Introduction

Breastfeeding is fundamental to human nutrition and the foundation of successful public health policy. Promoting breastfeeding is at the core of the UNICEF/World Health Organization (WHO) emphasis on nutrition and health in the first 1,000 days of life (UNICEF, 2017). The WHO recommends breastmilk as the sole source of nutrients for infants until around 6 months, and it continues to be important until two years and beyond (WHO, 2002). The World Health Assembly has endorsed targets for infant nutrition and specifically a target to increase exclusive breastfeeding (EBF) rates while acknowledging the link between undernutrition in childhood and the onset of overweight/obesity and noncommunicable diseases (NCDs) later in life. “Appropriate breastfeeding practices, including appropriate complementary feeding practices after 6 months of EBF, not only prevent malnutrition among young children, but are also associated with less susceptibility to overweight and NCDs later in life” (UNICEF & WHO, 2018; United Nations Subcommittee on Nutrition [UNSCN], 2015). The U.S. Surgeon General strongly advocates for the benefits of breastfeeding and the improvement of rates in the United States (U.S. Department of Health and Human Services, 2011). The USA Healthy People 2020 targets include increasing the proportion of infants ever breastfed, breastfeeding at 6 months (target 62%), and increasing the proportion of breastfeeding through three months (target 46%) (Office of Disease Prevention and Health Promotion, 2010, 2019). The promotion of breastfeeding (EBF for 6 months and then continuing) is probably the most beneficial and cost-effective public health interventions available (N. C. Rollins et al., 2016; Victora et al., 2016). Increasing breastfeeding is an important element of achieving the Sustainable Development Goals (SDGs; C. Binns, Lee, Low, & Zerfas, 2017; UNSCN, 2015).

The new European draft policy for health contains several references to the importance of breastfeeding in maintaining public health (World Health Organization European Regional Office, 2019):

The life of a mother and her baby are inextricably linked. Breastfeeding is an important aspect of caring for infants and young children. It leads to improved nutrition and physical growth, reduced susceptibility to common childhood illnesses and better resistance to cope with them, a reduced risk of certain noncommunicable diseases in later life and stimulating bonding with the caregiver and psychosocial development.

Definitions of Breastfeeding

The following are the definitions of breastfeeding as published by the WHO (2008). Often nonstandard definitions are used in studies and reports or the data is collected in a way that is inconsistent with these definitions.

Definitions used:

There are several important issues relating to how EBF is reported: definition, reporting method (point prevalence or period prevalence), and health implications for the infant. EBF is rarely measured according to the strict WHO definition, which makes it difficult to interpret some research results (C. W. Binns, Lee, Sauer, & Hewitt, 2012; Flores, Mielke, Wendt, Nunes, & Bertoldi, 2018; Inoue, Binns, Otsuka, Jimba, & Matsubara, 2012). It is sometimes reported as a period prevalence of EBF 0–6 months, based on cross-sectional studies (rather than a longitudinal cohort). The reported value then depends on the age composition of the sample. For example, an EBF rate 0–5 months could represent 100% of infants breastfeeding for 2 months or 33% breastfeeding for 6 months, with very different public health outcomes. For this reason, measurement of point prevalence (percentage breastfeeding at an exact point of time, e.g., at 6 months) is the preferred measurement. In some cases, EBF may not be measured since birth. A commonly used procedure is to ask how the infant has been fed in the past 24 hours and if only breastmilk has been given, the prevalence is reported as the EBF rate at that point in time. This method ignores the impact of earlier non-breast milk feeds as EBF should be defined as no other feeds since birth (see Table 1). Even in the relatively homogenous regions of Europe or in Australia, a variety of breastfeeding measurements are in use (C. W. Binns, Fraser, Lee, & Scott, 2009; Sarki, Parlesak, & Robertson, 2019). Many studies support the importance of promoting EBF until 6 months of life, but when assessing studies it is important to consider which definition is in use (C. W. Binns & Lee, 2014).

An example of how different definitions in use and different methods of measurement result in considerable variation in reported results is shown in Table 2.

The definition used is important because whether or not an infant is exclusively breastfed influences the development of a healthy microbiome. Dysbiosis of the microbiome appears to be associated with obesity and chronic disease later in life (Chong, Bloomfield, & O’Sullivan, 2018; Wells, 2018).

Breastmilk Composition

Breastmilk is a living tissue that includes maternal cells, probiotics, and a wide range of proteins, carbohydrates, lipids, minerals, micronutrients, and other chemicals. There are thousands of chemical entities with hundreds of bioactive compounds (Allen & Dror, 2018; Dror & Allen, 2018). The preparation of a consolidated table of breastmilk composition is not possible as it varies by the age of the infant, number of infants, and maternal nutritional status and diet. Further research is required to provide more details of the composition of breastmilk in different environments. This requires careful attention to methodology as the human-milk matrix differs markedly from blood, plasma, or urine matrixes and contains living bacteria and cells, including stem cells (Hampel, Dror, & Allen, 2018; Hassiotou & Hartmann, 2014; Wells, 2018). While in the future it may be possible to relate breastmilk composition to individual function, this is not generally possible and awaits more analysis (Hellmuth et al., 2018; Wells, 2018). Exceptions to this may be nutrients such as iodine and iron, but otherwise relating breastfeeding to infant and later life outcomes generally relies on epidemiological studies.

