Food Sensitivities, Allergies, & Intolerances


Ever wondered if you may be sensitive to a certain food or food group? A food sensitivity differs from what people commonly think of as a food allergy. A food allergy gives us the classic symptoms of anaphylaxis, or difficulty breathing, swelling and a rash. 

A food sensitivity may give rise to more vague and generalized symptoms that last longer, such as headaches, fatigue, brain fog, weight gain,  joint pain and rashes or acne. What causes these differences? Immunoglobulins. Basically, a protein produced by our immune system in response to food ingestion. 

There are a few types of immunoglobulins, but for the purposes of this article I will stick to those produced in an allergy, IgE proteins, and those produced in a sensitivity, IgG proteins. 

Food Allergies

Food allergies are relatively rare, occurring in about 2-5% of the population. food allergy produces this specific immune reaction. Upon ingestion of an allergic food, IgE is produced. Upon production, we have a series of immune reactions that create the immediate and dangerous symptoms of difficulty breathing, swelling and a rash. The symptoms come on very quickly and the IgE is cleared by the body within 24-72 hours of ingestion. 

Food Sensitivities

On the contrary, food sensitivities -- sometimes called delayed food allergies -- are more common; Occurring in about 45-60% of the population. When we eat a food we are sensitive to, our body will also produce an immune reaction, IgG. However, this protein is secreted more slowly over time, and takes longer to clear from body - usually 4-6 weeks. Due to the slower nature of secretion and time to build up, we get more vague symptoms that aren't always tied to food ingestion, as with an allergy. 

Food Intolerances

A food intolerance is when we lack the enzymes to break down a food properly in the small intestine. The most common intolerance, is lactose intolerance, where we lack the enzyme lactase to break down milk sugars. There are other intolerances that exist, but usually are easily identified by their relatively quick onset of symptoms (abdominal pain and bloating, diarrhea) with ingestion of the food, usually within 30 minutes to 2 hours. 

Testing for Food Sensitivities

Food allergies are often well known and diagnosed at an early age due to their acute nature. Food sensitivities are not so clear. The "gold-standard" is what is called an elimination diet. To perform an elimination style diet, see the steps below. Another option, for patients who do not want to go through the time and effort of an elimination style diet can perform blood testing. By a simple blood test, foods are combined with blood samples to assess for levels of IgG produced. If you are interested in testing, we offer a finger-prick test that can be performed in office or sent to your home. Included in the testing price is an initial consult and follow-up visit to go over the results of the test. 

Elimination Diet 

To perform an elimination diet, remove the top sensitivities from your diet for 6 weeks. These include: wheat, corn, soy, dairy, and eggs. Not consuming these foods for 6 weeks allows the opportunity for your system to clear any IgG present. After the 6 weeks, you slowly reintroduce each food group, one at a time. Pick a food to consume, eggs for example, and eat a small portion the first day. Eat another portion, larger this time, the second day and an even larger portion, or multiple servings throughout the day on the third day. Notice how you feel, monitor for headaches, fatigue, abdominal pain, or skin changes over the next 3 days. If you do not notice any changes, you tolerate this food and continue to eat it regularly! If you notice a development of symptoms, consider eliminating this food from your diet as you do not tolerate it well. Continue this for the rest of the foods removed. The clearance of IgG from your system gives you a true response to the foods reintroduced and a clearer picture to your symptoms. 

For more guidance or if you are interested in food sensitivity testing, schedule a visit with Dr. Hannah here