Implications of Artificial Milk Feeding

1. Implications of Artificial Milk Feeding Dr. Howard Tyler AnS 337 Lactation Biology

2. Introduction to Artificial Milks • Feeding milk or colostrum from one species to newborns of another widely practiced • Precocial vs. altricial species concerns • Cows milk is primary source • Calves one of most precocial species • Creates composition issues

3. History of Infant Formula Feeding • Formula feeding practiced since WWI • Early formulas had no lactose (considered toxic until ’30’s) • Knowledge base of infant nutrient requirements built on errors in formulation of infant formula

4. Proteins …

5. Cow’s Milk-based Formulas • Two main types: • 1. Protein diluted to reach amount in human milk • add back CHO, fat, vitamins and minerals • 2. Casein diluted to reach amount in human milk • add back lactalbumin, fat, vitamins and minerals

6. Infant Nutritional Requirements Related to: • Growth velocity • Most rapid rate during lifetime • FAR slower than precocial species • Neurological development • Vulnerability to dehydration • High surface area:mass • Developmental immaturity • Digestive tract • Renal function

7. Developmental Factors Affecting Infant Nutrition Digestive tract • Low lipase levels and bile salt concentration • Low disaccharidase activity except lactase • Low saliva production • Low pancreatic amylase activity • Small stomach volume (10-20 mL) • Low gastric acidity • Renal system • Low urine concentrating capacity (700 mOsm/L) • Immune system • Intestinal epithelium permeable to macromolecules

8. Reconciling Developmental Barriers to Infant Feeding

9. Osmolality & Renal Solute Load • Human milk: low, less than 300 mosmolar, gut can easily handle • Creates renal solute load of 13 mosmol/100kcal • Cow’s milk: higher osmolality • Renal solute load of 46 mosmol/100kcal • Skim milk with milk solids added: renal solute load of 86 mosmol/100kcal • Infant formulas: 18-25 mosmol/100kcal

10. Potential Problems • Mixing formulas too strong (or weak) • Skim milk to infants or children under 2 year old • Energy:protein ratio • Whole milk under 1 year old • Allergies • Bacterial contamination • Formula, utensils, water all can be sources • Length of time between mixing and feeding

11. Proteins Whey or soluble proteins form very light curds and are easy to digest Whey proteins in human milk high in IgA These antibodies coat the surface of the small intestine, blocking binding sites to prevent bacterial attachment and allergens Casein forms very thick curds and is very difficult to digest Incidence of colic or pain in abdomen is generally higher in babies fed on cow’s milk because of thick curds that are formed from high amount of casein

12. Fats Breast milk contains higher levels of essential fatty acids, linoleic and linolenic acid, which are essential for the development of CNS and eyes Also contains bile salt-stimulated lipase Fats in breast milk bind less calcium as compared to other milks

13. Carbohydrates Not all the lactose present in breast milk is absorbed Some gets fermented producing lactic acid This helps to make the pH of the lower gut acidic Acidic pH inhibits the growth of pathogenic bacteria thus reducing the chances of diarrhea Acidic pH helps to keep the iron in ferrous form thus promoting its absorption Galactose is used during myelinization of the nervous system

14. Vitamins

15. Iron

16. Calcium Breast milk contains only about a third of the calcium as compared to cow’s milk Absorption of calcium from breast milk is much better due to low level of phosphates High levels of lactose also promote absorption of calcium Less binding of calcium by fats in the breast milk also helps in promoting better calcium absorption

17. Advantages of Breast Milk Over Formula • Antibodies • Less sugar than infant formulas • Contains amino acids, fatty acids, cholesterol not found in formulas • Growth factors (epidermal growth factor, etc.) • GnRH • Delta sleep inducing peptide • Disadvantages of breast milk: • harmful substances ingested by mother can pass to baby (especially lipid-soluble substances)

18. Anti-infective Properties • Bifidus factor: stimulates bifidobacteria, which fight against pathogenic bacteria • IgA, IgM, IgG: immunoglobulins that guard the gut against infective bacteria • Lactoferrin: binds iron away from bacteria • Macrophages: phagocytosis of infective bacteria • B12 binding protein: removes B12 from bacteria

19. Protection Against Infection • Reduces risk and severity of infectious illness among infants • diarrhea • otitis media • lower respiratory infections • bacteremia • bacterial meningitis • necrotizing enterocolitis • infant botulism • urinary tract disease • sudden infant death syndrome (SIDS) • colic

