial breast-feeding was delayed slightly, but significantly, for older mothers, for male infants, and by mothers who did not report delivery complications. The percentage of mothers who fed their child colostrum was higher, and times to initial breast-feeding were shorter, than almost all previous reports from South Asia. These findings might be explained, in part, by methodological differences among studies, but it is suggested that recent changes towards earlier initiation of breast-feeding have taken place in rural Bangladesh.     

Perceived insufficient milk as a barrier to optimal infant feeding: examples from Bolivia

In its recently adopted Global Strategy on Infant and Young Child Feeding, the World Health Assembly called for urgent action in addressing the barriers to optimal feeding practices. This paper examines mothers' concerns about milk insufficiency as a major contributor to suboptimal infant feeding decisions, using survey data from peri-urban areas of two Bolivian cities. Mothers in the lowland modernizing city of Santa Cruz were more likely than mothers in the highland traditional city of Cochabamba to express concern about insufficient milk, and also less likely to feed their infants according to international recommendations. Furthermore, perceived milk insufficiency was particularly common among mothers of infants younger than 6 months of age -- an age at which infants are particularly vulnerable to the adverse effects of breast-feeding cessation and complementary feeding initiation. The paper concludes with policy, programme and research recommendations to address the critical problem of perceived insufficient breast milk.     

Nutritional status of under-five children in Bangladesh: a multilevel analysis

The nutritional status of under-five children is a sensitive sign of a country's health status as well as economic condition. This study investigated the differential impact of some demographic, socioeconomic, environmental and health-related factors on the nutritional status among under-five children in Bangladesh using Bangladesh Demographic and Health Survey 2007 data. Two-level random intercept binary logistic regression models were used to identify the determinants of under-five malnutrition. The analyses revealed that 16% of the children were severely stunted and 25% were moderately stunted. Among the children under five years of age 3% were severely wasted and 14% were moderately wasted. Furthermore, 11% of the children were severely underweight and 28% were moderately underweight. The main contributing factors for under-five malnutrition were found to be child's age, mother's education, father's education, father's occupation, family wealth index, currently breast-feeding, place of delivery and division. Significant community-level variations were found in the analyses.     

Physiological basis of longitudinal changes in human milk yield and composition

Currently in Western Australia more than 85% of women are breast-feeding after discharge from the hospital. Breast milk is the only fluid consumed by 64% of infants at 6 months of age, and 25% of infants are still breast-fed at 12 months of age. Therefore, many Western Australian mothers have optimized the art of breast-feeding and thereby provide an ideal population for studies of the physiological, pathological, and pharmacological factors affecting lactation. Reports from other countries conclude that the maximum milk yield of well-nourished women is 700-900 ml/24 h. Our studies have found the average milk yield of mothers breast-feeding single infants was in excess of 1100 ml/24 h for the first 6 months of lactation. Furthermore, mothers breast-feeding twins produced in excess of 2100 ml/24 h over this period, which demonstrates that the potential milk yield for mothers is much higher than 700-900 ml/24 h. Substantial alterations in the composition of breast milk occur at the initiation of lactation and after the cessation of suckling. During established lactation it is generally believed that there is only a slight variation in the composition of the milk. However, intensive studies have revealed acute changes in the concentrations of lactose, glucose, sodium, potassium, and chloride 5-6 days before and 6-7 days after ovulation. These findings suggest that unknown hormonal events associated with the reproductive cycle in women also influence breast milk composition.     

Transient Compartmentalization of Simian Immunodeficiency Virus Variants in the Breast Milk of African Green Monkeys

Natural hosts of simian immunodeficiency virus (SIV), African green monkeys (AGMs), rarely transmit SIV via breast-feeding. In order to examine the genetic diversity of breast milk SIV variants in this limited-transmission setting, we performed phylogenetic analysis on envelope sequences of milk and plasma SIV variants of AGMs. Low-diversity milk virus populations were compartmentalized from that in plasma. However, this compartmentalization was transient, as the milk virus lineages did not persist longitudinally.     

Perception of donor breast milk and determinants of its acceptability among mothers in a developing community: a cross-sectional multi-center study in south-east Nigeria

Background

Due to the health and economic benefits of breast milk, the World Health Organization (WHO) recommends that for infants who cannot receive breast milk from their own mothers, the next preferred option is donated breast milk. This recommendation is however rarely practiced in most developing countries where donor milk is not widely accepted.

