Will my child develop a food allergy in their first few years of life? This question is commonly asked by new parents. The next question we should be asking is: can this issue be prevented? Until recently, we did not have an answer to this important question, but emerging research says we may have a solution.

What are food allergies?

Over the last two decades, food allergies have been steadily increasing. There are few answers to why this issue is occurring as there is currently no conclusive evidence available, only theories to explain this phenomenon. A food allergy is defined as an immune system reaction that occurs after eating a certain food (1). The foods that account for 90 percent of allergic reactions are milk, eggs, peanuts, tree nuts, shellfish, fish, soy, and wheat. Reactions to these common allergens vary widely, ranging from tingling or itching in the mouth, hives, itching or eczema, swelling of the lips, tongue, and throat, abdominal pain or diarrhea, vomiting, and the most severe, anaphylaxis (1). These reactions, ranging from mild to severe, can vary from case to case.

What does the research say?

The American Academy of Pediatrics published guidelines in 2000 recommending that infants should not consume cow milk until they were one year of age, eggs until age two, and peanuts, tree nuts, fish, or shellfish until the age of three (2). A few years after these guidelines were published, there was still no evidence supporting how the delay of the introduction of these foods played a role in preventing food allergies; some studies showed it may even promote allergy development (3). In recent years, numerous studies have demonstrated that there are preventative measures to decrease the risk of developing food allergies.

A Swedish study, published in 2006, concluded that regular fish consumption in the first year of life correlates with a lower risk of allergic disease and reduced allergic sensitization for the first four years of life (4). Another study, published in 2010, demonstrated that delaying egg introduction for the first year of life resulted in a 3.4-fold higher risk of developing an egg allergy compared with egg introduction at any time between four and six months of age (5). The latest research, the Learning Early About Peanut (LEAP) allergy study, was a prospective trial randomly assigning high-risk infants to either an early introduction to peanut protein at four to eleven months of age or delayed introduction at three years of age (6). The “high risk” infants in this trial are defined as ones with severe eczema and/or egg allergy (7). This study found that the introduction of peanuts at four to eleven months of age significantly reduced the risk of developing a peanut allergy in high-risk infants.

With this new evidence demonstrating the benefit of introducing allergenic foods early, the National Institute of Allergy and Infectious Diseases (NIAID) released addendum guidelines for the prevention of peanut allergy in January 2017 (7). The new guidelines recommend introducing the highest risk infants to age-appropriate peanut-containing food as early as four to six months of age to reduce the risk of peanut allergy.

What can we take away from these findings?

The increase in food allergies over the last 20 years has become a major public health issue. This issue in part may be due to years of recommending the delayed introduction of allergens based on expert opinion only. The new guidelines from the NIAID recommend early introduction of peanuts for high-risk infants and numerous studies demonstrate that early introduction of other allergenic food may have a preventative effect on food allergies early in life. Although, additional research is required to give specific recommendations on other allergenic food introduction.

We know a window of opportunity exists where the immune system molds to either become tolerant to food or allergic to it. This window starts around four months of age and it is unknown precisely for how long the window is open; however, based on current research, this window is believed to occur between age four months and one year.

If an infant is in the high-risk category, there are options for introducing allergens in a safe way such as in-office testing, medically supervised ingestion, or oral food challenges. Introducing allergenic foods early and often will help ensure the window of opportunity for allergy prevention is not missed, and may lead to lower incidences of allergies in children.


  1. Food allergy. (2019, November 02). Retrieved from https://www.mayoclinic.org/diseases-conditions/food-allergy/symptoms-causes/syc-20355095
  2. American Academy of Pediatrics Committee on Nutrition. Hypoallergenic infant formulas. Pediatrics. 2000;106(2 Pt 1):346–9.
  3. Introduction of complementary foods in infancy and atopic sensitization at the age of 5 years: timing and food diversity in a Finnish birth cohort.

Nwaru BI, Takkinen HM, Niemelä O, Kaila M, Erkkola M, Ahonen S, Tuomi H, Haapala AM, Kenward MG, Pekkanen J, Lahesmaa R, Kere J, Simell O, Veijola R, Ilonen J, Hyöty H, Knip M, Virtanen SM

Allergy. 2013 Apr; 68(4):507-16.

  1. Fish consumption during the first year of life and development of allergic diseases during childhood.

Kull I, Bergström A, Lilja G, Pershagen G, Wickman M

Allergy. 2006 Aug; 61(8):1009-15.

  1. Can early introduction of egg prevent egg allergy in infants? A population-based study.

Koplin JJ, Osborne NJ, Wake M, Martin PE, Gurrin LC, Robinson MN, Tey D, Slaa M, Thiele L, Miles L, Anderson D, Tan T, Dang TD, Hill DJ, Lowe AJ, Matheson MC, Ponsonby AL, Tang ML, Dharmage SC, Allen KJ

J Allergy Clin Immunol. 2010 Oct; 126(4):807-13.

  1. Randomized trial of peanut consumption in infants at risk for peanut allergy.

Du Toit G, Roberts G, Sayre PH, Bahnson HT, Radulovic S, Santos AF, Brough HA, Phippard D, Basting M, Feeney M, Turcanu V, Sever ML, Gomez Lorenzo M, Plaut M, Lack G, LEAP Study Team.

N Engl J Med. 2015 Feb 26; 372(9):803-13.

  1. Addendum guidelines for the prevention of peanut allergy in the United States: Report of the National Institute of Allergy and Infectious Diseases-sponsored expert panel.

Togias A, Cooper SF, Acebal ML, Assa’ad A, Baker JR Jr, Beck LA, Block J, Byrd-Bredbenner C, Chan ES, Eichenfield LF, Fleischer DM, Fuchs GJ 3rd, Furuta GT, Greenhawt MJ, Gupta RS, Habich M, Jones SM, Keaton K, Muraro A, Plaut M, Rosenwasser LJ, Rotrosen D, Sampson HA, Schneider LC, Sicherer SH, Sidbury R, Spergel J, Stukus DR, Venter C, Boyce JA

Ann Allergy Asthma Immunol. 2017 Feb; 118(2):166-173.e7.