Methodology in Breastfeeding Research

Research into breastfeeding is challenging because of ethical issues and the difficulty of adjusting for all potential confounding factors. Unlike the randomized controlled trials (RCT) in clinical medicine, infant feeding research does not have a placebo or null option available. Mothers obviously cannot choose not to feed an infant (C. Binns, Lee, & Kagawa, 2017; Hurlimann, Pena-Rosas, Saxena, Zamora, & Godard, 2017; Lessen & Kavanagh, 2015). The most difficult aspect is the inability to randomize interventions as the known advantages of breastmilk make it impossible to conduct an ethical RCT (Binns, Lee, & Kagawa, 2017). The difficulties of understanding the effects of small differences in exposures in nutrition research are even more pronounced in infant feeding, as breastmilk is a living biological fluid that varies with infant age, maternal nutrition, and health (Barnard, Willett, & Ding, 2017; Ioannidis, 2018; Lessen & Kavanagh, 2015).

The most widely cited RCT in breastfeeding is the PROBIT cluster RCT that commenced in Belarus in 1996 with the recruitment of 17,046 mother–infant dyads (Kramer et al., 2001). The hospitals were randomized to receive training, modeled on the Baby-Friendly Hospital Initiative (BFHI), which was designed to increase the duration and exclusivity of breastfeeding. Only mothers who had initiated breastfeeding were included, and there was no control group of formula-fed infants (R. Patel et al., 2014). Only healthy newborns of at least 37 weeks’ gestation and at least 2500 grams birth weight with an Apgar score of at least 5 at 5 minutes were included. The enrollment of mothers was limited to those who were followed up at specific polyclinics associated with each hospital (Martens, 2012). Despite limitations, the study has been very useful and has shown, for example, the value of BFHI in prolonging breastfeeding duration and that cognitive development is related to breastfeeding quantity and quality. However, it lacks some information, such as prelacteal feeds and early supplementation, that could influence microbiome formation and later conditions such as obesity (Martens, 2012). Thus the PROBIT trial is a trial of a BFHI intervention that was successful in extending breastfeeding duration. It also showed that EBF reduced the rate of gastrointestinal infections. PROBIT does not allow for a comparison between breastfeeding and a formula (or placebo) group that would be required to study associations between obesity and infant feeding (Martens, 2012).

Because of the ethical limitations on RCTs, the science of breastfeeding must be based on laboratory studies and a variety of observational designs with the limitations of undisclosed confounders.

Global Breastfeeding Rates

Breastfeeding rates are below the levels required for optimal infant and lifetime health. “Any breastfeeding” rates are generally accurate, provided they are reported as a point prevalence or as “ever breastfed.” In Europe, there are significant differences in breastfeeding rates, data collection methods, and breastfeeding strategies. At the age of 6 months, 35% to 65% of infants in surveyed countries were breastfed, 13% to 39% exclusively or fully (Theurich, Weikert, Abraham, & Koletzko, 2018). UNICEF publishes data on EBF rates with a period prevalence 0–5 months (UNICEF, 2018). Globally, only 42% of mothers initiate breastfeeding within the first hour of birth, and about 40% of infants under 6 months of age are exclusively breastfed (period prevalence). Fewer than 75% children ages 12 to 15 months are still breastfeeding (UNICEF, 2018) (See Table 3). The WHO gives a similar rate of 40% exclusively breastfed 0–5 months (WHO, 2018a). Victora et al. (2016) provided a more detailed analysis of available data, with most mothers starting breastfeeding, and only three countries (France, Spain, and the United States) having rates below 80% for “ever breastfeeding.” Early initiation rates (breastfeeding within one hour of birth) were low at about 40% (Victora et al., 2016). In low-income and middle-income countries, 37% of infants younger than 6 months are exclusively breastfed, defined as the proportion of infants aged 0–5 months who are exclusively breastfed (Victora et al., 2016). The World Breastfeeding Trends Initiative and World Breastfeeding Scorecard provide resources on breastfeeding data collection, also based on period prevalence (UNICEF WHO, 2018; World Breastfeeding Trends Initiative, 2018).

Median breastfeeding duration varies considerably between countries, between rural and urban locations, and by other demographic, cultural, and socioeconomic subpopulations. Within the European Union EBF rates within the first 48 hours ranged from 88.4% in Latvia to 16.8% in Cyprus, with “any breastfeeding rates” of 96.9% in Slovenia and 54% in Ireland (European Commission, 2010). In a review of breastfeeding rates, Callen and Pinelli (2004) found the ranges of reported any breastfeeding rates at 6 months in Australia to be 50% to 52%, Canada 31% to 41%, Europe 19% to 52%, and the United States 19% to 33%. In low- and middle-income countries, rates of EBF are usually very low because of the high rates of prelacteal feeds while “any breastfeeding” rates are high. For example, in the Maldives 100% of mothers were breastfeeding on hospital discharge and 83% at 6 months, but the EBF 0–3 month was 8% (Abdulraheem & Binns, 2007). It is important that breastfeeding rates are regularly and accurately monitored for continuing health program evaluation.

