Food Allergy: Prevalence and Food Technology Approaches for the Control of IgE-mediated Food Allergy

Review Article

Austin J Nutri Food Sci. 2014;2(5): 1029.

Food Allergy: Prevalence and Food Technology Approaches for the Control of IgE-mediated Food Allergy

Ontiveros N4, Flores-Mendoza LK2, Canizalez-Román VA3 and Cabrera-Chavez F1*

1School of Nutrition Sciences. Autonomous University of Sinaloa, Mexico

2Mexican Social Security Institute (IMSS), CIBIOR, Immunology Department, Puebla, Mexico

3School of Medicine, Autonomous University of Sinaloa, Mexico

4Regional Program for PhD in Biotechnology, FCQB, Autonomous University of Sinaloa, Mexico

*Corresponding author: :Cabrera-Chavez F, School of Nutrition Sciences. Autonomous University of Sinaloa. Av. Cedros y Calle Sauces S/N, Fracc. Los Fresnos, 80019, Culiacán, Sinaloa, México

Received: February 20, 2014; Accepted: April 24, 2014; Published: April 29, 2014


IgE–mediated food allergy (FA) is a reproducible adverse immune reaction to certain proteins in food matrices and the only available treatment is to avoid the allergen of interest. Establishing the accurate prevalence of IgE–mediated FA is challenging as a number of factors affect the estimates and relevance of the type of FA. Based on recent studies, clinical FA affects less than 5% of the population and has become a serious health concern. Thus, there is an increasing interest to find strategies to give a solution for dietary restrictions which affect the patients’ quality of life. In this frame, some food technologies are proposed as good tools to reduce the allergenic or sensitizing potential of food proteins. This review presents and discusses the current prevalence data of FA and addresses the main food technologies used to control IgE–mediated FA. Also, the implications of these food technologies on the functional properties of foods are discussed.

Keywords: Food allergy; Prevalence; Modification of allergens; Food processing


FA: Food Allergy; IgE: Immunoglobulin E; IL–: Interleukin; IFN–γ: Interferon Gamma; Th1, Type 1 T Helper Cells; Th2: Type 2 T Helper Cells; FceRI: High–Affinity IgE Receptor; Mpa: Megapascal

Introduction and Background

Food allergy (FA) is defined as an adverse immune response that occurs reproducibly on exposure to a given food and is distinct from other adverse responses to food, such as pharmacologic reactions, toxin–mediated reactions, and food intolerance (an immunologically unrelated adverse reaction to food) [1–2]. FA can be mediated or not by IgE antibodies and includes, but it is not limited to, food–induced anaphylaxis, food protein–induced enterocolitis syndrome, and foodinduced eosinophilic gastrointestinal disorders [3]. Particularly, IgEmediated FA appears to be on the increase and has become a serious health concern in some countries such as U.S.A, Canada, Australia, China, and the United Kingdom [4–9]. On the basis of meta–analysis studies and systematic reviews, the overall prevalence of FA confirmed by oral food challenge tests (challenge–proven FA) is expected to be less than 5% [10,11], although a few population–based studies have found higher estimates (7.7% to 8.9%) [7,8]. Certainly, populationbasic studies of prevalence of FA can be influenced by some factors such as geographic location and study designs or methodologies. Therefore, prevalence data should be interpreted taking into account all those factors that could influence the estimates of prevalence and relevance of types of FA.

There are no currently accepted therapeutic approaches for FA and the only available treatment is to avoid the relevant allergen. However, accidental exposures to food allergens are common among individuals affected with FA [12,13] and restricted diets are usually costly and limit social activities [14]. An effective therapy that controls the allergic reaction by promoting immune tolerance to food allergens is expected to have a profound impact on the patient’s lifestyle and quality of life. In this context, specific therapies (e. g. oral and epicutaneous immunotherapy) are promising therapeutic approaches, but safety and efficacy of different dose–regiments are still main issues to be addressed specially using multiple food allergens simultaneously [15]. Other therapies, termed non–specific, have shown good results in preclinical and clinical studies [3] and could be particularly relevant in those cases where more than one food trigger the allergic reaction.

