🌿 The question around how to distinguish between food sensitivities and food allergies comes up commonly in my practice.
When we think of allergies, symptoms of anaphylaxis such as face swelling, throat closing, breathing difficulties and angry rashes come to mind. The body mounts this as an immediate response, and guides the process through the production of IgE antibodies. This can happen within seconds to minutes after consuming a food and is considered a medical emergency. Often it is very clear what specific food triggered the reaction.
Food sensitivities, on the other hand, are a bit more elusive and challenging to pin point. This is because they are guided by an IgG or "memory antibody" response that can take days to have an effect. You may eat something this morning and not experience the negative impacts of that food until tomorrow. To further blur the waters, symptoms of food sensitivities are also more generalized and could be easily overlooked. Although not life threatening, I commonly see food sensitivities negatively contribute to the following:
✨Abdominal pain and bloating
✨Burping or flatulence
✨Constipation or diarrhea
✨Fatigue or brain fog
✨Eczema, acne or psoriasis
✨Mood swings, anxiety and depression
Typically, allergies are identified either through IgE blood testing or through a skin prick test. The latter involves your allergist applying small drops of possible allergens to the skin surface to see if a reaction occurs.
Food sensitivities can be tested through either a blood draw or an at-home finger prick. Where these results are not meant to be used diagnostically as allergy testing is, I find that they are a useful clinical tool to guide dietary changes and support the more chronic concerns listed above. The alternative to this testing would be to follow an elimination diet, where the most common food sensitivities are eliminated for 4-6 weeks to see if symptoms improve. These foods often include gluten filled grains, diary, eggs, soy, nuts, corn, and nightshades. The benefit to this approach is it's free! But it often requires more trial and error to figure out which foods are problematic.