UNICEF UK Baby Friendly Initiative statement on new breastfeeding research

The authors are reported to have extrapolated from their findings that mothers' ability to breastfeed is entirely down to these hormone levels. They are also reported to have claimed that exposure to high levels of testosterone before birth account for the differences in health outcomes between breast and bottle fed babies. The findings of this small study are of interest and may warrant further investigation. However, the claims made in relation to these findings do not account for the large differences in breastfeeding rates between countries, with some having 99% of mothers successfully breastfeeding. They are also contradicted by the large body of evidence which shows that levels of successful breastfeeding can be increased by a range of improved support interventions.

The claims made relating to the health outcomes of breastfeeding do not account for the dose response found in many studies, which show that babies breastfed exclusively or for longer periods have the best overall outcomes.

The study does not account for or tally with the known mechanisms for how breastmilk protects against illness. For example, breastmilk contains a range of anti-infective properties including immunoglobulins, white cells, anti-inflammatory components, enzymes and non-antibody factors such as lactoferrin and the bifidus factor.

The body of evidence for the benefits of breastfeeding is very large and comes from a wide range of studies into many different illnesses, carried out by numerous researchers in many different universities. Systematic reviews of the literature have also been carried out and are especially useful, as they are able to eliminate weak studies and combine the findings of all the high-quality papers in order to demonstrate with the greatest reliability whether a protective effect truly exists. It is important to note that there is variability in the quality and depth of evidence in relation to some illnesses which is why the authors of these reviews tend to call for further research to clarify the finding. It remains the case, however, that the evidence for the advantages of breastfeeding is strong.

Although the protective effects of breastfeeding on gastroenteritis and respiratory infections have not been questioned, attempts have been made to dismiss these in developed countries as mere ‘tummy upsets' or ‘coughs and colds', whereas in reality a reduction in severe infection resulting in hospitalisation has been found.

It is important to be aware that the protective effect of breastfeeding is stronger in relation to some illness, notably gastroenteritis, than it is for other illnesses such as allergies. This does not mean that there is no protective effect against those other illnesses, rather that the risk to the bottle-fed baby is greater for some illnesses than for others. Importantly, where the evidence shows a slight protective effect of breastfeeding, this can still be the result of well performed research. Therefore, to describe the evidence as weak because of a lower degree of protection is inaccurate and misleading. It is important to note that a small protective effect of breastfeeding against a significant illness will have a dramatic effect across a population.

The role of the Baby Friendly Initiative and of health professionals is to give pregnant women and new parents the full facts about infant feeding based on the best available evidence in an objective and non-judgemental manner in order to allow informed decision making. We then need to help mothers to make decisions appropriate to their circumstances and to support them in their decision whatever that may be.