The Benefits of Breastfeeding

The public health benefits of breastfeeding at a population level have been well documented. The WHO Collaborative Study highlighted the excess of infant and child deaths in lower income countries when infants are not breastfed (WHO Collaborative Group, 2000). Protection provided by breastfeeding declined steadily with age during infancy, but for infants less than 2 months of age the odds ratios of dying if not breastfed was 5.8 (95% confidence interval [CI] 3.4–9.8). It has been estimated by Victora and colleagues (2016) that scaling up of breastfeeding to a near universal level could prevent 823,000 annual deaths in children younger than 5 years and 20,000 annual deaths in women from breast cancer. This is probably an underestimate if associations with a slightly lower level of evidence were included. Victora et al. summarize the benefits: “our meta-analyses indicate protection against child infections and malocclusion, increases in intelligence, and probable reductions in overweight and diabetes.” For mothers, benefits include reduced breast and ovarian cancer and increased birth spacing. Other reviews of the benefits of breastfeeding compared to formula feeds have indicated a wider range of associations including those shown in Table 4. This is a summary of breastfeeding benefits, and the original reviews should be consulted for details.

Reviews that provide further evidence linking breastfeeding and reduced risk of specific conditions include those on obesity (Matvienko-Sikar et al., 2018; McCallister, Medrano, & Wojcicki, 2018; Mihrshahi & Baur, 2018; Palou, Pico, & Palou, 2018; Tambalis, Mourtakos, Panagiotakos, & Sidossis, 2018), respiratory tract infection (McAllister et al., 2019), cardiovascular disease, hypertension, metabolic syndrome (Bonifacino, Schwartz, Jun, Wessel, & Corbelli, 2018; Faintuch & Faintuch, 2018; Heshmati et al., 2018; Wisnieski, Kerver, Holzman, Todem, & Margerison-Zilko, 2018), SIDS (Moon & Hauck, 2018; Young & Shipstone, 2018), asthma (Miliku & Azad, 2018; Moossavi, Miliku, Sepehri, Khafipour, & Azad, 2018), and necrotizing enterocolitis (A. L. Patel & Kim, 2018). The hypertension benefit is proportional to duration of breastfeeding (Qu, Wang, Tang, Wu, & Sun, 2018). Further analysis has confirmed an association between breastfeeding and adult intelligence and has ruled out genetic confounding (Horta, Hartwig, & Victora, 2018; Mortensen, 2015). Other conditions that have been reported to be associated with breastfeeding include leukemia, osteoporosis, coeliac disease, infant colic, and Alzheimer’s disease, but the evidence is variable in strength. Breastfeeding within one hour decreases neonatal deaths, and breastfeeding for ≤12 months was associated with decreased nutrition risk and healthier eating behaviors and dietary intake at 3 to 5 years of age (Borkhoff et al., 2018; Phukan, Ranjan, & Dwivedi, 2018).

Mothers also gain health benefits from breastfeeding (see Table 4). A large prospective cohort study in Japan (n = 140,420) found that mothers who breastfed had a lower risk of mortality during the 20-year follow-up (Otsuki et al., 2018). Postnatal depression and anxiety are reduced in mothers who breastfeed (Yusuff, Tang, Binns, & Lee, 2016). In Japan where excellent maternal care has substantially reduced maternal mortality, suicide due to postnatal depression is the most common cause of prenatal maternal death (Takeda et al., 2017). The promotion of breastfeeding provides one solution to this problem. The risks of breast cancer (Collaboration for Breast Cancer, 2002; Sauter, 2018) and ovarian cancer are reduced in mothers who breastfeed (Ali, 2018; C. W. Binns, Lee, & Lee, 2014; Su, Pasalich, Lee, & Binns, 2013; Unar-Munguia, Torres-Mejia, Colchero, & Gonzalez de Cosio, 2017; Zhang, Xie, Lee, & Binns, 2004). Breastfeeding for longer than 6 months is associated with smaller maternal waist circumference up to one decade after delivery (Snyder et al., 2019). Nonalcoholic fatty liver disease is an increasing problem in many societies and in a large cohort study, breastfeeding for longer than 6 months was associated with lower risk (Ajmera et al., 2019). A systematic review of breastfeeding and hypertension found a reduced risk that persisted for decades (Bonifacino et al., 2018). In the Women’s Health Initiative Observational Study (n = 80,191) a dose–response relationship was found between breastfeeding and a lower risk of stroke among postmenopausal women and, after adjustment, a 23% lower risk of stroke (Jacobson et al., 2018). One of the most important chronic diseases in terms of global disease burden is type II diabetes mellitus, and a meta-analysis found that this is reduced in mothers who have breastfed, although it is possible that this may be related to the weight loss following breastfeeding (Feng, Xu, Hu, & Pan, 2018). Breastfeeding has an important public health benefit in increasing birth spacing. During lactational amenorrhoea, the rate of pregnancy before 6 months of age is reduced to 2% to 3% (Duong, 2012; Van der Wijden, Kleijnen, & Van den Berk, 2003).

