Diet Diversity Through the Life-Course as an Opportunity Toward Food Allergy Prevention

Giulia C I Spolidoro,Carlo Agostoni,Matteo Cesari,Domenico Azzolino

doi:10.3389/falgy.2021.711945

Abstract

The prevalence of food allergies (FA) is increasing worldwide. Generally, the onset of allergies, including FA, begins in early childhood and may persist and/or develop through the life-course. Even though epidemiological studies have focused mainly on children, allergies can also occur for the first-time during adulthood. Within the prolongation of life, it is expected that allergies will be encountered more often even in older people. Recent findings suggest that an early exposure to diverse food antigens may promote the development of immune tolerance. Accordingly, diet diversity during the first year of life or even earlier may have a positive impact on the prevention of allergies. The anti-inflammatory properties of some dietary nutrients may positively contribute to a tolerogenic immune environment too. Diet diversity is associated with a more favorable microbiome, and increasing evidence suggests a promising role of gut microbiota manipulation in inducing immune tolerance. Unjustified avoidance of allergenic foods may expose to intakes of some nutrients below recommended levels through the life-course, even more in cases of self-diagnosis and treatment of presumed forms of food intolerance. Nutritional strategies including the early exposure to a variety of food antigens are a promising area of research for preventive purposes through the life-course possibly extending positive outcomes to older stages. The aim of this paper is to highlight the role of diet diversity in preventing the development of FA starting in early life, as well as to provide an overview of the main strategies to prevent related nutritional issues throughout the life-course.

Highlights

Over the last decades, the presence of allergies such as food allergies (FA), asthma, atopic dermatitis (AD) and eczema has become a prevalent issue for healthcare systems, especially in Western countries [1, 2]
The concept that diet diversity may have a positive influence on FA outcomes mainly derives from the observation that the promotion of diet diversity in the first year of life is negatively associated with the occurrence of allergies, including FA
Contrary to what is believed, FA are an issue mainly related to pediatric ages, as they can persist or even occur for the first time in adult life

Summary

INTRODUCTION

The presence of allergies such as food allergies (FA), asthma, atopic dermatitis (AD) and eczema has become a prevalent issue for healthcare systems, especially in Western countries [1, 2]. This has led to the hypothesis that the exposition of potentially highly allergenic foods, such as hen’s egg, peanuts and cow’s milk should be avoided until the end of the first year of life The basis of such recommendation was the belief that a certain degree of mucosal immunologic immaturity, present in infants, could negatively influence the challenge of the local immune cells with food antigens, resulting in increase of food allergen sensitization [14]. Nutritional deficiencies typical of older ages, such as micronutrient deficiencies - including low levels vitamin D, zinc and iron - may play an additional role in sensitization to food allergens in older people [43] These micronutrients modulate immune responses and have antioxidant properties [39]. Since a FA developed during childhood may persist in adult life, this may determine a lifetime cumulative exposure to nutritional deficiencies, negatively affecting the TABLE 1 | Overview of the original studies exploring the effects of diet diversity for the prevention of food allergy

Aims

Findings

CONCLUDING REMARKS