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 What makes mother's milk unique? Mouse milk is good for mice, kangaroo milk is good for kangaroos, and human milk is best for human babies. Milk is species specific. When the mother cannot or chooses not to nurse, infants are fed with formula. Most of the formulae use cow milk as their base because it is available in unlimited quantities in the western world. The following Table shows the quantitative differences in the main nutritional components between human and cow milk given in g/mL. About 87% is water. Human milk is sweet and has higher sugar content while cow milk is richer in protein. Fat content is about the same in both. In a formula, the differences are compensated by diluting and/or adding different components. However, the major differences are not in the quantities but in the qualities and composition of the nutrients. The sugar in milk is lactose, which is broken up in the gut into glucose and galactose. Glucose provides about 40% of the energy needed by the baby. The rapidly developing brain uses glucose as its fuel. Galactose is a component of the complex brain lipids that are also synthesized in large quantities in early life. Milk is an emulsion (fat in water), explains De. E. Vargha-Butler, a professor in collid chemistry. Human milk is unique because the fat droplets are very tiny and uniform (monodisperse). This quality makes human milk stable and the most easily disgestible milk. The amino acid composition (building blocks of proteins) of human milk is very different from cow milk. Human milk supplies those amino acids that are most needed for development. Some biochemical pathways in the infant are not fully developed and can not metabolizes efficiently certain amino acids. These are found in lower concentration in human milk. Human milk has significant amounts of immune globulins that can protect the infant from infection. One of these, secretory immunoglobulin A (IgA), acts locally in the gut and protects the child from diarrheal disease. Cow milk lacks this component. Lactoferrin, another protein in human milk, is also protective. Some bacteria require iron for their growth. Lactoferrin is an iron-binding protein. By this action, it deprives the bacteria of iron, thus inhibiting their growth. cow milk has only traces of this protein. While quantitatively the fat content is comparable in human and cow milk, there is an important qualitative difference. Human milk fat has shorter fatty acids, which are more readily absorbed in the gut. It is also much richer in essential fatty acids that are necessary for the growth and development of all organs, especially the brain. Tibor Heim, a professor of pediatrics and infant nutrition researcher states that the fatty acid composition of the human milk is highly dependent on the maternal diet. Breast milk's mineral content is also lower, and the ratio between calcium and phosphorous is more appropriate for the infant. Due to the lower sodium content, breast milk is more thirst quenching. Breast milk also contains infection fighting cells (macrophages) and bactericidal compounds, vitamins, enzymes, and growth factors. It is important to mention that both human and cow milk are low in iron and vitamin D. Iron reserves are sufficient up to 6 month of age, after which supplementation is needed. Vitamin D should be supplemented from birth. In the breastfed infant, the gut flora is almost exclusively lactobacillus bifidus, which produces an acidic environment and prevents the growth of other microbial species, especially E. coli. The smart breast milk To provide the best nutrient composition for an infant, human milk changes at different times following delivery and during the course of each feeding. During the first 2 to 4 days of lactation, the milk is yellow in colour, thick, and rich in protein and salt. This is called colostrum. It contains antibodies, growth factors and a compound that prevents the digestion of the antibodies so they are absorbed intact by the baby. From the 5th day, a transitional period of two weeks follows, after which mature milk is produced. There is also a change in milk composition during each breastfeeding session. At the start, the foremilk is watery and quenches thirst. Then gradually, it becomes richer in fat, looks whiter, and satisfies the hunger (hindmilk). This delicate adaptation during each breastfeeding provides the perfect nutrition to the infant over the course of a nursing session and can not be imitated by formula feeding. It is also known that the milk of mothers of premature infants is different from those who delivered a full-term infant, another indication that human milk composition and production is influenced by the specific needs of the infant. Over and above of ideal nutrition, breastfeeding has other advantages: it is always ready, at the right temperature, sterile and is free with no waste. There are scientific reports that suggest breastfed infants are less likely to develop some diseases later in life such as hypercholesterolemia, diabetes, inflammatory bowel disease, rheumatoid arthritis, and eczema. Women who breastfed also have a reduced risk of breast and ovarian cancer. The psychological and emotional aspects of breastfeeding cannot be overvalued either for the baby or the mother. The intimate closeness and touching create a secure environment. Breastfeeding quickly calms down an upset child. Medication during pregnancy and breastfeeding Mothers and physicians alike try to abstain from medications during pregnancy and lactation. However, certain medical conditions such as diabetes, hypertension, depression, and epilepsy require adequate pharmacological treatment to ensure maternal and fetal/infant well-being. The choice of medication has to take into consideration the available evidence on placental transfer, secretion into breast milk, and effects or risks for the fetus and infant. It cannot be stressed enough that no medication, supplement, or naturopathic compound should be taken without professional health consultation during pregnancy and breastfeeding. Defending formulas There are many mothers who by circumstances or by choice cannot or will not breastfeed. For them, formula feeding is the alternative. Active research in infant nutrition is leading to the continuous improvement of baby formulas. Manufacturers are making great efforts to improve their products based on newly available scientific evidence. There are formulas for premature, full term, and growing infants. The latest consideration is to fortify with omega-3 fatty acids that have been shown to improve visual and brain development and function. (See article on Omega-3 fatty acids on p.42.) There are also varying formulations to satisfy the needs of allergic babies and those who suffer from different metabolic disorders. Without baby formulas, many children who were not breastfed would have been greatly disadvantaged. Cow milk allergy Cow milk allergy is the most common food allergy in infancy. Cow milk proteins differ significantly from human milk proteins. Most babies can tolerate the cow milk formulas, but some develop allergies to variable milk proteins. Their immune system may become sensitized and regard these proteins as "foreign and harmful" thus mounting an immune response. Most of these sensitized infants have a genetic predisposition. The highest risk of sensitization is in the first 6 months of life when both the gut and the immune system are maturing. Breastfeeding is the most effective way to prevent milk allergy. Breast milk has immunological properties and growth factors that enhance the maturation of the gut, making it less permeable to sensitizing proteins. If breastfeeding is not an option, hydrolyzed, hypoallergenic formula is recommended. Soy based formula is not an alternative, since soy proteins are also known to cause allergies. Recommendations The Canadian Pediatric Society recommends exclusive breastfeeding in the first 6 months of life. Formula (cow milk-based) can be offered after 6 months. Because cow milk may cause some intestinal bleeding and anemia, formula is preferred over cow milk until 9-12 months of age. After that, the digestive system is matured enough so that pasturized whole cow milk (3.25%) can be introduced. Partially skimmed (2% and 1%)milk is not recommended under 2 years of age since it is poor in essential fatty acids. Breastfeeding may continue up to 2 years old (and beyond). |
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