Early infant feeding - Breast vs bottle week/lecture 3

Question 1

composition of breast milk

Answer 1

○ 90% water
○ 4% fat
○ 1% protein
○ 7% lactose
○ Immunological; antibodies, vitamins, minerals

Question 2

how does breast milk optimise survival?

Answer 2

○ Food readily available
○ Food brought to child
○ Risk of predators reduced because no foraging

Question 3

what does prolactin do?

Answer 3

stimulates the cells to produce milk

Question 4

what does oxytocin do?

Answer 4

makes the muscle contract to make the milk flow

Question 5

flow of milk through the breast:

Answer 5

• Alveolus –> milk duct –> lactiferous duct

Question 6

Hormones and milk production:

Answer 6

• Baby suckles
  
  • Sensory impulses pass from the nipple to the brain
  • Anterior part of the pituitary gland secretes prolactin
  • Posterior part of the pituitary gland secretes oxytocin
  • Oxytocin enables stored milk to flow for THIS feed
    Prolactin makes the breast produce milk for NEXT feed

Question 7

oxytocin reflex: ‘let down’

Answer 7

Unconditioned response –> conditioned response
Response to baby suckling –> response to thinking about, touching, seeing, hearing baby

Question 8

the first feed:
- when?
- why?
- how long does it last?

Answer 8

• Post birth
  
  • 6mins eyes open
  • 20mins rooting behaviour guided by olfactory cues
  • 80mins suckling begins (lasts about 10mins)
  • Infants suckle between 8-12 times in 24h period
  • Feeds can last 20-40mins
  • Irregular schedule

Question 9

stages of milk

Answer 9

• Colostrum
  ○ First 3-4 days
  ○ High concentration of immune factors
  
  • Mature milk
    ○ Antibodies decrease, volume increases
    ○ Still offer immunological protection
    ○ Foremilk and hindmilk at each feed
  • Not affected by mothers diet, BMI, size of breasts etc
  • Can be affected by very low caloric intake

Question 10

what’s so good about breast milk?

Answer 10

• Nutritionally superior
  
  • Formula milk can imitate breast milk if:
    ○ Substances are identifiable
    ○ The technology exists to synthesise them
    ○ It is economic to synthesise them

Question 11

why is breast milk required for digestive health?
- Add Josh et al., (2013) study

Answer 11

• At birth an infant’s gut is full of holes
  
  • Take many weeks to mature and close
  • Breast milk coats the gut and provides protection
  • Opens junctions and immaturity play a role in gut-related diseases and allergies
  • Formula and breast-fed babies have different gut flora
  • Introduction of formula changes gut flora of breast-fed baby to that of formula fed baby
  • Josh et al., (2013)
    ○ Good bacteria may be transferred from mother’s gut to that of the infant via breast milk

Question 12

breast vs formula: what does the choice depend on?

Answer 12

• Choice may impact upon:
  ○ Health (mother and infant)
  ○ Eating behaviours
  ○ Cog development
  ○ Mother-child attachment
  ○ Maternal self-esteem
  ○ Maternal body image
  ○ Lifestyle
  
  • Societal pressure and simultaneous disapproval

Question 13

individual factors and choice

Answer 13

• Trait personality may be important
  ○ Introverted/anxious significantly less likely to initiate/continue BF
  ○ High prenatal negative = less likelihood of BF
  ○ Higher self-concept significantly associated with exclusive BF
  
  • Self-objectification
    ○ Those who score higher on body-objectification measures more likely to view BF as indecent
    ○ Young/teen mums?

Question 14

normalisation via TV ads:

Answer 14

• Too much reality = ‘adult content’?

Question 15

rates of BF

Answer 15

• UK is lowest in the world
  
  • 66% babies received breastmilk within first 48 hours in 2005/6, rising to 74% in 2010/11, 72% in 2020/21
  • Rapid decrease in first 6 weeks - hardest period
  • Exclusive BF rates then continue to decrease
    ○ 6 weeks: 24%
    ○ 3 months: 17% (up from 13%)
    ○ 4 months: 12% (up from 7%)
    ○ 6 months: 1%
  • This is an improvement on 2005 figures (NHS infant feeding survey, 2010)
    WHO recommends exclusively BF for 6 months

Question 16

full and partial BF at 6-8 weeks

Answer 16

• Exclusive and mixed with formula feeds
  
  • England: 2016-17 is 44.4%
  • Slight increase on previous years at 43.2% (2015-16) and 43.8 (2014-15)
  • Still very low, especially when compared to countries like Norway, which achieves rates of 71% at 6-8 weeks

