Early infant feeding - Breast vs bottle week/lecture 3 Flashcards
composition of breast milk
○ 90% water
○ 4% fat
○ 1% protein
○ 7% lactose
○ Immunological; antibodies, vitamins, minerals
how does breast milk optimise survival?
○ Food readily available
○ Food brought to child
○ Risk of predators reduced because no foraging
what does prolactin do?
stimulates the cells to produce milk
what does oxytocin do?
makes the muscle contract to make the milk flow
flow of milk through the breast:
- Alveolus –> milk duct –> lactiferous duct
Hormones and milk production:
- 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
oxytocin reflex: ‘let down’
Unconditioned response –> conditioned response
Response to baby suckling –> response to thinking about, touching, seeing, hearing baby
the first feed:
- when?
- why?
- how long does it last?
- 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
stages of milk
- 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
- Mature milk
what’s so good about breast milk?
- Nutritionally superior
- Formula milk can imitate breast milk if:
○ Substances are identifiable
○ The technology exists to synthesise them
○ It is economic to synthesise them
- Formula milk can imitate breast milk if:
why is breast milk required for digestive health?
- Add Josh et al., (2013) study
- 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
breast vs formula: what does the choice depend on?
- 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
individual factors and choice
- 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?
- Self-objectification
normalisation via TV ads:
- Too much reality = ‘adult content’?
rates of BF
- 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
full and partial BF at 6-8 weeks
- 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
barriers to BF
- 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)
taste sensitivity in infants
- 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
familiarity and lack of variety
- Formula-fed infants show a preference for their own brand of formula
- Mennella and Beauchamp, 2005
spiked formula and later preferences
- 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)
tastes in breast milk
- 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?
are infants primed in utero
- 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
implications of early exposure in utero
- 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
BF and obesity: what is the risk?
- 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.
BF and obesity: milk content
○ 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)
BF and obesity: feeding experience
○ 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)
duration of BF and obesity
§ 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
why is there more obesity in bottle-fed infants?
- Differences in control of milk flow (bottle = less control = overeating)
- Less control over intake
post birth weight loss in mother
§ 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
BF and obesity: social influences
○ 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:
impact of BF on infant and mother health
- 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
sudden infant death syndrome
- 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
direction of effect of obesity and BF - ADHD
- 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
post-natal depression
- 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
- Early cessation or absence of BF related to PND
benefits of BF on maternal health
- 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).
- Diabetes
economic costs of BF
- 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
- To employers
