Properties of Breastmilk Flashcards
What are the main properties of breastmilk?
- Species specific
- Adapted to meet nutritional and anti-infective requirements of baby
- A ‘living’ food - ‘white blood’
- Adapts throughout BF continuum
How is breastmilk adapted for a baby that is preterm?
Contains more energy, lipids and proteins
Give some factors that influence breastmilk composition
- Stage of lactation
- Gestational age
- Stage of feeding (beginning or end)
- Baby’s demand
- Degree of fullness/emptiness of breasts
- Variation of breastmilk maturation during lactogenesis
How does the breastmilk adapt if the baby is ill?
Cells in mother can detect the illness and produce antibodies to transfer in breastmilk
What is colostrum?
- Lower in volume
- Anti-infective and anti-viral properties
- Rich in protein and minerals
- Lower in carbohydrates and fat
- Important for priming and protecting baby’s gut
- Has a laxative effect
Why is colostrum lower in volume?
Allows baby to learn how to suck and swallow while breathing
Why does colostrum have a laxative effect
Increases bowel movements because meconium contains many RBC so body needs to get rid of it as digested products of RBC can cause jaundice
What is the average volume of milk?
- Colostrum = 7-14ml/ feed (37ml in first 24 hours)
- By day 5 = 500ml/24 hours
- By 6 months = 800ml/24 hours
How much weight should newborns be putting on per day?
10g/kg
What is the nutritional value of breastmilk?
- BF is interactive and helps infant determine composition of feed
- 80% water
- Contains fat, lactose, protein, vitamins and micronutrients
Describe the fat content in breastmilk
- Main source of energy
- Provides half of breastmilk calories
- Most variable component
- 98-99% triglycerides
- Long chain polyunsaturated fatty acids
Describe the fat gradient
- Low fat at beginning of feed to quench thirst
- More fat at end of feed to satisfy hunger
Describe the carbohydrate content of breastmilk
- Lactose
- Oligosaccharides
- Galactose
- Fructose
Describe lactose
- Accounts for majority of carbohydrates
- Affected by maternal diet
- Enhances calcium absorption
- Metabolises readily into galactose and glucose
- Requires lactase to be converted
What are the 2 main types of protein in breastmilk?
Whey and casein
Describe the quantities of whey and casein proteins
- Casein low in early lactation, then rapidly increases
- Whey highest in early lactation, then rapidly falls
- Ratio whey:casein
Early lactation = 90:10
Mature milk = 60:40
Late lactation = 50:50
Describe whey proteins
- Form soft curds
- Quickly digested
- Continuous nutrient flow
- Play important role in immunological defence
- Examples: Serum albumin, Lactoferrin, Lysozyme
Describe casein proteins
- Form a tough, less digestible curd
- Requires high energy expenditure for incomplete digestion
Describe the vitamins and micronutrients in breastmilk
- Vary with maternal diet
- Vitamins A and E
- Vitamin K in small amounts
- Little vitamin D
- Small amount of iron
- Lactoferrin
Why does vitamin K content increase?
Rises at lactation matures and baby’s gut is colonised with bacteria
What is lactoferrin?
Iron transfer factor - absorbed into blood and is an anti-infective (sits in gut and ‘catches bugs’)
What are the anti-infective properties in breastmilk?
- Healing properties (sticky eyes)
- Bifidus factor
- Transfer factors (e.g. lactoferrin)
- WBC
- Viral fragments
- Oligosaccharides
- Anti-inflammatory molecules
- Influence on gut pH
Describe the layers of protection that breastmilk provides
- Top tier; secretory antibodies
- Fatty acids and lactoferrin
- Oligosaccharides
Describe immunoglobulins
- Antibodies from previous maternal infections
- slgA (secretory immunoglobulin A) - coats and lines the digestive tract
- Entro-mammary and broncho-mammary pathways
What does breastmilk contain that formula doesn’t?
- Enzymes
- Growth factors
- Anti-parasites
- Anti-viruses
- Hormones
- Antibodies
What do both breastmilk and formula contain?
- Water
- Protein
- Carbohydrates
- Fat
- Vitamins and minerals
Describe milk marketing
- Food Standards Agency monitors formula
- If additives are found to be beneficial, they have to be added to all formula
- No milk that is better than another
- Milk companies adapt statistics to make them look better
