Understanding Food Sensitivities

Over the last several thousand years, the need for survival has seen humans develop a high tolerance to most foods. However, some people’s immune systems react to certain food components – antigens– by seeing them as a threat to health. When this happens the immune system tries to destroy these invading antigens, which provokes an allergic reaction in the body. This is what we refer to when we use the term ‘food allergy’. How a food allergy is treated depends on the type of allergy it is.

Types of food allergies, their symptoms and treatment

There are three types of food allergy, scientifically differentiated by the antibodies produced and the pathological pathways seen.

The most acute of food allergies is acute symptomatic food allergy type 1. This type brings on symptoms within minutes or even seconds after ingestion of the offending food. Typical symptoms include itching and redness of the skin, caused by releasing large amounts of histamine which leads to swelling of mucosa (linings of the skin). Swelling of the lips or throat is also common in type 1 food allergy and in severe cases, anaphylaxis can occur.  Immediate treatment is crucial in treating type 1 allergic reactions – and in critical cases this may involve intensive care.

Far less severe is asymptomatic food allergy type 1. The antibody released by the immune system in this case is IgG4 (whereas acute symptomatic food allergy type 1 releases IgE). IgG4 does not produce an inflammatory reaction and patients rarely suffer any symptoms, in fact they may never even know they have a food allergy.  This type of allergy is considered harmless however, depending upon the ratio of Ig4 to IgE antibodies, may become symptomatic over time.

Finally, a food allergy type III, which is characterised by delayed symptoms manifesting themselves between two hours to three days after ingestion. These are also known as food intolerances.  Symptoms of food intolerance may include skin conditions, gastrointestinal complaints, sore joints, tiredness, headaches, even depression and anxiety.

Though the symptoms of food allergy type I can be treated medically (for example with anti-histamine), the only lasting treatment for all food allergies is the elimination of offending foods from the diet.  Type 1 allergies are usually permanent, whereas type III allergies can change over time depending on your diet.

Type I food allergies usually need to be treated by allergy specialists, while a type III allergy or food intolerance can be managed quite easily by the individual once a test has been undertaken. Many health practitioners are now offering food intolerance testing and assisting people to manage their diets effectively. This kind of treatment can require a bit of time to take effect and deep nutritional knowledge to be effective.  Eliminating foods from your diet on your own, or guessing which foods you may be intolerant to, is not recommended and can make a difficult situation a lot more frustrating. This kind of practice can also lead to cutting out foods unnecessarily leaving you nutritionally deficient. It is best to undertake a food intolerance test in order to correctly identify which foods you should avoid and which ones are safe for you to eat.

What causes food allergies?

While the existence of a food allergy is ‘in the blood’, current thinking is that type III food allergy is becoming more prevalent and is encouraged by a number of contributing factors including:

  • A monotonous diet (eating the same foods too often)
  • Composition of modern foodstuffs, especially gluten
  • Increase in the use of processed foods
  • Increase in environmental pollution
  • Increase in the use of drugs


Food allergy type I and type III are caused by separate immune responses and can lead to different diseases requiring individual health management routines.
If left untreated, food allergy type III can lead to chronic inflammatory diseases such as IBS, crohn’s, coeliac, rheumatoid arthritis, asthma and more.
A simple IgG test will identify possible foods causing food allergy III, and by avoiding these foods inflammation can be allowed to lower and quality of life may be greatly improved.