Testing for Food Sensitivities
Food sensitivities can cause a range of different symptoms making them difficult to identify.
Food Sensitivity, food intolerance or food allergy? What is the difference?
Food allergies are immediate, possibly life-threatening reactions triggered by IgE antibodies.
Food sensitivities are mostly triggered by a different class of antibodies called IgG. They can be delayed and may only occur after repeated or higher exposure to problematic foods.
Food intolerances are non-immune (or non-antibody) reactions generally due to lack of the enzymes that break down food components. Examples include lactose intolerance or fructose intolerance.
Food sensitivities are quite common and it is estimated that up to 45% of the population may experience them. Many people with food sensitivities have more than one symptom and react to more than one food. It is important to mention that food sensitivities may not be the main cause of your symptoms as they may be a secondary effect of leaky gut (or intestinal permeability), however eliminating moderate or severely reactive foods whilst healing our gut can give you some much needed relief. Our aim is to reduce symptoms, heal your gut and then gradually reintroduce these foods to build tolerance and ensure you are eating a wide variety of foods as quickly as possible. In our opinion, long-term restrictive diets generally do more harm than good.
Symptoms of food sensitivities can be vague and delayed, making it very difficult to elicit the problem food or foods. When someone with a food sensitivity is exposed to their problem food, they may not have a reaction for a number of hours or even days. Also, the severity of the reaction may vary, with some people having minor symptoms such as feeling tired or having a foggy head, while others have urgent diarrhoea or migraine. Many people don’t realise that the symptoms they have been experiencing are due to food intolerances, until they remove the offending food/s and notice their persistent symptoms disappear.
The symptoms of food sensitivities can be delayed for many hours or even days, making it difficult to identify the problem foods.
In contrast, food allergies are quite rare, with only about 2.5% of the population being diagnosed with the condition. The most common instances of food allergy are to wheat, peanuts, tree nuts (almonds and Brazil nuts), eggs, milk, fish and shellfish. When someone who is allergic is exposed to the provoking food, their body makes specific antibodies (IgE) to “attack” the allergens found in these foods, so when the food is next eaten it triggers an immune system response, which results in the release of histamine and other inflammatory naturally-occurring chemicals. Allergic reactions to food can vary considerably in their presentation and severity from hayfever to anaphylaxis (airway closure) and generally require long-term (or even life-long) elimination.
How does this test vary from the common skin scratch test?
The scratch test screens for IgE allergy reactions and the procedure involves a small amount of the food (or environmental irritant) being placed just under the skin. If the skin reacts to that particular food, then it is deemed an allergy, with the stronger the reaction the more severe the allergy.
Food sensitivity testing measures reactions by a different antibodies such as IgG and in rarer cases IgA. These tests can either require a finger prick sample or a blood draw at a pathology centre depending on the test ordered. IgG antibodies are delayed reactions, so this can make it difficult to identify without testing, as reactions can appear 2-3 days after exposure.
Why don’t you recommend food sensitivity testing using hair samples?
Food sensitivity testing using hair samples has recently become popular however there appears to be no scientific evidence to support it and we could not find any rational explanations on how it works or on its “potential” accuracy. Testing companies apparently test for energy changes in the hair (according to homeopathic principles) and “some how” link this to specific reactions to foods. Considering that hair is actually not living, it is difficult for us to grasp how you can measure energy changes to hundreds of different food potentially eaten months ago (especially since hair takes a long time to grow).
Food sensitivities are delayed immune reactions certain foods
Food sensitivities are not life-threatening and may require higher exposures to the problematic foods. Food sensitivities can run in families and are highly linked with intestinal permeability (or leaky gut). Damage to the gut lining can result in larger protein molecules crossing into your blood stream and triggering your immune system to produce antibodies against the “invading” food. Therefore improving your digestion and healing your gut can in some cases allow you to tolerate the troublesome. That is why you should always work to improve your gut health and not just eliminate reactive foods.
Symptoms of food sensitivities may include:
- Anxiety and/or heart palpitations
- Arthritis and Joint pain
- Asthma
- Bloating
- Fatigue and lethargy
- Constipation and bloating
- Diarrhoea especially with urgency
- Fibromyalgia
- Gastritis, reflux or heart burn
- Headaches or migraines
- Incontinence (fecal and urinary) – may include bed wetting
- Irritable Bowel Syndrome (IBS)
- Eczema or dermititis
- Malabsorption and nutrient deficiencies
- Sleep Disturbances
- Fluid Retention
- Weight Control Problems
- Brain fog and poor concentration