What Food Sensitivity Testing Looks Like & How it Can Benefit You

In the last couple of decades, more and more awareness has been brought to the issue of food sensitivities. With the rise of industrial pesticide use, higher stress levels, and more chemical additives in our foods, more Canadians are experiencing food intolerances and sensitivities more than ever before. 

As we’ve gained a better understanding of how these sensitivities impact our health, we can use food sensitivity testing as a useful tool in determining what is going on in the body, as well as support healing by eliminating certain foods from the diet. 

Many people are not aware that food sensitivities could be a factor for them, so I wanted to put together a guide showing how food sensitivities can impact us, symptoms, potential causes, as well as highlight the process of sensitivity testing within the naturopathic setting. 

Are Food Sensitivities Allergies?

While similar in that both food sensitivities and allergies are the body responding adversely to a particular food, food sensitivities differ from allergies in how the body responds. 

On exposure to foods, the immune system can react by releasing proteins called antibodies.  Two types of antibodies are commonly produced in response to foods:  IgE and IgG.  Food allergies and food sensitivities differ by the type of antibody produced and the speed of the reaction.  A food allergy is an immediate reaction caused by the production of IgE antibodies, while a food sensitivity is a delayed reaction caused by the production of IgG antibodies to specific foods.

IgE reactions generally occur within minutes of eating a reactive food and can, on rare occasions, be life-threatening (peanut allergies).  Symptoms may include itching, hives, swelling, breathing and digestive problems.  Oftentimes people may be having milder histamine reactions such as headaches, stuffy nose, skin issues such as eczema, joint pain, anxiety, or trouble sleeping.

Allergies develop when your body is exposed to an food or allergen and reads it as a ‘threat’ as it would a bacteria or virus. The body then ‘remembers’ this allergen and becomes hypersensitive to its presence and keeps a supply of IgE ready for immediate release if it “sees” the allergen again.   

Food sensitivities on the other hand produce IgG antibodies and can take hours or days to develop, making it difficult to determine the food cause without testing.  Conditions associated with food sensitivities include: digestive disorders such as IBS, migraines/headaches, fatigue, mood and memory disturbances, asthma, skin conditions, joint inflammation and many more.

Both types of reactions do have a detrimental effect on the health, and can often go unidentified as people don’t connect the symptoms with the foods they’re eating.

How Testing Works

There are several ways that your healthcare provider may work with you to determine food sensitivities and allergies. 

First, there may be a process of elimination, where you will stop eating a suspected food for a period of time in order to see if there is any change in symptoms. This can be a good approach if there is already enough supporting experiential evidence to have narrowed down the culprit food. This is particularly used in the realm of food sensitivities, which may not show up on allergy tests.

There are food sensitivity blood tests that will measure the IgG antibody immune response.  Antibody levels are measured via an ELISA (Enzyme-Linked Immunosorbent Assay) microarray method.  

Food allergy testing can be done via the blood or scratch test (on the skin).  The blood allergy testing will be measuring the IgE immune response whereas the scratch test is looking for the immediate immune response on the skin (hives/itching/redness).

Common Food Allergies & Sensitivities

The most common food allergies are milk, eggs, fish, shellfish, tree nuts, peanuts, wheat, and soybeans. 

As far as food intolerances and sensitivities, we commonly see dairy (lactose intolerance), gluten (gluten intolerance), eggs, aspartame, msg, food colorings, yeast, fructose (fructose malabsorption), sulfites, FODMAPs (common in people with IBS), and amines (histamine intolerance from fermented foods). 

What Next?

Determining what food allergies or sensitivities you may have allows you to create a diet eliminating or avoiding these foods in order to stop placing these additional stressors on your body. 

Eating foods that cause an immune or digestive response does increase inflammation within the body, and can have both short term acute symptoms along with long term cumulative effects on the body's digestion and regenerative capacities where your body essentially never has a chance to repair any tissue damage from these foods with repeated exposure. 

When we give our bodies a break, the healing cycle can begin. In the case of sensitivities, small amounts of the food may be reintroduced after enough of a repair period has occurred. 

Talk to your health care provider or ND about how food allergy and sensitivity could support you in better health.