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The Pharmaceutical Journal Vol 264 No 7089 p471-475
March 25, 2000 Special Feature

Nutrition

Infant milk - an update

By Pamela Mason, PhD, MRPharmS

Summary: Role of the pharmacist in infant nutrition

Milk is normally the only food required by infants during the first few months of life, and the choice is between breast milk and an infant formula. Breastfeeding should be strongly encouraged and supported wherever possible. There are few circumstances where it is not in the best interests of the infant.
However, the skills associated with breastfeeding have to some extent been lost in our society, and with increasing family fragmentation many mothers have no one to ask when they experience problems. Concerns may also arise with bottle fed infants. Pharmacists can be a useful source of help and advice, particularly if they know where to refer parents who have difficulties.

Breast milk

Breast milk is the optimal form of nutrition for the majority of infants. It is a complete, species-specific and easily digested food, which, in addition to nutrients, provides a range of immunological and biochemical factors for the growing child, including proteins, hormones and cytokines. Although recent research has considerably progressed knowledge of breast milk components, the complex balance of ingredients and their relevance to infant health is still not fully understood.

breast feeding
Breastfeeding should be encouraged and supported wherever possible. This article examines breast milk, breastfeeding and infant formulas

Benefits

Epidemiological research shows that breast feeding provides advantages to infants in terms of general health, growth and development while reducing the risk and/or severity of several diseases, including diarrhoea,1-3 respiratory tract infection,4,5 urinary tract infection,6 otitis media7,8 and necrotising enterocolitis.9 Breast feeding may also provide protection against sudden infant death syndrome,10 ulcerative colitis and Crohn's disease11 and it may contribute to the enhancement of cognitive development.12
Not only does breast milk have advantages for infants, it also has possible health benefits for mothers, such as earlier return to prepregnancy body weight and more rapid return of the uterus to its normal shape and size. There is also some evidence that women who have breastfed their infants have a reduced risk of premenopausal breast cancer,13 ovarian cancer,14 and hip fracture,15 compared with women who have not, which may be due to improved bone remineralisation16 after childbirth.
In addition to the health benefits of breastfeeding, there are potential cost savings for the health service. It has been estimated that the NHS spends £35m a year in England and Wales in treating gastroenteritis in bottle fed infants and that for each 1 per cent increase in breast feeding at 13 weeks, a saving of £500,000 in the treatment of gastroenteritis would be achieved.17

Controversies

Some studies show that breast milk reduces the risk of allergic conditions,18,19 but it has also been recognised for many years that some infants can become sensitised to dietary antigens present in breast milk. For example, a Finnish study20 found a marked improvement in atopic eczema after cessation of breastfeeding and initiation of an amino acid formula. Elimination of presumed antigens from the mothers' diets was associated with a small improvement but had a negative effect on infant growth and weight gain.
Research has also indicated that breastfeeding may protect against type 1 diabetes. A link between the risk of insulin dependent diabetes and the early introduction of cows' milk and short duration of breastfeeding (< 2-3 months) has been found.21,22
Exposure to cows' milk protein early in life has been suggested to cause susceptible individuals to become sensitised to bovine serum albumin,23 the antibodies to which react with pancreatic islet cells, leading to the destruction of these cells, a feature which precedes the onset of diabetes. However, the design of these studies has been criticised, and a more recent prospective study24 showed no association between duration of breastfeeding or introduction of cows' milk and the development of islet autoimmunity in infants who had a first degree relative with type 1 diabetes.
The role of breastfeeding and cows' milk in the development of type 1 diabetes is therefore controversial, and it is not clear whether any effect is caused by early cows' milk introduction or duration of breastfeeding.

Contraindications

There are very few circumstances where breastfeeding needs to be stopped or discouraged. Advice on medication and breastfeeding can be found in the British National Formulary, but the help of the local drug information centre should be sought in specific cases. There are relatively few medicines that mothers may need to take that may make it necessary to interrupt breastfeeding.
Other circumstances where it is inadvisable to breastfeed include the infant whose mother has untreated active tuberculosis, the infant with galactosaemia and the infant, in developed countries, whose mother has been infected with human immunodeficiency virus.
In less developed countries, where there is a risk that mothers may not - because of poverty and/or lack of education - be able to feed their infant with safe breast milk substitutes, the impact of witholding breastfeeding in HIV-positive mothers should be considered.25

Prevalence of breastfeeding

Breastfeeding rates increased slightly in the UK between 1990 and 1995 but there has been little significant change since 1980, and the UK continues to have one of the lowest breastfeeding rates in Europe. Moreover, national statistics (Table 1) hide considerable differences relating to the age, educational status and social class of the mother and the area where she lives.
The highest rates of breastfeeding are observed in first time mothers aged 30 or over, those who remained in full time education until they were 18, those in higher social class groups and those living in the south of England.