In this frame, food processing technologies such as heat treatment and enzymatic proteolysis are promising strategies for accelerating immune tolerance acquisition in individuals affected with cow’s milk [16–18] or raw egg allergies [19]. Notably, these allergenic processed foods are well tolerated by the majority of the individuals [7, 20,21]. Furthermore, other food processing methods have also shown potential to reduce the IgE–mediated allergic immune response in mouse models [22–24]. This includes high pressure conditions and irradiation of foods as well as chemical modification of food allergens.

In this review we aimed to present current prevalence data of FA as well as the main food processing technologies used for preventing or reducing the immune response to allergenic food proteins undergoing digestion and leading to IgE–mediated FA.

Analyses and Interpretation

Prevalence of food allergy

Except for those cases where the cause of a severe FA reaction can be clearly identified, FA diagnosis should be confirmed by food challenge tests, the “gold standard”, ideally performed as a doubleblind placebo–controlled food challenge test. However, just a few studies have based their prevalence data on this laborious and time consuming clinical practice. As an alternative, other studies of prevalence of FA are based on questionnaires⁄interviews (self reported FA) or at less extend on allergen–specific IgE serology tests and⁄or skin prick test (where a tiny amount of allergen is introduced into the skin and may elicit a localized allergic response) to estimate the prevalence of adverse reactions or sensitization to food.

Certainly, self–reported FA studies are influenced by other food related conditions leading to an overestimation of the prevalence of FA [25]. Although the assessment of “convincing” symptoms of immediate hypersensitivity (e.g., wheezing, trouble for breathing, skin with hives, vomiting, and diarrhea) could improve the performance of these studies [5, 26], the main value of self–reported FA prevalence is thought to serve as groundwork for further investigations based on objective diagnostic criteria (e.g., allergen–specific IgE, skin prick test, and food challenge tests). With regards to IgE levels in blood, clinical studies have proven that higher allergen–specific IgE levels indicate a greater probability of clinical FA [27,28] and this could be helpful to better estimate prevalence of FA [29].

A research study on FA funded by the European Commission (EuroPrevall program) carried out a meta–analysis that included 51 articles published in the period of January 1990 to December 2005 [11]. Under the basis of self–reported FA, combination of symptoms plus sensitization, and challenge–proven FA, the estimates of overall prevalence to specific foods were as follows, respectively: cow’s milk (3.5%, 0.6%, 0.9%), hen’s egg (1%, 0.9%, 0.3%), peanut (0.75%, 0.75%, not available), fish (0.6%, 0.2%, 0.3%), and Shellfish (1.1%, 0.6%, not available). Prevalence of self–reported FA to any food varied widely (from 3% to 35%) showing heterogeneity among studies. Additionally, the EuroPrevall working group also reported prevalence of plant food allergy in a systematic review that included 36 studies published in the time period of January 1990 to December 2006 [30]. Notably, 27 of the studies were originated from Europe. Overall estimates of prevalence of self–reported FA, skin prick test, and challenge–proven FA ranged as follows, respectively: fruits (0.03% to 11.5%, 0.03% to 4.2%, 0.1% to 4.3%), vegetables⁄legumes (0.01% to 13.7%, 0.01% to 2.7%, 0.1% to 1.4%), nuts (0% to 7.3%, 0.02% to 4.5%, 0.1% to 4.3%), wheat (0.2% to 1.3, 0.03% to 0.2%, 0% to 0.5%), soy (0.03% to 1.3%, 0.03% to 0.2%, 0% to 0.7%), and other food items (<1.3%, <1%, <0.1% one study only). Estimates of IgE sensitization to wheat and soy were <3.7% and <3% respectively.

A recent meta–analysis that included 30 studies published in the period of January 2000 to 30 September 2012 evaluated the prevalence of FA in Europe [10]. It was found a prevalence of perceived FA to any food of 6.8% in children and 5.0% in adults. The overall prevalence of sensitization was 10.1% and 2.7% on the basis of blood levels of allergen–specific IgE or skin prick tests respectively. When this analysis was performed including symptoms (clinical FA), the prevalence of sensitized FA was 2.7% (5 studies) and 1.5% (4 studies) respectively. With regards to challenge–proven FA (12 studies), its prevalence was 0.99% in children and 0.89% in adults.