The Human Microbiome

The composition and activity of the gastrointestinal microbiome has gained in importance in public health in the past decade and has been linked to health and diseases as diverse as asthma, allergy, diabetes, depression, obesity, and arthritis (Gaufin, Tobin, & Aldrovandi, 2018; Gilbert et al., 2018). During birth infants are exposed to microbes in the birth canal, breastmilk, and the environment to initiate establishment of the gut microbiome. Within the first year of life, an estimated 10¹⁴ microbes, comprising 500 to 1,000 species, colonize the gastrointestinal tract (Gilbert et al., 2018). Breastmilk contains bacteria and prebiotics (oligopolysaccharides) to promote the growth of healthy bacteria. The establishment of a normal, healthy microbiome is disrupted by preterm birth, caesarean delivery, not breastfeeding, and the use of perinatal antibiotics (Chong et al., 2018; Iozzo & Sanguinetti, 2018; Stiemsma & Michels, 2018). The use of infant formula early in life leads to changes in the microbiome that are consistent with later obesity (Forbes et al., 2018). The development and preservation of a healthy microbiome has important social, ethical, and public health implications (O’Doherty, Virani, & Wilcox, 2016).

Public Health Costs of Not Breastfeeding

Not breastfeeding imposes health and economic costs on the infant, the family, and society. Any breastfeeding is beneficial, but overall benefit is proportional to the duration and whether the breastfeeding is exclusive. The infant incurs costs from increased susceptibility to infectious disease and increased incidence of longer term chronic disease. The infant and society incur social capital costs through lower levels of cognitive development and increased healthcare costs. Mothers incur costs due to increased rates of breast and ovarian cancers and other chronic illnesses. Society loses due to the environmental costs of infant formula production, increased health costs, and lower productivity. Global infant formula industry sales were $US44.8 billion in 2014, but at the same time the cost to society resulting from less breastfeeding was estimated at $US302 billion, representing 0.49% of the world’s gross national product (GNP; N. C. Rollins et al., 2016; Victora et al., 2016). In the United States, costs of excess deaths from infant formula was estimated at $14.2 billion with the majority attributable to maternal expenses (M. C. Bartick et al., 2017). There have been many other studies of the costs of not breastfeeding, but the huge value of the contribution, and the future potential contribution of mothers’ milk production to global GNP, has yet to be acknowledged (Baker et al., 2016; M. Bartick, 2011, 2013; M. Bartick & Reinhold, 2010; M. C. Bartick et al., 2017; Colaizy et al., 2016; J. P. Smith, 2013; J. P. Smith, Thompson, & Ellwood, 2002; Stuebe et al., 2017). The excess of infant deaths due to the availability and inappropriate marketing of infant formula in the 1980s in less developed countries has been estimated to be as high as 9.4% (Anttila-Hughes, Fernald, Gertler, Krause, & Wydick, 2018). Despite the known public health risks of infant formula, the increase in the use of formula continues and is most marked in the middle-income countries of East Asia, particularly in China and Indonesia (Baker et al., 2016; Boue et al., 2018).

Public Health Factors and Breastfeeding Rates

In traditional cultures almost all mothers, perhaps 99%, were able to breastfeed satisfactorily (C. W. Binns, 1976). In the rare cases that this was not possible or following the illness or death of the mother, another woman from the village would become a wet nurse. Unfortunately, without extended families and village support and the entrenched traditional culture of breastfeeding, breastfeeding rates in high-income societies are low and of short duration. The specific reasons have been widely studied as a basis for inclusion in health promotion programs and do vary between cultures (C. Binns et al., 2018; Cohen et al., 2018; National Health and Medical Research Council, 2013; Scott & Binns, 1999; Scott, Binns, Oddy, & Graham, 2006).

Important influences include the following (Cohen et al., 2018):

Maternal and family education about breastfeeding should begin before pregnancy or in the early stages of pregnancy. The earlier the decision is made to breastfeed, the more likely breastfeeding is to be successful. The role of fathers is increasingly recognized as being important in extending breastfeeding duration (Kuliukas et al., 2019; Mahesh et al., 2018; Maycock et al., 2013). The National Health and Medical Research Council (2012; NHMRC) Infant Feeding Evidence review found strong evidence for antenatal and perinatal support for breastfeeding to increase the proportion of women breastfeeding (both exclusive and nonexclusive) up to age 6 months. With almost universal access to smartphones at an individual or village level, the use of breastfeeding apps has become an important breastfeeding promotion tool (McKay et al., 2018; White, Burns, Giglia, & Scott, 2016; White, Giglia, Scott, & Burns, 2018).

The level of maternal education influences breastfeeding outcomes. In higher income Western societies, women with higher levels of education are more likely to breastfeed (Holowko, Jones, Koupil, Tooth, & Mishra, 2016; Mangrio, Persson, & Bramhagen, 2018). In Asia the opposite is the case, with more educated mothers breastfeeding less, perhaps related to historical practices of the ruling class who often used wet nurses for their infants (Zhao, Zhao, Du, Binns, & Lee, 2017b).

In the United States, lower income mothers are less likely to breastfeed, while in other countries such as China, the reverse is the case (Liu et al., 2013; Mercier, Burcher, Horowitz, & Wolf, 2018; Tang, Binns, Luo, Zhong, & Lee, 2013). Intimate partner violence and other disruptive family events decrease breastfeeding (Mezzavilla, Ferreira, Curioni, Lindsay, & Hasselmann, 2018). Maternal illness, including gestational diabetes and perinatal depression, reduce breastfeeding rates. However, mothers who do manage to breastfeed improve the outcomes of both conditions (M. C. Bartick et al., 2013; Chamberlain et al., 2017; Xu et al., 2014; Yusuff et al., 2016).

