Breastfeeding: Maternal diet and lifestyle • Maternal nutrient needs for successful lactation • Impact of maternal diet on milk composition • Can infant health outcomes be influenced by manipulating the deit of lactating women?
Breastfeeding: Maternal diet and lifestyle • Lifestyle issues • Supportive of sustained lactation • Impacting milk production and compostion • Health and safety issues • Drug exposure • Environment contaminants • other
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 • Under neuroendocrine control that varies with timing and stage of lactation • Prolactin • Lactogens • Estrogen • Thyroxine • Growth hormone • ACTH • other • Stimulus: infant suckling
Milk synthesis and sectretion • Exocytosis (protein, lactose, Ca/Ph, citrate) • Fat synthesis (TG synthesized in cytoplasm and smooth endoplasmic reticulum + precursors imported from maternal circulation): alveolar cells syntesize SCFA • Secretion of ions and water • Immunoglobins transferred from extracellular spaces
Milk synthesis • Protein: vast majority of proteins present in human milk are specific to mammary secretions and not identified in any quantitiy elsewhere in nature: • Immunoglobins transferred from plasma in early stages of lactation • De novo protein synthesis by mammary gland
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.
Association of maternal diet with milk composition? • Volume • Nutrient composition • Can diet alter nutrient composition of maternal milk? * in general milk composition maintained to meet infant needs. * water soluble vitamins * fat/fatty acids
Science and Lactation: Frank Hytten • “ In general, it is probable that the breast has a high priority for nutrients and that moderate maternal undernutrition 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”
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,…..
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 beri-beri….. • Fat soluble vitamin content not improved with supplementation • Fatty acid composition (DHA and ARA) altered by maternal diet and supplementation
Breast milk composition and Diet • DHA levels of breastmilk vary with diet. Increased amounts of DHA have been found in the breaskmilk of mothers consuming fish or fish oil, and with suppleemntation. • 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 apear to change the content of breastmilk. • Supplementation of fat soluble vitamins do not appear to alter the content of breastmilk • Iron supplementation does not appear to alter the iron content of breastmilk
Questions regarding Breast milk composition and Diet Maternal deficiencies and infant health Infant health vs maternal health Treatment of specific conditions or “supermilk” through dietary modification
Nutrient Needs • Increased Needs? • Replace maternal losses to milk? • Increased energy needs---- increase in specific vitamins (ie B vitamins) • Association of maternal diet with milk composition?
Estimate need to produce 850 ml/day 600 kcal/d 80% efficiency 750 kcal/day Fat stores of pregnancy may provide 1/3 + 500 kcal above non lactating women Energy
Energy • Does a breastfeeding woman need to consume more energy to sustain lactation? • Energy deficits may not impact milk volume • ? Estimating energy cost • Variety of ways to meet energy needs • Increased consumption • Decreased expenditure • Mobilization of stores
Calcium • Calcium intake has little impact on calcium content of breastmilk • ? Is there an impact on maternal calcium status and bone density
Calcium • Calcium is mobilized from bone to maintain milk content during lactation • Phenomena of bone loss and recovery during lactation and after weaning has been documented by several researches (Cross, Kalkwark, Specker) and may represent normal physiology • ? Consequences of inadequate intake on long term maternal bone health
NAS Food and Nutrition Board 1992 • Healthful diet based on DRI/RDA • Avoid or drastically reduce the use of potentially harmful substances • Take enough fluids to keep from getting thirsty • At least 1800 kcal/d to maintain milk production • Limit intake of coffee, cola or other caffeine sources to 2 servings or less per day • Avoid alcoholic beverages
Cultural/religious customs • Vegan/vegetarian diets • dieting
Frequently seen advise to breastfeeding women • Eat to hunger • Drink to thirst • Don’t worry
Modification of infant health through maternal diet • DHA • Allergy • Colic
Allergies: Breastmilk • May be protective due to sIgA and mucosal growth factors • Maternal avoidance diets in lactation remain speculative. May be useful for some highly motivated families with attention to maternal nutrient adequacy.