Barriers to breastfeeding

Factors which discourage the initiation of breastfeeding include:

  • Inadequate prenatal information
  • Disruptive hospital policies, such as ina-ppropriate interruption of breastfeeding and the infant not being put straight to the breast after birth
  • Early hospital discharge without appropriate education and follow up
  • Maternal employment, especially in the absence of workplace facilities and supp-ort for breastfeeding
  • Lack of family and social support
Table 1: Prevalence of breastfeeding (per cent) in the UK
Age of baby UK England & Wales Scotland Northern Ireland
Birth 66 68 55 44
1 week 56 58 46 35
2 weeks 53 54 44 32
6 weeks 42 44 36 25
4 months 27 28 24 12
6 months 21 22 19 8
9 months 14 14 13 5
Figures from the Office for National Statistics infant feeding survey conducted in 1995.26 The next survey will be conducted in 2000 and will probably be published in 2002

Removal of these barriers requires action from government, health authorities, health professionals, local communities, businesses, voluntary organisations and individuals. In 1991, UNICEF and the World Health Organisation launched the "baby friendly initiative", the aim of which was to reverse the negative impact that maternity hospital practices may have on breastfeeding. As part of its remit, the baby friendly initiative works with health services to ensure that all parents are enabled and supported to make informed choices about how they feed their babies. It has developed practice standards - known as the "10 steps to successful breastfeeding" - for the care of mothers and babies by the maternity services. Similar standards have been developed to encourage community providers to get involved. These are known as "the seven point plan for the protection, promotion and support of breastfeeding in community health care settings".
In England, the Department of Health's national breastfeeding working group has recommended that purchasers should incorporate the 10 steps into their commissioning plans, while a Scottish breastfeeding group has encouraged all NHS facilities to adopt the 10 steps.
Most UK health care trusts have taken some action and 21 have fully implemented all 10 steps. A few community trusts and GP surgeries are developing a commitment to the seven point plan for community services. Pharmacists may want to consider working with primary care groups and primary care trusts on implementing best practice policies to encourage breastfeeding.

Breastfeeding difficulties

Many mothers who start breastfeeding stop within a short time. Indeed, 10 per cent of mothers stop breastfeeding after less than a week.
The most common reasons given for stopping are:

All these problems (Table 2) could be avoided or solved if mothers were better supported. Most problems with breastfeeding stem from difficulties relating to poor technique, lack of appropriate information and the mother's lack of confidence. Advising a mother to discontinue breastfeeding and start bottle feeding is rarely the best solution. What the the mother usually needs is the help and support of a skilled person.

Table 2: Common breastfeeding difficulties (none of these means that breastfeeding should be discontinued)
Problem Signs and symptoms Possible reasons Possible solutions
Sore/cracked nipples Red, painful, tender nipples. May be blistered, cracked or bleeding Incorrect positioning/attachment of baby at breast. The tip of the nipple may have rubbed against the baby's tongue or palate. Sore nipples in the early days of breastfeeding are generally due to inappropriate positioning of infant Continue breastfeeding; correct positioning
No other intervention necessary
Thrush Sore nipples, may be red and flaky in appearance. There may be deep breast pain and itching and burning - often after feeds. The baby may have nappy rash and oral thrush. Can happen at any time, but more common after the early weeks of breastfeeding May occur after taking antibiotics Refer to GP. Both mother and baby require treatment with an antifungal
Engorgement Swollen, tender, lumpy breasts, which feel sore and uncomfortable (some feeling of breast fullness is normal). Occurs most commonly in the early days after the birth If the baby is not sucking well or regularly, milk builds up in the breasts leading to discomfort. It can also happen if the baby is feeding well Early engorgement usually goes away by itself after a few days as the baby takes more milk. Feed frequently (every 1-2 hours). A well supporting bra can help. A warm compress can be used to soften breasts before feeding. A cold compress can be used after feeding to relieve discomfort
Blocked ducts A red area on the breast, usually with lump. Can happen any time but is most likely after a period of engorgement Caused by milk not being able to flow through one part of the breast.
Often no clear reason		 Good positioning and attachment will help the baby latch on to the breast
Mastitis Painful, hot breasts with a red area. Sometimes 'flu-like symptoms. Can happen at any time, but most likely after a period of engorgement Due to inflammation or infection of the breast. May be caused by blocked duct Frequent breastfeeding and, if unwell, bed rest for the mother. Refer to GP if problem does not resolve after 24 hours. Antibiotics may be needed
Concerns about milk supply The baby may be unhappy/frustrated at the breast, or listless and lacking in energy. Over a period of weeks, growth may be poor. Although the mother's concern may be real, the milk supply may be fine. Can be due to poor positioning and feeding the baby according to a schedule rather than on demand. Removing the baby before feeding is finished. Giving bottles of formula milk and/or other fluids can interfere with milk supply Make sure the baby is well positioned and attached. Feed frequently and on demand. Offer both breasts at each feed

