HEALTH BENEFITS ASSOCIATED WITH BREAST-FEEDING
Prevention of Infections
The preventive effect on infections is by far the most important health benefit in relation to breast-feeding, especially in developing countries. The Dutch and the Agency for Healthcare Research and Quality (AHRQ) meta-analyses concluded that breast-feeding was convincingly associated with a lower risk of gastrointestinal infection and of acute otitis media (AOM), whereas the protective effect on other respiratory tract infections was more doubtful (4,5). The meta-analysis by AHRQ showed that breast-feeding was always associated with a lower risk of AOM than exclusive bottle-feeding (odds ratio [OR] 0.77, 95% confidence interval [CI] 0.64–0.91) (5). The reduction in the risk of AOM was greater when comparing exclusive breast-feeding with exclusive bottle-feeding, either for more than 3 to 6 months duration (OR 0.50, 95% CI 0.36–0.70). Chien and Howie (40) identified 14 cohort studies and 2 case-control studies from developed countries that qualified for inclusion in their systematic review/meta-analysis on the relation between breast-feeding and the development of gastrointestinal infections in children younger than 1 year of age. The summary crude odds ratio of the 14 cohort studies for the development of gastrointestinal infections in breast-fed infants was 0.36 (95% CI 0.32–0.41), whereas that of the 2 case-control studies was 0.54 (95% CI 0.36–0.80). A recent case-control study of good/adequate methodology from England showed that breast-fed infants had a reduced risk of diarrhoea compared with nonbreast-fed infants (OR 0.36, 95% CI 0.18–0.74) (41). However, the protective effect of breast-feeding did not persist beyond 2 months after cessation of breast-feeding. There is no clear protective effect of breast-feeding on the occurrence of lower respiratory tract diseases. However, breast-feeding may have a preventive role in the risk of severe lower respiratory tract infections, severe being defined by the need for hospitalisation. A meta-analysis of 7 cohort studies showed a 72% reduction in the risk of hospitalisation secondary to respiratory diseases in healthy full-term infants less than 1 year of age who were exclusively breast-fed for at least 4 months compared with those who were formula-fed (relative risk 0.28, 95% CI 0.14–0.54) (42). The protective effect of breast-feeding against the risk of hospitalisation for lower respiratory infection was recently confirmed in the United Kingdom Millennium Cohort study (6). Collectively the available data indicate an association of breast-feeding with a well-documented reduced risk of infectious diarrhoea as well as AOM, and a possible protection against other infections where level of evidence is less convincing.
A randomised trial in the early 1980s comparing the use of banked human milk with preterm formula for feeding premature infants showed that mean diastolic blood pressure at ages 13 to 16 years was higher when assigned preterm formula than banked human milk: 65.0 versus 61.9 mmHg (95% CI for difference −5.8 to −0.6; P = 0.016) (43), which differs considerably in energy and nutrient density. No difference was found for systolic blood pressure. No data were published to compare the outcome of preterm infants fed banked human milk and term formula, which are more similar in energy and nutrient supply. A meta-analysis of Owen et al (44) showed a pooled mean difference in systolic blood pressure of −1.10 mmHg (95% CI −1.79 to −0.42) in participants breast-fed as infants. No difference was found for diastolic blood pressure. Another meta-analysis, including an extra approximately 10,000 subjects from 3 studies with more than 1500 participants each, showed that breast-feeding was associated with a −1.4 mmHg (95% CI −2.2 to −0.6) difference in systolic blood pressure and a −0.5 mmHg (95% CI −0.9 to −0.04) difference in diastolic blood pressure (45). In these 2 meta-analyses, the association weakened after stratification for study size, suggesting the possibility of bias in the smaller studies. A recent meta-analysis included 4 additional studies and other publications identified by 2 independent literature searches at WHO and at the University of Pelotas, Brazil (39). Systolic (mean difference −1.21 mmHg, 95% CI −1.72 to −0.70) and diastolic (mean difference −0.49 mmHg, 95% CI −0.87 to −0.11) blood pressures were lower among subjects who had been breast-fed as infants. However, in the cluster-randomised PROBIT trial, no effect of breast-feeding on blood pressure was found at age 6.5 years (46).
