In my practice I am frequently asked about the difference between food allergies and food sensitivities. Both of these reactions involve the activation of the immune system. The difference lies in the part of the immune system being activated and how fast the reaction occurs.
Food allergies involve the production of specific IgE antibodies and the release of histamine (type I Hypersensitivity). The symptoms occur within seconds or minutes after ingestion of the reactive foods. The symptoms could include difficulty breathing, rashes, sneezing, and anaphylactic shock.
Food sensitivities usually cause delayed reactions and involve the production of the IgG antibodies (Type III Hypersensitivity). The symptoms have a much slower onset and could take several hours to days to develop.
Food sensitivity reactions might include gastrointestinal upset, IBS/IBD, eczema, migraines, mood swings, irritability, joint pain, weight problems, and fatigue.
Reactions to foods could be non-immune mediated as well. They are generally referred to as food intolerances, however could be also referred to as food sensitivities. One of the most common example of food intolerance is inability to digest milk sugar due to the lack of the enzyme lactase. As a result, digesting dairy products would cause great intestinal discomfort with diarrhea and bloating.
Foods causing type I Hypersensitivity allergic reactions should be avoided for life. With Type III Hypersensitivity however, usually the elimination of the reactive foods for an extended period of time would decrease the level of IgG antibodies significantly, and the symptoms they are causing. The offensive foods could be re-introduced in the diet after about 12 months of strict elimination.
At RHNC we offer screening tests for multiple food sensitivities (120 - 200 common foods). In my practice I find this test to be quite specific and sensitive, and elimination of the reactive foods usually produces favorable results. Sometimes the test is repeated once elimination phase is completed to assess the new levels of the IgG antibodies. In most of the cases we see a dramatic reduction in the IgG levels and considerable improvement in symptoms. The foods are usually re-introduced in the diet on a rotation basis (e.g. once or twice a week) to prevent sensitivities from re-occurring. Please contact our clinic for more information on these tests and
talk to one of our naturopathic doctors to see if the test is clinically indicated.