Breastfeeding support

There are several sources of breastfeeding support (Panel 1), and the UK organisations listed have details of local breastfeeding counsellors and support groups.
In addition, there is a relatively new breed of health professional - at least new to the UK - known as a lactation consultant. There are about 150 of these professionals in the UK and they are trained and accredited to provide education and management to prevent and solve breastfeeding problems as well as to encourage a social environment that actively promotes breastfeeding. They also provide basic training for health professionals. Most of them work in the NHS.
Other sources of support include community midwives and health visitors. In addition, some maternity units have established breastfeeding support units, drop-in centres and/or 24-hour helplines. It is worthwhile finding out about all the support available in your locality and keeping this information in the pharmacy so that mothers can be referred.

Panel 1: Sources of breast feeding information and support

  • 1. Association of Breastfeeding Mothers: 26 Holmshaw Close, Sydenham, London SE26 4TH. Tel: 0208 778 4769
  • 2. Breastfeeding Network: Tel: 0870 9008787. Web site address: www.breastfeeding.co.uk/bfn
  • 3. Health Education Board, Scotland: Breastfeeding in Scotland. Web site address: www.show.scot.nhs.uk/breastfeed/support.htm
  • 4. La Leche League, PO Box BM 3424, London WC1N 3XX. Tel: 0207 242 1278. Web site address: www.lalecheleague.org
  • 5. Lactation consultants of Great Britain: 2 Glenmore Gardens, Norwich, Norfolk, NR3 2RN
  • 6. National Childbirth Trust (NCT): Alexandra House, Oldham Terrace, Acton, London W3 6HN. Tel: 0208 992 8637
  • 7. Unicef UK Baby Friendly Initiative: PO Box 29050, London WC2H 9TA: Tel: 020 7836 5901; fax: 020 7379 5797. Web site address: www.babyfriendly.org.uk
  • 8. World Health Organisation:. web site address: www.who.int

Infant formulas

For mothers who do not wish to breastfeed, there is a range of infant formulas (Table 3) and either a whey or casein based formula is a suitable choice for infants from birth to the age of 12 months.
Follow-on formulas, which contain more iron and vitamin D than ordinary formulas, are available for infants over the age of six months. Special formulas are also available for preterm infants and for those infants who have allergies or intolerances to cows' milk. Many of these formulas are available on prescription under the borderline substances arrangements, and ideally should be supplied only when a proper diagnosis of intolerance has been made.
Table 3: Infant formulas available in the UK
Manufacturer Whey formula* Casein formula* Follow on milk†
Boots Formula 1‡ Formula 2‡ Follow on milk
Cow & Gate Premium Plus Step up
Farley's First milk‡ Second milk Follow on milk
Milupa Aptamil‡ Milumil Forward
Sainsbury First menu first stage First menu second stage First menu follow on milk
SMA Gold White Progress
*Iron content 0.5-0.7 g/L †Iron content 1.2-1.3 g/L
‡Contain long chain polyunsaturates (LCPs)
NB: All formulas are suitable for vegetarians, Hindus, Jews and Muslims, but not for vegans

Cows' milk is not suitable as a main drink for children under the age of 12 months (Table 4). It contains little iron and vitamin D and may lead to intestinal blood loss in some children. Skimmed and semi-skimmed milks should not be used in infancy because of their low energy content. Semi-skimmed milk may be used from the age of 2 years where it is the milk used in the household and the infant's diet is varied. However, skimmed milk should not be used under the age of 5 years. Fruit juice is not necessary, but helps the absorption of iron from fruit, vegetables and cereals.
It is important to remember that many parents do not receive instruction on appropriate technique for making up bottles (Panel 2); if formula preparation is not done properly, the baby may be at risk of dehydration and over- or under-nutritrion.

