The Mysterious World of Food Allergies

By: Dr. Carly Wendler peanuts 250

It seems like everywhere you look you hear about food allergies, food sensitivities, or food intolerances and their role in overall health and wellness. There is lots of information out there and at times it can be both confusing and overwhelming to know whether you are actually dealing with a food issue, how and where to get it diagnosed, and what to do about the results. This article is meant to help guide you through the mysterious world of food allergies.

What is the difference between a food allergy, food intolerance, and food sensitivity?

When the term allergy was first coined in ancient times it was defined simply as an ‘altered reactivity’. It meant an allergy was an adverse response to a substance by one person but not by most people. Moving centuries forward into the early 1920’s, European and American allergists redefined and narrowed the definition of the term allergy to mean an ‘immunological reaction that is measurable and detectable in the blood,’ usually showing an IgE allergen-antibody response. This redefinition severely limits what can now medically be recognized and diagnosed by medical doctors and allergists as an allergy. In order to now be diagnosed with a food allergy you must show a measurable immune system reaction with an IgE response.

A food intolerance is any other food reaction in which the immune system is not measurably involved.

A food sensitivity is an umbrella term used to cover a food allergy, food intolerance, or any other adverse reaction to food.

What are the symptoms and signs of a food allergy or sensitivity?

Even though these terms are defined in different ways the symptom presentation can look similar or even identical. Food allergies or intolerances are often only associated with digestive or tummy troubles (like, gas, bloating, pain, or diarrhea), but symptoms can occur anywhere in your body, not just in your digestive system. But symptoms unrelated to food including headaches and migraines, eczema and skin rashes, and weight gain can also be indicative of food issues and for this reason often times your food allergies or sensitivities remain undiagnosed for years. Other symptoms that can indicate a food reaction include: constant runny nose, watery eyes, recurrent ear infections, fatigue, low stamina, itchy ears or throat, puffy face and eyes and infertility. The bottom line is: a food allergy and intolerance can cause the same type of symptoms regardless of their definition.

What happens during an allergic reaction? 

During an allergic reaction, your body identifies a food protein as foreign (i.e. the body mistakes it for a bacteria, virus, or fungus), and tries to remove it through various symptoms like diarrhea, sneezing, skin rash, and runny nose. Foods that most commonly cause food reactions include: wheat, dairy, corn, soy, sugar, chocolate, eggs, and nuts.

Are there different types of food allergy?

The first type is the classic IgE anaphylactic reaction. This reaction takes place immediately, usually within minutes to hours, after eating the offending food. The symptoms may include difficulty breathing, a sensation of choking, swelling of the face, lips, or in the mouth. This allergy requires immediate emergency care or an epi-pen. Shellfish and peanuts are the most common foods causing this type of food allergy.

The second type of allergy is called a delayed onset allergy. This type of reaction can cause symptoms up to 3-5 days after eating the problematic food, making it difficult to properly diagnose. Symptoms may include headaches, migraines, watery eyes, stuffy nose, sinus congestion, itchy eyes, ears, and throat, gas, bloating, water retention, diarrhea, low energy, and fatigue.

How do I know which type of food allergy I have?

Immediate food reactions are detected through blood work ordered by your family doctor or allergist. S/he will order a test to measure IgE levels. Delayed food reactions are also diagnosed using blood work, but this requires a test to measure IgG levels (now you can see where some of the confusion comes from!). IgG tests are not routinely available through medical doctors, however, many naturopathic doctors and some pharmacies now offer this option.

What can cause a food allergy or intolerance?

There are many potential causes of allergic reactions and a thoroughly review of your health history is important in helping to sort out the underlying causes of your food reactions. Potential causes for food reactions include: an overactive immune system, lack of stomach acid (frequently seen with long term use of reflux medication), a damaged intestinal lining, insufficient good gut bacteria, and chronic, low grade infections.

How do I treat food allergies or intolerances?

First you need to identify the triggering foods either using blood work or an elimination and rechallenge diet (this is where you take out the food(s) for a time, and reintroduce to see if there is a negative reaction). Secondly, you need to identify and address the other, if any, underlying factors involved in your food reactions. Often times supplementation with HCl, enzymes, and other gut supporting herbs are required for poor digestive function; herbal medicine is indicated for chronic infections or immune system involvement, and probiotics are always a good idea for infants, children, or adults with suspected food reactions.
Dr. Carly Wendler’s clinical expertise lies in maternal and pediatric medicine. She brings to her practice and educational workshops over six years of clinical experience, an evidenced-based approach, and a passion for helping families get and stay healthy. For more information on pregnancy, birth, post partum, and infant health visit

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