Life Cycle Nutrition: Lactation PDF

Life Cycle Nutrition: Lactation (feeding in the first 6 months of life) Faculty of Science Department of Biochemistry The ability to breastfeed is not instinctive….it is learned...

Life Cycle Nutrition: Lactation (feeding in the first 6 months of life) Faculty of Science Department of Biochemistry The ability to breastfeed is not instinctive….it is learned Successful breast‐ feeding requires education for the new mother, support from the family and partner, and access to support from community health care systems. Faculty of Science | Department of Biochemistry Faculty of Science | Department of Biochemistry What do the Experts Say? Canadian Pediatric Society (2013, reaffirmed 2016) “Breastfeeding is the normal and unequalled method of feeding infants.” American Academy of Pediatrics (2012) “Given the documented short‐ and long‐term medical and neurodevelopmental advantages to breastfeeding, infant nutrition should be considered a public health issue and not only a lifestyle choice” Infant Feeding Recommendations for the 1st year of life: EXCLUSIVE breastfeeding for the first 6 months of life Continue breastfeeding while introducing other complementary foods, starting with sources of iron (~6 mo) Unmodified cow’s milk should not be introduced until after 1 year of age http://www.hc‐sc.gc.ca/fn‐an/nutrition/infant‐nourisson/recom/index‐eng.php Faculty of Science | Department of Biochemistry How are we doing? Among Canada’s provinces and territories, breastfeeding initiation rates ranged widely, from 57% in Newfoundland and Labrador to 96% in British Columbia and the Yukon in 2011–2012. Initiation is 76% in NL in 2016, up from 30% in 1970s. According to Eastern Health, breastfeeding rates for 2017: 82 per cent in St. John's. 79 per cent in Labrador City. 72 per cent in Gander/Grand Falls‐Windsor. 69 per cent in Happy Valley‐Goose Bay and St. Anthony. 60 per cent in Carbonear. 58 per cent in Clarenville. 51 per cent in Burin. Gionet, L. (2013). Health at a glance: Breastfeeding trends in Canada (Catalogue No. 82‐624‐X). Ottawa, Canada: Statistics Canada. Faculty of Science | Department of Biochemistry Maternal Diet Quality and Lactation Nutritional quality of the milk varies only slightly with maternal diet Absolute macronutrient content (energy/protein) in milk is NOT affected by maternal diet Quality of fat in the diet is affected by maternal intake – high maternal n‐3 FA intake will translate into higher n‐3 FA in milk Water soluble vitamins may vary with maternal diet ‐ deficiency is rare and excess intake doesn’t cross the mammary gland into the milk Excess fat soluble vitamins (esp Vit A) may lead to very high milk conc’ns Lactating women Minerals in milk are unrelated to quality of the maternal diet with poor diets still calcium extracted from maternal skeleton to support milk synthesis, but produce maternal skeleton is repleted after BF ends nutritionally maternal iron stores sacrificed for pregnancy and lactation complete milk! Faculty of Science | Department of Biochemistry Nutrient Recommendations for Lactation During established lactation, ~650 mL milk is produced per day Depending on the age and size of the baby (“made to order”) The metabolic “cost” of milk production = ~ 500 kcal/d Additional energy (EER) = 330 kcal/d (0‐6 mo), and 400 kcal/d (> 6 mo) The energy deficit can be supplied by maternal fat stored during pregnancy Dieting while breastfeeding is NOT recommended Maternal nutrient supplements should be used with caution Include food sources of n‐3 fatty acids such as fish If using supplements, be sure to use high quality products that contain a “Natural Product Number (NPN)” (product tested for contaminants) Do not use cod liver oil (vitamin A content may be too high) Faculty of Science | Department of Biochemistry Nutrient Recommendations for Lactation A very high fluid intake is necessary for adequate milk production May be a cause of lactation failure, and dehydration in the infant Total of 3.8 L/d, with ~3 L as fluid including water Limit caffeine intake to < 300 mg/d (< 500 mL coffee/d) Alcohol will pass into the breast milk and affect milk production No specific types of foods need to be restricted Components of foods that the mom consumes may enter her milk, such as: Cow milk proteins, peanut proteins – concern for sensitizing infant towards allergies in high risk families – likely not so important… Onions, garlic etc may add scent or flavour to mother’s milk, but no reason to avoid this – some evidence of better food acceptance by young children who were breastfed Faculty of Science | Department of Biochemistry Why is human milk important for human health? Infants who are breastfed experience: Lower rates of respiratory infections, GI infections and ear infections Lower risk of sudden infant death syndrome (SIDS) Very good evidence Ideal rate of growth in early life, with lower risk of obesity in infancy Lower risk of obesity in childhood Good evidence Better cognitive development, better school performance scores in childhood, higher IQ Lower risk of developing food allergies Lower rates of autoimmune diseases including type 1 diabetes, and celiac disease Probable evidence Faculty of Science Department of Biochemistry Why is human milk important for human health? SIDS deaths have declined in Canada over the past 30 years, likely due to: Placing infants on their backs to sleep (“Back to Sleep” campaign) Increased breastfeeding rates Decline in smoking during pregnancy and in the home (2nd hand smoke is a risk factor) Faculty of Science | Department of Biochemistry Why is human milk important for human health? Nutritional Composition for Infants is (almost) Ideal Composition and volume changes within a day, within a feeding, and over the weeks to months following birth Early milk (colostrum) (first few days) is high in immune factors, to protect the infant Initial ‘foremilk’ within a feeding event is “watery” and high volume/high lactose, to quench thirst Later ‘Hindmilk’ in the same feeding event is high fat, perhaps to signal satiety. Nutrients low in concentration are absorbed VERY efficiently ‐ Iron is low, but specialized proteins in the milk assist in iron absorption Faculty of Science | Department of Biochemistry Why is human milk important for human health? Nutritional Composition for Infants is (almost) Ideal Protein composition is ideal to meet nutritional reqts, but also: Immune‐protective proteins (antibacterial, antiviral proteins) Antibodies ‐ designed by the maternal immune system to target pathogens in their environment Hormones that alter infant’s gut immune function, growth and metabolism Large quantities of non‐digestible carbohydrates in milk “feed” the gut microbes, to encourage a healthy microbiome Human milk contains hundreds (thousands?) of bioactive peptides/molecules with (currently) unknown functions Faculty of Science | Department of Biochemistry Nutritional Composition of Human Milk is (almost) Ideal Why (almost) Ideal? Vitamin D concentration is low, compared to current estimates of requirements Some cases of D‐deficiency rickets have been identified in BF toddlers Canadian Pediatric Society recommends 10 μg/d (400 IU) vitamin D3 supplement for all BF infants Iron concentration plus body stores satisfy infant’s iron needs for ~6 mo, but then another dietary source of iron should be introduced Faculty of Science Department of Biochemistry Table 13‐7 Benefits of Breastfeeding Faculty of Science Department of Biochemistry Table 13-9. 10 Steps to Successful Breastfeeding Ensuring breastfeeding success MUST be a priority of our health care system through education of physicians, nurses, and the training and funding of lactation consultants Faculty of Science | Department of Biochemistry Breast Milk versus Infant Formulas Cow’s milk based infant formulas are widely used. Modified significantly to try to mimic the composition of human milk – called “humanized”, but remains vastly different Higher in nutritional protein than human milk (contributes to early obesity?) Formula is homogeneous in composition Recent advances include: Addition of n‐3 fatty acids Addition of non‐digestible carbs (ie. soluble fibre) High cost of formula feeding! Faculty of Science | Department of Biochemistry