It might be time for a change in the strategy in the way food allergy prevention is handled.
This was the message in the media last month from
Prof Andrew Kemp, Professor of Paediatric Allergy and Clinical Immunology at Sydney's Westmead Children's Hospital.
Prof Kemp, quoted in the Sydney Morning Herald and on ABC Radio
(September 26, 2008), said the incidence of food allergies had risen over the past 20 years at the same time as parents had been warned to be cautious about introducing specific foods.
This strategy had not worked and it might be time to "reverse the thinking", Prof Kemp said.
"We shouldn't be restricting the access of young infants or babies as they start to eat solids," he said.
"It may well be by letting them get exposed to the allergenic foods as well, they might even have potentially less allergy."
Prof Kemp is not saying that children with known allergies should be given foodstuffs that will make them ill but rather that parents should not try to pre-empt possible allergies by keeping babies and young children away from certain foods such as peanuts.
Prof Kemp said recent evidence suggested any particular food could be introduced at any time after babies started eating solids without raising the child's allergy risk.However there might be other reasons - such as a choking risk - why some foods were unsuitable for babies.
The Chairman of the Australasian Society of Clinical Immunology and Allergy (ASCIA) paediatric committee
Prof Mimi Tang said the current National Health and Medical Research Council recommendation that children should not have solid foods before six months would not prevent food allergies.
She said ASCIA would recommend that the NHMRC change its current guidelines which were last updated in 2003.
Earlier this year the
American Academy of Pediatrics updated its guidelines after finding there was no good reason to avoid certain foods during pregnancy however it has recommended that the introduction of solid foods be delayed to beyond six months.
Dr Frank Greer, Professor of Pediatrics at the University of Wisconsin School of Medicine, and
Dr Scott Sicherer from the Mt Sinai School of Medicine's Jaffe Food Allergy Institute, helped write the new guidance report for paediatricians which was published in the January 2008 issue of the journal
Pediatrics:
- There is no convincing evidence that women who avoid peanuts or other foods during pregnancy or breast-feeding lower their child's risk of allergies
- For infants with a family history of allergies, exclusive breast-feeding for at least four months can lessen the risk of rashes and allergy to cow's milk
- There is no good evidence that soy-based formulas prevent allergies
- There is no evidence that delaying the introduction of foods such as eggs, fish or peanut butter to children prevents allergies. However babies should not get solid food before four to six months of age.
Earlier research by
Dr Peter Vadas at the University of Toronto (ref. "Detection of peanut allergens in breast milk of lactating women", JAMA, Vol 285, 2001, pp1746-1748) had found peanut protein in breast milk and this work is often cited as a reason for nursing mothers to avoid eating peanuts.
Dr Vadas is still advising breastfeeding mothers to avoid peanuts
but only if there is a family history of peanut allergy.
"There's really no reason to engage in a lot of dietary manipulation except in very specific instances," he said.
In 2007, the House of Lords Science and Technology Committee found that current advice to parents in the United Kingdom may also be wrong.
It called on the British Government to stop advising pregnant women and young children to avoid eating peanuts, warning that the information was out of date and may actually increase the risk of developing peanut allergy.
"We are very concerned that Department of Health dietary advice regarding peanut consumption for pregnant women and infants is based upon evidence that was reported nine years ago ... We recommend that this advice should be withdrawn immediately, pending a comprehensive review," the committee reported.
It cited recent research by
Dr Carina Venter and
Dr Tara Dean from the University of Portsmouth who found that maternal consumption of peanuts during pregnancy and breastfeeding were not associated with peanut sensitization in infants (ref. "Government advice on peanut avoidance during pregnancy - is it followed correctly and what is the impact on sensitization?", Journal of Human Nutrition and Dietetics, Vol 20, 2007, pp95-99) and evidence that in Israel, where peanut snacks are commonly used in weaning foods, the incidence of peanut allergy is lower than in the UK.
The committee also recommended that specialist medical centres be set up and more allergy training should be provided to medical students and GPs. It also supported the
Learning Early About Peanuts (LEAP) study which is being conducted in London by
Professor Gideon Lack at St Thomas' Hospital which is testing the hypothesis that early ingestion of peanuts may protect children from peanut allergy.
However, not all allergy experts necessarily agree with the new strategies.- Anaphylaxis Australia president Maria Said called for further research: "There needs to be further research before people are going to accept this as maybe being the way to go," she told the ABC.
- Dr Robert Loblay, director of the Allergy Unit at Royal Prince Alfred Hospital said there were "big dangers in extrapolating from one community to another".
- Montreal paediatrician Dr Anne Desroches of Sainte-Justine Hospital says her unpublished research, which involved mothers filling in questionnaires, showed that eating peanuts during pregnancy may quadruple the risk that the baby will be allergic to nuts. Critics have claimed the findings may be flawed by "recall bias", where mothers of peanut-allergic children would be more likely to remember eating peanuts than women who have no reason to remember eating peanuts.
- Dutch research published by the American Thoracic Society earlier this year (ref. "Maternal Food Consumption during Pregnancy and the Longitudinal Development", Journal of Respiratory and Critical Care Medicine of Childhood Asthma, Vol 178, pp124-131) found that eating peanuts and peanut products during pregnancy may raise an infant's risk of developing asthma. The study indicated an increased risk if there was daily consumption versus rare consumption but the authors cautioned "these findings need to be replicated by other studies before dietary advice can be given to pregnant women".
And so the debate continues ....- Click on the arrow to hear an interview with Prof Andrew Kemp, first broadcast on ABC Radio National on Friday, September 26, 2008
- Click on the arrow to hear an interview with Dr Robert Loblay, first broadcast on ABC News Radio on Friday, September 26, 2008