Potential Public Health Interventions

Breastfeeding benefits society through reduced health costs, increased productivity, and environmental protection. It is the responsibility of society to create a supportive environment for such a public health benefit and to promote its use at every opportunity. A review of public health and breastfeeding has identified the following areas for intervention (Brown, 2017):

Health services in the context of breastfeeding include hospitals and all other levels of service, which should all follow the steps advocated in the BFHI that have been endorsed by most public health authorities, including WHO and UNICEF (Aryeetey & Dykes, 2018). Implementation of the BFHI has been shown to improve breastfeeding duration (Kramer et al., 2001; Patterson, Keuler, & Olson, 2019; Perez-Escamilla, Martinez, & Segura-Perez, 2016; Zarshenas, Zhao, Binns, & Scott, 2018).

Multidimensional antenatal programs have also been shown to be effective in promoting breastfeeding. A cluster RCT in Burkino Faso has shown that multidimensional antenatal programs with community support increased the EBF rate 0–6 months to 93%, evidence of a remarkably successful large-scale intervention (control 53%) (Cresswell et al., 2019; N. Rollins & Doherty, 2019).

In traditional societies the expectation is that all mothers will breastfeed. In modern society it is important to educate mothers and family members on the benefits of breastfeeding. Discussion of infant feeding should begin as early in the pregnancy as possible, as the earlier the decision is made, the more likely breastfeeding will be established (National Health and Medical Research Council, 2013). Population-level promotion would include school and community education programs on the importance of breastfeeding for health and development (Patnode, Henninger, Senger, Perdue, & Whitlock, 2016).

Maternal legal rights include the provision of paid maternity leave, the availability of facilities for mothers to breastfeed or express milk, and the freedom to breastfeed wherever and whenever they wish. Maternity leave increases breastfeeding (Espghan Committee on Nutrition et al., 2009; Kim, Shin, & Donovan, 2019; Navarro-Rosenblatt & Garmendia, 2018; Ratnayake & Rowel, 2018; Scott et al., 2006). When a mother has to return to work, it is still possible to continue to breastfeed on a part-time basis with great benefit to mother and infant (Lakati, Binns, & Stevenson, 2002a, 2002b).

Care, support, and advice for parents, but particularly mothers, after delivery, are important. Perinatal depression is common in all societies, and in severe cases medical treatment may be required (Avalos, Flanagan, & Li, 2019; Molenaar, Kamperman, Boyce, & Bergink, 2018; Xu et al., 2014; Yusuff, Tang, Binns, & Lee, 2015). Breastfeeding is associated with lower rates of postnatal depressive symptoms (Yusuff et al., 2016). The U.S. Preventive Taskforce has published guidelines on the prevention of perinatal depression, finding counseling interventions can be effective in preventing perinatal depression (O’Connor, Senger, Henninger, Coppola, & Gaynes, 2019; U.S. Preventive Services Task Force, 2019). Other common difficulties include mastitis, the management of low birthweight infants, and perceived breastmilk inadequacy (National Health and Medical Research Council, 2013). Maternal obesity may pose additional difficulties in breastfeeding (Dutton, Borengasser, Gaudet, Barbour, & Keely, 2018; Flores et al., 2018; Lyons, Currie, Peters, Lavender, & Smith, 2018). In traditional villages, mothers would had the support of an extended family, but in modern societies a formal care structure may be needed. An RCT has shown that smartphone apps can be used to extend breastfeeding and may be more practical on a population level (White et al., 2016; White, Martin, et al., 2016). Mothers also need to be provided with access to contraception. While lactational amenorrhoea provides some protection for 6 months (up to 98%), the use of a low-dose progesterone pill has been shown to have no significant effect on breastmilk (Berens & Labbok, 2014; Duong, 2012; Van der Wijden & Manion, 2015). After the introduction of complementary foods or the cessation of amenorrhoea, additional contraception should be used. For mothers who are breastfeeding and become pregnant, breastfeeding may continue during pregnancy and after delivery.

The mother’s weight should be monitored (as it usually is) as the extra energy required for breastfeeding may reduce weight gain. Mothers who have type I diabetes and are pregnant and breastfeeding require additional monitoring of glucose levels. Mothers who are HIV positive and pregnant and also breastfeeding who are on ART require special monitoring of blood levels. Mothers can continue breastfeeding their first baby and their new baby as well if so desired (Lopez-Fernandez, Barrios, Goberna-Tricas, & Gomez-Benito, 2017).

The marketing of infant formula has an impact on breastfeeding rates. There is no doubt that modern infant formula is a quantum leap above traditional breastmilk substitutes, but it cannot match the benefits of the living tissue that is breastmilk. The widespread promotion and incorrect claims related to formula have contributed to lower rates of breastfeeding. The World Health Assembly (WHA) passed a resolution

calling on all countries to implement the WHO’s Guidance on Ending the Inappropriate Promotion of Foods for Infants and Young Children to further protect breastfeeding, prevent obesity and chronic disease, and promote a healthy diet. In addition, the guidance aims to ensure that caregivers receive clear and accurate information on feeding.

