Midwives and Health Visitors — Key messages about allergy
For many years there was speculation that babies in families prone to allergies may become sensitised while they are in the womb, or through their mother’s breast milk. The Department of Health issued guidelines to women in 1998, suggesting that they “may wish” to avoid nuts and peanuts during pregnancy and while breastfeeding if there is allergy in the immediate family. The guidelines also stated that peanuts and tree nuts should not be introduced to children until after three years of age.
In early 2009, the Food Standards Agency decided that the Government advice on avoiding peanuts during pregnancy, breastfeeding and early life should be revised in light of new evidence. It was suggested that the strategy reflected in the 1998 guidelines had not worked and that it was possible, but not then proven, that early introduction of peanuts to the diet may actually prevent the development of peanut allergy.
Subsequently and based on data generated in the Learning Early About Peanut (LEAP) trial, the results of which were published early in 2015 in the New England Journal of Medicine, and existing guidelines, an “interim” guidance document was published to assist the clinical decision-making of healthcare providers, highlighting emerging evidence to existing guidelines regarding potential benefits of supporting early, rather than delayed, peanut introduction during the period of complementary food introduction in infants.
“Consensus Communication on Early Peanut Introduction and the Prevention of Peanut Allergy in High-Risk Infants” was published on behalf of American Academy of Asthma Allergy and Immunology, American Academy of Pediatrics, American College of Allergy, Asthma & Immunology, Australasian Society of Clinical Immunology and Allergy, Canadian Society of Allergy & Clinical Immunology, European Academy of Allergy and Clinical Immunology, the Israel Association of Allergy and Clinical Immunology, the Japanese Society for Allergology, Society for Pediatric Dermatology, and the World Allergy Organization.
A follow-up paper – “Effect of Avoidance on Peanut Allergy after Early Peanut Consumption” was published on 4th May 2016.
The “Persistence of Oral Tolerance to Peanut (LEAP-On)” study was a 12-month extension of the LEAP trial. Researchers investigated whether participants who had consumed peanut in the primary trial would remain protected against peanut allergy after cessation of peanut consumption for 12 months. The study design represented an opportunity to investigate the mechanisms of loss of protection from allergic responses, with potential implications for other food allergies and immune-mediated diseases.
The study concluded:
“Among children at high risk for allergy in whom peanuts had been introduced in the first year of life and continued until 5 years of age, a 12-month period of peanut avoidance was not associated with an increase in the prevalence of peanut allergy. Longer-term effects are not known.”
Read the full study here.
“Enquiring About Tolerance (EAT)” Study
Results of the EAT Study were announced on the 4th March 2016
The Enquiring About Tolerance (EAT) study aimed to find out whether introducing certain foods early in a child’s diet along with continued breastfeeding could stop infants developing food allergy.
This important and exciting study is a great step towards reducing the risk of developing food allergies. Follow up studies will consolidate the results and lead to more accurate Government infant feeding advice for parents.
In the meantime it is important for parents to continue to follow existing Government advice and discuss any questions or concerns they may have with their treating doctor, health visitor or allergy specialist.
The key positive points of the study as we see it are:
When all of the participants originally recruited to the study (including those who did not adhere strictly to the study protocol) were included, the results were not significant. However,
- the early introduction of allergenic foods was found to be safe, with no cases of anaphylaxis during the initial introduction of the foods and no adverse effects on breast-feeding or growth.
- in those that adhered strictly to the study protocol by eating the recommended amounts of allergenic foods there was a significant 67% lower relative risk of food allergy overall in the early-introduction group.
- In those that adhered strictly to the study protocol by eating the recommended amounts of allergenic foods, significantly lower relative risks of peanut allergy and egg allergy were observed in the early introduction group than in the standard-introduction group.
Until results of these trials have been translated into UK practice guidelines, the FSA’s messages for high risk families (those with a history of allergy) still hold.
- Mothers who eat peanuts can continue to eat them during pregnancy and breastfeeding.
- There is little evidence to suggest that introducing peanut products to children (e.g. peanut butter) will lead to peanut allergy.
- Families should discuss their individual case with their GP or another health professional if they are concerned.
Despite the lack of answers, there is still sound advice that can be followed by mothers in high-risk families if they wish to reduce the chances of their child developing allergy:
- Avoid smoking during the pregnancy or afterwards, and avoid exposing your baby to cigarette smoke.
- While pregnant and breastfeeding, eat a healthy balanced maternal diet with sufficient portions of fresh fruit, vegetables and n-3 fatty acids. Going on an exclusion diet is not advised.
- Exclusively breastfeed for at least four months (preferably six).
If breastfeeding is not possible, an extensively hydrolysed casein formula should be given until the age of six months.
- Avoid exposure to high levels of house dust mite. A high-efficiency vacuum cleaner with filter is important. Reduce other environmental allergens, such as moulds, cat and dog hair, and bird feathers. Keep the humidity levels down. Consider doing away with carpets, and using blinds instead of curtains.
- Introduce one food group at a time e.g. dairy products (milk, yoghurt, cheese) and wait five days before introducing a new food, e.g. wheat (bread, pasta, cereal). Keeping a food/symptom diary during this period may well be useful to identify allergic symptoms.
Updated 10/3/16 to incorporate EAT and LEAP-ON study results