Question 17

barriers to BF

Answer 17

• Medications etc
  
  • Issues producing oxytocin (attachment issues)
  • PND
  • Lifestyle (want to drink alcohol, go to work etc)
  • Lack of support
  • Difficulties with latching
  • Anxiety and lack of confidence
  • Tiredness
  • Lack of family history/encouragement
  • Pressure from friends
  • Sexualisation of breasts
  • Unhealthy relationships (abusive partner)

Question 18

taste sensitivity in infants

Answer 18

• Taste buds 8 weeks gestation
  
  • Stimulate sweet, sour and bitter tastes in infants
  • Prefer sweet: neonates will consume more water if sweetened
    ○ Evolutionary - survival
    ○ Analgesic - crying and circumcision
  • Insensitive salt <4 months
  • Breastmilk is sweet

Question 19

familiarity and lack of variety

Answer 19

• Formula-fed infants show a preference for their own brand of formula
  
  • Mennella and Beauchamp, 2005

Question 20

spiked formula and later preferences

Answer 20

• Formula:
  ○ Soy formula ‘spiked’ (+sweet, sour and bitter)
  ○ 2-5 month infants accept ‘spiked’ formula, 6+month reject it. Critical period?
  ○ Greater preference for bitter apple juice at 4-5 years
  Manella & Beauchamp 1991; Manella et al., 2001 (directed reading)

Question 21

tastes in breast milk

Answer 21

• Sensitive to food flavours in breast milk
  ○ Garlic (Mannella ad Beauchamp, 1991)
  § Consume more when flavoured
  § Only initially - sensory-specific satiety?
  ○ Vanilla extract (Manella and Beauchamp, 1996)
  § Feed longer and consume more
  § Same when added to formula
  ○ Alcohol (Mannella and Beauchamp, 1991 and 1993)
  § Consumed less milk after mother ingested alcohol
  § Unpleasant taste? Effects on milk production? Increased fat content of milk?

Question 22

are infants primed in utero

Answer 22

• Taste buds develop around 8 weeks gestation
  
  • Detect tastes by 14 weeks gestation
  • Detect olfactory molecule by 24 weeks gestation
  • Exposure to flavours in amniotic fluid

Question 23

implications of early exposure in utero

Answer 23

• Variety in pregnant and BF mums is important to increase exposure to children
  
  • BF baby had early exposure and experience and aren’t as fussy in the weaning stage

Question 24

BF and obesity: what is the risk?

Answer 24

• BF offers a small but consistent protective effect
  
  • Can cut chances of child becoming obese by 25% (WHO, 2019; study across 16 countries)
  • Infants who are bottle-fed are at significantly higher risk for rapid weight gain compared with infants who are exclusively BF; rapid weight gain in infancy is strong predictor of later obesity risk.

Question 25

BF and obesity: milk content

Answer 25

○ Formula milk has increased protein content leading to increased weight gain due to increased insulin
○ Formula milk also has decreased leptin which leads to decreased satiety which may lead to increased intake
○ Also evidence that babies fed formula have higher insulin levels in their blood which can stimulate fat deposition (WHO, 2019)

Question 26

BF and obesity: feeding experience

Answer 26

○ Fundamental behavioural difference

	○ Bottle and milk type:
		§ Use of a bottle for feeding is associated with greater weight gain, irrespective of contents (i.e. formula or expressed breastmilk)
			□ Li et al., 2012
		§ % of children who in late infancy drink from a cup until empty
			□ 27% of those who had been exclusively BF
			□ 54% of those who had been. Mixed-fed (breast and bottle)
			□ 68% of those who had been exclusively bottle fed
				® Li et al., 2010

	○ Bottle and visual cues:
		§ Ventura and Golen (2015)
			□ Opaque bottles VS regular, clear bottles
			□ Abolishes cues about consumption to parent/caregiver

	○ Effects on maternal responsiveness and consumption:
		§ Ventura and Golen, 2015
	○ Effects of infant cues:
		§ Ventura and Hernandez (2019)

Question 27

duration of BF and obesity

Answer 27

§ McCroy and Layte (2012) - dose-response r-ship:
□ Exclusive BF for 13-25wks = 38% reduction in obesity risk
□ Exclusive BF for 26+ wks = 51% reduction
§ Scott et al., 2012: 2066 Australian 9-16 yr olds
□ BF for 6+ months associated with decreased risk of overweight or obesity
□ Controlled for maternal characteristics, level of physical activity, caloric intake, screen time, sleep duration
§ But others find no effects when controlling for confounding variables

Question 28

why is there more obesity in bottle-fed infants?