(WHO, 2016b)

One hundred ninety-nine countries signed the WHO Code on the Marketing of Breastmilk Substitutes and 84 countries have enacted legislation implementing all or many of the provisions of the Code and subsequent relevant WHA resolutions. Infant formula manufacturers are not permitted to distribute samples in hospitals or to parents in any way or provide incentives to health providers. Manufacturers frequently skirt advertising restrictions by using the same product names for infant formula and for products directed at older children (Berry, Jones, & Iverson, 2012). Implementing and enforcing the WHO Code is an important step to control inappropriate and misleading advertising. The WHO is calling for greater enforcement of the Code as only one-third of countries have legal restraints on advertising foods for infants under 6 months of age (WHO, 2018b). The United States and the Republic of Korea remain the only countries not to sign the Code. The Code is in need of modification to cover all infant formula to 12 months and “follow-on” formulae marketed to toddlers, as the advertising of these products promotes brand recognition for all infant formula, regardless of their target age group (J. Smith, Galtry, & Salmon, 2014).

Caesarean Section and Breastfeeding

The increasing rates of caesarean section (C-section) pose a public health risk in their own right through risks common to any surgical intervention, increased use of antibiotics, increased costs, and lower rates of breastfeeding (Chen et al., 2018; Qiu, Binns, Zhao, Lee, & Xie, 2008; Sandall et al., 2018; Zhao, Zhao, Du, Binns, & Lee, 2017a). Anesthesia and the type of pain relief for C-section may reduce the amount of breastfeeding (Lim et al., 2018). Boerma et al. (2018) estimated based on data from 169 countries (98.4% of the world’s births), that 29.7 million (21.1%, 95% uncertainty interval 19.9–22.4) births occurred through C-section in 2015, double that in 2000 (Boerma et al., 2018). Armenia is an example of a middle-income country that has seen an upward trend in C-sections increasing from 7.2% in 2000 to 31.0% in 2017 (Tadevosyan et al., 2019). Rates as high as 80% for C-section are not uncommon in the larger cities of Asia and South America (Giordano, Nascimento, Godoy-Miranda, & Surita, 2019; Haider et al., 2018). C-section rates in Vietnam have increased rapidly and were reported as 57.6% for public and 70.6% for private patients (Giang, Ulrich, Tran, & Pozza, 2018). C-section is associated with lower rates and shorter duration of breastfeeding (Chen et al., 2018; Prior et al., 2012; Zanardo et al., 2010). The disadvantage of C-section is reduced if infant to mother contact can be made within one hour of delivery and breastfeeding initiated (Prior et al., 2012).

C-section is often followed by a period of complete bed rest for several days during which infants may receive infant formula. Best practice in C-section allows the mother to remain conscious with epidural/spinal anesthesia and to breastfeed her infant within minutes of delivery, just as happens following a vaginal delivery. C-section carries an economic cost due to the resources required, and the lower rates of breastfeeding impose an additional burden. Infants delivered in this way have altered microbiome due to lack of contact with the birth canal and the almost universal use of antibiotics for prophylaxis against infection.

Smoking

The tobacco epidemic is one of the biggest public health threats the world has ever faced, killing more than 7 million people a year. More than 6 million of those deaths are the result of direct tobacco use while around 890,000 are the result of nonsmokers being exposed to second-hand smoke. Around 80% of the 1.1 billion smokers worldwide live in low- and middle-income countries, where the burden of tobacco-related illness and death is greatest (WHO, 2018d). Many women quit smoking during pregnancy, but up to 90% resume smoking within 12 months, a time when ideally mothers should still be breastfeeding (Pollak et al., 2015). Nicotine levels in the breastmilk of women who smoke are three times higher than nonsmokers; 24-hour breastmilk volume is reduced, and the duration is shorter (Lok, Wang, Chan, & Tarrant, 2018; Xu, Binns, Zhang, Yang, & Zhao, 2010). Smoking causes adverse changes to the milk’s composition by reducing its protective properties (Napierala, Mazela, Merritt, & Florek, 2016). Mothers who quit smoking before pregnancy are more likely to initiate and continue breastfeeding (Carswell et al., 2018).

Communicable Disease Risks

Breastfeeding may transmit communicable diseases including HIV, hepatitis, cytomegalic virus, HTLV1, Ebola, Zika, and Flavi viruses. Brucellosis has also been reported (Tuon, Gondolfo, & Cerchiari, 2017). Because of the advantages of breastfeeding in many cases, particularly in resource-poor communities, the benefits of breastfeeding often outweigh other risks to the infant. While the WHO has given some reasons for not breastfeeding, in many cases in the decade since the publication of these guidelines, advances have allowed breastfeeding to continue (WHO, 2009). With HIV infection, the use of ART chemotherapy allows breastfeeding to continue (Fowler, Flynn, & Aizire, 2018).

