Food Intolerance or Food Allergy?
There are three ‘arms’ of the immune system when it comes to allergic reactions – IgA, IgE and IgG mediated allergies. ‘Ig’ refers to immunoglobulins, or “antibodies” which are produced by your immune system in response to foreign invaders. A hypersensitive immune system will respond, not just to bacteria and viruses, but also to many foods, pollens, pet dander, dust or any other environmental irritant.
IgA immunoglobulins are present in our mucus membranes to help us fight bacteria and viruses. IgA can increase in response to foods when those foods are causing inflammation in the body, just as disease would.
IgE-mediated reactions are considered true allergies and are associated with immediate and sometimes severe reactions. They are responsible for anaphylactic reactions that can result in death. Symptoms develop within seconds to hours of eating the offending food and may include a rash, hives, wheezing, coughing, a runny nose, vomiting, swelling of the lips, tongue or throat, tearing or redness of the eyes, or even a weak pulse and loss of consciousness. Common foods that trigger IgE reactions are peanuts, shellfish, egg, dairy products, soy, tree nuts, wheat and fish.
An IgG-mediated reaction to food can develop within minutes or hours. It can take up to 72 hours for symptoms to present. Although not life threatening, food intolerance should never be underestimated as its impact on sufferers can be significant, sometimes affecting their ability to live normal healthy lives. The incidence of food intolerance is extremely wide and it is estimated that 45% of the population could be affected.
Many people with food intolerance experience more than one symptom. Symptoms can often be vague and the root cause of the problem, food, is not always correctly diagnosed. Depending on which food you are reacting to you may experience one or many of the following symptoms: brain fog, fatigue, headaches, migraines, low energy, constipation, loose stools, nausea, gas, bloating, low immunity and/or chronic skin conditions.
You can develop a food intolerance at any time. An assault to the immune system or digestive system often precipitates it. Chronic stress can lead to Irritable Bowel Syndrome (IBS), causing a ‘leaky guy’. A leaky gut allows proteins from foods to enter your blood stream where they don’t belong. Your immune system recognises them as foreign invaders and mounts an immune response.
Most people know when they have an IgE-mediated allergy because they’ve had such a severe reaction they’ve been to their doctor. They may have had a skin prick test at the lab for food and environmental allergies. Celiac Disease is an example of gluten allergy that may be diagnosed by testing the blood for Transglutaminase Antibodies (tTG-IgA) antibodies and, if positive, a bowel biopsy to confirm. A negative celiac blood test doesn’t rule out Gluten Intolerance.
We now test for food intolerances in Auckland Skin Clinic. We only invest in tests that are scientifically validated. The Food Detective test identifies IgG antibodies in your blood in response to 59 commonly eaten foods. We don’t generally test for IgA because it is expensive and is usually not necessary. It is when this first line of defense is down that IgG-mediated allergies usually develop and are sustained long-term.
Click Here for information about Food Detective testing at Auckland Skin Clinic.