02 Feb 2023 Article

Food intolerance is not an official medical diagnosis. Actually, this term is usually used in marketing and not in hospitals.

Food allergies and food intolerances both cause unwanted reactions from your body to food. Food allergies and food intolerances can cause similar symptoms. This is why most people confuse the two.

With food allergies, unwanted reactions occur in your body due to an immunological mechanism. With food intolerances, there is a non-allergic reaction in which your immune system plays NO role.

Food allergy

The symptoms of food allergy are very diverse and can occur anywhere in the body: on the skin, in the respiratory tract, in the gastrointestinal tract…

In principle, you can be allergic to any food, but most allergic reactions occur to fourteen foods: cow’s milk, shellfish and crustaceans, fish, chicken, eggs, nuts, peanut, lupine, soy, apple, celery, mustard, sesame seed and sulphite. These foods, also known as allergens, must therefore always be clearly stated on the packaging of food. The reason for this is that in some people an allergic reaction can be so severe that it can, in extreme cases, lead to death. This is due to anaphylaxis, also known as anaphylactic shock. Anaphylaxis can lead to cardiac arrest. People who are known to be at risk of anaphylactic shock should always carry an adrenaline syringe with them. Adrenaline immediately relieves the symptoms of anaphylaxis.

As you just read, a food allergy is no small thing. It is a disease of the immune system. The only way to deal with this is by not eating the food you are allergic to.

But what about food intolerance?

Food intolerance is difficult to diagnose because the symptoms are very diverse and they are not really unique. By this, I mean that the symptoms can indicate a variety of conditions. If you search the Internet for symptoms of food intolerance, you will find a very long list. And you (just like everyone else) most probably suffer from at least one or more of these symptoms (who doesn’t occasionally suffer from stomach-aches, headaches, fatigue, lack of energy, etc.?).

Lactose intolerance

Lactose intolerance is one of the most common food intolerances in the world. It is estimated that as many as three quarters of the world’s population are lactose intolerant. This is because most people produce little or no lactase. Lactase is the enzyme that our body needs to break down lactose. However, people with lactose intolerance can eat some dairy products without any problems, as long as those products don’t contain too much lactose. For example, hard cheese types. But a glass of milk, which does contain a lot of lactose, should not be drunk by these people, because they will get cramps, a bloated stomach and/or diarrhoea.

Gluten intolerance

The term gluten covers a group of proteins found in some grains, namely wheat, rye, and barley. Some people have an innate intolerance (celiac disease) to gluten. Celiac disease is a serious condition. There are also people with non-celiac gluten sensitivity (aka NCGS). A gluten-free diet is vital for people suffering from celiac disease, which is one percent of the world’s population. It’s not clear how many people suffer from non-celiac gluten sensitivity. Despite the scientific efforts made, this condition remains poorly defined. And it’s still a matter of debate whether NCGS is caused by gluten or by other components of wheat.

For most people, a gluten-free diet is not beneficial, but instead poses a risk of a deficiency of essential nutrients such as fiber, iron, B vitamins and iodine.

Other common intolerances

Some people are intolerant to legumes (such as lentils, beans, peas), or to certain fruits or vegetables. In the case of legumes, the reason for the intolerance is most likely a low level of the enzymes responsible for breaking down legumes. Usually, you can help your body not by banning legumes, but by eating them more often!

In the case of fruit and vegetables, intolerances often have to do with specific types of fiber and sugar that these fruits and vegetables contain. They are harmless but can cause unpleasant sensations such as flatulence or a bloated abdomen.

People with irritable bowel syndrome are sensitive to certain types of carbohydrates called FODMAPs and changing their diet can alleviate their symptoms.

Is a food intolerance test trustful?

Can you test food intolerance? The answer is: NO. As a dietitian, I often see people in my practice who have had a food intolerance test done, mostly online. All of them get a resume that shows they are intolerant to many foods. Unfortunately, these food intolerance tests are not reliable at all. For example, read this article by Doruntina Islamaj of Korrespondent.net (the article is in Dutch) in which she tells us how she had a food intolerance test done (anonymously) five times, and that she got five different results. So basically, these tests are simply a scam, I can’t say it any other way.

What to do if you think you have a food allergy or intolerance?

Other than the breath tests that gastroenterologists sometimes use to diagnose certain intolerances, such as those for lactose or fructose, there are no validated tests for food intolerances. The only way to tell if you have a sensitivity to certain foods or ingredients is to see how your symptoms change after you remove them from your diet, ideally with the help of a registered dietitian.

Do you notice that you react strongly to a certain food? Consult your GP or a dietitian. They can determine whether it is an allergic reaction or intolerance. Or maybe something completely different is going on. Self-diagnosis is not recommended.