However, food intolerances must be taken seriously for our own well-being, and we must consider the possibility that they may affect us as well. Why, and what else should we know about food intolerance? Dóra Varga, dietitian, a certified nutrition expert, answers.
What do we mean by food intolerance?
According to some studies, nearly 20% of adults are affected by some form of food intolerance. In such cases, a normally consumed amount of food or food component triggers unpleasant symptoms, which is a non-immunological response. The cause can be the food itself or the body's abnormal reaction.
How is it different from food allergy?
In everyday language, the two terms are often confused, but medically they refer to two different origin problems.
Medically, we speak of adverse food reactions when unexpected, unpleasant symptoms occur related to food consumption or the digestion process. This umbrella term (adverse reaction) includes food allergies (including oral allergy syndrome), food intolerances/pseudoallergies.
While food intolerance mostly involves non-immunological reactions with various, partly still unknown causes, allergies are caused by an abnormal immune response.
The following aspects are worth considering when comparing food allergy and food intolerance:
- Allergy usually involves an immediate reaction after food consumption (within 1-2 hours), while intolerance symptoms often appear later (even days after consumption).
- Allergy prevalence is low - (2-4% in adults, 5-6% in children), intolerance is higher, nearly 10-20%, but mainly characteristic of adulthood.
- Allergy usually presents with one main symptom, e.g., redness, sneezing, hay fever, breathing difficulties, asthma, even anaphylactic shock; while intolerance patients generally report multiple symptoms; headache, digestive problems, skin issues may occur, sometimes simultaneously.
- Allergic reactions can be fatal, whereas intolerance typically does not involve life-threatening conditions.
- Allergy typically lasts a lifetime (although childhood allergies can sometimes be outgrown), while intolerance is mostly reversible and may become tolerable to some extent for the offending substance/food.
- Different diagnostic methods are used to investigate allergy and intolerance.
Which foods most commonly cause intolerance?
The most common are lactose intolerance (milk sugar sensitivity), histamine intolerance, and fructose intolerance.
An interesting note on terminology is that gluten sensitivity, which belongs to a third group and is the result of an autoimmune process, is often included in everyday language here, but medically it is not a food sensitivity or allergy, but an autoimmune disease.
Medically, food intolerances can be divided into 4 groups:
The first group is based on enzyme defects or absorption disorders. This includes lactose intolerance, fructose intolerance, among others.
The second group includes foods high in biogenic amines or releasing histamine (tomato, strawberry, chocolate, etc.). These can provoke symptoms resembling food allergy. The most common clinical manifestation is histamine intolerance.
Pseudoallergy can produce symptoms similar to allergic reactions, mostly triggered by toxins in foods (e.g., aflatoxin, scombroid toxin), heavy metals, and pesticides.
The last group includes hard-to-classify conditions that are related to foods in some respects (reflux, redness provoked by certain foods).
What symptoms indicate it?
There are no symptoms exclusive to food intolerance, so no one should try to self-diagnose at home. Warning signs may include:
- Bloating, gas, diarrhea after consuming milk and dairy products, or fruit, sweets.
- Redness caused by certain foods -> typically wine, champagne.
- Frequent headaches, migraines without medical explanation.
- Skin problems, e.g., rashes.
What health risks can occur if a food intolerance is not recognized?
In most cases, it "only" causes unpleasant symptoms. For example, needing to rush to the restroom unexpectedly, clothes not fitting properly due to bloating, experiencing uncomfortable gas.
Nevertheless, it is worth investigating the problem early in the symptom onset phase, rather than dealing with complaints after years of persistent and worsening symptoms. The sooner the cause is identified, the sooner and more quickly the problem can be resolved.
Where can we turn with our complaints?
The first step is always to find out the cause behind the symptoms. It is necessary to consult a specialist experienced in the topic. For digestive complaints, a gastroenterologist experienced in allergology is recommended, while for skin problems, a dermatologist experienced in allergology is advised. Once the diagnosis is made, a dietitian can help create an optimal diet, select ingredients, and discuss shopping and cooking.
Is lifelong strict diet the only solution for food intolerance, or are there other options?
In most cases, an initial (4-8 weeks) stricter diet is needed for food intolerance, then the problematic foods can be gradually reintroduced, and an individual tolerance develops, allowing amounts of the offending foods to be included in daily meals.
Additionally, certain enzyme replacement products can support the diet in some intolerances, such as lactase tablets/drops for lactose intolerance and histamine-degrading enzyme preparations for histamine intolerance, and similar aids are now available for fructose intolerance as well.