Table 4: Drinks for infants
  0-6 months 6-12 months After 12 months
Breast or infant formula Yes Yes Yes
Follow-on milk No Yes Yes
Whole cows' milk No No Yes
Semi-skimmed or skimmed milk No No No

Formulation

During the past 10 years, infant milk formulation has been the subject of intensive research, and knowledge gained from research on human milk - research on long chain polyunsaturated fatty acids (LCPUFAs), nucleotides, oligosaccharides and so on - has been applied to the formulation of infant milks.27 However, because breast milk is a living fluid, its composition, and more importantly the outcomes for health, cannot easily be mimicked. Moreover, merely adding ingredients present in breast milk without proper testing of their efficacy and safety in the bottle fed infant can lead to problems.
It cannot be assumed that the bioavailability of ingredients from an infant formula will be the same as that from breast milk. Examples of problems include those previously encountered with vitamin D, protein and electrolytes, all of which have in the past had deleterious effects on infant health, because they were present in excessive quantities in infant milks. The formulation of infant milks is controlled by UK and EU legislation, which is designed to prevent the use of untested novel substances in the manufacture of infant formulas. Changes to infant formulas should not be made without proper trial. Nevertheless, debate on the value of certain ingredients continues, and this is illustrated by recent research on two components - long chain polyunsaturated fatty acids (LCPUFAs) and iron.

Panel 2: Tips for making up bottles

Most babies who are bottle fed in hospital start on the liquid "ready-to-feed" type and parents will generally have their first experience of making up the powdered variety when they arrive home. It is important that bottles are made up correctly and the following advice may be considered:

  • Check the "best before" date before opening the tin or packet
  • Follow the instructions carefully. Make sure scoops are level. Do not add extra scoops
  • Use water straight from the cold tap, boil it and allow it to cool before making up feeds
  • Artificially softened water and some types of filtered water are unsuitable for babies
  • Most bottled spring and mineral waters are too high in minerals for babies. In an emergency, still water is the best, but it should be boiled
  • A day's feeds can be made at one time, but they must be stored at the back of the refrigerator until required. Do not use the door compartments as the temperature may be too high, encouraging growth of bacteria. Throw away any unused milk after 24 hours
  • Do not heat milk and leave it in a vacuum flask for night feeds. This encourages growth of bacteria
  • Never add sugar or cereal to bottle feeds
  • Microwaves should not be used to heat feeds. This is because microwaves heat unevenly and there is a risk of scalding the baby

LCPUFAs

There is growing interest in the quality of dietary fat supplied during infancy, because of its potential effect on growth and development of visual acuity and the nervous system. Breast milk contains a range of LCPUFAs, such as docosahexanoic acid and arachidonic acid, whereas most infant formulas are fortified only with the essential precursor fatty acids linoleic acid (LA) and alpha-linolenic acid (ALA).
Both preterm and term infants can convert LA and ALA to their longer chain derivatives. However, there is some evidence that bottle fed infants are unable to produce their full requirement of LCPUFAs from these precursors, since they have less DHA and arachidonic acid in their erythrocytes than breast fed infants. This finding has prompted trials designed to examine whether addition of LCPUFAs to infant formula has beneficial effects on the development of the eye and the nervous system. These trials have shown advantages of LCPUFA supplementation for pre-term infants whereas benefits for full term infants remain controversial.
Some trials involving manipulation of the LA:ALA ratio or LCPUFA supplementation of infant formula to term infants have shown improvement in visual function,28 while others have not.29,30
Another trial showed no beneficial effect on motor or cognitive development in infants fed formula milk supplemented with LCPUFAs.31 However, a recent study32 showed that supplementing a standard infant formula (in term infants) with two fatty acids - arachidonic acid and docosahexanoic acid - substantially enhances an infant's mental development. The fact that results have been equivocal may be due to the variety of LCPUFA supplements and fat blends used as well as different testing techniques for visual acuity and cognitive function. However, current evidence does not appear to be strong enough to support the addition of LCPUFA to infant formulas.
Safety issues are also important in considering whether to add new ingredients to infant formulas. A higher incidence of necrotising enteritis has been reported in preterm infants, compared with a control group, given a formula fortified with LCPUFA,30 and there is also some evidence that LCPUFAs interact with amino acids in formula fed infants.31 Earlier concerns that LCPUFAs could inhibit infant growth appear unfounded, with studies showing growth of infants receiving breast milk and supplemented or unsupplemented formula to be broadly similar.28,29,31

