Essentially, these terms all relate to an adverse physiological response to a particular food; however the mechanisms by which this occurs are very specific to the individual type of food sensitivity in question.

IgE reaction is a food allergy and is immediate and could be life threatening. You must contact your GP if you think you may have a food allergy.

IgG reaction takes longer to develop and can lead to a lot of digestive discomfort but is not life threatening. We can test for this reaction in clinic.

Food sensitivity is usually due to an enzyme deficiency which can lead to a lot of digestive discomfort. This can usually accurately be assessed in clinic by reviewing food diaries and symptoms.

These reactions can be categorised as either immunological (IgE or IgG mediated) or non-immunological in nature and can initiate an immediate (minutes to hours) or delayed (several hours to days) response to a particular food.

Identifying the specific reactive mechanism triggered by the ingestion of this food is vital to understanding the management and implementation of appropriate dietary interventions to limit potentially unpleasant (and in some cases, life threatening) symptoms.

IgE food allergy
A classic IgE allergy occurs when the immune system produces this type of antibody that mediate the release of histamine and other reactive substances, leading to an immediate allergic reaction.

IgE allergy is not something that we test for, and so it will not be identified by the IgG mediated food intolerance tests. If an individual suspects that they may have an IgE allergy, then they should consult their GP to be tested for this.

IgG Food intolerance
IgG-mediated responses to a particular food can take a long time to develop which means it can be difficult to determine which foods are causing a problem.

The Food Detective Test employed in the clinic, uses specific food extracts to identify the corresponding level of circulating IgG antibodies to these potential antigens and can therefore detect foods to which the immune system is reacting.

As the food components in patients with increased intestinal permeability (leaky gut syndrome) enter the bloodstream from the intestinal lumen on a continuous basis, the immune mechanisms undergo constant activation. This can eventually overload the immune system’s ability to clear such complexes efficiently, which results in chronic inflammation.

Food sensitivity
Non-immunological food intolerance is generally caused by a genetically inherited defect in an individual’s ability to metabolise a food component due to enzyme deficiencies.

Some examples of this type of intolerance include enzyme deficiencies, such as lactose intolerance which is caused by the absence of the enzyme lactase. This can be identified in clinic by looking at a food diary and examining symptoms.