20. Other Health Benefits for Infant • Enhanced immune response to immunizations • Polio • Tetanus • Diptheria • haemophilus influenza

21. Other Breastfeeding Benefits for Baby • Promotes cognitive development • Better teeth and jaw development • Promotes facial and muscular development • Promotes normal weight gain • Promotes a strong bond between baby and mother • Reduces spitting up

22. Longer-term Health Outcomes • Reduces risk of chronic illness in childhood • Some food allergies • Type-1 insulin dependent diabetes • Lymphoma • Asthma • Obesity

23. Health Benefits for the Mother • Promotes more rapid return to pre-pregnancy weight • Reduces risk for certain cancers (lower estrogen) • Breast cancer • Uterine, ovarian, and endometrial cancers • Reduces post-partum hemorrhage • Promotes maternal attachment to baby • Reduces risk of osteoporosis • Saves money (~$1200/year)

26. Preterm and SGA* Infants: High Nutritional Risk • Physiologically immature • Metabolic abnormalities • Fluid and electrolyte imbalances, acidosishypo- or hyperglycemia • Illness present • Respiratory distress, sepsis, pneumonia, meningitis • Poor nutrient stores • Fat, glycogen, micronutrients • High nutrient requirements • Intravenous (parenteral) feeding often necessary *Small for gestational age

27. Premature Infants • Better growth when fed high-protein formula • Human milk inadequate? • Pooled mid-lactation breast milk • Milk from mothers of premature infants differs • High protein, high caloric density • Low iron, riboflavin, vitamin D, folate • No deficiency symptoms • Breast-fed premature infants have higher IQ at age 8 • About 8 points on average

28. Composition of Milk

29. Excerpts from the American Academy of Pediatrics Policy Statement (Dec. 1997) • Human milk is uniquely superior for infant feeding • Human milk is the preferred feeding for all infants, including premature and sick newborns • When direct breastfeeding is not possible, expressed human milk, fortified when necessary for the premature infant, should be provided • Exclusive breastfeeding for approximately 6 months • Continuation of breastfeeding for at least 12 months and thereafter for as long as mutually desired (WHO says 2 yrs. of age or beyond) • http://www.aap.org/policy/re9729.html

30. Milk Consumption by Adult Humans • Proteins have high biological value, although can be allergenic • Lactose intolerance primary problem • Passes into large intestine • Cramps, bloating, diarrhea • Most commonly develops between ages 1 and 4 • Ethnic differences • 10% white European descent, 70% in blacks • Also high in people of Mediterranean descent • Lactase levels both constitutive and induced • Some dietary manipulation possible

31. Neonatal Reflexes in Breast Feeding

32. Sucking or Suckling? • Sucking – application of negative pressure • Like when you drink through a straw • Suckling involves a co-ordinated use of the tongue, lips and gums • Premature infants often lack coordination to suckle

33. Suckling • Nipple, areola, & underlying breast tissue are drawn into the infant’s mouth • Lips & cheeks form a seal, with the lips flanged outward • Nipple elongates to 2-3 times its resting length into a teat by suction • Jaw moves the tongue up, compressing the areola against the alveolar ridge, causing expression from the milk sinuses • The tongue then moves in a peristaltic motion, channeling milk to the pharynx for swallowing • Jaw lowers, filling the milk sinuses again

34. Palate Teat Tongue

36. Problems During Suckling • Low suction • Inconsistent, irregular suckling bursts • Poor endurance • Patent ductus arteriosus

37. Nipple Confusion Action of sucking from the bottle is very different from suckling at the breast In bottle feeding, the baby sucks at the nipple and uses his tongue to stop the flow of milk In breast feeding, the baby uses the tongue to express milk from the breast Babies who have been bottle-fed try to suck at the mother’s nipple rather than suckle - often called nipple confusion

38. Comparison of Breastfeeding with Bottle-feeding (Oral Skills) In bottlefeeding: • Mouth less open, lips don’t need to be everted • Bottle doesn’t have to be far back in the mouth • Protective tongue action of anterior-superior tongue movement to stop fluid flow • Difficult to rest at the bottle – milk keeps flowing

39. Breast feeding Bottle feeding Tongue used to express milk Tongue used to stop milk