Iron

Iron deficiency is common in infancy, particularly in developing countries. It also remains a problem in more developed countries. Iron deficiency may lead to anaemia and affected infants may be at risk of delayed mental and motor development. There are several effective sources of iron such as red meat, and also fortified breakfast cereals, bread and pulses, particularly if these are consumed with a source of vitamin C. However, despite parents' best efforts, food intake varies enormously during the early years of a child's life. Attention has therefore focused on the role of infant formulae in preventing iron deficiency.
When compared with cows' milk, follow-on formulas (which are fortified with iron) have been shown to improve indices of iron status (eg, haemoglobin, serum ferritin),33-35 but to have no effect on development and growth.34 However, in a group of inner city children,35 iron fortified formula reduced the decline in psychomotor development which is often seen in such infants from the age of six months, and the authors argued for an iron supplemented formula milk rather than cows' milk to be provided to children living in inner cities who are not being breast fed.

Dr Mason is a pharmacist with a postgraduate qualification in nutrition

References

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14. Rosenblatt KA, Thomas DB. WHO collaborative study of neoplasia and steroid contraceptives. Int J Epidemiol 1993;22:192-7.
15. Cumming RG, Klineberg RJ. Breastfeeding and other reproductive factors and the risk of hip fractures in elderly women. Int J Epidemiol 1993;22:684-91.
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21. Mayer EJ, Hamman RF, Gay EC, Lezotte DC, Savitz DA, Klingensmith DJ. Reduced risk of IDDM among breastfed children. The Colorado IDDM registry. Diabetes 1988;37:1625-32.
22. Gerstein HC. Cows' milk exposure and type 1 diabetes mellitus. Diabetes Care 1994;17:13-19.
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24. Couper JJ, Steele C, Beresford S, Powell T, McCaul K, Pollard A et al. Lack of association between duration of breastfeeding or introduction of cows' milk and development of islet autoimmunity. Diabetes 1999;48:2145-9.
25. WHO Collaborative Study Team on the role of breastfeeding on the prevention of infant mortality. Effect of breastfeeding on infant and child mortality due to infectious diseases in less developed countries: a pooled analysis. Lancet 2000;355:451-5.
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28. Makrides M, Neumann M, Simmer K, Pater J, Gibson J. Are long-chain polyunsaturated fatty acids essential nutrients in infancy? Lancet 1995;345:1463-8.
29. Auestad N, Montalto MB, Hall RT, Fitzgerald KM, Wheeler RE, Connor WE et al. Visual acuity and growth in term infants fed formulas with long chain polyunsaturated fatty acids for one year. Ross Pediatric Lipid Study. Pediatr Res 1997;41:1-10.
30. Lucas A, Stafford M, Morley R, Abbott R, Stephenson T, MacFayden U et al. Efficacy and safety of long–chain polyunsaturated fatty acid supplementation of infant-formula milk: a randomised trial. Lancet 1999;354:1948-54.
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32. Birch EE, Garfield S, Hoffman DR, Uauy R, Birch DG. A randomised controlled trial of early dietary suppy of long-chain polyunsaturated fatty acids and mental development in term infants. Developmental Medicine & Child Neurology 2000;42:174-81.
33. Bramhagen A-C, Axelsson I. Iron status of children in southern Sweden: effect of cows' milk and follow-on formula. Acta Paediatr 199;88:1333-7.
34. Morley R, Abbott R, Fairweather-Tait S, MacFayden U, Stephenson T, Lucas A. Iron fortified follow on formula from 9 to 18 months improves iron status but not development or growth: a randomised trial. Arch Dis Child 1999;81:247-52.
35. Williams J, Wolff A, Daly A, MacDonald A, Aukett A, Booth IW. Iron supplemented formula milk related to reduction in psychomotor decline in infants from inner city areas. BMJ 1999;318:693-8.