HTLV1 is transmitted by breastfeeding, but this condition is only rarely screened for. Serologic screening in pregnant women is not required as a public health policy even in endemic countries such as Brazil. But if it is identified by chance, formula feeding may be the safer option if the conditions required for its safe use can be met (Oliveira, Kachimarek, & Bittencourt, 2018; Pasquier et al., 2018). Because the health advantages of breastfeeding are considered greater than the potential risk of transmission, the WHO recommends that mothers with possible or confirmed Zika virus infection or exposure continue to breastfeed (Mann et al., 2018). The management of hepatitis B has been changed by treatment and vaccination options (Centers for Disease Control and Prevention, 2018b; Qiu, Binns, Zhao, Zhang, & Xie, 2010).

Medications and other drugs may also be present in breastmilk. Most medications can still be used while breastfeeding (Anderson, 2018a, 2018b; Cuomo et al., 2018; Wong, Seto, Wong, Yuen, & Chan, 2018). However, the use of drugs of addiction requires special management (Reece-Stremtan & Marinelli, 2015). Breastmilk may also contain low levels of environmental contaminants. Since 1987 the WHO and United Nations Environment Programme have carried out worldwide monitoring of persistent organic pollutants, including dioxins, PCBs, and DDT in breastmilk. After reviewing three decades of data, van den Berg and colleagues (2017) concluded:

Based on our present knowledge, we conclude that the benefits of breastfeeding far outweigh the toxicological disadvantages that are associated with certain POPs. . . . Experimental and epidemiological studies indicate that future risk–benefit assessments should focus more on the in utero situation, rather than on the breastfeeding period. Consequently, the risk–benefit debate of breastfeeding may well be redundant (p. 94).

Breastfeeding–Nutritional Risks

Breastmilk is the most nutritionally complete food available. While breastmilk can be low in several nutrients, under most circumstances this does not cause any difficulty or public health solutions are available. Breastmilk is relatively low in iron, which is probably a defense mechanism against bacterial infection. Iron is present in the form of lactoferrin, which is readily absorbed. Mothers are usually given iron supplements to ensure adequate iron status at birth, and the introduction of appropriate complementary foods (iron-rich or iron-fortified foods) at 6 months overcomes this potential deficiency (WHO, 2016a). Excessive use of iron increases the risk of malaria in endemic countries. Over the age of 6 months, WHO (2016a) recommends iron supplementation for infants in regions where the prevalence of anemia is >40%.

Vitamin D deficiency in breastfed infants has been the subject of many studies. Some countries (e.g., the United States) recommend supplementation, while others (e.g., Australia) do not, unless the mother has been vitamin D deficient (National Health and Medical Research Council, 2013; Taylor & Academy of Breastfeeding Medicine, 2018; Wagner, Greer, Sect, & Comm, 2008). The WHO (2019) does not recommend supplementation with vitamin D and states “further research is needed before specific recommendations can be made.”

Vitamin K is routinely given by injection to prevent neonatal hemorrhagic disease although in some countries an oral course may be substituted (Puckett & Offringa, 2000). The prophylactic use of vitamin K in infants is effective and safe (Sankar et al., 2016; Turck et al., 2017).

Iodine deficiency is widespread across many regions of the world; most countries use iodized salt, and mothers are supplemented during pregnancy (National Health and Medical Research Council, 2010). The WHO has recommended that where iodized salt consumption is adequate, no supplementation is required, but in other deficient areas mothers should continue to take iodine supplements during lactation (Andersson, de Benoist, Delange, & Zupan, 2008; Nazeri, Kabir, Dalili, Mirmiran, & Azizi, 2018). This situation needs to be carefully monitored as most sets of dietary guidelines recommend restricting salt use due to hypertension (C. W. Binns et al., 2017; Frieden & Bloomberg, 2018). Also agar from seaweed is no longer used as a thickener in food processing, which was an additional source of iodine (Nazeri, Tahmasebinejad, et al., 2018).

There is an increase in the use of breastmilk that has been expressed, stored, shared, or sold. This exposes infants to a number of potential risks including infection, contamination, and adulteration. Breastmilk gathered in low-income countries may be offered for commercial sale in richer countries, raising questions of safety and ethics (J. P. Smith, 2015). These include the age of the infant of the mother providing the milk (breastmilk composition changes over time) and the exploitation of women in low-income countries. The safe management and storage of expressed breastmilk is becoming an important public health issue (Peters, McArthur, & Munn, 2016; Picaud et al., 2018).

Environmental Benefits

Children are the population segment most susceptible to the effects of climate change, bearing an estimated 88% of the increased burden of disease (Philipsborn & Chan, 2018; Stanberry, Thomson, & James, 2018). The health benefits of breastfeeding will provide some protection against the effects of climate change. The SDGs, officially known as “Transforming Our World: The 2030 Agenda for Sustainable Development,” were approved by the General Assembly in September 2015. They comprise a set of 17 interrelated goals with 169 more specific targets that are applicable to countries at all stages of economic development and include several references to the importance of breastfeeding (United Nations, 2017). Breastfeeding and appropriate introduction of complementary foods is the foundation of child health and development. The introduction of feeding breaks at places of employment, with political support, is an important intervention for promotion of the SDGs (Richter et al., 2017). The alternative to breastfeeding is infant formula, which is usually based on cow milk. While milk production in the 21st century is more efficient than in the past per unit of production, the total impact is greater due to increased production (Capper, Cady, & Bauman, 2009). Dairy milk production uses very large amounts of water, which will be in scarce supply as a result of climate change (Sultana, Uddin, Ridoutt, & Peters, 2014). Breastfeeding is the best protection for infants against the effects of climate change (C. Binns, Lee, Low, et al., 2017).

