Food allergies and Intolerance

NuoyaYang

[Abstract] Objective：To Nowadays， diseases like food allergy and food intolerance affects a growing number of people all over the world. This has led to much research into these phenomenons to provide a better understanding and to help cure these conditions. This paper aims to summarize the allergy researching progress in recent years and will focus on given a clear definition for these two terms and their differences； the pre-existing diagnosis， treatments and substitution for food allergy； dif-ferent perspectives between Westerners and Asians regarding food allergies.

【中圖分類號】R201.2 【文獻標識碼】A 【文章編號】2095-6851（2018）09--01

What is Food Allergies and Food Intolerance？

Adverse reactions to food include immune mediated food allergies and non-immune me-diated food intolerances.Food allergies and intolerances are often confused by health profes-sionals，patients and the public.Food allergy is an adverse immune‐mediated response，which occurs reproducibly on exposure to a given food and is absent during avoidance.Food allergens are those specific components of food or ingredients within food that are recognized by allergen-specific immune cells and elicit specific immunologic reactions.1Sometimes，food allergy also coexists with asthma，atopic dermatitis and can cause anaphylaxis reaction，which is severe enough to be life-threatening.2

Undesirable reactions to food do not involve the immune system are termed food intoler-ances.Some food intolerances involve an organic pathophysiological process，others reported in irritable bowel syndrome（IBS） patients.1Food intolerance of functional origin is often caused only by an isolated functional disorder and is initially unaccompanied by any other anatomical or morphological changes in the gastrointestinal tract.3

Pre-existing Diagnosis， Treatments and Substitution for Food Allergies

The National Institute of Allergy and Infectious Diseases Expert Panel identified4 cate-gories of immune-mediated adverse food reactions，namely IgE-mediated，non–IgE-mediated，mixed，or cell-mediated reactions.Skin prick test is the most commonly used methods to identify the food allergens.This test is to prick small among of purified allergen on to the skin surface and determine the specific kind of allergens according to the skin reactions and appearances.2Anoth-er test is food allergen specific serum IgE which is the measurement of sIgE antibodies in serum.However，SIgEs are not helpful if the history is not supportive of IgE‐mediated allergy as there is a reasonably high chance of a false positive result.1

However，with the wide spreading of food allergies，there hasnt been a treatment to cure food allergy.The most common current food allergy management relies on adherence to a strict elimination diet and prompt response to any accidental exposure.But several new therapies also evolves in recent years.One approach aims to induce tolerance to specific allergens using immu-notherapy，and another aims to tackle allergies more broadly by general suppression of IgE res-ponses.1The idea behind the first approach is to constantly exposing your immune system under allergen.The allergens would help your body to achieve a state of immunity，like a vaccine，so that your immune system would get used to allergens，in another way，get tired to fight it.How-ever，immunotherapy can only tackle single allergies at a time and its potential role in treating food allergy is currently under investigation.1

Though good medical treatment for allergies has not been discovered yet，people from food industry had developed all kinds of substitutes to replace those allergens but still provide the similar taste.For people with wheat allergies，they could use nut flour，coconut flour，tapioca flour instead.For people with dairy allergies，they could replace regular milk with nut milk or soy milk.For people with soy allergies，they could use coconut aminos for soy souse.

Differences in Food Allergies Between Westerners and Asians

The overall prevalence of food allergy in Asia is somewhat comparable to the West.However，the types of food allergy differ in order of relevance.Shellfish is the most common food allergen from Asia，in part due to the abundance of seafood in this region.4 Population sur-veys show prevalence rates in teenagers in Philippines and Singapore of 5.12% and 5.23% re-spectively.5 In contrast，a similar survey from the US showed a prevalence of shellfish allergy of 0.7% in 6-17 year olds.6 Despite these observed differences in prevalence，there is also a huge gap in the level of technology.EpiPen was introduced in Taiwan in2009 and was relatively ex-pensive，so it had very low prevalence rate.7 However，in United States，where Epipen had been first introduced no later than2000.8 And most of the American parents are fully informed on how to use an Epipen and also urge their kids to bring the Epipen with them everyday.Moreover，treatment such as immunotherapy only works towards allergic rhinitis in Asian countries，China specifically.And there is barely any long term treatment for food allergies and the public merely recognize allergies as a significant disease.

Summary

Though the severity and prevalence of food allergies has been increasing，there is no treatment to cure food allergy thoroughly.It is very important to spread the correct knowledge and information of food allergies，in order to eliminate many existing misconceptions，such as “food allergies are not serious enough to be life-threatening.” And if most people can be aware of food allergies，then they can respect and help to take care of those who are suffering from the disease.However，there is still lots of unknown regards food allergies or food intolerance like why some allergies could be outgrow，if there is a better treatment.All of these questions merit future researches.

Source

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