Infant Feeding: Human Milk and Formula

Infant Feeding: Human Milk and Formula

Infant Feeding: History and Perspective • Human Milk • Human Milk Substitutes • Science, Medicine and Industry

Feeding the Infant • Considerations • Infant (needs, tolerance, acceptance, safety) • Family preferences • Cost and availability • Prevention, health, development, and programming

Feeding the Infant • Choices: • Human Milk • Standard Infant Formula (Cow, Soy) • Hypoallergenic (hydrolysates vs. amino acid based • Other specialty formulas • Beikost/solids/table foods

History Human milk substitutes Health and welfare Programs Formula Industry

Human Milk Substitutes Early evidence of artificial feeding Majority of infants received breast milk Maternal BF Wet nurses Wealthy women Orphans, abandoned, “illegitimate” Prematurity or congenital deformities

Wet Nurses • Work demands, societal needs, vanity, health requirements, social diversion • Proper selection: Questionable character-- Infant would suck in her vices • Wet Nurse Industry: emerging infant mortality/abuse • Impact of industrial revolution: Wet nurses made better money in factories

Human Milk Substitutes: Infant Mortality • Artificial feeding in first weeks of life associated with 100% mortality • 19th century infant mortality with “hand feeding” was 88% • Foundlings: 80% • In Dublin Foundling hospital 1775-96: 99.6%

Science, Medicine, and Industry Growth of child Health and welfare in early 20th century

Science, Medicine, and Industry Infant Morbidity and Mortality Recognition of association with human milk substitutes, and infection Industrial development Storage Safety Food industry

Human Milk Substitutes 1920-1950’s: evaporated or fresh cow’s milk, water and added CHO (prepared at home) 1950’s to present commercially prepared infant formulas have replaced home recipes

Infant Formulas - History Cow’s milk is high in protein, low in CHO, results in large initial curd formation in gut if not heated before feeding Early Formulas from 1920-1950 majority of non-breastfed infants received evaporated milk formulas boiled or evaporated milk solved curd formation problems cho provided by corn syrup or other cho to decrease relative protein kcals

Historical timeline 1900 Pasteurization of milk in US Association between bacteria and diarrhea 1912 U.S Children’s Bureau Public Health and Pediatricians efforts to improve infant/child health and decrease mortality 1920 Intro evaporated milk Cod liver oil prevents rickets Curd tension of milk altered Increased availability of refrigeration Vitamin C isolated Vitamin D prepared in pure form Improved sanitation

1940 Homogenized milk widely marketed 1960 Further advances in technology and packaging Commercially prepared infant formula becoming increasingly popular Historical timeline

1784: Underwood recommends cows milk as alternative to breast feeding 1800: glass feeding bottles 1838: Simon determines protein CM>BM 1845: Pratt patents rubber nipple 1856: Borden patents condensed milk 1883: Meyenberg patents evaporated goats milk 1885: Meigs analyses human milk Interesting Milestones in Infant Nutrition

Interesting Milestones in Infant Nutrition • 1911: MJ introduces Dextri-maltose • 1915: SMA • 1920: Franklyn (Similac) • 1929: MJ markets Sobee, hypoallergenic • 1930-60: Concentrated liquid, hydrolysed, elemental, and ready to feed formulas introduced • What now?

Infant Formula - History, cont. 50s and 60s commercial formulas replaced home preparation 1959: iron fortification introduced, but in 1971 only 25% of infants were fed Fe fortified formula Cow’s milk feedings started in middle of first year between 1950-1970s. In 1970 almost 70% of infants were receiving cow’s milk.

“No two hemispheres of any learned professor’s brain are equal to two healthy mammary glands in the production of a satisfactory food for infants” - Oliver Wendell Holmes

Human Milk Complements infant Immaturity Promotes maturation Epithelial growth factors and hormones Digestive enzymes - lipases and amylase

Characteristics and Advantages of Human Milk • Low renal solute load • Immunologic, growth and trophic factors • Decrease illness, infection, allergy • Improved digestion and absorption • Nutrient Composition: CHO, Protein, Fatty Acid, etc • Cost • Other

Human Milk • Colostrum • Higher concentration of protein and antibodies • Transitions around days 3-5 • Mature by day 10

Human Milk Nutrient composition of human milk is remarkable for its variability, as the content of some of the nutrients change during lactation, throughout the day, or differ among women, while the content of some nutrients remain relatively constant throughout lactation.

