Today I am going to let you know about a seismic shift that has occurred in the past year with regards to our understanding of allergy; specifically food allergy and likely all types of allergy that children can develop. We’ve known for a long time that children born into Western cultures, during the 20th century, had a much higher chance of developing one of the allergic diseases than do those not born elsewhere. Those allergic diseases are asthma, hay fever, eczema, and the subject of today’s talk, food allergies. We’ve talked about this a lot in various pedcasts on DocSmo in the past five years but the reasons behind this growing allergy trend are beginning to come clear. If you want to listen to some of my old posts, go right ahead. Here they are.
Why so much allergy is the subject for today’s pedcast and, more importantly, what are the current recommendations by experts to help parents avoid having their children becoming food allergic, specifically, peanut allergic.
First before we get started, let me remind my listeners that I a pediatrician, not a pediatric allergist but I read a lot and I think I am pretty well informed. If, what I am about to tell you today is true, it may be at the starting line of better understanding why some children develop allergy and conversely, why most children do not . As I said before, we have had an inkling for a long time that environmental exposures at critical times in a child’s development have something to do with whether a child becomes allergic. For instance, we have known for a long time that children born to moms who take probiotics during pregnancy, children raised on farms, children raised in homes with older children and pets, and children whose parents hand wash their dishes, have less chance of developing allergic diseases as they get older. The theme here is that early exposure to germs seems to induce more tolerance to the stuff that many children become allergic to. Researchers feel that a the amount and kind of bacteria that colonizes a newborn’s intestines in infancy, to a large degree, determines how their immune system w develops and whether or not they will become allergic.(1) A new study called the LEAP study has also she more light on a process called “immune tolerance”, specifically tolerance to peanut protein. (2) Researchers doing this study found that many children who were at high risk of developing peanut allergy, if exposed to peanut protein between 4-11 months of age, on a regular basis, developed tolerance to peanut protein and avoided becoming allergic. The data was so dramatic that this one study has led to a new recommendation from the Academy of Pediatrics; Infants at high risk of developing food allergies should be given at least 3 teaspoons/week of peanut protein to help them induce immune tolerance and avoid peanut allergy. (3) To get this effect of allergy reduction, children in the LEAP study were fed the following forms of peanut protein:
Box 2. Examples of peanut-containing foods used in the LEAP trial
• Smooth peanut butter (1 teaspoon) mixed with milk or with mashed or pureed fruit
• Bamba snack* (Osem; approximately two thirds of a 1-oz (25 g) bag; 21 sticks of Bamba)
— For young infants (<7 months), softened with 20 to 30 mL water or milk and mixed with milk or with mashed or pureed fruit or vegetables
• Peanut soup
• Finely ground peanuts mixed into other foods, such as yogurt
*Other foods more customary to particular nations/cultures can be substituted.
Whole peanut is not recommended for introduction because this is a choking hazard in children less than 4 years of age.
While the LEAP study only studied the benefits of giving peanut protein to children with severe eczema, it seems logical that the same benefit of allergy reduction would apply to children without eczema. In fact, the lead author of the LEAP study, Dr. Gideon Lack, recommends that low risk children be given peanut protein as they are weaned. (4) Parents who have traditionally given peanut protein to their young infants like the Israeli’s and many Africans cultures find that peanut allergy is quite rare among their children. Lesson learned-early exposure means tolerance and not allergy. This observation jives with the LEAP study. If you have an infant in your house, it is important that you talk to their pediatrician about this new information and get their recommendation. Early peanut protein introduction is not for every child so make sure this subject comes up at your infant’s checkups between 4-11 months of age. If you could avoid your child becoming peanut allergic, wouldn’t that be a wonderful thing.
As you can see, this new information probably has tremendous implications for the future of allergy research. Scientists have probably been asking the wrong question for a long time. Instead of wondering what triggers allergy in children, they should have been wondering what would induce immune tolerance in children, especially during infancy. It looks like we are getting a little closer at knowing what those factors are likely to be, at least for peanut protein and possibly for a lot of other allergy inducing foods, dusts, and who know what?
Well, that’s a lot to think about. Fascinating though, wouldn’t you say and potentially very important for infants and children in today’s allergic world. Thank you for joining me for this edition of Portable Practical Pediatrics. If you want to get a free pediatric education and almost assuredly be the best informed parent in the room, subscribe to my blog and get notice of my weekly posts or subscribe to my podcast, Portable Practical Pediatrics on iTunes. Either way, I feel certain you will be glad you did. This is Doc Smo, bringing you today’s fact, about which little ones will likely react. Until next time.
(1) Clin Perinatol. 2011 Jun; 38(2): 321–331.
Cesarean versus Vaginal Delivery: Long term infant outcomes and the Hygiene Hypothesis
Josef Neu, MDa,b,a,b and Jona Rushing, MDc,c://
(2) Randomized Trial of Peanut Consumption in Infants at Risk for Peanut Allergy
George Du Toit, M.B., B.Ch., Graham Roberts, D.M., Peter H. Sayre, M.D., Ph.D., Henry T. Bahnson, M.P.H., Suzana Radulovic, M.D., Alexandra F. Santos, M.D., Helen A. Brough, M.B., B.S., Deborah Phippard, Ph.D., Monica Basting, M.A., Mary Feeney, M.Sc., R.D., Victor Turcanu, M.D., Ph.D., Michelle L. Sever, M.S.P.H., Ph.D., Margarita Gomez Lorenzo, M.D., Marshall Plaut, M.D., and Gideon Lack, M.B., B.Ch. for the LEAP Study Team
N Engl J Med 2015; 372:803-813February 26, 2015DOI: 10.1056/NEJMoa1414850
(3) Statement of Endorsement
CONSENSUS COMMUNICATION ON EARLY PEANUT INTRODUCTION AND THE PREVENTION OF PEANUT ALLERGY IN HIGH-RISK Pediatrics
September 2015, VOLUME 136 / ISSUE 3
From the American Academy of Pediatrics
(4) How Can Peanut Allergies Be Prevented?