Breastfeeding babies exclusively without introducing other foods until they are six months old may not be in their best interest, suggest UK researchers in a study published this week in BMJ.

The recommendation that mothers in the UK should breastfeed their babies exclusively for six months is a controversial area of child nutrition, and after reviewing the evidence, Dr Mary Fewtrell, a consultant paediatrician at the Institute of Child Health in University College London (UCL), and colleagues, said while they back exclusive breastfeeding early in life, they question whether this should continue until babies are six months old.

You can read how they came to their conclusions in the 13 January online issue of BMJ.

Fewtrell and colleagues support the World Health Organization (WHO) recommendation of six months exclusive breastfeeding in less developed countries, where clean water and safe weaning foods are not available to everyone, and there is a high risk of infant death and illness. But they question whether it is right for babies raised in the UK.

The authors point out there is a difference between breastfeeding, which can continue after babies start eating solid foods, and exclusive breastfeeding, where apart from vitamins and mineral supplements, babies have no other source of nutrition.

In their background information they cite evidence that what babies consume in their first half year of life makes a big difference to their long term health, for instance by “programming aspects of subsequent cognitive function, obesity, risk of cardiovascular disease, cancer, and atopy [hypersensitivity to allergens]”.

In 2001, the WHO asked member states to adopt its global recommendation that babies should be exclusively breastfed for the first six months of their lives. The US, 65 per cent of EU countries, and other western nations, chose not to follow this recommendation in full, and some have not at all.

Supporting the WHO recommendation is a systematic review done in 2000 of 16 studies, including 7 studies of babies in developing countries. The review concluded that exclusively breastfed babies developed fewer infections and experienced no growth problems.

In 2003, the health minister said the UK would comply with the WHO recommendation, but this “major, population-wide change in public health policy” was backed by evidence that “underwent surprisingly little scrutiny”, write Fewtrell and colleagues, in fact, even the Department of Health’s own Scientific Advisory Committee on Nutrition (SACN) was not invited formally to look at the scientific evidence.

In view of this omission, and given that the European Food Safety Authority (EFSA) has since released new data and an expert review that concludes that for babies in the EU, it is safe for them to start having complementary foods between four and six months, the authors suggest now is the right time to question the UK’s position.

Fewtrell and colleagues argue, with references to studies, that giving babies only breast milk is not enough nutrition for their first six months of life. They say such babies have a higher risk of iron deficiency anaemia, and may also be at higher risk for celiac disease and food allergies by not being exposed to certain solid foods earlier.

They also suggest that giving babies only breast milk for six months reduces the window of opportunity for introducing them to new tastes, particularly the bitter foods, which can affect the extent to which they accept green leafy vegetables later. This could predispose them to unhealthy eating and obesity, they argue.

“Six months of exclusive breast feeding: how good is the evidence?”
Mary Fewtrell, David C Wilson, Ian Booth, Alan Lucas.
BMJ, 2011; 342:c5955; Published online 13 January 2011.
DOI: 10.1136/bmj.c5955

Additional source: BMJ press release, 13 Jan 2011.

Written by: Catharine Paddock, PhD