People often wonder just how long they should stay on an elimination diet to see if it is any help. Some good research has shown that time to symptom improvement is almost always by four weeks, with only 2 in 100 taking eight weeks. Parents can feel supported by this research too.
Why is this research important? It stops people expecting results after two or even one week, and so missing out on an improvement that may happen, or supporting those who think diets may take months to show results, and they stay on a baseline elimination diet when challenges could have begun and the diet could become less strict after the four weeks.
Another reason this research is important is that it is that it is a clinical study done at the well known Great Ormond Street Hospital for Children and published in the highly respected Paediatric Allergy and Immunology Journal. Research on allergy is well accepted in the scientific community as allergy tests show clearly what patients react to.
This highly respected research group are discussing reactions that would not have been accepted around twenty to thirty years ago when parents were not believed when they said their child reacted to a food that had shown a negative allergy test.
The reference is: Time to symptom improvement using elimination diets in non-IgE-mediated gastrointestinal food allergies.
Lozinsky AC, Meyer R, De Koker C, Dziubak R, Godwin H, Reeve K, Dominguez Ortega G, Shah N.
Pediatr Allergy Immunol; 2015 Aug;26(5):403-8.
An important aspect of this research is that it shows that symptoms do improve on elimination diets, something that some scientists still do not believe. This study reported on young children who did not have the usual allergic, that is IgE, reactions, so their reactions are called non-IgE-mediated reactions. They reacted to whole foods such as milk, soy, egg, wheat, potato, rice, fruits and vegetables.
These respected workers provide some very useful information along the way. They remind us that the non-IgE-mediated reactions are complex and are often delayed until up to 72 hours after ingestion. The diagnosis is therefore dependant on clinical improvement following an elimination diet and reappearance of symptoms during food challenges. Parents who do an elimination diet will be pleased when they report change and are believed.
The researchers also provide a very useful table: the Likert scale symptom questionnaire of the gut symptoms worthy of note in small children. These include diarrhea, constipation, vomiting, rectal bleeding, abdominal pain, wind/flatus, bloating, screaming/back arching and food aversion.
Of the 131 children in the research study, 30 did not improve. This study researched a particular group of whole foods [ those usually causing usual allergic reactions], studying a particular group of symptoms [only those in the gut]. The children who did not improve could be children who react to other substances in food which are also non-IgE reactions. These substances include food additives, salicylates, amines, MSG and other glutamates. In Australia the low chemical diet excluding this group of food chemicals has been used not just for gut symptoms, but also for ADHD, eczema and other allergic symptoms, and irritability, sleep problems and other symptoms.
My book Fussy Baby provides a chapter called Is your baby food sensitive? and also includes a detailed report on 15 small children I followed up with some young researchers. That work reported on what parents found caused symptoms in their children. These included foods high in additives [including paediatric syrups]foods high in salicylates, chocolate and MSG, as well as to whole foods such as those these researchers studied.
Now that we know that children react to all of these any research should exclude both suspect food chemicals as well as the suspect whole foods at the beginning of the study, and then record what parents find, to best help distressed babies where food sensitivity is suspected.