When I was in public school in the 1970s, I honestly recall few kids with food allergies. Today, child food allergies are so high, some school system ban peanut butter and jelly sandwiches for lunch. And if you’re an American, peanut butter and jelly sandwiches are an iconic lunch food for school age children.
My recollection of few of any child food allergies when I was a child myself. As an anecdote, that’s not too powerful, but it’s borne out by actual scientific data. For example, Australian children have the highest rate of food allergy in the world, with up to 10% of infants and 20% of school-aged children who have been diagnosed with a food allergy. Large studies, including a retrospective study of over 1 million children in the USA, have shown that overall food allergy prevalence was 6.7%. The most common allergenic foods were peanuts (2.6%), milk (2.2%), egg (1.8%), shellfish (1.5%), and soy (0.7%). Furthermore, food allergies were associated with development of respiratory issues such as asthma (2.16X risk over those without food allergies) and rhinitis (2.72X risk).
In Australia, there has been a 50% increase in hospital visits for anaphylaxis from 1998 to 2012, the most severe allergic reaction. Infants and toddlers accounted for much of this increase. Anaphylaxis is the most serious allergic reaction to anything including food.
What stumps a lot of researchers is why the increase? Has our food supply become more allergenic? Some blame the addition of GMOs to our food supply, but that’s nonsense. In fact, some very good research may point us toward new recommendations to prevent child food allergies.
New research into child food allergies
A large size meta review, published recently in the Journal of the American Association, provides us with robust evidence that early introduction of some highly allergenic foods to children is linked to lower rates of allergy. The study examined 200,000 children from 146 separate studies that made the inclusion criteria of the meta-review. What they found was provocative – early introduction of eggs (at 4-6 months) and peanuts (at 4-11 months) is linked to lower incidence of allergies to those foods.
They also found some evidence, though it wasn’t statistically significant, that there might be some evidence that early introduction of milk, shellfish, tree nuts (such as almonds) and wheat might also be linked to lower incidence of allergies. As opposed to the myth that early introduction of gluten have some risks, the researchers found that it was not associated with an increase of incidence of coeliac disease (an autoimmune disease that actually requires one to avoid gluten for a lifetime).
According to Dr Robert Boyle, lead author of this research,
[infobox icon=”quote-left”]This new analysis pools all existing data, and suggests introducing egg and peanut at an early age may prevent the development of egg and peanut allergy, the two most common childhood food allergies.
Until now we have not been advising parents to give these foods to young babies, and have even advised parents to delay giving allergenic foods such as egg, peanut, fish and wheat to their infant.[/infobox]
Typical of meta-reviews, these researchers analyzed the combined results of 146 separate published trials that investigated whether food allergens in babies’ diets either exacerbated or prevented the development of allergies to certain foods. They concluded that there was “moderate” certainty that the early introduction was associated with lowered incidence of egg and peanut allergy. The term “moderate certainty” was used because there was some variability in the quality and design of the reviewed articles. For example, these type of feeding studies are almost impossible to randomize and blind the participants and the researchers, so some of the studies had inherent bias baked into the results.
Because of the high variability in the quality of the underlying research (despite the fact that there were 146 studies), the researchers strongly recommended higher quality and better designed studies to better determine the precise timing for the introduction of eggs and peanuts (along with possibly other allergenic foods) for babies.
We got to the belief that giving foods, like peanuts and eggs, to children actually caused allergies because a lot of studies in the early 1990s indicated that that those foods might cause later allergies to those same food. These studies focused on the mother avoiding allergens during pregnancy and breastfeeding. Several researchers questioned the validity of those older studies. They believed they were faulty, because they did not account for a major confounding variable – mothers with a family or personal history allergies, tend to adhere to recommendations better than those without. This introduces bias towards lower rates of allergies for these foods.
The studies included in the meta-review accounted for that bias, and clinical research into food allergies continue to account for that confounding bias.
Unfortunately, these early studies were the basis of recommendations to parents to avoid those foods in many countries. These national guidelines generally recommended that parents avoid feeding babies either eggs or peanuts. But the problem became that there was a lot of changes in these guidelines, with, of course, a lot of pseudoscience pushed by the usual woo-pushing websites, that we got confusion.