Methods

This cross-sectional multi-center study enrolled mothers attending antenatal or pediatric clinics in six tertiary institution in south-east Nigeria using purposive and convenient sampling method. Data collection was done using pretested questionnaires. The study aimed to assess the knowledge, acceptability and willingness to donate breast milk and/or use donated breast milk for their infants It also explored factors that determine this behavior.

Results

A total of 1235 mothers participated; 39% (480/1225) have heard about the concept of donor milk, while only 10% (79/759) and 7% (81/1179), respectively, had adequate knowledge of the concept and policy on donor milk. Sixty percent indicated willingness to use donor milk or donate breast milk if need arises. Respondents with lower age (p?=?0.049) and with higher occupational status (p?=?0.001) were more likely to have adequate knowledge of donor breast milk, while respondents with lower educational attainment (p?=?0.002) and those who are non-Christians (p?=?0.004) were more likely to request financial inducement for donating their breast milk. Adequate knowledge of the concept of donor milk (p?=?0.001), preference of donor milk to infant formula (p?=?0.001) and requirement of financial remuneration (p?=?0.001) were the only significant predictors of willingness to donate and/or receive donated breast milk.

Conclusion

The knowledge of the concept of donor breast milk and awareness of policies regulating its practice in Nigeria is low, but the prospect of its acceptability is high among mothers surveyed in south-east Nigeria. Targeted public education by relevant government agencies in collaboration with clinicians, community and religious leaders about the concept of donor breast milk to families may help increase the acceptance and practice of donating breast milk and/or use of donated breast milk among mothers in the region.

     

May mothers given warfarin breast-feed their infants?

Warfarin was measured with a sensitive and specific method in the plasma and breast milk of 13 mothers. Less than 0-08 micronmol warfarin per litre (25 ng/ml) of breast milk was found in each instance. Seven of the mothers were breast-feeding their infants, in none of whom was warfarin detected in the plasma; furthermore, in three the British corrected ratio of the plasma was appreciably less than that of the mother and was within the expected range. We conclude that nursing mothers given warfarin may safely breast-feed their infants.     

Assessment of Aflatoxin M1 and Heavy Metal Levels in Mothers Breast Milk in Famagusta,Cyprus

Breast milk contributes towards optimal nutrition for infants. However, studies showed that it can also contain different toxins and heavy metals, which reduce its health benefits. The aim of this study is to determine the level of contaminants such as aflatoxin M1 (AFM1), Pb, Cd, As, and Hg in breast milk samples from Famagusta, Cyprus. Correlations between moldy food consumption, smoking habits of the mothers, and contaminant levels in breast milk were also investigated. Breast milk samples from 50 lactating mothers in rural and urban areas of Famagusta District were analyzed for AFM1 by ELISA. Eighty percent of them were found to be contaminated with AFM1 with the mean measurement of 7.84?±?1.72 ng/l. Socio-demographic status, moldy food consumption habits, and smoking status do not have any effect on the AFM1 levels observed in breast milk. Heavy metal levels in breast milk were examined by inductively coupled plasma mass spectrometry, and the mean measurements were1.19?±?1.53 ppm for Pb, 0.73?±?0.58 ppm for As, 0?±?0.20 ppm for Hg, and 0.45?±?0.23 ppm for Cd. This study indicates that the levels of these contaminants in breast milk samples obtained in Famagusta District are well within the acceptable levels. However, the presence of AFM1 and heavy metals still may pose risks for infant health.     

"Kissing a Baby Is Not at All Good for Him": Infant Mortality, Medicine, and Colonial Modernity in the U.S.-Occupied Philippines

Feminist scholars have begun to consider the ways indigenous practices of child rearing were and are challenged in (post)colonial discourse and practice, and how these practices have become a terrain on which definitions of nation, state, and economy are contested. In this article, I adopt a historical anthropological approach to consider how Filipino child-rearing strategies were described and stigmatized in educational, public health, and public welfare discourses in the U.S.-occupied Philippines in the early 20th century. I demonstrate how public health practices and discourses that were generated as part of a "benevolent" campaign against high rates of infant mortality were strategically used as a weapon against Filipino arguments for independence. I also consider how discourses constructing Filipino caregivers as overly indulgent were linked to metropolitan concerns about production of the "new industrial man" and were used to develop a racialized critique of the cultural practices of Filipinos.     

