Allergy or food intolerance?

In recent years, elimination diets have become very popular. When going on an appointment with a dietician, some people assume that certain products will be eliminated. Usually, it concerns eliminating gluten and/or dairy products. However, we must be aware of the fact that elimination diet is justified only in specific cases, and implementing it without consulting a specialist may bring more harm than good. Elimination diet is introduced following a thorough nutritional and medical examination and diagnostic tests based on referral from a specialist.

CLASSIFICATION OF FOOD SENSITIVITIES

Food sensitivities can be divided into two types, depending on the involvement of the immunological mechanism. We distinguish between food allergies and non-immunological food sensitivities.

The general classification of food sensitivities is as follows:

  1. Food allergy – including the immune system
  • IgE-dependent allergy (atopic or non-atopic allergy),
  • IgE-independent allergy (allergy dependent on IgG, eosinophilia, T lymphocytes, etc.).
  1. Food sensitivity – not involving the immune system
  • enzyme intolerances, e.g. intolerance to lactose,
  • pharmacological intolerances,
  • idiopathic intolerances.

FOOD ALLERGIES...

Let’s start with food allergies. In short, IgE allergies are immediate reactions, while IgE-independent (IgG-dependent) allergies are delayed reactions of the immune system. Both types of sensitivities are connected with an incorrect response of the immune system caused by an ingredient in our diet. The reaction consists in an increased number of IgE or IgG class antibodies in blood.

IgE-dependent allergies are easy to identify, because they are characterised by an immediate reaction (symptoms appear within several minutes to one hour after contact with the allergen). Symptoms usually involve the respiratory tract, skin or digestive tract.

In most cases, swelling, skin redness, urticaria, abdominal pain, runny nose or bronchospasm appears. An acute allergic IgE-dependent reaction may even lead to anaphylactic shock, which requires fast medical intervention.

It is also worth adding that not many people suffer from this condition – approx. 1-3% of adults and 4-5% of children. These allergies are diagnosed primarily during childhood.

Unfortunately, we cannot say the same about IgE-independent allergies. This issue still remains unclear and is a subject of numerous scientific studies, while it is estimated to affect more than 50% of the population.

Identification is problematic due to late symptoms, which can usually be observed 8-72 hours after contact with the allergen. To complicate things even further, intensification of symptoms is also connected with the quantity of a given ingredient of diet, and usually there are several ingredients and not one as in the case of IgE-dependent reaction.

FACTORS TRIGGERING FOOD ALLERGIES

In the case of food allergies, the problem is triggered by the immune system, which can be stimulated by genetic or environmental factors. Studies show that the majority of IgE allergies are acquired in the first two years of life. It is connected with immaturity of the immune system, which is very sensitive to external stimuli.

Among factors conductive to IgE-dependent food allergies are:

  • vitamin D3 deficiency,
  • incorrect diet during infancy,
  • environment pollution,
  • exposure to tobacco smoke.

Preventive factors:

  • breastfeeding,
  • including new ingredients in the child's diet in an appropriate way,
  • maintaining the right intestinal microflora.

In the case of IgG-dependent allergy, environmental factors are considered to have an increasingly larger effect. It seems that IgG-dependent allergies can result from the leaky gut syndrome, i.e. a condition in which the intestinal barrier becomes more permeable and non-digested food particles pass through the intestine, stimulating the immune system and leading to the development of an immunological complex and inflammation. However, these assumptions require further studies.

NON-ALLERGIC FOOD SENSITIVITIES  

The immune system does not play any part in the mechanism of formation of these sensitivities. They usually concern food intolerance related to a deficiency of an enzyme. This can be, for example, intolerance to lactose, fructose, histamine, etc. Diagnosis is made based on breath and genetic tests. Treatment involves elimination diet and/or digestive enzymes supplementation.

FOOD ALLERGIES DIAGNOSTICS

Diagnostics of IgE-dependent allergies is simple and includes interview, immunological tests, such as the assessment of IgE antibodies in serum and skin tests.

IgE-dependent allergies are diagnosed on the basis of tests assessing specific IgG antibodies in relation to food ingredients.

WHEN IGG ALLERGIES CAN BE SUSPECTED AND WHEN TO MAKE SPECIALIST TESTS?

A large variety of symptoms, which are often classified as conditions of unknown origin, make correct diagnostics difficult. Tests are usually recommended for people who are treated for diseases mentioned below and do not show any improvement. This primarily concerns the following conditions:

  • irritable bowel syndrome,
  • inflammatory bowel diseases,
  • autoimmunological diseases,
  • depression,
  • skin lesions (atopic dermatitis, acne, psoriasis),
  • chronic fatigue,
  • migraines,
  • recurrent infections,
  • infertility,
  • obesity and overweight.

OBESITY, INFLAMMATION VS. IGG ALLERGIES...

From dietary point of view, the problem of obesity and overweight seems especially puzzling. Body weight reduction seems to be easy. With introducing a suitable caloric deficit and with a little bit of consistency the effect should be guaranteed. Unfortunately, it is not always this easy.  There are patients who despite reduced caloric intake still find it very difficult to lose weight. The situation starts to complicate even further if we are dealing with chronic inflammatory state connected with an increased level of inflammatory mediators (TNF-α, IL-1, IL-6 and CRP). It is worth adding that an excess of fat tissue alone will generate an inflammatory state. As a consequence of inflammation, other different conditions and diseases may appear, such as insulin resistance, diabetes, hypertension or atherosclerosis, which will additionally enhance the inflammation in the body, impeding all attempts of slimming. Body weight optimisation seems the first recommendation to improve the health situation. The problem is that in order to lose weight, inflammation needs to be dealt with first, as this state is certainly related to obesity, but may be intensified by IgG-dependant allergies. This is why IgG-dependent allergy tests are recommended to people who despite following dietary recommendations and physical activity still find it difficult to reduce body weight.

Studies show a positive effect of an elimination diet (based on IgG-dependent allergy diagnostic tests) on reducing body weight in patients having problems slimming down.

Recapitulating, the subject of food sensitivities is highly topical nowadays, and plenty of information is available from various sources. I recommend caution with self-diagnosing and eliminating entire groups of food products on one's own. An adequate elimination diet supported by suitable tests and/or an interview conducted by a specialist may bring considerable benefits, however, doing it on one’s own without consulting a specialist may lead to nutritional deficiencies and health deterioration.

Please remember that the key to health improvement is a holistic approach, diet rationalisation – without following temporary trends – and nurturing good habits.

by ipws