Although there is no consensus on whether sodium intake during infancy has an influence on blood pressure later in life (47), it is possible that the low sodium content of breast milk may play a role in the reduction of blood pressure. The high content of long-chain polyunsaturated acids (LCPUFA) in breast milk may also be relevant, since LCPUFA are incorporated into cell membranes of the vascular endothelium and supplementation with LCPUFA lowers blood pressure in hypertensive subjects. A randomised controlled trial showed that dietary supplementation with LCPUFA from birth to 6 months was associated with a significant reduction in mean and diastolic blood pressure at 6 years of age (48), and in a randomised intervention study with fish oil supplementation from 9 to 12 months of age, systolic blood pressure at 12 months was 6.3 mmHg lower in infants receiving fish oil (49).
The magnitude of the effect of breast-feeding on blood pressure is similar to the effect of salt restriction (−1.3 mmHg) and weight loss (−2.8 mmHg) in normotensive subjects, and is likely to have substantial public health implications (50). A lowering of population-wide mean blood pressure by 2 mmHg could reduce in adults the prevalence of hypertension by 17%, and the risk of coronary heart disease, stroke, and transient ischemic attacks by 6% and 15%, respectively.
A meta-analysis of 37 studies showed that blood total cholesterol (TC) differed with age. TC concentrations were higher in breast-fed than in formula-fed infants (<1 year), because of the markedly higher content of cholesterol in breast milk than in most commercially available formulae (mean TC difference 0.64, 95% CI 0.50–0.79 mmol/L) (51). Mean TC in childhood or adolescence (1–16 years) was not related to feeding patterns in infancy. However, TC in adults was lower among those breast-fed in infancy (mean TC difference −0.18, 95% CI −0.30 to −0.06 mmol/L). Patterns for low-density lipoprotein (LDL) cholesterol were similar to those for TC throughout. Whatever the underlying programming stimulus, long-term modifications in cholesterol metabolism are likely to occur, either by regulation of hepatic hydroxymethylglucaryl coenzyme A (HMG-CoA) reductase activity or LDL-receptor activity. The meta-analysis of the WHO confirmed that in adults (>19 years) breast-fed subjects had a mean TC 0.18 mmol/L (95% CI 0.06–0.30 mmol/L) lower than those who were bottle-fed whereas the association was not significant for children and adolescents (39). The association found in adults did not seem to be due to publication bias or confounding. A recent review including data available from 17 studies (17,498 subjects; 12,890 breast-fed, 4608 formula-fed) also confirmed that initial breast-feeding (particularly when exclusive) was associated with lower blood cholesterol concentrations in later life (52).
An important question is whether the potential effects of breast-feeding on later blood pressure and lipid metabolism may lead to a reduction in cardiovascular risk in adulthood. Two studies showed a positive relation of the duration of breast-feeding with arterial distensibility, which is considered a marker of endothelial dysfunction, in 10-year-old children and in adults, respectively (53,54). However, the study performed in adults showed no difference in distensibility between participants who had been bottle-fed and those breast-fed for less than 4 months. A recent Finnish study showed that young adult men who had been breast-fed had better brachial endothelial function compared with men who had been formula-fed. Breast-feeding was not significantly associated with carotid artery intima media thickness (IMT) and carotid artery compliance. No difference was observed between breast-fed and formula-fed women (55).
