Food Allergen

Food allergy is the term given to hypersensitive response induced in healthy human individual due to the certain food or food additive. And food allergen are naturally occurring proteins in food & food additives that can trigger the immune response causing hypersensitivity. Being a global problem, approximately 25% population in India suffers from food allergy, which is comparatively low to western countries where the percentage is high up to 40%. Percentage of food allergies in children’s are higher than that in adults. Allergies can be out-grown with age, might develop in later phase of life or may remain lifelong. Earlier due to lack of knowledge regarding consequence and non-specific and wide range of symptoms of food allergy, medical or concerned authorities did not entertain cases. Hence, first reported case was in 20th century and allergy caused was due to dairy product.

As the effect of food allergens can toxic or nontoxic in nature, food manufacturing industries as well as government regulatory authorities are putting considerable effort on combating the issues caused by food allergens by promoting awareness and prevention method and one such initiative is labeling of allergens on the packs. Non-existence of any specific cure to food allergy, prevention possible by getting self-aware of the food items one is allergic and avoiding the consumption of all foods containing allergen.

Response of Food Allergen

Hypersensitivity by individual Food allergens can stimulate different type of response. It can be either toxic or nontoxic in nature. Figure 1 shows the response and its classification and figure 2 summarizes the sub classification used for food Allergen & food intolerance.

Food sensitivity response can be

a.      Immediate Type Food Allergy Response – Most commonly seen in young children that show allergic reaction when containing allergic food. In adults it’s generally observed, when specific food item is combined with alcohol, exercise or non-steroidal drugs chances are quite high to allergic reaction.

b.      Delayed-onset Type Food Allergy Response- Occurrence of allergic response is after several hours or days. It is an auto immune disease (Type III food allergy), where immune cells in the body recognizes the allergen protein and produce compounds such as histamines and other chemicals.  

Is Food intolerance same as that to Food Allergen?

Two terms are highly confused to be same but it is not. Food intolerance is the body’s abnormal reaction to a food, but in a way that does not involves immune system. On the other hand, a food allergy is triggered by an immune response. When comparing the two, a food allergy poses a much greater health risk than a food intolerance.

Mechanism of Allergen

Human immune system tends to produce antibodies against entry of any pathogenic or foreign compound. These produced antibodies in response to pathogen entry that may be caused due to the entry of pathogen. This is how human body protects itself through inbuilt immune system. Food Allergens develop quite similar conditions in human body in case of IgE mediated allergic reaction. When food allergens are ingested, our body’s defense system secretes and distributes IgE antibodies (Immunoglobulin E) in body. Some of the IgE antibodies comes in contact with mast cell and form sensitized cell. Sensitized cells reacts with  allergic proteins, forming chemical substances such as histamines and other compounds that  that escalates the allergic symptoms in body known as hypersensitivity.

Food sensitivity response can be

a.      Immediate Type Food Allergy Response – Most commonly seen in young children that show allergic reaction when containing allergic food. In adults it’s generally observed, when specific food item is combined with alcohol, exercise or non-steroidal drugs chances are quite high to allergic reaction.

b.      Delayed-onset Type Food Allergy Response- Occurrence of allergic response is after several hours or days. It is an auto immune disease (Type III food allergy), where immune cells in the body recognizes the allergen protein and produce compounds such as histamines and other chemicals.  

Is Food intolerance same as that to Food Allergen?

Two terms are highly confused to be same but it is not. Food intolerance is the body’s abnormal reaction to a food, but in a way that does not involves immune system. On the other hand, a food allergy is triggered by an immune response. When comparing the two, a food allergy poses a much greater health risk than a food intolerance.

Mechanism of Allergen

Human immune system tends to produce antibodies against entry of any pathogenic or foreign compound. These produced antibodies in response to pathogen entry that may be caused due to the entry of pathogen. This is how human body protects itself through inbuilt immune system. Food Allergens develop quite similar conditions in human body in case of IgE mediated allergic reaction. When food allergens are ingested, our body’s defense system secretes and distributes IgE antibodies (Immunoglobulin E) in body. Some of the IgE antibodies comes in contact with mast cell and form sensitized cell. Sensitized cells reacts with  allergic proteins, forming chemical substances such as histamines and other compounds that  that escalates the allergic symptoms in body known as hypersensitivity.

Other Allergens- Apart from above stated list, there are few fruits and vegetables (Apple, Peach, Carrot, Tomato, and Banana etc.)  that has shown potential of being allergic but has not been included by CAM and causes Oral Allergy Syndrome (OAS)

Symptoms

Allergy causing protein can affect the functioning of human body leading to disease related to skin, gastrointestinal, digestive, respiratory and cardiovascular. Most common symptoms are skin rashes, flushed skin, hives, itchy sensation in mouth, swelling of face, lips & tongue, abnormal cramps, vomiting, nausea, diarrhea, or constipation, wheezing & coughing, difficulty in breathing and loss of consciousness.

Apart from such unspecific & common issues, at times, food allergy can poses threat to life. Anaphylaxis is one of the most common condition that yearly results in deaths. This condition leads to drop in blood pressure, suffocation and breathing problem due to swelling in throat and airways in the lungs.    

Precautionary Steps  

1.      Avoidance: Avoidance is rejection of foods that can cause allergic reaction in any individual is highly recommended. It shall be helpful to be fully aware and note down of any history pf allergic reaction by consuming any specific food item, and eliminating it from diet.

2.      Food Labelling: Manufacturing Industry should let know their consumer if the product contains any type of allergen material or has been processed in a line that has been used for manufacturing allergen containing product. This type of cautionary labels are required, as chances of cross contamination cannot be denied if same processing line is being used for allergen and non-allergen product. 

Way Forward

Allergen management in food industry is highly advisable and for more detailed information and understanding on DO’s and DO NOT’s of food industry, following link can be accessed. https://www.pmg.engineering/2019/07/19/allergen-management-components/

Having diverse food culture in India, there are many food item that can lead to food allergy however, majority of them are not life threatening. Sometimes mild symptoms during early phase may escalate with time leading to conditions such as anaphylaxis. Children being prone to these allergies due to weak immune system have chances of outgrowing the allergy with time. No current treatment have led to avoidance as only preventive method, which has opened up vast opportunity for research & development in this field. It is one of the most challenging clinical problem and has major public importance.