Breast Milk Content Flashcards
Main source of energy in breast milk and contained inside
TAGs 55-60% of energy
Contained in membrane enclosed (phospholipids, cholesterol, proteins) milk fat globules
Main type of SFA in breast vs cow’s mik?
Palmitic acid in both, although breast milk lower in SFA overall (14C, 16C, 18C)
Breastmilk - palmitic is at position 2 on glycerol
- forms micelle more easily
- higher absorption rate (better LPL activity)
Cow’s milk: at position 1 or 3
- hydrolyzed by pancreatic lipase
- bound to Ca/Mg ions
- excreted as Fa-insoluble soap (loss of energy and minerals)
MUFA and PUFA content in breast milk vs. cow’s milk?
in breast milk:
- Higher oleic acid
- 5x EFA than cow’s milk, though formula is even higher
- Much higher in AA and DHA compared to formula (gives precursors)
(infants don’t have matured enzymes)
- 5x long chain PUFAs (AA and DHA) in breast milk than formula
How does the FA profile in breastmilk change over time?
Early milk/colostrum is high in C20/C22 PUFAs (prostaglandins, nerve cell division)
Mature milk is high in MFA and MCFA (nerve myelination)
What are the immune factors found in milk?
High IgA (90%) - binds food proteins so they won’t be absorbed by gut, helps with gut lining maturation/mucosal layer
- formed from B cells travel to mammary
Low IgG (infant colic), IgE (allergies), IgM
Anti proteases in whey fraction protect immune factors
Bifidus factor - N-containing CHO which promotes growth of lactobacilli
Anti-staphylococcus factor contain lysozyme, Lactoperoxidases - kill streptococci and enteric bacteria
Lactoferrin competes for Fe binding, B-12 binding protein outcompetes for B12
Lipases - FFA/MAG have anti viral properties
Interferon - inhibits intracellular viral replication
Neutrophils, macrophages (phago, synth C3/4, lactoferrin, lysozymes) and lymphocytes (synth IgA)
Growth factors in breast milk
cortisol, thyroxine, insulin, insulin-like growth factor
prostaglandins stimulate mucous secretion and ↑ cell division, polyamine (spermidine, spermine), nucleotides
Stimulation of intestinal enzyme synthesis and gut mucosa maturation to increase barriers of the gut and reduce leakiness
Proteins in breast milk vs. cow’s
higher lactalbumin - binds Ca and Zn
Presence of lactoferrin (absent in cow’s)
Xanthine oxidase higher - binds Fe and Mo
Glutathione peroxidase higher - binds Se
lipases, amylases, proteases presentt
No B-lactoglobin - can produce allergic response, allergen in cow’s milk
High IgA, low IgG
Higher NPN 15-25% of N in breastmilk (urea, growth factors, etc)
Higher osteopontin - accelerated GI maturation
Better and flexible AA balance
Taurine higher - for bile acid conjugation, conditionally essential
Lower Met vs. Cys - cystathionase develops late - excess Met can be neurotoxic
Higher cys → glutathione and ↓ RBC lysis
Lower Phe/Tyr - late developed enzymes → excess Phe/Tyr adverse effects on CNS
CHO content of breast milk
[Lactose] 70g/L and stable (not influenced by diet)
- Forms soluble chelates to aid mineral absorption
- Stimulates beneficial bacterial growth in gut
- glucose preferentially used as precursor
Oligosaccharides - unconjugated glycans act as prebiotics in colon
- highly abundant in breastmilk - NOT in formula
- Linked with anti-bacterial, anti-viral, and anti-inflammatory effects
Advantageous proteins in breast milk vs. cow’s milk (9)
1) higher lactalbumin - binds Ca and Zn
2) Presence of lactoferrin (absent in cow’s milk)
3) Xanthine oxidase higher - binds Fe and Mo
4) Glutathione peroxidase higher - binds Se
5) Macronutrient digestive enzymes: lipases, amylases, proteases
6) No B-lactoglobin - can produce allergic response, most common allergen in cow’s milk
7) High IgA, low IgG (high in cow’s milk, associated with infant colic/bloating)
8) Higher NPN (nucleotides/orotic acid) and much higher osteopontin (accelerated GI maturation)
9) Better AA balance