Disaster Situations

Infant feeding after disasters, including earthquakes and tsunamis, in conflict zones, and in other emergency situations provide challenges to parents, health services, and relief agencies. In situations of disaster or food insecurity, infants who are not breastfed have a markedly higher risk of infant mortality and morbidity from infectious diseases (Chantry, Eglash, & Labbok, 2015; Eidelman, 2013). After the Great Western China (Wenchuan) earthquake, large quantities of infant formula were donated with the familiar logos of the major formula quantities. The amounts were so large that stocks remained five years later and contributed to a marked increase in prelacteal feeds (C. W. Binns et al., 2012). A similar situation was noted after the Nepal earthquake (DeYoung, Suji, & Southall, 2018). Mothers who are injured or short of food can still continue breastfeeding and do not need formula. Of course, they do need clean water and food as soon as it can be obtained. Where formula must be used, health workers need to follow the highest ethical standards to avoid promoting infant formula to vulnerable communities in the post-recovery phase. Formula companies should donate supplies only in the quantities needed and in plain-labeled containers to avoid it becoming an advertising opportunity (C. W. Binns et al., 2012). After the Japanese earthquake and tsunami it was found that there was an increase in obesity, probably due to disruption of infant feeding (Yokomichi et al., 2018). In summary, in managing disasters every effort should be made to allow mothers to continue breastfeeding their infants to minimize additional morbidity and mortality.

Breastfeeding in the Arts

The arts reflect the views and practices of society and provide the means of discussion and advocacy of new ideas. It is informative to examine the ways breastfeeding has been portrayed in the many media of the arts. Until the mid- and late 19th century, breastfeeding was portrayed as natural part of human existence and indeed a noble virtue. Uruguay has promoted the health of its infants, including promoting breastfeeding, since its foundation and has a statue that includes a mother breastfeeding outside its parliamentary building (Birn, 2005). The temples and museums of Egypt contain many statues of the god Isis breastfeeding her son Horus (UNESCO, 2018). Even older are the clay statuettes in the Istanbul Archeological Museum of breastfeeding mothers. In the Christian Era the portrayal of a breastfeeding Madonna to show caring and nurturing has been a feature of Christian art. There are said to be 10,000 portraits of the breastfeeding Madonna (Madonna lactans) in the churches of Europe, but the best known are now in museums. Leonardo da Vinci’s wonderful painting “Madonna Litta” in the Hermitage, St Petersburg, is an excellent example. Another wonderful portrait is by Pierre-Auguste Renoir “A Woman Nursing a Child” in the National Gallery in Edinburgh, painted in 1894 (C. Binns, 2018).

Opera is the pinnacle of Western art but rarely, if ever, includes a portrayal of breastfeeding. However, a new work commissioned by Stuttgart Opera “Erdbeben Träume” (Earthquake Dreams) with music by the Japanese composer Toshio Hosokawa brings breastfeeding to the center of the stage. The opera is a series of images of how populations react to disasters. It tells the story of a major earthquake in Santiago, Chile, two centuries ago with many deaths and, amid the chaos, the survival of a child who is rescued and breastfed by a policewoman. The opera draws on the iconic image of a policewoman breastfeeding a baby after the Great Western China Earthquake of 2008, which went viral around the world (Zhu & Hu, 2009). There are many more examples of breastfeeding portrayed in art which can help to normalize the perceptions of breastfeeding in the community.

Breastfeeding in the Goals of International Organizations

Because of their importance to infant health, maternal well-being, overall public health, and a sustainable environment, goals and targets for breastfeeding are included in many international policy documents. The United Nations SDG 2 states “end hunger and ensure access by all people, in particular the poor and people in vulnerable situations, including infants, to safe, nutritious and sufficient food all year round.” This includes promoting breastfeeding. “Breastfeeding is the smartest investment families, communities and countries can make” (p. 1) for the health of infants and the environment (C. Binns, Lee, Low, et al., 2017; United Nations Sustainable Development Goals, 2017). UNICEF and WHO have assessed the 2030 global targets for breastfeeding against current statistics and found that none of the 198 countries in the United Nations system are meeting the targets (UNICEF & WHO, 2018). The report notes that “less than half of newborns begin breastfeeding in the first hour after birth. 41% of infants less than 6 months of age are exclusively breastfed” (Selim, 2018; WHO, 2018c).

Action is required to support WHO and UNICEF to improve the collection of breastfeeding statistics and to monitor and promote the BFHI. There are important modifications needed to extend the WHO International Code on the Marketing of Breastmilk Substitutes.

Conclusion

There are great public health benefits to be gained from promoting breastfeeding in reducing morbidity and mortality and improving the well-being of infants and mothers. Breastfeeding has always had important benefits for society, and in modern times it is more important than ever that the contribution of breastfeeding mothers toward healthier populations through cost savings and reducing stress on the environment be recognized by society.

In sum, the public health motto for infant feeding should be: “Babies are born to be breastfed, the more the better.”

Authoritative General Reference Sources on Breastfeeding