The different types of food intolerance

More and more people are complaining that they cannot tolerate certain foods. What causes a food intolerance? And what can you do about it?


Daniela Diener

Many people suffer from digestive problems. They often prematurely attribute it to a specific food, without knowing if that is the actual reason. However, is the apple or milk really what caused the diarrhoea? What exactly does a food intolerance mean? An intolerance is when the body has an adverse reaction after eating certain foods. We are aware of three types of intolerance: food allergy, food intolerance and food poisoning. Knowing what the differences are helps to better classify the symptoms. 

In case of an allergy, foods like celery, apples, peanuts, eggs and seafood (like mussels) are considered to be particularly frequent triggers of physical reactions. Nuts also belong on this list (like walnuts and hazelnuts). 

Lactose, fructose, gluten or histamine are often responsible for an intolerance. They are found in foods like milk, persimmon, avocado, garlic, bread, tomatoes and wine. These forms of intolerance are also referred to as lactose, gluten or histamine intolerance and fructose malabsorption.

Mushrooms or foods which have gone off are the main suspects where food poisoning is concerned. Incorrectly stored fish (such as sushi) is dicey, for example. Insufficiently cooked chicken is also dangerous (salmonella). Incorrectly stored mushrooms can cause food poisoning. It is especially risky to eat mushrooms you collected yourself without having them inspected beforehand by the mushroom inspection office. 

In case of serious allergies and food poisoning, symptoms occur very quickly. Symptoms appear shortly after the sufferer has eaten a particular food. Even the smallest amounts suffice where this is concerned. Typical symptoms include skin irritations or circulatory disorders. The reactions to an allergy can be life-threatening. The most severe form of an allergic reaction is anaphylactic shock. This can result in a drop in blood pressure, shortness of breath, organ failure and circulatory arrest within minutes. In case of intolerance, on the other hand, there can be a delayed onset of symptoms after eating, including digestive problems like flatulence and diarrhoea as well as skin rashes. However, these symptoms are not life-threatening for sufferers.

In case of an allergy, the body reacts hypersensitively to intrinsically harmless food substances.

In case of an intolerance, on the other hand, the digestive tract cannot fully digest certain food components after eating.

The most important methods include skin, breath or blood tests – or professionally monitored elimination diets. Sufferers leave suspect foods out of their diet. In case of a suspected intolerance, you should always consult a doctor first. Depending on the diagnosis, they might recommend nutrition counselling. You should not self-diagnose or go on any non-medically prescribed diets. They have proven to be risky and can, for example, result in unnecessary restrictions. Possible consequences include deficiency symptoms. In addition, self-diagnoses can result in underlying illnesses remaining undetected for too long. 

Anyone who has an allergy to certain foods should avoid eating them. It is also advisable to check the lists of ingredients before buying food. Sufferers must carry any medically prescribed emergency medication with them at all times.

Even if you are intolerant to a specific food, small quantities thereof are often unproblematic. People have varying degrees of tolerance, and this can be determined with the aid of legally recognised dietitians (HF/FH).

Would you like to know more about this topic? Detailed information sheets on allergies and intolerances are available from the Swiss Society for Nutrition (SSN).  Information and advice for sufferers is also provided by the aha! foundation Swiss Allergy Centre

Dietitian Fabienne Bischof Dietitian Fabienne Bischof

Dietitian Fabienne Bischof

Fabienne Bischof (BSc in nutrition and dietetics) works as a nutrition expert at the Swiss Society for Nutrition SSN. Her specialist area is enjoyable, balanced nutrition in different stages of life. Fabienne Bischof provided the editorial team with advice and editorial support for this article.


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