This is why this meta-review is so important. This research provides some robust scientific evidence that the earlier introduction of foods such as egg and peanuts, at approximately six months of age, seem to protect against food allergies. If the exact timing of when to introduce these foods can be established, government agencies can provide more accurate advice.
Just a side note – children who already have exhibited signs of these allergies will not benefit from this strategy, since early introduction of these foods do not reverse the existence of allergies.
Based on this and other newer research, infant feeding recommendations began to evolve into a guideline that stated that earlier introduction peanuts and eggs did not increase the risk of allergies to these food, but may actually be protective. In fact, a randomized trial of peanut consumption in infants, published in 2015, concluded that “the early introduction of peanuts significantly decreased the frequency of the development of peanut allergy among children at high risk for this allergy and modulated immune responses to peanuts.”
What does this all mean? Well, the American Academy of Pediatrics, the leading organization dedicated to children’s health issues in the USA, recently updated it’s child food allergies recommendations to parents for peanuts – “If your child doesn’t have any food allergies and or extra risk, consider introducing some peanut products into his or her diet.”
Australia has also changed its guidelines for food allergies based on the updated research. Australian child food allergies guidelines now recommend that exposure to egg, peanut and other foods that are frequently associated with food allergy should occur in the first year of life to offer protection, unless contraindicated by known allergies or other risk factors.
We have reached the point that we have better scientific evidence which gives us better information about certain food allergies. We now have enough data to support giving eggs and peanuts (along with maybe other foods like selfish and tree nuts) at a young age to prevent later food allergies. This is how science works in these situations – keep gathering data to either confirm previous beliefs, or to provide us with enough evidence to move in a new direction. The data supporting early introduction of peanuts and eggs is robust and powerful. That’s why recommendations are changing worldwide.
- 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. Randomized trial of peanut consumption in infants at risk for peanut allergy. N Engl J Med. 2015 Feb 26;372(9):803-13. doi: 10.1056/NEJMoa1414850. Epub 2015 Feb 23. Erratum in: N Engl J Med. 2016 Jul 28;375(4):398. PubMed PMID: 25705822; PubMed Central PMCID: PMC4416404.
- Hill DA, Grundmeier RW, Ram G, Spergel JM. The epidemiologic characteristics of healthcare provider-diagnosed eczema, asthma, allergic rhinitis, and food allergy in children: a retrospective cohort study. BMC Pediatr. 2016 Aug 20;16:133. doi: 10.1186/s12887-016-0673-z. PubMed PMID: 27542726; PubMed Central PMCID: PMC4992234.
- Ierodiakonou D, Garcia-Larsen V, Logan A, Groome A, Cunha S, Chivinge J, Robinson Z, Geoghegan N, Jarrold K, Reeves T, Tagiyeva-Milne N, Nurmatov U, Trivella M, Leonardi-Bee J, Boyle RJ. Timing of Allergenic Food Introduction to the Infant Diet and Risk of Allergic or Autoimmune Disease: A Systematic Review and Meta-analysis. JAMA. 2016 Sep 20;316(11):1181-1192. doi: 10.1001/jama.2016.12623. PubMed PMID: 27654604.
- 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. Can early introduction of egg prevent egg allergy in infants? A population-based study. J Allergy Clin Immunol. 2010 Oct;126(4):807-13. doi: 10.1016/j.jaci.2010.07.028. PubMed PMID: 20920771.
- Loke P, Koplin J, Beck C, Field M, Dharmage SC, Tang ML, Allen KJ. Statewide prevalence of school children at risk of anaphylaxis and rate of adrenaline autoinjector activation in Victorian government schools, Australia. J Allergy Clin Immunol. 2016 Aug;138(2):529-35. doi: 10.1016/j.jaci.2016.02.014. Epub 2016 Apr 12. PubMed PMID: 27084405.
- Mullins RJ, Dear KB, Tang ML. Time trends in Australian hospital anaphylaxis admissions in 1998-1999 to 2011-2012. J Allergy Clin Immunol. 2015 Aug;136(2):367-75. doi: 10.1016/j.jaci.2015.05.009. Epub 2015 Jul 14. PubMed PMID: 26187235.