Many people suffer from unpleasant digestive symptoms, such as bloating, abdominal pain, cramps or diarrhoea, which are often caused by some form of food intolerance. These symptoms can significantly impair quality of life, and many people are at a loss as to how to deal with the problem, not knowing what to do. In this article, we take a detailed look at the world of food intolerances: we examine the difference between intolerance and allergy, outline the most common types, and offer practical advice on putting together a suitable diet.
Food intolerance is a digestive reaction that occurs when the body is unable to properly digest a particular component of a food. It is important to understand that this is not the same as a food allergy, which is an abnormal response by the immune system. Whilst an allergy can cause severe, even life-threatening symptoms, the symptoms of intolerance are generally less severe, but can be extremely unpleasant and may affect many areas of life.
An accurate diagnosis and a personalised diet plan are key to alleviating symptoms. Find out how to identify the underlying causes and what steps you can take to lead a healthier, symptom-free life.
What is the difference between a food intolerance and a food allergy?
Although the symptoms may sometimes be similar, food intolerance and food allergy are two conditions based on entirely different mechanisms. Distinguishing between them is essential for the correct treatment.
- Food intolerance: This is a digestive problem. The body either lacks a particular enzyme (e.g. lactase in the case of lactose intolerance) or has difficulty processing certain substances (e.g. fructose, FODMAPs). The reaction takes place in the digestive system. Symptoms usually appear a few hours after consuming the problematic food, or even days later. The severity of the symptoms often depends on the amount consumed: a small amount of the problematic food may not cause any symptoms, whilst a larger portion may. Food intolerance is not life-threatening.
- Food allergy: This is an overreaction of the immune system. The body regards a harmless food ingredient (allergen, e.g. milk protein, egg, peanuts) as a dangerous intruder and produces antibodies (immunoglobulin E, IgE) against it. Upon contact with the allergen, the immune system triggers a vigorous defensive reaction. Symptoms can appear almost immediately, within minutes of eating the food, and may affect not only the digestive system but also the skin (hives, eczema), the respiratory tract (shortness of breath, asthma) and the circulatory system. In the most severe cases, anaphylactic shock may develop, which can be fatal without immediate medical intervention. Even a minimal amount of allergen can trigger a severe reaction.
From eosinophilic oesophagitis a specific condition that lies on the borderline between allergy and intolerance. It is a chronic, immune-mediated oesophageal disorder characterised by the accumulation of eosinophils (a type of white blood cell) in the oesophagus. It is often triggered by food allergens and is associated with symptoms such as difficulty swallowing (dysphagia), chest pain or food getting stuck. Treatment requires a specialised elimination diet.
The most common types of food intolerances
Many substances can cause intolerance, but some are particularly likely to be responsible for symptoms. Let’s take a look at the most important ones.
Lactose intolerance
Lactose intolerance is the most common type of food intolerance. It essentially means that the body does not produce enough of the enzyme lactase, which is responsible for breaking down milk sugar (lactose). In the absence of lactase, lactose passes undigested into the large intestine, where it is fermented by gut bacteria.
- Symptoms: Bloating, abdominal cramps, increased gas, diarrhoea, nausea. Symptoms usually appear between 30 minutes and 2 hours after eating food containing lactose.
- Diagnosis: The most reliable diagnostic method is the hydrogen breath test. In this test, the patient drinks a solution containing lactose, and the hydrogen content of their exhaled breath is then measured at specific intervals. When lactose is broken down by bacteria, hydrogen is released; this travels through the bloodstream to the lungs and can therefore be detected in the exhaled air.
- Treatment: A lactose-free diet, or taking lactase enzyme tablets before consuming dairy products. It is important to note that most people affected can consume a certain amount of lactose without experiencing any symptoms.
Fructose malabsorption (fructose intolerance)
Malabsorption of fructose (fruit sugar) is also a common problem. In such cases, the small intestine is unable to absorb fructose effectively, which – like lactose – then begins to ferment in the large intestine.
- Symptoms: The symptoms are similar to those of lactose intolerance: bloating, abdominal pain, flatulence and diarrhoea.
- Diagnosis: Fructose intolerance can also be diagnosed using a hydrogen breath test; in this case, however, the patient consumes a fructose solution.
- Treatment: Avoid foods rich in fructose (e.g. honey, apples, pears, mangoes, cherries, watermelon, high-fructose maize syrup).
Histamine intolerance
Histamine is a biogenic amine that occurs naturally in the body and plays an important role in the immune response. Histamine intolerance develops when too much histamine builds up in the body, either because the activity of the enzyme diamine oxidase (DAO), which is responsible for breaking it down, is reduced, or because we consume too many foods containing histamine.
- Symptoms: They can vary greatly: headaches, migraines, redness, rashes, a runny nose, digestive problems (bloating, diarrhoea), and a sensation of a racing heart.
- Diagnosis: It is difficult, as there is no single reliable test. Measuring DAO enzyme levels in the blood can provide useful information, but the most important factor is observing the improvement in symptoms following a low-histamine diet.
- Treatment: A low-histamine diet. Avoid mature cheeses, processed meats (sausages, salami), sauerkraut, tomatoes, spinach, avocado, citrus fruits, red wine and sparkling wine. Capsules containing the DAO enzyme may also help.
