There has been a rise in publicity for food intolerance testing kits, with claims to test for both allergies and intolerances such as coeliac disease and lactose intolerance. Some also claim to identify specific food/ ingredient intolerances such as chicken, rice and potato allergies, which are exceptionally uncommon. According to Allergy UK 1 in 4 people in the UK have a diagnosed allergy. Approximately 10% of the UK have a food intolerance however up to 20% of the population experience symptoms from food which they believe to be a food allergy (BDA).
What is a food allergy?
Food allergies often get confused with food intolerances. A food allergy is when the immune system reacts to a food/ component in food; this is essentially the immune system ‘over-reacting’. There are two types; ‘IgE mediated’ and ‘non-IgE mediated’. Non-IgE mediated allergies often do not present immediately after consuming an allergen and sufferers often get symptoms such as vomiting, bloating and diarrhoea. Whereas, IgE mediated allergies tend to occur within minutes of eating and get symptoms such as hives, vomiting, redness to the skin and anaphylaxis. Food intolerances are known as ‘non-allergy hypersensitivities’. This means, symptoms are often experienced however the immune system is not involved. Some common food ‘allergies’ include nuts, eggs, shellfish and gluten (in the case of coeliac disease) and examples of ‘intolerances’ include lactose or fructose intolerance
What are home allergy/ food intolerance kits?
Food intolerance/ allergy kits utilize a number of different methods to ‘identify’ dietary triggers. Here is a few ways home kits/ alternative testing is offered:
- Bio-resonance testing (aka hair sample)
- Kinesiology – this follows the theory that certain foods create an energy imbalance in the body, which can be detected in the response to the muscle.
- Cytoxic test – a blood test whereby the blood sample is mixed with the potential dietary intolerance and a dietary intolerance is diagnosed via the white blood cells swelling.
- Vega test – Tests the ‘electromagnetic conductivity of the body’ on the premise that a dietary intolerance will cause a ‘dip’ in the electromagnetic conductivity.
Do they work?
Only IgE mediated allergies can be diagnosed. This is because IgE (Immunoglobulin E) is an antibody produced by the immune response present in the blood. Therefore requiring a blood test for diagnosis. Your doctor/ dietitian should interpret these tests.
Non-IgE allergies and dietary intolerances can only be determined by monitoring symptoms when excluding potential allergens from your diet. You may have heard about hydrogen breath testing for lactose intolerance, which I will also do a post for!
The bottom line is that, at present there is not convincing evidence that alternative allergy testing kits accurately identifies dietary allergens. In regards to food intolerances, claims to ‘identify’ these are incorrect as the only way to identify food intolerances is through symptom monitoring and exclusion, which should be done with the support of a dietitian to ensure the correct food/ component in food, is identified. Failure to identify the correct dietary trigger can be dangerous and lead to un-necessarily restricting your diet and increasing the risk of nutritional deficiencies. I will discuss this in another post! And please
For any other health care professionals/ in training these guidelines from ‘sense about science’ are an interesting read!