Nestle Nutrition workshop series. Paediatric programme最新文献

Consumption of dairy products and their milk proteins increase satiety and reduce food intake and blood glucose response when consumed alone or with carbohydrate. Dairy proteins are of interest because proteins are more satiating than either carbohydrate or fat, and they regulate food intake and metabolic functions by the combined actions of the intact protein, encrypted peptides and amino acids on gastrointestinal and central pathways. As shown in this review, milk proteins have physiologic functions that contribute to the maintenance of a healthy body weight and control of factors associated with the metabolic syndrome through their effects on mechanisms regulating food intake and blood glucose. More recent reports show that these benefits can be achieved within the range of usual consumption of dairy. In addition, recent research points to an intrinsic value of small amounts of milk protein or dairy consumed shortly before a meal to reduce the glycemic response to carbohydrate and that this is not at the cost of increased demand for insulin.

Cow's milk is a major food for young children. Whole cow's milk is known to be detrimental to infants, mainly due to its low iron content. The negative association with iron status led to recommending the introduction of formula feeding in infancy during the weaning period or when breastfeeding ceased. More recently, the literature suggests that consuming whole cow's milk in infancy has unfortunate effects on growth, especially weight acceleration and development of overweight in childhood. These issues are discussed in the following chapter. Other suggested reasons for the avoidance of whole cow's milk in infancy are touched upon, such as milk protein allergy and high renal solute load. The hypothesis about early cow's milk introduction in the pathology of certain diseases, mainly through the peptide β-casomorphin-7, is briefly reviewed, showing that there is no clear evidence for the suggested associations. The chapter gives a recent example of introducing formula at 6 months of age instead of whole cow's milk in infants' diet in Iceland. Several aspects of consuming whole cow's milk in infancy can be found in recent reviews.

Insulin and insulin-like signaling regulate survival and lifespan in a variety of animal species, from nematodes and flies to higher vertebrates and mammals. Recently, it was shown that brain IGF-I receptor and brain IRS2 control mammalian lifespan, and that this occurs through neuroendocrine mechanisms, control of energy metabolism and modified stress resistance. Furthermore, it was demonstrated that insulin receptor substrate molecules are implicated downstream of insulin and IGF receptors in the extension of lifespan. We showed recently that early postnatal diet plays a significant role in the development of the somatotropic axis, and that part of the neuroendocrine plasticity of growth hormone secretion depends on postnatal nutrition. We also showed that the prevalence of cardiovascular and metabolic pathologies varied with the development of somatotropic function. Neuroendocrine pathways are also prime targets for pharmacological treatments, and administration of rapamycin to adult mice has indeed recently been reported to prolong lifespan in mice. With respect to human aging, new studies identified several genes of the somatotropic axis as longevity determinants, and a recent study shows that variants of FOXO3A, downstream signaling molecule in the insulin/IGF pathway, are associated with extreme longevity in humans. Finally, several functional mutations of the human IGF-IR have been discovered in centenarians.

The provision of donor human milk instead of formula is an important contribution to the nutrition and protection from infections for preterm infants. Systematic reviews suggest a lower risk of necrotizing enterocolitis with pasteurized donor human milk (PDHM) as opposed to artificial formula, although evidence supporting PDHM use from randomized control trials is limited. Human milk banks (HMBs) must have a risk management system to maintain a safe product especially as many operate in an unregulated environment. To ensure safety, the HMB in Australia has committed to meet the appropriate standards recommended in the Code of Good Manufacturing Practices (Blood and Tissues) and models risk management during processing on Codex HACCP (Hazard Analysis Critical Control Point) requirements. There is scope to continually reevaluate the screening of donors and quality standards recommended during HMB. This will be most effective if strong networks of HMBs are developed with regional reference laboratories to encourage compliance with safety guidelines. Further research and development is needed to refine technology for treating donor milk such as thermal ultrasound and ultraviolet light, aimed at the retention of full bioactivity. HMB networks will facilitate collection of evidence for refining HMB practice which should translate to improved outcomes for preterm and sick infants. Cost effectiveness is most likely when HMBs are associated with large neonatal intensive care units.

