Tuesday, April 5, 2016
Prevention of Food Allergy
Children are afraid of a lot of things: the dark, strangers, and even the bogeyman. But for more and more kids, ordinary foods, like peanuts, eggs, and milk, are becoming sources of fear. Food allergies are becoming increasingly common in the developed world, and we don’t have a good explanation of why. In this month’s issue of JACI, du Toit and his colleagues talk about the factors that lead to food allergies, and what can be done to prevent children from developing food allergies (J Allergy Clin Immunol 2016; 137(4): 998-1010). It’s clear that there are some risk factors that we just can’t change: male gender, a family history of food allergies, and even race can put children at a higher risk for developing food allergies. But there are other things that we can possibly change. Since children with eczema (atopic dermatitis) tend to have food allergies, there have been some discussion about whether preventing and controlling eczema by regularly applying moisturizers could help prevent food allergies. Attendant to the link between high levels of aerosolized peanut dust and the development of peanut allergies, it has been suggested that, at least for peanuts, children may become sensitized through the skin and not the gut. Thus, it is possible that by keeping the skin barrier intact, we may be able to prevent peanut allergy. Studies are still ongoing; if successful, these would be simple ways to stop food allergies in their tracks.
Another big hope has been that we can mitigate the development of food allergy by modifying the types of food that the mother takes while pregnant or lactating. To date, these studies have been inconclusive. Likewise, there is not much data on the efficacy, or even safety of, dietary interventions such as fatty acids, antioxidants, pre- and probiotics and vitamin supplementation.
The one glimmer of hope is that early introduction of common food allergens during infancy may be a pro-active approach. Two major trials, LEAP (Learning Early About Peanut Allergy), and EAT (Enquiring About Tolerance) have suggested that introducing children to peanuts during infancy does not lead to food allergy, and may actually help to prevent them.
Food allergy is an enormous problem but new research on prevention may help to bring it under control, and make sure that children can have at least one less thing to be afraid of.