The follow-up of the British Boyd-Orr cohort showed in 63- to 82-year-old participants that breast-feeding was associated with lesser ultrasound-measured IMT of common carotid and bifurcation as well as lesser carotid and femoral plaques, compared with bottle-feeding (56). However, there was no evidence of a duration-response relation between breast-feeding and IMT. The study of the same cohort on the basis of a larger number of subjects and a systematic review with meta-analysis of 4 studies failed to show any beneficial effect of breast-feeding on cardiovascular disease mortality (57). The study of the cohort of Caerphilly, Wales, UK, showed a positive association between breast-feeding and coronary heart disease mortality. There was however no duration-response effect (58). In contrast, the study of the participants of the Nurses' Health Study reported an 8% reduced risk of coronary heart disease associated with breast-feeding (59). The Committee concludes that although there are indications for effects of breast-feeding on later blood pressure and blood lipid levels, currently there is no convincing evidence that breast-feeding has an effect on cardiovascular morbidity and mortality.
Overweight, Obesity, and Type 2 Diabetes
In a recent meta-analysis including 33 studies, breast-fed individuals were less likely to be considered overweight and/or obese in childhood and adolescence (OR 0.78, 95% CI 0.72–0.84) (39). The effect was no longer evident in adulthood. Control for confounding, age at assessment, year of birth, and study design did not modify the protective effect of breast-feeding. Because a statistically significant protective effect was observed among those studies that controlled for socioeconomic status and parental anthropometry, as well as with more than or equal to 1500 participants, the effect of breast-feeding was not likely to be due to publication bias or confounding (39). Some but not all studies show a dose-response effect, with a more marked effect associated with a longer duration of breast-feeding (60). In the cluster-randomised PROBIT trial, no protective effect of longer breast-feeding on weight and adiposity was found in the group of breast-fed infants at age 6.5 years (46). The mechanisms by which breast-feeding may protect against later obesity have been reviewed in detail (61). A behavioural explanation could be that because breast-fed babies control the amount of milk consumed they may learn to better self-regulate their energy intake later in life. Lower protein and energy content of breast milk compared with infant formula may also influence later body composition. A lower protein intake may also contribute to a diminished insulin release and thereby fat storage and obesity. The preventive effect of breast-feeding on overweight and obesity may also be related to the slower growth during the first year of life in breast-fed infants as compared with formula-fed infants (62). Two systematic reviews clearly showed that upward percentile crossing for weight and length in infancy was associated with late obesity (odds ratios for obesity risk ranging from 1.2 to 5.7 in infants with rapid growth) (34,35).
Little information is available on the long-term development of body composition of previously breast-fed infants. Butte et al (63) have looked at the development of lean and fat mass and observed that, although weight velocity was lower in breast-fed infants in the 3- to 6-month period, fat mass and fat mass percentage were higher in breast-fed compared with formula-fed infants in the same interval. These issues deserve further attention.
A review of 7 studies including 76,744 subjects suggested that breast-feeding may provide a degree of long-term protection against the development of type 2 diabetes (OR 0.61, 95% CI 0.41–0.85), with lower blood glucose and serum insulin concentrations in infancy and marginally lower insulin concentrations in later life (64). This risk reduction for type 2 diabetes was also reported in the WHO meta-analysis (39).
In conclusion, the potential for breast-feeding to contribute to reduction of later obesity development, and its possible effects on type 2 diabetes should be explored in more detail.
Disorders of the Immune System
In the 1930s, a large 9-month follow-up study involving more than 20,000 infants found an impressive 7-fold reduction in the incidence of eczema comparing breast-feeding with cow's milk (65). Although the impact of breast-feeding on the development of allergies has been investigated continuously ever since, the issue remains controversial today. The potential for reverse causation should also be considered as an additional methodological drawback for assessing the impact of breast-feeding on the risk for allergy. Indeed, mothers who know that their infants are at risk for allergy may be more likely to breast-feed but also to breast-feed for a longer time than mothers of infants with no family risk for allergy. Moreover, strong genetic and environmental factors interact with breast-feeding.