FODMAP intolerance
FODMAP is an English acronym (Fermentable Oligo-, Di-, Mono-saccharides and Polyols) which refers to fermentable, short-chain carbohydrates. These include fructose, lactose, fructans (found in wheat and onions), galactans (found in pulses) and polyols (sugar alcohols, e.g. sorbitol, xylitol). These carbohydrates are poorly absorbed in the small intestine and draw water into the intestine by osmosis; they are then rapidly fermented by bacteria in the large intestine, producing gases. This mechanism is one of the main causes of the symptoms of irritable bowel syndrome (IBS).
- Symptoms: The typical symptoms of IBS are: abdominal pain, bloating, discomfort, flatulence, diarrhoea or constipation (possibly alternating).
- Diagnosis: There is no specific test. The diagnosis is made on the basis of symptoms and after ruling out other conditions (e.g. coeliac disease, inflammatory bowel disease). The introduction of a low-FODMAP diet and an improvement in symptoms confirm the suspicion.
- Treatment: The low-FODMAP diet is a multi-stage dietary therapy. First, during a 6–8-week elimination phase, all foods high in FODMAPs are removed from the diet. If symptoms improve, this is followed by a reintroduction phase, during which different FODMAP groups are gradually reintroduced one at a time to determine which ones the patient can tolerate and in what quantities.
Gluten intolerance (coeliac disease) and non-coeliac gluten sensitivity
It is important to distinguish between coeliac disease and non-coeliac gluten sensitivity.
- Coeliac disease (gluten sensitivity): This is an autoimmune disease triggered by the consumption of gluten (a protein found in wheat, barley and rye) in genetically susceptible individuals. In response to gluten, the immune system attacks the lining of the small intestine, damaging the villi. This can lead to malabsorption and nutrient deficiencies. Diagnosis is made through blood tests (detection of specific antibodies) and a small intestine biopsy. Treatment involves a strict, lifelong gluten-free diet.
- Non-coeliac gluten sensitivity (NCGS): In this case, consuming gluten causes symptoms similar to those of coeliac disease and wheat allergy (e.g. bloating, abdominal pain, headaches, fatigue), but tests for coeliac disease and wheat allergy come back negative. The mechanism is not yet fully understood, and it is likely that not only gluten but also other components found in cereals (e.g. FODMAPs such as fructans) play a role. The diagnosis is based on the principle of exclusion: if coeliac disease and wheat allergy have been ruled out, and symptoms improve on a gluten-free diet but reappear when gluten is reintroduced, then the condition can be diagnosed as NCGS.
How should we plan a diet for food intolerance?
The basis of treating food intolerance is identifying the food(s) causing the reaction and either eliminating them from the diet or reducing the amount consumed.
- Medical examination: The first and most important step is to undergo a specialist gastroenterological examination. Do not attempt to diagnose yourself or embark on drastic diets without first seeing a doctor! It is important to rule out other, more serious conditions (e.g. inflammatory bowel diseases, tumours) that may cause similar symptoms. A specialist centre such as the Endomedix Gastroenterology Centre, using modern diagnostic procedures (e.g. breath tests, endoscopy) and specialist doctors, it can help to establish an accurate diagnosis.
- Keeping a food diary: Keep a detailed diary of what you eat and drink, and when your symptoms occur. This will help you identify any possible links between the foods you eat and your symptoms.
- Elimination diet: It is advisable to start under the supervision of a dietitian. During this process, you will eliminate the suspected foods from your diet for a certain period (usually 4–8 weeks). If your symptoms disappear or improve significantly during this time, this confirms the suspicion.
- Redirection (provocation): After the elimination phase, reintroduce the excluded foods into your diet one at a time and in small quantities, and monitor your body’s reactions. This will enable you to determine exactly which food is causing the problem and the quantity that your body can still tolerate.
Expert advice: Why is it important?
It is easy to get lost in the maze of food intolerances. The information circulating online is often inaccurate or misleading. Consulting a gastroenterologist and a dietitian is essential for successful treatment.
- Gastroenterologist: He or she makes an accurate diagnosis, rules out other conditions and prescribes the necessary tests. The Endomedix Gastroenterology Centre Its specialists use their up-to-date knowledge and empathy to support patients throughout the examination process.
- Dietitian: It helps you put together a personalised, balanced and nutrient-rich diet. During an elimination diet, it ensures that no nutritional deficiencies develop, and provides practical advice on alternative products and recipes.
Summary: The path to a symptom-free life
Food intolerances can have a significant impact on everyday life, but the good news is that, with a proper diagnosis and a personalised diet, the symptoms can be effectively managed. Don’t let bloating, abdominal pain and discomfort take over your life! The first step is to recognise the problem and seek expert help.
A thorough medical examination carried out at a professional institution, such as the Endomedix Gastroenterology Centre These tests are carried out by specialists and are essential for making an accurate diagnosis. You can then identify the problematic foods by following an elimination and reintroduction diet devised with the help of a dietitian. Conscious eating and appropriate lifestyle changes will deliver the expected results and put you back on the path to a balanced, symptom-free life.
