September 20, 2016

expert reaction to study of feeding allergenic foods to babies

Publishing in JAMA a group of scientists have reviewed the evidence around food allergies and report that early introduction of egg or peanut to the diet of infants was associated with lower risk of developing allergies to those foods.

Dr Louisa James, British Society for Immunology spokesperson, said:

“Previous guidelines recommended that parents and guardians delay the introduction of allergenic food to infants’ diets. This view has been challenged recently by clinical studies demonstrating that early consumption of peanut and egg may in fact protect against the development of food allergy.

“Considering the increased prevalence of food allergies over recent decades, new guidelines on the timing of introduction of allergenic food to the infant diet are warranted. By combining the data from several clinical studies, Ierodiakonou and colleagues provide evidence that the early introduction of egg at 4-6 months and peanut at 4-11 months reduces the risk of developing egg and peanut allergy respectively. Unfortunately the number of reported studies that could be included in this analysis was small and there were important differences in the way each study was conducted. This means that, despite positive findings overall, additional evidence is now needed before any new specific recommendations on the timing of introduction of allergenic food can be made.

“Despite the limitations, these findings are encouraging and support the growing consensus that the timing of introduction of allergenic food to the infant diet can influence the natural history of food allergy.”

Prof. Graham Roberts, Professor and Honorary Consultant Paediatrician in Paediatric Allergy and Respiratory Medicine at the University of Southampton, said:

“Dr Robert Boyle’s group at Imperial College has undertaken a comprehensive review of how different approaches to weaning infants might decide whether or not they will develop allergies.

“The authors conclude that the early introduction for peanuts and egg into the diet of infants stops them developing peanut and egg allergy respectively.

“However, an element of caution is required. Firstly, early introduction of egg into the diet of infants only protected them from developing egg allergy in some of the studies and many infants developed allergic reactions when they were introduced to egg. Doctors need to understand why only some trials worked, this may help them develop an approach that is both safe and effective.

“Secondly, early introduction of peanuts seems to be most effective in babies who are most at risk of developing peanut allergy. As there is a chance that they will already have allergy, they need to be initially assessed with allergy testing.

“So what should parents do at the moment? If you have a baby with severe eczema or a food allergy, they should be assessed in a children’s allergy clinic. This should include allergy testing for peanut and egg allergy, if testing is negative, the paediatrician may recommend that you introduce peanut and egg into your baby’s diet.

“Dr Boyle’s work was funded by the UK Food Standards Agency. They are using the results to develop updated infant guidelines which should be available in 2017. These should hopefully provide parents and healthcare professionals with clear guidance on how to wean babies, especially those who are at risk of developing allergies.”

Prof. Anthony Frew, Professor of Allergy & Respiratory Medicine at Brighton & Sussex Medical School, said:

“While the meta-analysis has been properly conducted, it is highly debatable – I would say doubtful – whether you can take the earlier studies, done at a time when the risk of food allergy was much lower, and combine this with the convincing data from more recent studies. So while the paper is technically sound, and its conclusions fit with current medical and scientific opinion, the planks on which it is built are rather shaky. The recent studies are much more applicable to the current day situation.

“A more general point, highlighted in the editorial, is that earlier medical advice (not to delay introducing potentially allergenic foods) has largely been vindicated. In fact earlier introduction may be appropriate! Much anxiety and some harm was caused by UK government Committee on Toxicology’s 1998 advice on peanut avoidance in high-risk infants being extrapolated to the wider low-risk population. Midwives and mothers’ groups assumed that in view of the targeted advice, it might be a good idea for all parents to avoid introducing these foods regardless of their child’s risk of becoming allergic. We now know that the opposite was in fact true.”

‘Timing of allergenic food introduction to the infant diet and risk of allergic or autoimmune disease: a systematic review and meta-analysis’ by D. Ierodiakonou et al published in JAMA on Tuesday 20 September 2016. 

Declared interests

Dr Louisa James: Louisa has no conflict of interest to declare.

Prof. Graham Roberts: “I was one of the researchers in the LEAP peanut study and chaired the Trial Steering Committee for the EAT egg and peanut studies.”

None others received