Intestines on high alert: Intolerance or Allergy?

The most common intolerances

Lactose and fructose intolerances, histamine intolerance as well as gluten intolerance, or coeliac disease, belong to the most common intolerances. Lactose intolerance, an intolerance towards the milk sugar lactose, is an enzymatic ailment. „Not enough of the enzyme Lactase is produced. As a result, lactose can’t be broken down into glucose and galactose in the intestines. Instead, lactose is digested by intestinal bacteria. This leads to typical symptoms such as intense bloating and diarrhoea“, clarifies the nutritionist. Lactose intolerance is very wide-spread: 80-90% of the population in northern countries can metabolize lactose, whereas only 10-30% of the inhabitants in southern Europe and only 1-2% of the population close to equator and Asia can.

Histamine intolerance is also an enzymatic intolerance. Histamine is broken down by the enzyme Diamine oxidase (DAO) in the intestine. If too little DAO is produced, not enough Histamine is biodegraded. This can occur when the DAO-Enzyme is oversaturated through a high dietary Histamine intake (e.g. red wine, cheese, nuts etc.). Furthermore, if the bowel mucosa is either diseased or under acute stress, the DAO-Enzyme is incapable of completing its task. Consequently, symptoms may include: headaches, stomach-aches, diarrhoea, itchiness, rashes, a running nose, occasionally even asthma and cardiac arrhythmias.

An intolerance towards certain foods – in comparison to allergies – doesn’t involve the immune system but rather an enzyme defect.

With fructose intolerance, we must differentiate between fructose malabsorption, in which fructose isn’t completely absorbed, and hereditary fructose intolerance. Flatulence, stomach cramps, and nausea can occur in both forms of fructose intolerance through the intake of fruit, jam, fruit-juices and certain vegetables.

A gluten intolerance – not to be confused with a wheat allergy – is an intolerance towards the adhesive protein Gluten, which is included in many types of grain such as rye, oats, spelt and wheat. The most severe form of gluten intolerance, Coeliac disease, is an autoimmune disease which leads to a chronic inflammation of the small bowels. As a result, the function of the small bowels and absorption of nutrients is severely affected. Due to this loss of function, patients suffer from deficiencies, digestive problems and a wide range of other symptoms. The resulting atrophy of the villi or, in other words, loss of small bowel villi (these are the many small protrusions on the surface of the mucosa) is typical for Coeliac disease (refer to the illustration above). Affected patients must make sure they have a sufficient nutritional intake and most importantly, a completely gluten-free diet.

Lesser-known intolerances

Besides the well-known intolerances, there are also rare, lesser-known intolerances – so-called pseudo allergies. The expert, Mag. Hammerl, explains: “These intolerances are very seldom with a probability of 0,1%. Patients more commonly assume they suffer from such intolerances. People with hives, a.k.a. urticaria, tend to suffer more from pseudo allergies.”

Among these are intolerances towards sulphur dioxide and sulphites. These sulphur bonds are mainly used for the preservation of foods, such as preventing dried fruit from going brown. However, they are also found naturally in foods. Wine, Sauerkraut, grape-juice, and lemons all contain high amounts of sulphites. Even other food additives, also labelled as E-numbers, can lead to pseudo-allergic reactions in rare cases. These substances include conservatives such as benzoic acid, different dyes, artificial flavours or the flavour enhancer glutamate. A glutamate intolerance often goes hand in hand with the so-called „China-restaurant-syndrome“, which is characterized by headaches, inner tension in the head and face, sweating attacks and dizziness. The food groups and substances that cause pseudo-allergies, only lead to symptoms in large amounts and can easily be avoided or taken off the menu in day-to-day life.

Diagnosing intolerances in many cases isn’t easy and can take up a lot of time. In the case of fructose malabsorption or lactose intolerance, a diagnosis can be made using the H2-Breath-Test. For this test, a fructose or lactose solution is ingested and then the hydrogen concentration in the patient’s breath is measured at regular intervals. Hereditary fructose intolerances, on the other hand, are diagnosed using gene testing.

At the moment, there is no consistent test to guarantee the detection of histamine intolerances. In this case, the help of the affected is needed. First of all, a targeted medical history is needed, usually through an allergist, as well as the diamine oxidase blood concentration. If the DAO concentration is too low, a histamine intolerance is very likely. Self-awareness is an essential step towards a diagnosis: affected patients should change to a low histamine diet for about three to six weeks and should observe their symptoms. Afterwards, all foods should be reintroduced step-by-step into their diet under medical supervision. Patients should always write down what foods were reintroduced and possibly what discomforts they caused in a diary. This is an easy way to recognize suspicious substances. Additionally, skin tests with different allergens and further blood tests can be carried out. These tests can, however, lead to incorrect results. „This is why provoking symptoms with identified foods is the most reliable diagnostic method. It should, nevertheless, be performed carefully due to a possible immunological reaction“, emphasises the expert. The diagnosis should ideally be accompanied by a nutritional therapy in the case of a suspected histamine intolerance.

Coeliac disease can be detected by certain antibodies with the help of a blood test. A biopsy of the small bowel puts the results beyond any doubt. Diagnostic tools have improved tremendously in the last few years. That is the reason why more and more people are being diagnosed with gluten intolerance.