Some breast-fed infants with atopic eczema may benefit from elimination of cow's milk, egg, or other antigens from their mother's diet. Maternal dietary antigens also have the ability to cross the placenta. However, prescription of an antigen avoidance diet during pregnancy is unlikely to reduce substantially the child's risk of atopic disease, and such a diet may adversely affect maternal or fetal nutrition, or both (66). There is also no convincing evidence for a long-term preventive effect of maternal diet during lactation on atopic disease in childhood (67). The benefits of breast-feeding seem to be limited to at-risk infants, that is, those with a first-degree relative (father, mother, sibling) presenting with confirmed atopic disease. The AHRQ and Dutch meta-analyses pointed to a transient, protective effect of exclusive breast-feeding for at least 4 months on atopic dermatitis, wheezing, and asthma in infancy and early childhood (4,5). It is unlikely that a policy of exclusive breast-feeding would prevent allergy, especially its respiratory manifestations. Whatever this protective effect, women with a family history of allergy should breast-feed their infants like everyone else, and, in this targeted population, exclusive breast-feeding is recommended until the age of 6 months.
Type 1 Diabetes
Two meta-analyses suggest that breast-feeding for at least 3 months reduced the risk of childhood type 1 diabetes compared with breast-feeding for less than 3 months, with a 19% (95% CI 11%–26%) reduction and a 27% (95% CI 18%–35%) reduction, respectively (4,5). In addition, 5 of 6 studies published since the meta-analyses reported similar results (5). The Dutch and the AHRQ meta-analyses also suggest a possible protective effect of breast-feeding on the occurrence of diabetes type 1 later in life (4,5). Early introduction of cow's milk protein into the infant diet may be the main contributory factor. More information will come from the TRIGR (Trial to Reduce IDDM in the Genetically At-Risk) study, randomising high-risk infants to different supplemental formulae, either a hydrolysed feed or a regular cow's milk–based formula, after breast-feeding for 6 to 8 months of life (68).
A recent review of 6 observational studies suggested that breast-feeding may protect against the development of coeliac disease (CD) (69). With the exception of a small study, an association was found between increasing duration of breast-feeding and reduced risk of developing CD. The meta-analysis showed that the risk of CD was markedly reduced in infants who were breast-feeding at the time of gluten introduction as compared with nonbreast-fed infants (OR 0.48, 95% CI 0.40–0.59). However, breast-feeding may not provide a permanent protection against CD but may only delay the onset of symptoms.
Morris et al (70) recently reported that both early (less than or equal to 3 months) and late (more than or equal to 7 months) introduction of gluten-containing cereals were associated with an increased risk of CD. This study was based on a cohort at risk for the development of CD or diabetes mellitus, based on human leukocyte antigen typing, or having a first-degree relative with type 1 diabetes mellitus. On the basis of current data the Committee considers it prudent to avoid both early (below 4 months) and late (7 or more months) introduction of gluten and to introduce gluten while the infant is still breast-fed (23).
Inflammatory Bowel Disease
A meta-analysis showed a protective effect of breast-feeding on the risk of inflammatory bowel disease (IBD): the risk for Crohn disease (CD) and for ulcerative colitis (UC) decreased by 33% and 23%, respectively (71). However, out of a total of 17 studies, only 4 studies of CD and 4 studies of UC were of high methodological quality. The Dutch meta-analysis pointed to evidence of a protective effect of breast-feeding against CD and to insufficient evidence for UC (4). A paediatric, population-based, case-control study was performed in northern France to examine the environmental risk factors associated with IBD (72). In a multivariate model adjusted for mother's education level, breast-feeding (partial or exclusive) was a risk factor for the development of CD (OR 2.1, 95% CI 1.3–3.4; P = 0.003), but not for UC. Further studies are needed to fully understand the relation between breast-feeding and IBD.