AAP: Breast milk and allergy • 1.Breast milk is an optimal source of nutrition for infants through the first year of life or longer. Those breastfeeding infants who develop symptoms of food allergy may benefit from: • a.maternal restriction of cow's milk, egg, fish, peanuts and tree nuts and if this is unsuccessful, • b.use of a hypoallergenic (extensively hydrolyzed or if allergic symptoms persist, a free amino acid-based formula) as an alternative to breastfeeding.
David Hill et al Effect of Low allergen Maternal Diet on Colic among breastfed Infants: A Randomized controlled Trial, Pediatrics Vol 116 #5 Nov 2005 709-15 Colic and maternal diet
David Hill et al • N107 infants <6weeks of age with colic defined by elevated Cry/Fuss Score. • Study Group: 53, 680 minutes/48 hours • Control: 54, 631 minutes/48 hours
Study: Low allergen. Maternal elimination of cows milk, peanuts, treenuts, wheat, soy, and fish. 47 completed Control: Diet as usual. 43 completed Hill et al
Study Group Reduction in cry score by 25% (35 of 47) 30/47 still had colic as defined by cry/fuss scores >360 min/48 hours Control Group Reduction of cry score by 25% (16 of 43) 31/43 still had colic as defined by cry/fuss score > 360 min/48 hours Hill et al
Authors Conclusion: Exclusion of allergenic foods from maternal diet was associated with a reduction in distressed behavior among breast fed infants <6 weeks of age.
What advise? • Diet restrictions • Diet supplements • Allergens • other
Drugs and Human Milk • Maternal considerations • Drug Characteristics • Concentration in milk • Volume of milk consumed • Infant Characteristics
Maternal considerations • Route • Dose • Duration • ? Treatment • ? alternative
Drug Characteristics • Size of molecule • Solubility in lipids and water • Protein binding capability • Drug pH • Diffusion rates • Half life • Metabolites
Drug Characteristics • Drugs transferred by: simple diffusion, carrier mediated, active transfer, pinocytosis, reverse pinocytosis. • Transfer and solubility gradient
Concentration in milk X amount milk consumed = potential dose infant exposed to
Infant Characteristics • ? Absorption from infant gut • ? Infant metabolism • Can infant detoxify and excrete? • Will amounts accumulate • What doses/ levels are safe?
Infant • Is this a drug normally given to an infant? • Amount, side-effects, safe dose and level known. • Is this a drug not usually given to infant? • More difficult question, is safety known, is there any evidence or data to make a decision, is there fetal or animal data on safety?
AAP statement on Drugs and Human Milk • Pediatrics 2001 108(3) 776-788 • 7 tables • 1) cytotoxic drugs that may interfere with infant metabolism • 2) drugs of abuse for which adverse effects on infants have been reported • 3) radioactive drugs requiring temporary cessation of nursing • 4) drugs with unknown effects • 5) drugs with some associated effects that should be used with caution • 6) medications compatible with nursing • 7) food and environmental agents that may have effects on breastfeeding
NAS Food and Nutrition board 1992 • Environmental contaminants: • Heavy metals e.g. mercury • Organic chemicals e.g. pesticides • DDT, PCB’s
Drug use and Pregnancy • Drugs contraindicated • Should be avoided if there are alternatives • No known risk
AAP: Breastfeeding and Smoking • 1994: Nicotine placed in Contraindicated secondary to decrease in milk production, decrease weight gain in infant, and increase in respiratory illness etc. • ? Breastfeeding and smoking vs bottle feeding and smoking…..protection against respiratory illness • 2001: In the interest of supporting breastfeeding, Nicotine was removed from the previous Table. • Advise against smoking. Provide support for smoking cessation.
Smoking: nicotine exposure, carbon monoxide, risk of 2nd hand smoke, burns
AAP: Drugs of abuse for which adverse effects have been reported • Amphetamine: irritability, poor sleeping pattern • Cocaine: cocaine intoxication, irritability, vomiting, diarrhea, tremulousness, seizures • Heroin: tremors, restlessness, vomiting, poor feeding • Marijuana: only one report in literature, no effect mentioned, very long half life for metabolites (see animal studies)
Marijuana: animal studies show structural changes in brain cells of newborns exposed to cannabis through maternal milk, impaired RNA/DNA formation. Infant would be exposed through milk and environment