Six months of exclusive breast feeding: how good is the evidence?

BMJ 2011; 342 doi: (Published 13 January 2011) Cite this as: BMJ 2011;342:c5955

Very low dietary iron intakes but normal haemoglobin levels at 8 months among fully breastfed infants starting solids at around 6 months

In their recent review Fewtrell et al. suggest that exclusive
breastfeeding to 6 months could increase risk of anaemia. In view of this
we would like to share some of our preliminary findings from a study
currently being conducted in Brighton.

We are exploring the feeding practices and iron status of infants
breastfed for at least six months. Most of these infants also conformed to
the Government's recommendation to delay introducing solid foods until
around 6 months and all were exclusively breastfed until at least 4
months. Even though our sample size was small, we found consistent
evidence that in this group dietary iron intakes at 8 months were very
low, with mean total iron intakes from all foods and drinks including
breast milk being less than half the currently recommended levels (1). A
sizeable proportion of participants actively avoided giving their children
foods rich in bioavailable iron such as red meat. We found no evidence of
low haemoglobin levels with all haemoglobin measurements being well within
the normal range for this age group, as described by Emond et al (2).

It appears that despite low dietary iron intakes, haemoglobin levels
are maintained at least until 8 months of age in this group of infants.
Possible explanations for this may include sufficient iron endowment
prenatally (in terms of maternal health and nutrition) and perinatal
factors such as variations in cord clamping practices (3) or a possible
over estimation of iron requirements in the 6-9 month age group.
Publication of the results will follow shortly.

1.COMA (1991). Dietary Reference Values for Food Energy and Nutrients
for the United Kingdom, Report on health and social subjects, No. 41,
HMSO. London

2.Emond, A. M., Hawkins N., et al. (1996). Haemoglobin and ferritin
concentrations in infants at 8 months of age. Arch Dis Child 74 (1): 36-9

3.Chaparro, C.M., Neufeld L.M., Tena et al. (2006). Effect of timing
of umbilical cord clamping on iron status in Mexican infants: a randomised
controlled trial. Lancet 367: 1997-2004

Competing interests: P. Emmett has received small amounts of research funding from two companies manufacturing infant formula and infant foods in the past three years.H. Rabe is the first author of the Cochrane Review on early versus slight delay of cord clamping in preterm infants.

31 January 2011
Antiopi Ntouva
PhD Student / Dietitian
Pauline Emmett, Angela MacAdam, Heike Rabe, Sarath Ranganathan, Carol Williams, Imogen Rogers
School of Pharmacy and Biomolecular Sciences, University of Brighton