Breast milk may have a role in the prevention of malignant disease by stimulating or modulating the immune response and promoting its development in early life. A recent meta-analysis showed that long-term (>6 months) breast-feeding was associated with a small but significant reduction in the risk of acute lymphocytic leukaemia (OR 0.80, 95% CI 0.71–0.91) (5). The Dutch meta-analysis concluded that there is a possible reduced risk for childhood leukaemia in breast-fed infants (4). Kwan et al (73) reported a reduction in the risk of acute myelogenous leukaemia for long-term breast-feeding (OR 0.85, 95% CI 0.73–0.98) but not for short-term breast-feeding (less than or equal to 6 months) (OR 0.90, 95% CI 0.80–1.02). A meta-analysis of 11 studies showed that breast-fed women have a slightly reduced risk of premenopausal breast cancer (relative risk 0.88, 95% CI 0.79–0.98) but not of postmenopausal breast cancer (74). The evidence for a causal relation between breast-feeding and protection against malignant disease must be considered weak.
Many studies have shown that breast-feeding is associated with an enhanced neurodevelopment, but causal relation is difficult to establish because of many confounding factors. The meta-analysis of Anderson et al (75) showed an increment in cognitive function of 3.2 points after adjustment for maternal intelligence in breast-fed infants compared with formula-fed infants. Better cognitive development was present as early as 6 months of age and was sustained throughout childhood and adolescence. Low-birth-weight infants derived larger benefits (5.2 points) than did normal-weight infants (2.7 points). Increasing duration of breast-feeding was accompanied by an increase in cognitive development. The most important residual confounding factor is the influence of maternal socioeconomic status on the child's cognitive development. However, a study from the Philippines evaluated the relation between breast-feeding and cognitive development in a population in which socioeconomic advantage was inversely correlated with rate of breast-feeding, the opposite of industrialised countries (76). Scores at 8.5 and 11.5 years were higher for infants breast-fed longer (1.6 points and 9.8 points higher among normal birth weight and low birth weight infants, respectively, breast-fed infants for 12 to 18 months versus <6 months). The large cluster randomisation study from Belarus showed that breast-feeding promotion resulted in a significant increase in verbal IQ (7.5 points; 95% CI 0.8–14.3) (77). Teachers' academic ratings were significantly higher in the experimental group for both reading and writing.
Little is known about the effects of breast-feeding on adult cognition. A positive association between duration of breast-feeding and cognitive functions was observed in 2 samples of young Danish adults, assessed with 2 different IQ tests (78). In men ages 60 to 74 years from the Caerphilly cohort, having been artificially fed was associated with a lower cognitive function only in those with a birth weight below the median (79). However, differences in age-related decline in cognitive function may weaken the association, so that it was only significant among those with low birth weight.
The use of sibling comparisons weakens the effect of familial confounding variables. Evenhouse and Reilly examined the relation between breast-feeding history and cognitive ability in 2734 sibling pairs from the US National Longitudinal Study of Adolescent Health. The benefit of the effects of being ever breast-fed on intelligence score (Peabody Picture Vocabulary Test) assessed during adolescence was 1.7 and 2.4 points within and between families, respectively, and the difference was statistically significant (80). Another recent study involving >5000 US children also used sibling comparison analysis. Any confounding factor that was the same for both members of a pair of siblings was automatically controlled for (81). The mother's IQ was more highly predictive of breast-feeding status than were her race, education, age, poverty status, smoking, the home environment, or the child's birth weight or birth order. One standard deviation advantage in maternal IQ more than doubled the odds of breast-feeding. Breast-feeding was associated with an increase of around 4 points in mental ability that was mostly accounted for by maternal intelligence. When fully adjusted for relevant confounders, the benefit in breast-fed infants was small and not significant (0.52, 95% CI −0.19 to 1.23). However, sibling comparisons cannot completely eliminate bias because of unobserved factors that lead a mother to feed 2 infants differently and that also drive children's later outcomes.
