Recommendation of 6 Months of Breast-Feeding Scrutinized

From Medscape Medical News

Emma Hitt, PhD

January 18, 2011 — The evidence in favor of 6 months of exclusive breast-feeding has come under scrutiny in a new study published by the BMJ.

A review article assessing the evidence was published by researcher Mary Fewtrell, MD, from the Child Nutrition Research Center at the University College London Institute of Child Health, United Kingdom, and colleagues was published online January 13 in the BMJ.

Current World Health Organization guidelines recommend that infants be exclusively breast-fed for 6 months; that is, with a diet that excludes solids or any fluids other than breast milk, including infant formulas. These guidelines, announced in 2001, were adopted by the United Kingdom in 2003.
Exclusive breast-feeding may not adequately meet infants' energy needs for a full 6 months.

"The critical question is whether the United Kingdom should alter its advice on the introduction of complementary foods while new evidence is assembled," the authors note.

The current report maintains that this change in policy occurred without formal consideration of the scientific evidence. Since the announcement of the World Health Organization guidelines, findings from a number of studies suggest that breast milk may not be a reliable single source of nutrition for the first 6 months of life. In addition, the European Food Safety Authority recently concluded that it was safe to introduce complementary foods between 4 and 6 months' of age for infants residing in the European Union.

In the current study, Dr. Fewtrell and colleagues reassessed the evidence in favor of 6 months of exclusive breast-feeding and concluded that exclusive breast-feeding may not adequately meet infants' energy needs for a full 6 months. Higher rates of iron deficiency anemia are an additional concern, having been linked to poorer long-term mental, motor, and social development. Furthermore, existing data suggest an increased risk for reaction to certain allergens (eg, gluten, which has been linked to celiac disease) when their introduction is delayed past 6 months.

Even in the case of protection from infection — considered to be a clear benefit of breast-feeding — a study conducted in Spain showed that these benefits largely accrue to infants breast-fed for 3 months, providing little "extra" benefit thereafter. However, a large study based in the United States did find that infants breast-fed exclusively for more than 6 months had a lower risk for otitis media and pneumonia when compared with infants who were breast-fed exclusively for 4 to 6 months.

Dr. Fewtrell and colleagues conclude that, in light of data that have accumulated during the last 10 years (ie, since the World Health Organization guidelines came out in 2001), the time is ripe for an evidence-based reappraisal of the United Kingdom's stance in this important, yet controversial, area.

According to independent commentator Richard Aubry, MD, MPH, a professor of obstetrics and gynecology at Upstate Medical University in New York, this work does not add any new evidence about the pros and cons regarding adding other foods earlier than 6 months' age.

He told Medscape Medical News that clinicians "need to keep the message clear: Exclusive breast-feeding is the preferred method for feeding the baby until approximately 6 months of age, and then mothers should be encouraged to continue breast-feeding as long as they can. These are the specific terms and overall advice by [the American Congress of Obstetricians and Gynecologists]."

This study was not commercially funded. Three of the 4 authors of the study report having performed consultancy work and/or received research funding in the past 3 years from companies that manufacture infant formulas and baby foods.

BMJ. Published online January 13, 2011.