Breast milk study wrong, say midwives

Supporters of breastfeeding are worried that recent research into allergies may interfere with what they say is essential nutrition for young babies. Antonia Maiolo reports

Midwifery experts are challenging research by the Australian National University that found exclusively breastfed babies had a higher risk of nut allergies. The analysis of 15,140 children from the ACT found that breastfeeding was not protective of nut allergies.

The likelihood of developing a nut allergy was 1.5 times higher in children who were solely breast fed in the first six months of life, than in children who were exposed to other foods and fluids.

“Despite breastfeeding being recommended as the sole source of nutrition in the first six months of life, an increasing number of studies have implicated breastfeeding as a cause of the increasing trend in nut allergy,” said the study’s author and professor of general practice at the ANU Medical School, Marjan Kljakovic.

But a senior lecturer from the division of nursing and midwifery at RMIT University, Dr Jennifer James, says the ANU study results contradict the opinion of health experts. James said the research, which has been published in the International Journal of Pediatrics, is flawed.

The study conducted between 2006 and 2009 asked parents to fill in a questionnaire, which covered a range of health issues including infant feeding practices and peanut allergies. In relation to feeding, parents were asked questions about their child’s feeding habits in infancy, including whether the baby had been breastfed, how long it had been breastfed and at what age other foods or drinks had first been introduced.

Parents were also asked whether their child had ever had a “strong allergic reaction to peanuts, peanut products, and or other nuts, nut products”, and if they answered yes, it was recorded as a self-reported nut allergy. From this, the results showed: children who were solely breastfed were found to have a 5 per cent nut allergy rate, whilst those who were fed anything else other than breast milk had a 2.7 per cent allergy rate, and children who were fed a mixture had a 3.7 per cent rate.

James said the questions posed to parents whose children were five to six years of age were poorly worded. “Asking them, has your child had a significant reaction, well what does that mean clinically?” She also said the research was weakened as it had such a long recall period, expecting parents to remember allergic reactions and exactly when other fluids and or foods were introduced.

“We know that to recall anything up to about 12 months is pretty accurate but four or five years later is ridiculous.”

James added that if an infant has a reaction to a skin prick test then that is not necessarily the same as having a clinical reaction to having eaten a peanut product, and that a parent wouldn’t necessarily know the difference. Despite the ANU’s study results, James said there isn’t any proper evidence to suggest we should be interfering with the World Health Organisation’s (WHO) recommendation of exclusive breastfeeding for up to six months.

Because there are not currently significant exclusive breastfeeding rates in Australia, James said this study could be particularly harmful. WHO says that about 14-15 per cent of Australian children are being breastfed exclusively for the first six months.

The Australian Department of Health and Aging says breastfed babies are less likely to suffer from conditions such as gastroenteritis, respiratory illness and otitis media (middle ear infection). Breastfeeding also benefits a mother’s own health by promoting faster recovery from childbirth and reducing the risks of breast and ovarian cancers in later life.

James said breastfeeding is also important for providing antibodies to aid development of the immune system. Infants immune systems develop slowly and they are particularly vulnerable in the first six months, and breast milk boosts their immune systems until they have matured. “You don’t get that from formula, you get basic nutrition from formula, that’s it,” she said.

Professor Kljakovic is aware of how controversial his study’s results are. “I’ve never had a research project that’s had so much interest,” he said. He noted that news outlets all over the world have reported the study findings, with the wrong message getting out suggesting that he is against breastfeeding, “Well I’m not!” Kljakovic said.

“Our results contribute to the argument that eating nuts while breastfeeding may in fact be causative of allergy,” he said. But he clarified that he doesn’t believe breast milk is responsible for causing nut allergies but rather it is possible that the nut traces found in breast milk is what causes the allergy. “Maybe it’s the food the mother eats … I would like to conduct further research,” he said.

James said that additional research is vital. She said it is evident the researchers tried to strengthen the study but that they haven’t done a good job. “[This study] really doesn’t add to our body of knowledge about why there is a rise of incidence of nut allergies in Australia,” she said.

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