In a recent research paper published in the Brazilian Society of Pediatrics' Jornal de Pediatria, researchers reviewed the role of elimination diets in children with food allergies, highlighting the need for a multidisciplinary management plan that supports each child's nutrition, health, and growth.
Review article: Elimination diet in food allergy: friend or foe? Image Credit: Africa Studio / Shutterstock
Food allergies can cause severe symptoms, and medical guidance often recommends avoiding allergens to prevent adverse reactions. For non-Immunoglobulin E (IgE)-mediated allergies, which do not cause anaphylaxis but affect the gastrointestinal tract, doctors may suggest temporarily eliminating and then reintroducing one or more items from the child's diet to diagnose the source of the allergy. Safe items can then be consumed, and allergens can be eliminated.
However, these restrictions come with their challenges. They exact an emotional toll on the child and their family, affect socialization in school and beyond, and can also have consequences for the growing child's development. Managing food allergies must not jeopardize dietary quality and diversity, particularly at a young age.
Elimination diets for diagnosis and management
Food protein-induced allergic proctocolitis (FPIAP) is an example of a non-IgE-mediated allergy. Children with FPIAP react to foreign food proteins, which causes inflammation in the colon.
In these cases, doctors recommend following an elimination diet for one or two months. Children are asked to follow the diet for two weeks or more for IgE-mediated allergies before being reintroduced to the food under medical supervision.
It may not be necessary to eliminate foods entirely or permanently. Allergen-specific oral immunotherapy may be effective in inducing a certain level of tolerance. Children often outgrow food allergies with time; it is important to reassess whether a food is still an allergen periodically so they do not have to follow unnecessary restrictions.
Similarly, a recent development in allergy management is the use of low-dose oral challenges, which allow doctors to understand what dose of the food will cause a reaction. Sometimes, children allergic to cow milk (CM) and eggs can tolerate them in certain preparations, such as when they have been baked or cooked thoroughly.
Substituting allergy-causing foods after elimination
Once a food allergy is confirmed, eliminating the allergen and finding suitable substitutes may be necessary. For example, children under the age of 2 who have CM allergies can be given baby formula that is soy-based, hydrolyzed, or contains amino acids.
Nutrition plays a vital role in finding a suitable substitute for an allergen. Elimination reduces the chances of an adverse effect, but preventing and treating nutritional deficits is as critical. Restricted diets risk lowering dietary diversity, which can reduce immunity.
When substituting foods, it is important to consider that they can have different nutritional values. The authors classify food substitutes as (1) nutritional substitutes, which have some or all the nutrients present in the allergen, and (2) cooking substitutes, which do not have equivalent nutritional values. Many vegan cheeses, for example, are poorer in protein and calcium than dairy-based cheese.
For this reason, eliminating allergens without introducing suitable nutritional alternatives can impair children's growth and development and lead to short stature. Other children have suffered from obesity as a result of inappropriate substitutes, leading to unbalanced diets.
Dietary balance, quality, and diversity
Healthy diets are predominantly made up of minimally processed and unprocessed foods, which are rich in micro- and macronutrients, antioxidants, and fiber. However, many children with allergies are deficient in nutrients such as calcium, iodine, iron, vitamins A and D, zinc, and selenium.
The risk of developing a deficiency increases with the number and type of excluded foods. Allergic children who do not consume dairy can have lower energy because they are not obtaining enough lipids and proteins.
Dietary diversity is not simply the number of food groups the child consumes but also their frequency and nutritional value. A diverse diet can prevent the development and severity of allergies. Children who are introduced to more foods between 6 months and one year old are less likely to show signs of food allergies before age ten.
Allergy risk also increases if the child consumes high levels of ultra-processed foods and other poor nutrition and health outcomes. This could be mediated through an increase in stomach inflammation and a reduction in beneficial intestinal microbes.
Excluding certain foods should not compromise nutritional quality or quantity, and dietary advice must consider these factors. Health providers should use detailed medical histories, prioritize locally available foods based on the family's economic ability, and guide caregivers accordingly.
While elimination diets may be the best way to manage some food allergies, they should not compromise the child's nutrition and growth. With proper guidance, caregivers can identify substitutes for allergens and devise affordable, balanced, and healthy diets that are rich in fiber and nutrients and low in processed foods.