The benefits of breast milk may be related to its content of docosahexaenoic acid (DHA, 22: 6ω3), that plays an important role in brain and retina development. Breast-fed infants undergoing postmortem examination because of sudden death had a greater proportion of DHA in their brain cortex relative to those fed formula (82). The role of DHA is also suggested by the effect of DHA supplementation of breast-feeding mothers from delivery to 4 months postpartum. There was no effect on visual function at 4 and 8 months or on neurodevelopmental indices at 1 year. In contrast, the Bayley Psychomotor Development Index, but not the Mental Development Index was significantly higher in the supplemented group at 30 months of age (83). It has been recently shown that the association between breast-feeding and better cognitive development was moderated by a genetic variant in FADS2, a gene encoding the delta-6 desaturase that is the rate-limiting step on the metabolic pathway leading to arachidonic and DHA production (84). Brain sialic acid may play a beneficial role in brain development and cognition (85); concentrations have been reported to be different between breast-fed and formula-fed infants.
The available evidence suggests that breast-feeding may be associated with a small but measurable advantage in cognitive development that persists into adulthood. Although the effect size of cognitive benefits may not be of major importance for an individual, it could provide a significant advantage on a population basis.
SUPPLEMENTATION OF BREAST-FED INFANTS
The vitamin D status of European women of childbearing age and thereby the vitamin D content of breast milk is often inadequate because of the limited use of vitamin D supplemented cows' milk and dairy products, lack of sunshine, and ethnic tradition of covering of the body. Moreover, the risk of sunburn (short-term) and skin cancer (long-term) attributable to sunlight exposure makes it prudent to counsel against sun exposure and to support the use of sunscreen in infancy (24). Breast-fed infants should receive daily vitamin D supplementation regardless of maternal vitamin D status. The breast-fed infant has limited sources of vitamin K, usually present only in low concentrations in human milk. Generally, European paediatric societies recommend a vitamin K supplementation during the first weeks or months of life, either only to breast-fed infants or to all infants (86). There are different practices of fluoride supplementation in Europe, which take into account the fluoride content in drinking water. Premature and low birth weight infants as well as infants with iron deficiency require early iron supplementation that can be administered while continuing exclusive breast-feeding. During the complementary feeding period, >90% of the iron requirements of a breast-fed infant must be met by complementary foods, which should provide sufficient bioavailable iron (23).
CONTRAINDICATIONS TO BREAST-FEEDING
There are a few conditions under which breast-feeding may not be in the best interest of the infant. The main contraindication to breast-feeding is maternal human immunodeficiency virus (HIV) infection. Transmission of HIV during breast-feeding is a multifactorial process. The risk factors are maternal viral load, maternal immune status, breast health, pattern and duration of breast-feeding. To minimise the risk of HIV-transmission, WHO recommends “when replacement feeding is acceptable, feasible, affordable, sustainable and safe, avoidance of all breast-feeding by HIV-infected mothers is recommended, otherwise, exclusive breast-feeding is recommended during the first months of life” (87). Indeed, a study performed in South Africa showed that exclusive breast-feeding was associated with a lower risk of postnatal transmission at 6, 12 and 18 months than predominant breast-feeding and mixed breast-feeding (88). An intervention cohort study in South Africa also showed that breast-fed infants who received solids during the first 6 months were nearly 11 times more likely to acquire HIV infection than those exclusively breast-fed, and that infants who at 14 weeks of age were fed both breast milk and formula milk were nearly twice as likely to be infected as those exclusively breast-fed (89). In Europe, HIV-positive women should be counselled not to breast-feed.
Breast-feeding is also contraindicated in mothers who are human T-cell lymphotropic virus (HTLV) type I– or II–positive, and in mothers who have herpes simplex lesions on a breast (90). Breast-feeding is not contraindicated for infants born to mothers who are hepatitis B surface antigen–positive and those who are infected with hepatitis C virus (90). Cytomegalovirus (CMV) infection transmitted via breast milk is usually asymptomatic in term infants, whereas preterm infants are at greater risk of symptomatic CMV infection, such as sepsis-like symptoms (91). In very low birth weight infants (<1500 g or gestational age <32 weeks) born to CMV-seropositive mothers, the benefit of breast-feeding should be weighed against the risk of CMV transmission. Milk pasteurisation prevents CMV infection. Freezing significantly reduces the CMV viral load in breast milk and may also reduce the risk of infection.