Answer 28

• Differences in control of milk flow (bottle = less control = overeating)
  
  • Less control over intake

Question 29

post birth weight loss in mother

Answer 29

§ Lactating mother burns 525-625 calories per day producing milk
§ Predicts significantly greater weight loss - up to 12kg (Baker et al., 2008)
§ Less likely to suffer with weight-related health problems

Question 30

BF and obesity: social influences

Answer 30

○ Initiation and length tends to vary with social class
○ Associated with education (+), age (+), smoking (-)
○ Targeted education for high risk groups
○ Education in context:
§ The chance of exclusive BF til 6months was 55% less for the female children when compared to male children
□ 50% less in higher SES
□ 90% less in lowest SES (Angadi and Jawaregowda, 2015)
§ Son preference = limited BF of girl children in order to try to have a son (Jayachandran and Kuziemko, 2011)
○ Cultural pressures
§ National family and health survey data, 2015 (Dutta et al., 2022)
□ Girls have 19% less chance of exclusive BF than boys
□ Birth order and sex composition of siblings are important determinants of feeding practices
® E.g. if the last-born child is a girl, she has a 26% lower chance of being exclusively BF in a household that already has two or more daughters but if she is born in a family that has two sons then then chances of fair treatment in access to minimum dietary diversity are 16% higher
○ Empowerment of women:
§ Increase in exclusive BF by 42% for girls and 38% for boys (Dutta et al., 2022)
○ Inclusive support:

Question 31

impact of BF on infant and mother health

Answer 31

• If 45% of babies in the UK were exclusively BF for 4 months and 75% in neonatal units BF before discharge:
  ○ 3285 fewer babies hospitalised for gastroenteritis
  ○ 5916 fewer babies hospitalised with respiratory illness
  ○ 21405 fewer ear infections
  § UNICEF UK

Question 32

sudden infant death syndrome

Answer 32

• Leading cause of death amongst 0-12 months old
  
  • 2007: meta analysis of 6 studies: BF infants had lower risk of experiencing SIDS than never BF infants
  • 2011: meta analysis: infants who were BF any amount for at least 2 months had significantly less risk than never BF infants (Hauck et al., 2001)
  • Link with BF is unclear but may be related to:
    ○ Immunological and anti-inflammatory qualities of milk
    ○ Lighter sleep

Question 33

direction of effect of obesity and BF - ADHD

Answer 33

• ADHD: Ptacek and Kuzelova (2013)
  ○ 200 mothers (100 ADHD, 100 non-ADHD)
  ○ ADHD children BF significantly shorter time (avg 2.5 mths) than non-ADHD children (avg 7.8 mths)
  ○ But behavioural differences in children may influence mothers behaviour and result in shorter BF duration

Question 34

post-natal depression

Answer 34

• Affects 1 in 8 mothers
  
  • Early cessation or absence of BF related to PND
    ○ Ip et al., 2009
    ○ Direction or effect?
  • Prolonged feeding associated with less PND
    ○ Protective effect?
  • Evidence related to lactation itself
    ○ Countries where exclusive BF is norm, peaks at 9 mths post-birth
    ○ Countries where formula is norm, peaks at 3 mths post-birth
    § Labbok, 2001

Question 35

benefits of BF on maternal health

Answer 35

• Osteoporosis
  ○ stronger bones, reduction is risk of hip fractures in later life
  ○ (Cumming & Klineberg, 1993)
  
  • Diabetes
    ○ never breastfed had 1.7x higher chance of developing Type II diabetes than those who had BF for > 2 yr over lifetime
    ○ (Stuebe et al., 2005)
  • Cardiovascular disease
    ○ 10-20% greater risk in those who have never BF compared to BF for 13-24 mths
    ○ (Schwarz et al., 2009)
  • Breast and ovarian cancers
    ○ reduced risk as BF suppresses ovulation and limits estrogen which is implicated in cell differentiation, mutations, and fuelling growth.
    ○ Meta-analysis of 23 studies concluded a protective effect of BF, regardless of duration (Bernier et al., 2000).

Question 36

economic costs of BF

Answer 36

• To mother
  ○ Cost of formula milk, bottles etc not present
  ○ Loss of earnings??
  
  • To employers
    ○ Time off work
    ○ Sick days
  • To environment
    ○ Reduced carbon footprint