Role of Human Milk Components in GI Development: Current Knowledge and Future Needs: Donovan J Pediatr 2006:149:S49-S61 “ existing clinical and epidemiological studies support a developmental advantage for breastfeeding. However, our understanding of the mechanisms by which HM components exert their actions within the human infant are limited by the large number of bioactive compounds in milk and the complexity of the potential interactions among the components and with the developing intestine”

Human Milk Compartments • Aqueous Phase • Ca, Mg, Ph, Na, Cl, CO2, casein proteins, whey proteins (lactoalbumin, lactoferrin, IgA, lysozyme, albumin) Lactose, amino acids, water soluble vitamins • Colloidal Dispersion • Caseins, Ca, Ph • Fat emulsion • Fat (phospholipid, TG, cholesterol) protein as fat globule membrane, enzymes, trace minerals, fat soluble vitamins, macrophages, neutrophils, lymphocytes

Milk Synthesis • Mammary gland contains stem cells and highly differentiated secretory alveolar cells at the terminal ducts. Stimulated by insulin and HGH synergized by prolactin, these cells are active in milk synthesis and secretion

Milk synthesis and secretion • Exocytosis (protein, lactose, Ca/Ph, citrate) • Fat synthesis (TG synthesized in cytoplasm and smooth endoplasmic reticulum + precursors imported from maternal circulation): alveolar cells synthesize SCFA • Secretion of ions and water • Immunoglobins transferred from extracellular spaces

Paracellular Pathway (5th process) • The paracellular spaces between alveolar cells normally prevent transfer secondary to tight junctions. If these spaces become “leaky” plasma constituents may pass directly into the milk.

Milk Synthesis and secretion • Under neuroendocrine control that varies with timing and stage of lactation • Prolactin • Lactogens • Estrogen • Thyroxine • Growth hormone • ACTH • other • Stimulus: infant suckling

Milk synthesis • Protein: vast majority of proteins present in human milk are specific to mammary secretions and not identified in any quantity elsewhere in nature: • Immunoglobins transferred from plasma in early stages of lactation • De novo protein synthesis by mammary gland

Diet, milk production, and milk composition There is a great variation in milk composition during a feed, from feed to feed, and even between breasts. The impact of dietary variation and milk composition is unclear. Overall milk composition remains relatively unaffected by diet variations although there are reports to the contrary: DHA and ARA supplementation, vegan diet, drugs and environmental contaminants,…..

Breast milk composition and Diet DHA levels of breast milk vary with diet. Increased amounts of DHA have been found in the breast milk of mothers consuming fish or fish oil, and with supplementation. Water soluble vitamins may vary with diet. Diets inadequate in B12 or thiamin have been associated with case reports of deficiency in infants. High intakes of Vitamin C, however, does not appear to change the content of breast milk. Supplementation of fat soluble vitamins do not appear to alter the content of breast milk Iron supplementation does not appear to alter the iron content of breast milk

Influence of diet on milk composition • Protein-energy malnutrition impacts milk volume. Composition remains relatively unaffected • Water soluble vitamins move readily from serum to milk thus dietary fluctuations are more apparent • B12 vegan, case report of beriberi….. • Fat soluble vitamin content not improved with supplementation • Fatty acid composition (DHA and ARA) altered by maternal diet and supplementation

Science and Lactation: Frank Hytten “ In general, it is probable that the breast has a high priority for nutrients and that moderate maternal under nutrition will have little effect on milk production. But severe malnutrition, which rarely exists without associated ill-health and other adverse circumstances, may reduce milk yield”

Distribution of Kcals: Breast milk

Protein: Predominant protein of human milk is whey. Casein/whey ratio is between 40:60 and 30:70 Casein: proteins of the curd (low solubility at pH 4.6) Whey: soluble proteins (remain soluble at pH 4.6) Lactalbumin Lactoferrin Secretory IgA Lactoglobulin