In the classic variant of galactosaemia, in which no erythrocyte galactose-1-phosphate uridyl transferase (gal-1-put) activity occurs, the infants are unable to metabolise galactose, so that breast-feeding should be avoided. In the milder variant of the disease, with partial reduction in the amount of gal-1-put, the infants may be breast-fed or at least partially breast-fed because of a higher tolerance to galactose (90). There are few other inborn errors of metabolism representing absolute contra-indications to breast-feeding, for example, disorders of long-chain fatty acid oxidation and related disorders, as well as congenital lactase deficiency, whereas some amounts of breast milk may be tolerated in other disorders such as hyperchylomicronaemia (type 1 hyperlipidaemia) and abetalipoproteinaemia. Although there is no definite evidence that breast-feeding improves the outcome of phenylketonuria from randomised trials, observational studies have shown some developmental advantages, suggesting that breast-feeding should be encouraged to the extent permitted by the individual phenylalanine tolerance (92,93). Further work is needed in developing guidelines for feeding and for clinical and biochemical monitoring for breast-fed infants with inherited metabolic disorders (94).
Breast-feeding is contraindicated in mothers who are receiving diagnostic or therapeutic radioactive isotopes or have had exposure to radioactive materials, and in those who are receiving specific medications (95).
Most drugs transfer into human milk, but most do so in subclinical amounts and it is often safe to breast-feed while using a medication. However, the choice of medication is extremely important. Health professionals and parents are advised to carefully choose those with limited adverse effect profiles. Almost always, with the adequate choice of medication, breast-feeding can be continued while the mother undergoes drug therapy (14).
Human milk may be compromised by unwelcome chemicals from the environment, especially persistent organic pollutants, which accumulate in the food chain, as a result of eating, drinking, and living in a technologically advanced world. However, the presence of an environmental chemical in human milk does not necessarily indicate that a serious health risk exists for breast-fed infants. No adverse effect has been clinically or epidemiologically demonstrated as being associated solely with consumption of human milk containing background levels of environmental chemicals (96). In Europe the general downward trend in the level of persistent organic pollutants, such as dioxins, dibenzofurans, and dioxin-like polychlorobiphenyls, indicates a continuing decline in exposure as measures to reduce emissions have been implemented. The health benefits of breast-feeding still far outweigh the potential harmful effects related to the presence of environmental contaminants in breast milk.
Breast-feeding is the natural and advisable way of supporting the healthy growth and development of young children. There are numerous indicators of benefits of breast-feeding on child health, both during infancy and later in life; a reduced risk of infectious diarrhoea and acute otitis media are the best documented effects.
Exclusive breast-feeding for around 6 months is a desirable goal, but partial breast-feeding as well as breast-feeding for shorter periods of time are also valuable. Continuation of breast-feeding after the introduction of complementary feeding is to be encouraged as long as mutually desired by mother and child.
Although it is acknowledged that parents are responsible for decisions on breast-feeding of their infants, the role of health care workers, including paediatricians, is to protect, promote, and support breast-feeding.
Health care workers should be trained in breast-feeding issues and counselling, and they should encourage practices that are in line with the International Code for Breast Milk Substitutes. Societal standards and legal regulations that facilitate breast-feeding should be promoted, such as providing maternity leave for at least 6 months and protecting working mothers.
Breast-feeding practices should be regularly monitored, applying agreed-upon definitions of breast-feeding, and strategies for improving practice should be scientifically evaluated.
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Keywords:© 2009 Lippincott Williams & Wilkins, Inc.
Breast-feeding; Breast milk; Health benefits; Public health