Food Allergies

Allergies come in many forms, the most common cause of an allergy being particles in the air such as with hay fever.

Allergies are the body’s reaction to a specific protein or, in the case of sulphites, a specific chemical. The body mistakenly believes the protein or chemical to be an allergen and musters the body’s immune system to create antibodies to protect against that allergen.

A recent study shows that 1 in 13 Canadians have a serious food allergy. This equates to over 7.6% of Canadians and does not include Celiac Disease or food intolerances.

When the body is first exposed to a specific protein and identifies it as an allergen, antibodies are created and they attach themselves to mast cells. The next time the person is exposed to that allergen, the proteins of that allergen become attached to the antibodies. The mast cells then explode, causing histamines to be released into the body and the symptoms begin.

Symptoms of a minor allergic response can include:

• runny, itchy, stuffy nose;
• sneezing;
• watery, itchy eyes;
• fatigue;
• headache

These are very similar to cold symptoms. People with asthma may find that their attacks are triggered by allergens. For people who experience these symptoms hours or days after eating a sensitive food, this is known as an IgG response.

Like a minor allergic response, the body goes through the same process of creating antibodies and attaching themselves to mast cells, exploding and releasing histamine when the body is exposed to the specific allergen again. However, with a major allergic response (also known as anaphylaxis), the explosion of histamine overwhelms the body and can cause death. This is known as an IgE reponse.

Symptoms of a major allergic response can include one or some of the following:

• wheezing or difficulty breathing;
• tingling in the mouth;
• swollen lips, throat, tongue or face;
• hives, skin rash, itching, feeling of warmth;
• significant swelling around the site of an insect sting;
• abdominal cramps, nausea, vomiting;
• faintness or loss of consciousness;
• anxiety/feeling of impending doom

When a person has a minor allergic reaction or just one anaphylactic symptom, they often perceive that they have a minor food allergy. The issue with this is that the body creates more antibodies every time exposure to that specific allergen occurs. What does that mean?

It means that a reaction this time could show minor symptoms but the next time the body is exposed to that food, the histamine explosion could be enough to prompt a full anaphylactic response. If a person believes that their food allergy is minor, they are completely unprepared for this major response, putting their life at risk.

Unfortunately, no one can accurately predict the nature of the next response. It might be minor but the risk is very real for anaphylaxis. This is why it is very important to treat a food allergy seriously and see your medical professional about how to manage it.

In other areas of the world, common foods to certain cultures may become a top food allergen such as buckwheat (used in soba noodles) in Japan or sesame in the Middle East.

Not a true food allergy yet mimicking some of the same symptoms in the mouth and throat, Oral Allergy Syndrome is a specific reaction to proteins in certain fruits, vegetables and nuts. Those with Oral Allergy Syndrome may react with raw foods such as apples but not react when those foods are cooked, such as with applesauce.

An oral allergy reaction is often preceded by hay fever symptoms and is often worse during pollen season. While rare, Oral Allergy Syndrome reactions can be severe, including anaphylaxis.

For more information and to see the foods and environmental allergies often associated with this syndrome, please see the Canadian Food Inspection Agency’s report on Oral Allergy Syndrome.

No one knows for certain what causes allergies. What we do know is that all allergies and asthma are on the rise, along with all autoimmune disorders. For some reason, third world countries do not see the same immune system issues that developed countries do although this is changing.

Over the last decade, Hygiene Theory was thought to be the main cause for the explosive rate of food allergies. This theory is based on the hypothesis that we have become too clean in our daily living. In the past, it is believed that our immune systems developed by exposure to dirt, animals, and bacteria. Now that we live in a more hygienic world, the premise is that our immune systems have not fully developed and are turning on what should be innocuous substances (food) as if they were a mortal threat.

Because anaphylaxis is the response of the immune system known as an IgE, response, this theory bears some weight. The IgE response in humans is normally associated with the body’s fight against parasites. Yet in the modern, urban world, we rarely encounter parasites like our ancestors did, which may be causing the IgE to respond to certain foods instead.

This theory was brought into question more recently because it was largely based on the fact that third world countries, with their more rural populations and a lack of sanitation infrastructure, had lower rates of food allergies and autoimmune disorders. However, now that their rates of food allergies have begun to rise, this theory has lost some of its validity.

While Hygiene Theory may explain some, but not all, of the rise of autoimmune disorders, it's now recognized that our gut health has a much larger role to play than originally believed. The health of the microbes in our intestines, known as our microbiome, has shown in recent studies to have a significant effect on our immune system.  

At this point in time, no one factor or combination of multiple factors has been determined to cause food allergies and autoimmune disorders. Clearly, more research is needed.