Fetal and early life may be a critical period for the development and/or programming of metabolic systems, including the skeleton. There are increasing human data from cohort studies on the association between early life nutrition and bone development in children. Breastfed children initially have lower bone mass than bottle-fed children, but longer-term studies suggest that they have higher bone mass (size adjusted) by age 8 years, especially in children born at term. By the time of peak bone mass, both preterm and term children have higher bone mass indicating a different bone accrual trajectory curve. These children also have lower fracture risk. Diet in utero has also been associated with subsequent bone mass from ages 6 to 16 years (but not fracture). Positive associations include milk, phosphorus, magnesium, potassium, protein, folate, calcium and vitamin D, while fat intake is negative. Smoking also interferes with bone mineralization possibly due to impaired placental function, but this deleterious effect on bone mass appears to diminish over time. All of these associations are statistically significant and independent of important confounders and later environmental exposures, suggesting that osteoporosis prevention programs need to start very early in the life cycle.

Food-derived peptides, specifically those derived from milk, may adversely affect health by increasing the risk of insulin-dependent diabetes. This position is based on the relationship of type 1 diabetes (T1D) and the consumption of variants A1 and B β-casein from cow's milk. It appears that β-casomorphin-7 (BCM-7) from β-casein may function as an immunosuppressant and impair tolerance to dietary antigens in the gut immune system, which, in turn, may contribute to the onset of T1D. There are thirteen genetic variants of β-casein in dairy cattle. Among those variants are A1, A2, and B, which are also found in human milk. The amino acid sequences of β-casomorphins among these bovine variants and those found in human milk are similar, often differing only by a single amino acid. In vitro studies indicate BCM-7 can be produced from A1 and B during typical digestive processes; however, BCM-7 is not a product of A2 digestion. Evidence from several epidemiological studies and animal models does not support the association of milk proteins, even proteins in breast milk, and the development of T1D. Ecological data, primarily based on A1/ A2 variations among livestock breeds, do not demonstrate causation, even among countries where there is considerable dairy consumption.

The main aspects of infant feeding that have been studied in humans in association with the subsequent development of adipose tissue include breastfeeding, rapid infancy weight gain, and weaning practices. While observational studies have consistently shown a protective effect of breastfeeding on the development of obesity, these studies may be confounded by unmeasured or unknown factors, as suggested by one study using a sibling design and one study using a randomized breastfeeding promotion intervention design. Observational studies and findings from a limited number of experimental studies suggest that rapid weight gain during infancy may be associated with an increased risk for obesity in childhood and adulthood. The association of weaning practices with later obesity has not been extensively studied, and the preliminary findings are inconsistent. Additional research studies, especially randomized interventions with long-term follow-up, are necessary in order to assess if short nutrition interventions during the critical period of infancy can have long-term benefits on the prevention of obesity.

The etiology of micronutrient deficiencies in infancy is well described. The deficiencies are caused by one of the following four scenarios: (a) low initial stores of micronutrients from micronutrient deficiency during gestation, premature birth or low birthweight; (b) rapid postnatal growth; (c) ingestion of foods with low concentration of micronutrients, and (d) gastrointestinal pathology resulting in the malabsorption of nutrients, including micronutrients. Understanding the cause of the deficiencies is essential in planning interventions to either prevent or treat them. This chapter will focus on the dietary causes of micronutrient deficiencies and recent strategies to correct them.

Food habits, an integral part of all cultures, have their beginnings during early life. This chapter reviews the development of the senses of taste and smell, which provide information on the flavor of foods, and discusses how children's innate predispositions interact with early-life feeding experiences to form dietary preferences and habits. Young children show heightened preferences for foods that taste sweet and salty and rejection of that which tastes bitter. These innate responses are salient during development since they likely evolved to encourage children to ingest that which is beneficial, containing needed calories or minerals, and to reject that which is harmful. Early childhood is also characterized by plasticity, partially evidenced by a sensitive period during early life when infants exhibit heightened acceptance of the flavors experienced in amniotic fluid and breast milk. While learning also occurs with flavors found in formulae, it is likely that this sensitive period formed to facilitate acceptance of and attraction to the flavors of foods eaten by the mother. A basic understanding of the development and functioning of the chemical senses during early childhood may assist in forming evidence-based strategies to improve children's diets.