A study on the “Prevention of Food Allergy” has been published in the Journal of Allergy and Clinical Immunology. The study includes findings from the Learning Early About Peanuts Allergy (LEAP) and Enquiringly About Tolerance (EAT) studies and looks at the relevance of factors such as genetics, race and sex; whether there might be a “window of opportunity” for preventing the development of food allergy; sensitisation through the skin and skin barrier dysfunction and maternal and infant diet. It also looks at the possible role of vitamin D.
The Anaphylaxis Campaign welcomes this and other studies that helps to shed light on how food allergy develops and looks forward to further research in this important area
The following questions are addressed:
- The LEAP study only included high-risk infants with severe AD, egg allergy, or both. Would this strategy be protective for infants without these risk factors?
- In the LEAP study, 76 children were excluded before randomization based on a peanut SPT response of 5 mm or greater, because a high likelihood of reacting to an oral peanut challenge was assumed. If we had intervened in these children at an earlier window of opportunity, such as 3 to 4 months of age, would we have been able to prevent the development of PA?
- Are the benefits of allergy protection sustained, or are they dependent on ongoing peanut consumption?
- Does the LEAP intervention protect against the development of PA even in infants who were sensitized (based on SPT responses, sIgE levels, or both) at baseline; that is, did the study demonstrate both primary and secondary allergy prevention?
- Are these findings applicable to children of different ethnic groups or in different geographic settings?
- Are similar findings demonstrated in other interventional studies using hen’s egg for the prevention of egg allergy?
- Acceptability of early dietary interventions: How do we maintain and bolster adherence?
- Are the dietary interventions allergen specific?
- There is evidence that a large proportion of the allergy burden is inherited, but genetic predisposition alone cannot explain the disturbing increase in FA.
- Studies on changes in gene function in relation to environmental influences (ie, epigenetic modifications) are beginning to provide evidence to explain the mechanisms underlying the development of FA.
- Sensitization and FA can occur early in infancy, and it appears that prevention strategies should ideally commence during these early-life periods of immunologic vulnerability.
- The evidence supporting use of dietary interventions in high risk pregnant and/or lactating women for the prevention of FA is weak; noted effects are inconsistent, and furthermore, such interventions might compromise maternal and fetal nutrition.
- Although there are many health benefits of breast-feeding for both the mother and infant, it is not certain whether exclusive breastfeeding for any length of time offers protection against FA development.
- For high-risk infants who are not exclusively breast-fed, the use of hydrolyzed formula might offer some protection against allergic disease, but these effects appear weak and are generally limited to the development of atopic dermatitis (AD).
- It might also be that any reduction in AD arises because of treatment of underlying cow’s milk allergy, as opposed to representing tertiary allergy prevention.
- The findings of studies investigating the use of dietary interventions (such as fatty acids, antioxidants, prebiotics and probiotics, and vitamin supplements) are unconvincing, inconsistent, or not adequately tested. Furthermore, there are safety concerns surrounding some of these interventions.
- Numerous questions remain about how to implement early food introduction, and which groups of infants should be targeted. However, it is clear that the paradigm has shifted from recommending avoidance of common food allergens in infancy, to consideration of early consumption strategies to prevent allergy development.
- The recent publication of interventional studies aimed at the prevention of FA heralds a significant advance in our quest to contain this modern-day epidemic. The LEAP study findings have already influenced recommendations across many allergy societies for the introduction of peanut in at-risk populations.
- The EAT study results add to these findings and strengthen the argument for a wider revision of infant feeding recommendations.
- It is reassuring that the interventions themselves are safe, nutritionally favourable, affordable, accessible, and—with appropriate health care support—acceptable.
Access the full paper here http://www.jacionline.org/article/S0091-6749(16)00288-8/pdf