Breast-feeding: A commentary by the ESPGHAN Committee on Nutrition

Breast- v. formula-feeding: impacts on the digestive tract and immediate and long-term health effects

The health benefits of breast-feeding have been recognised for a long time. In particular, breast-feeding is associated with lower incidence of necrotising enterocolitis and diarrhoea during the early period of life and with lower incidence of inflammatory bowel diseases, type 2 diabetes and obesity later in life. The higher nutritional and protective degree of human milk is related to its nutritional composition that changes over the lactation period and to the biological activities of specific components while lower growth rate of breast-fed infants may be attributed to their self-regulation of milk intake at a lower level than formula-fed infants. Many results now suggest that the developmental changes in intestinal and pancreatic function that occur postnatally are modulated by the diet. Indeed, formula-feeding induces intestinal hypertrophy and accelerates maturation of hydrolysis capacities; it increases intestinal permeability and bacterial translocation, but does not induce evident differences in microbiota composition. Whether these changes would be beneficial for enhancing absorptive capacities and for educating the gut-associated immune system remains to be further studied. Moreover, it is evident that formula-feeding increases basal blood glucose and decreases plasma ketone body concentrations, while discrepancies on postprandial glycaemia, insulin and incretin responses in both human studies and experimental studies are inconclusive. Manipulating the composition of formula, by reducing protein content, adding prebiotics, growth factors or secretory IgA can modulate intestinal and pancreatic function development, and thereby may reduce the differential responses between breast-fed and formula-fed neonates. However, the developmental responses of the digestive tract to different feeding strategies must be elucidated in terms of sensitivity to developing diseases, taking into account the major role of the intestinal microbiota.

Science base of complementary feeding practice in infancy

PURPOSE OF REVIEW

The review presents a selection of publications on complementary feeding in industrialized countries during 2008-2009, after the publication of the ESPGHAN position paper in early 2008.

RECENT FINDINGS

The WHO recommendation for introduction of complementary feeding at 6 months is adapted in many countries, but the issue is still discussed and many mothers introduce complementary feeding as early as before 4 months. The European Food Safety Authority recently published a comprehensive review on the appropriate age for the introduction of complementary feeding and concluded that introduction between 4 and 6 months is safe. One study showed that delaying introduction of complementary feeding up to 6 months resulted in lower risk of overweight as adult. Milk protein is stimulating insulin-like growth factor-1 and growth and a recent study supports a long-term programming of the insulin-like growth factor-1 axis. There is now a broad consensus that there is no need to delay the introduction of hyperallergenic foods, which might even increase the risk of allergic disease. Randomized studies show that docosahexaenoic acid may affect heart rate and thereby cardiovascular regulation.

SUMMARY

Despite some recent interesting publications, there is still a need for more large randomized studies to further explore to what degree the time of introduction and composition of complementary foods have effects on growth, development and especially the long-term risk of diseases.

Clinical practice: Breastfeeding and the prevention of allergy

The increase in allergic disease prevalence has led to heightened interest in the factors determining allergy risk, fueled by the hope that by influencing these factors one could reduce the prevalence of allergic conditions. The most important modifiable risk factors for allergy are maternal smoking behaviour and the type of feeding. A smoke-free environment for the child (to be), exclusive breastfeeding for 4-6 months and the postponement of supplementary feeding (solids) until 4 months of age are the main measures considered effective. There is no place for restricted diets during pregnancy or lactation. Although meta-analyses suggest that hypoallergenic formula after weaning from breastfeeding grants protection against the development of allergic disease, the evidence is limited and weak. Moreover, all current feeding measures aiming at allergy prevention fail to show effects on allergic manifestations later in life, such as asthma. In conclusion, the allergy preventive effect of dietary interventions in infancy is limited. Counselling of future parents on allergy prevention should pay attention to these limitations.

Determinants of breast-feeding in a Finnish birth cohort

OBJECTIVE

To assess milk feeding on the maternity ward and during infancy, and their relationship to sociodemographic determinants. The validity of our 3-month questionnaire in measuring hospital feeding was assessed.

DESIGN

A prospective Finnish birth cohort with increased risk to type 1 diabetes recruited between 1996 and 2004. The families completed a follow-up form on the age at introduction of new foods and age-specific dietary questionnaires.

SETTING

Type 1 Diabetes Prediction and Prevention (DIPP) project, Finland.

SUBJECTS

A cohort of 5993 children (77 % of those invited) participated in the main study, and 117 randomly selected infants in the validation study.

RESULTS

Breast milk was the predominant milk on the maternity ward given to 99 % of the infants. Altogether, 80 % of the women recalled their child being fed supplementary milk (donated breast milk or infant formula) on the maternity ward. The median duration of exclusive breast-feeding was 1.4 months (range 0-8) and that of total breast-feeding 7.0 months (0-25). Additional milk feeding on the maternity ward, short parental education, maternal smoking during pregnancy, small gestational age and having no siblings were associated with a risk of short duration of both exclusive and total breast-feeding. In the validation study, 78 % of the milk types given on the maternity ward fell into the same category, according to the questionnaire and hospital records.

CONCLUSIONS

The recommendations for infant feeding were not achieved. Infant feeding is strongly influenced by sociodemographic determinants and feeding practices on the maternity wards. Long-term breast-feeding may be supported by active promotion on the maternity ward.