Carbohydrate • Predominant carbohydrate of breast milk is lactose (7.3 g/dl) • Oligosaccharides (1.2 g/dl) • Prebiotics: nondigestible CHO that enhance the growth of “favorable” bacteria and contribute to the unique GI bacterial characteristics of BF infant (bifidobacteria)

Fat • 2.5- 4.5% Fat (provides approx 50% of calories) • Contained in membrane enclosed milk fat globules • Core: TG (98-99%of total milk fat) • Membrane: phospholipids, cholesterol, protein • DHA/ARA: wide variations

DHA/ARA concentration variation in human milk • DHA: 0.1-1.4% • ARA: 0.31- 0.71% • DHA lowest in populations with high meat intake and highest in populations with high fish intake

Breast milk and establishment of core microbiome Definition: Full collection of microbes that naturally exist within the body. Alterations or disruptions in core microbiome associated with chronic illness: Crohns disease, increased susceptibility to infection, allergy, NEC, etc

Microbiome • Beneficial effect for the host: • Nutrient metabolism • Tissue development • Resistance to colonization with pathogens • Maintenance of intestinal homeostasis • Immunological activation and protection of GI integrity

Human milk and microbiome • Core microbiome established soon after birth • Core microbiome of breastfeeding infant similar to core microbiome of lactating mother • Components of breast milk supporting establishment of microbiome • Prebiotics,probiotics

AAP Policy Statement: Breastfeeding and the use of human milk • AAP statement includes 15 recommendations on Breastfeeding healthy term infants including: • Establish peripartum policies and practices supporting breastfeeding • Place infant skin to skin after delivery until first feeding is accomplished

AAP Policy Statement:Recommendations continued • Supplements (water, glucose water, formula) should not be given unless medically indicated • Avoid pacifier during initiation (? Recent OHSU report) • 8-12 feedings at the breast every 24 hours during early weeks • All newborn breastfeeding infants should be seen by HCP at 3-5 days and again at 2-3 weeks of age • All breast feeding infants should receive 200 (changed to 400) IU Vitamin D

AAP Policy Statement: Breastfeeding and the use of human milk: Pediatrics 115 #2 2005 • Human milk is species specific and uniquely superior for infant feeding • Exclusive breastfeeding is the reference or normative model against which all alternative methods must be measured in regards to growth, development and health • Research provides strong evidence that human milk feeding decreases the incidence and/or severity of a number of infectious diseases (meningitis, Otitis media, UTIs, Respiratory tract infections, NEC, diarrhea)

AAP Policy Statement: Breastfeeding and the use of human milk: • Contraindications to breastfeeding • Galactosemia • Maternal use/exposure to certain radioactive or chemotherapeutic agents • Maternal abuse of “street drugs” • Active HSV lesions of breast • Maternal HIV (in USA)

AAP Policy Statement: Breastfeeding and the use of human milk: • Some studies suggest decreased incidence of SIDS, diabetes (type 1 and 2), leukemia, obesity, hypercholesterolemia, and allergy (asthma and atopy) • Breastfeeding has been associated with slightly enhanced performance on tests of cognitive development.

Newborn Visit: Breastfeeding Maternal care rest fluids relieving breast engorgement caring for nipples eating properly Follow-up support from the health professional by telephone, home visit, nurse visit, or early office visit.

Cautionary Tales Cooper et al. Pediatrics 1995. Increased incidence of severe breastfeeding malnutrition and hypernatremia in a metropolitan area. Rolf et al. ACTA Paediatrica 2009. A nationwide study on hospital admissions due to dehydration in exclusively breastfed infants in the Netherlands:its incidence, clinical characteristics, treatment and outcome Lozoff et al. J Pediatrics 2009 Higher Infant Blood Levels with Longer Duration of Breastfeeding

Cooper. 5 breastfed infants admitted to Children’s hospital in Cincinnati over 5 months period for breastfeeding malnutrition and dehydration Age of admission: 5-14 days Weight loss at admission 23%, range 14-32% Serum Na: 186 mmol/L, range 161-214 (136-143 wnl) mothers were between the ages of 28 and 38, had prepared for breastfeeding 3 had inverted nipples and reported latch-on problems before discharge 3 families had contact with health care providers before readmission including calls to PCP and home visit by PHN

Infant Feeding: Human Milk and Formula