With the incidence of food allergies and in particular, peanut allergy being on the increase; researchers, allergists and paediatricians have been searching for answers on ways to curb this epidemic. In the past we have been cautious and have advised on the avoidance of peanuts, particularly amongst high risk groups (i.e those with severe eczema, egg allergy or a first degree relative with allergies). A recent study published in The New England Journal of Medicine in February of this year has potentially flipped this thinking on its head!
The highly anticipated Learning Early about Peanut (LEAP) study suggests that early introduction of peanuts may offer protection against the development of peanut allergies. The study was led by Professor Gideon Lack and our very own home-grown Dr George du Toit, at King’s College, London. Professor Lack and the LEAP study team enrolled 640 infants between the ages of 4 – 11 months of age. These infants were considered to be at risk of developing peanut allergies because of the presence of severe eczema, egg allergy, or both. These infants were divided into groups based on whether they showed sensitivity to peanut extract or not (as determined by either positive or negative skin prick tests respectively). The infants in each group were then randomly assigned to either consume 6g of peanut protein per week – in the form of peanut butter or a peanut based snack called Bamba – or to avoid peanuts until 60 months (5 years) of age.
Remarkably, the overall prevalence of peanut allergy in the peanut-avoidance group was 17.2% compared to only 3.2% in the consumption group. The prevalence of peanut allergies in children with negative skin prick tests early in life was at 13.7% in the avoidance group and 1.9% in the consumption group. Similarly, children already sensitive to peanuts reflected a 35.3% prevalence of peanut allergy in the avoidance group, compared to only 10.6% in the consumption group.
In summary, the LEAP study has demonstrated that the early introduction of peanut protein dramatically decreases the risk of developing a peanut allergy by a staggering 70-80%. This intervention was shown to be effective in not only in high-risk infants who show no sensitivity to peanuts early on, but also effective in infants who already demonstrate peanut sensitivity.
The results showed that the window of opportunity to prevent peanut allergy is narrow, suggesting that as soon as infants develop the first signs of eczema or egg allergy in the first months of life, they should receive skin testing to peanut and then eat peanut products either at home if the test is negative or first under clinical supervision if the test if positive. The study also suggests that infants without signs of eczema should be fed peanut products from four months of life, bearing in mind that infants should not be fed whole peanuts because of the risk of choking.
Whilst the study is called LEAP, it is really only the first step for re-writing the food allergy guidelines. Other questions remain, such as what is the minimum amount of peanut protein required to reduce allergy risk and will this protective effect wear off in time? The study authors are continuing to follow up their participants in a study called LEAP-on and hopefully in the not too distant future we will have guidelines to help reverse the increasing prevalence of peanut allergy.
Please note! If you are already dealing with children with food allergies, this study does not apply to your situation. The LEAP study was aimed at prevention and has nothing to do with reversing an already established food allergy.
