Overview

Food allergies are symptoms caused by a particular food or food constituent that can vary from mild to severe, and at times life-threatening. They are a result of the immune system's response to a specific content (usually protein) in food. Food allergies affect millions of people and present a unique set of challenges.

In the recent two to three decades, there has been extensive data to suggest that food allergies have been on the rise, with up to 10% of the population affected. Allergies appear to be disproportionately prevalent in industrialised and high-income populations and are also more common in children as compared to adults.¹

Beyond the immediate allergic reactions, individuals and their families must remain constantly vigilant, and grapple with stress regarding their diet, navigating their diets to ensure adequate nutrition while avoiding allergens. 

In this scenario, Medical Nutrition Therapy (MNT) has emerged as a crucial strategy in managing food allergies, by offering individualised dietary plans and suggestions to promote well-being and mitigate the impact of allergenic foods.

 In this article, we will understand Medical Nutrition Therapy, its benefits in managing food allergies, and how it can be incorporated into healthcare so that it is accessible to everyone.

What are food allergies?

Before delving into the concept of Medical Nutrition Therapy, it is important to understand what food allergies are. The eight most common food allergens are eggs, milk, peanuts, tree nuts, soy, wheat, crustacean shellfish, and fish.² When a person with a food allergy consumes the allergy-inducing food, their immune system perceives it as a threat and triggers an allergic reaction. 

Allergic responses may be immunoglobulin-E (IgE) mediated, cell-mediated, or mixed reactions. IgE-mediated reactions are also called Type-1 Hypersensitivity reactions and account for most immune-based reactions.³ This is the form that we shall be discussing in this article.

The reactions can range from mild symptoms, such as breakouts or hives and itching, to severe and life-threatening reactions known as anaphylactic reactions. IgE-mediated food allergies are often characterised by skin manifestations, such as itching, rashes, urticaria(hives), or angioedema (swelling of the body part exposed to the allergen, which in severe cases may be the throat).

Beyond these immediate risks, food allergies can impact an individual's overall health by restricting nutritional intake, causing anxiety and worry over accidentally exposing oneself to the allergen, and potentially leading to deficiencies or imbalances while avoiding certain foods.

The role of medical nutrition therapy (MNT) in food allergies

Medical Nutrition Therapy is an approach that involves the assessment and intervention of an individual's nutrition status to address health concerns and promote overall well-being. In the context of food allergies, MNT plays a pivotal role in managing nutritional needs while accommodating dietary restrictions.

Being a multifactorial condition, food allergies are influenced by genetics, the environment, and their various interactions. The main risk factors involved in the expression of an allergy or sensitisation to it include:⁴

• Sex: in particular, allergies are more common in children Assigned Male at Birth (AMAB)
• Race and ethnicity: the risk of developing or expressing an allergy is higher among Asian and black children
• Genetics: This includes a family history of food allergies, especially in close relatives

Other potential risk factors which can also contribute to a food allergy include:

• Atopic comorbidity, that is other allergies
• Increased hygiene such as excessive washing and disinfection
• Microbiome, which is the healthy bacteria that live within and on the surface of our body
• Blood vitamin D levels
• Diets, such as low consumption of omega-3-polyunsaturated fatty acids and reduced intake of antioxidants
• Excessive use of antiacids
• Obesity
• The timing of food introduction in babies
• Exposure to foods in a different way from the gastrointestinal one, such as through eczema-affected skin

MNT for food allergies is a highly individualised process, and cannot be used as a one-size-fits-all strategy. The therapy must be personalised to fulfil the unique requirements of each individual. Thus, an individualised allergen avoidance plan is the cornerstone of the nutritional management of food allergy and differs depending on whether it is being used on a child or adult.

This therapeutic strategy considers the specific allergens, the nature of the allergy, the symptoms and manifestations as well as their severity, nutritional deficiencies, and the individual's lifestyle to create a sustainable and nourishing dietary plan.

Key concepts of medical nutrition therapy (MNT) for food allergies

Accurate diagnosis and identification of the causative antigen

The first step to effectively utilise MNT for food allergies lies in making an accurate diagnosis and identifying the allergenic foods. This is done by healthcare professionals, allergists or immunologists, by conducting thorough assessments, such as skin-prick tests and blood tests. This helps to pinpoint specific allergens.⁵

Planning personalised meals and dietary modification

Once allergens are identified, the next step involves creating individualised meal plans and making necessary dietary modifications to exclude foods that trigger a reaction while ensuring adequate nutritional balance in the diet.⁶ This also entails substituting allergenic ingredients with alternatives that are nutritionally equivalent and can maintain a balanced diet.

Nutritional counseling and education

Nutritional counselling is a cornerstone of Medical Nutrition Therapy. Especially in the management of food allergies, it helps healthcare staff in providing individuals and their caregivers with the knowledge and skills needed to navigate dietary restrictions successfully.

Nutritional Education includes imparting knowledge to patients and their caregivers regarding label reading while purchasing foods, strategies to look out for and effectively avoid allergens, and tips on how to cook so as to enhance nutritional intake and maintain a balanced diet.

Regular monitoring and adjustments

Once a dietary plan is made and explained to the patient and their family, the next step is to make sure it is effective. This involves monitoring the individual’s progress with regular follow-up appointments with the dietician or allergist.

This allows healthcare professionals to monitor a patient’s nutritional status and make adjustments to their meal plan as required. Periodic blood tests are performed to assess nutrient levels and ensure that the patients maintains optimal health despite food allergies. Allergy testing is also repeated from time to time. 

Depending on these evaluations and tests, further management decisions can be discussed and any required changes can be made.

Challenges in medical nutrition therapy

While Medical Nutrition Therapy is a valuable tool in treating and managing food allergies, it is not without its challenges. The therapy requires a collaboration between various healthcare staff including specialised dietitians, doctors, allergists and immunologists, as well as specialised tests and evaluations. There is always a risk of nutritional gaps when dietary restrictions are introduced, and the psychological impact of dietary restrictions that individuals and caregivers may face also adds to the challenges. 

It is important that healthcare professionals, dietitians, and individuals with food allergies collaborate and discuss every stage of the management and maintain open communication to overcome these challenges.

Summary

Food allergies are a result of the immune system's overactive response to specific proteins in food. Medical Nutrition Therapy is an approach backed by science that involves the assessment and intervention of an individual's nutrition status to address health concerns and promote well-being. Medical Nutrition Therapy for food allergies offers immense promise for individuals seeking to balance nutritional needs with allergen avoidance. By incorporating various facets like individualised meal plans, nutritional counselling, and regular monitoring, MNT empowers individuals to understand and navigate their food allergies while promoting overall health.

As research continues to study and identify new information about food allergies and their management, the integration of Medical Nutrition Therapy into standard care becomes increasingly important.