In a systematic review published in 2010 the prevalence of FA was summarized as affecting more than 1% or 2% but less than 10%of the US population [2]. A recent study from the National Health and Nutrition Examination Survey reported that the prevalence of self–reported FA in U.S.A was 6.5% in children and 9.7% in adults[31]. The main allergens reported in this study were milk, peanut and shellfish. Alternatively, based on the study by Liu et al., [29] the prevalence of sensitization to food or clinical FA (considering allergen–specific IgE levels and age–based criteria) was summarized as 16.8% and 2.5% respectively. In this US nationally representativecohort study, blood levels of allergen–specific IgE to peanut, cow’s milk, egg white, and shrimp were assessed.

Other recent studies have reported estimates of prevalence of FA in Canada, Australia, Asia, and Latina America. A nationwide telephone survey reported that the prevalence of self–reported FA in Canadian population was 7.1% in children and 8.3% in adults [32]. Milk, shellfish, fruits⁄vegetables, tree nut, and peanuts were the most reported allergens. In a challenge–proven FA study representative of the Melbourne (Australia) population, Osborne et al. [7] reported that the prevalence to peanut, raw egg, and sesame was 3%, 8.9%, and 0.8% respectively. In the same study, the estimates of sensitization to cow’s milk and shellfish assessed by skin prick test were of 5.6% and 0.9% respectively.

In Asia, some studies found that the prevalence of self–reported FA and challenge–proven FA ranged from 4.8% to 16.7% and 1.1% to 3.8% respectively [8,33–36]. Different from others geographic locations, fish seems to be the most reported allergen in Asian population and this has been attributed to the abundance of seafood in this region [37]. With regards to Latin America, Marrugo et al. [38] found an overall prevalence of self–reported FA of 14.9% in a cohort of 3099 individuals from Cartagena Colombia aged 1–83 years. Fruit⁄vegetables, seafood, and meats were the most reported allergens. In another self–reported FA study, Hoyos–Bachiloglu et al. [39] found an overall prevalence of 5.5% in a cohort of 455 Chilean school–aged children. In this study, typical symptoms of immediate hypersensitivity allergic reactions were assessed in a second questionnaire. Therefore, walnut, peanut, egg, chocolate, avocado, and banana were the most reported allergens.

Taking into account the background presented above, we consider that estimates of prevalence of FA are influenced by several factors such as, dietary exposures, differences between populations (age, race⁄ ethnicity), study designs or methodologies, among others. This make challenging to determine the prevalence of FA with certainly. Also we believe that the prevalence data of FA are widely variable among populations and therefore an overall prevalence of challenge–proven FA of less than 5% could be considered an appropriated estimate.

Basic pathogenesis of IgE mediated FA

By passing oral tolerance and generating allergen–specific IgE antibodies with subsequent sensitization of mast cells or basophils are central events to trigger the allergic immune response. These basic events are typically called sensitization and effector phases [40,41] (Figure 1). The former involves antigen presenting cells, T cells, Th2 cytokines such as interleukin (IL)–4, IL–5 and IL–13, cross–linking of allergens with B–cell receptors, and IgE production. Sensitization occur after antigen presenting cells such as dendritic and B cells have recognized allergenic segments or “epitopes” in the protein component of food or ingredients within food. Then, allergen antigens are loaded on MHC class II molecules and antigen presentation to T cells may occur. This interaction activates allergen–specific T cells which produce Th2 cytokines and promotes the production of IgE antibodies by allergen–specific B cells [41]. IgE antibodies may bind to IgE receptor FceRI on the membrane of mast cells and basophils generating sensitized cells.

Citation: Ontiveros N, Flores-Mendoza LK, Canizalez-Román VA and Cabrera-Chavez F. Food Allergy: Prevalence and Food Technology Approaches for the Control of IgE-mediated Food Allergy. Austin J Nutri Food Sci. 2014;2(5): 1029. ISSN: 2381-8980.