Socio-Economic and Health Access Determinants of Breast and Cervical Cancer Screening in Low-Income Countries: Analysis of the World Health Survey

Background

Breast and Cervical cancer are the two most common cancers among women in developing countries. Regular screening is the most effective way of ensuring that these cancers are detected at early stages; however few studies have assessed factors that predict cancer screening in developing countries.

Purpose

To assess the influence of household socio-economic status (SES), healthcare access and country level characteristics on breast and cervical cancer screening among women in developing countries.

Methods

Women ages 18–69 years (cervical cancer screening) and 40–69 years (breast cancer screening) from 15 developing countries who participated in the 2003 World Health Survey provided data for this study. Household SES and healthcare access was assessed based on self-reported survey responses. SAS survey procedures (SAS, Version 9.2) were used to assess determinants of breast and cervical cancer screening in separate models.

Results

4.1% of women ages 18–69 years had received cervical cancer screening in the past three years, while only 2.2% of women ages 40–69 years had received breast cancer screening in the past 5 years in developing countries. Cancer screening rates varied by country; cervical cancer screening ranged from 1.1% in Bangladesh to 57.6% in Congo and breast cancer screening ranged from 0% in Mali to 26% in Congo. Significant determinants of cancer screening were household SES, rural residence, country health expenditure (as a percent of GDP) as well as healthcare access.

Discussion

A lot more needs to be done to improve screening rates for breast and cervical cancer in developing countries, such as increasing health expenditure (especially in rural areas), applying the increased funds towards the provision of more, better educated health providers as well as improved infrastructure.     

Breast-feeding and respiratory syncytial virus infection.

The pattern of breast-feeding in 127 infants admitted to hospital with respiratory syncytial virus infection was compared with that in 503 age-matched controls. Thirty per cent of children with infection had been breast-fed compared with 49% of controls. The approximate relative risk of being admitted to hospital with respiratory syncytial virus infection if not breast-fed was 2.2. Several other factors were also considered, including an assessment of maternal care and home environment; the mother''s age, marital state, and smoking habits; the number of siblings; and gestation. Adverse factors were all associated with an increased risk of admission with infection, but breast-feeding still appeared to provide protection after controlling for these other factors in turn. These findings provide further support for encouraging mothers to breast-feed their infants and should prompt further studies into the immune status of mothers and into the nature of the protective factors in their breast milk.     

Female Genital Surgeries: The Known, the Unknown, and the Unknowable

This article reviews the literature on female genital surgeries and examines the extent to which available research supports commonly accepted "facts" about the prevalence and harmful effects of these practices, in particular their possible health complications, and their effect on sexuality. While information regarding the prevalence of female genital surgeries is becoming increasingly available, the powerful discourse that depicts these practices as inevitably causing death and serious ill health, and as unequivocally destroying sexual pleasure, is not sufficiently supported by the evidence. The article discusses some of the implications of research on female genital surgeries for the societies that are involved—not merely those where the practices are found, but also those whose gaze has been so intensely focused on the customs of others, [female genital surgeries/mutilation, prevalence, health complications, sexuality]     

Milk sharing: from private practice to public pursuit

After only six months, a commerce-free internet-based milk-sharing model is operating in nearly 50 countries, connecting mothers who are able to donate breast milk with the caregivers of babies who need breast milk. Some public health authorities have condemned this initiative out of hand. Although women have always shared their milk, in many settings infant formula has become the "obvious" alternative to a mother's own milk. Yet an internationally endorsed recommendation supports mother-to-mother milk sharing as the best option in place of a birth mother's milk. Why then this rejection? Several possibilities come to mind: 1) ignorance and prejudice surrounding shared breast milk; 2) a perceived challenge to the medical establishment of a system where mothers exercise independent control; and 3) concern that mother-to-mother milk sharing threatens donor milk banks. We are not saying that milk sharing is risk-free or that the internet is an ideal platform for promoting it. Rather, we are encouraging health authorities to examine this initiative closely, determine what is happening, and provide resources to make mother-to-mother milk sharing as safe as possible. Health authorities readily concede that life is fraught with risk; accordingly, they promote risk-reduction and harm-minimisation strategies. Why should it be any different for babies lacking their own mothers' milk? The more that is known about the risks of substituting for breast milk, the more reasonable parental choice to use donor milk becomes. We believe that the level of intrinsic risk is manageable through informed sharing. If undertaken, managed and evaluated appropriately, this made-by-mothers model shows considerable potential for expanding the world's supply of human milk and improving the health of children.