As an ND I am often asked about food allergies and food sensitivities in practice. What is important is to help patients understand the difference between food allergies and sensitivities and how they are affecting their health.
Food Allergy – IgE reaction – Immediate
These are the reactions diagnosed with a skin prick test. The reaction is quick and can be life threatening in the case of anaphylaxis. Other common reactions include hives, eczema, breathing and digestive problems. Because they are immediate they are much easier to diagnose.
Allergen → Body releases IgE → Triggers release of histamine → Allergic reaction
Food Sensitivity – IgG reaction – Delayed reaction can take 24-72 hours to develop
In food sensitivities, the body is exposed to an allergen and releases IgG antibodies which bind to the allergen. Although the body usually removes this complex, if it becomes too much, it can lead to inflammation which can affect various body systems. Symptoms can include abdominal pain, gas, bloating, itchy skin, rashes, bronchitis, asthma, joint pain, or muscle stiffness. Because they are delayed they can be difficult to pin point.
Allergen → IgG released → IgG binds to the allergen → Leads to inflammation throughout the body
How do I know if I have food sensitivities?
There are 2 main ways to identify food sensitivities:
- Elimination Diet: this involves removing the most common foods that cause sensitivities for a minimum of 3 weeks. After the elimination phase, foods are gradually reintroduced in a systematic order to determine if any reactions occur.
- Food sensitivity Testing: this testing is done through a simple blood draw. It measures how your immune system reacts to a variety of foods. The results of the test allow you to determine exactly which foods your body doesn’t tolerate well.
I personally find value in both options depending on the symptoms. The elimination diet can provide almost immediate relief for some people. Often these patients find a few foods that trigger their symptoms and the correlation is easy to make. For others, the thought of eliminating the biggest allergens can be daunting. In this case the food sensitivity test helps to give a road map of what to avoid.
Once the test has been run and the results are in…what do you do next? Stay tuned as I outline some of the most common food sensitivities and how to navigate your new diet.