Food intolerance or allergy: what are the differences?

Food intolerance or allergy: what are the differences? 

After a meal, do you suddenly feel sick to your stomach? Hives? Do your lips swell? It's a food allergy or intolerance, the first can be much more serious than the second. You still need to be able to differentiate between them.

Food allergy and food intolerance are different in their biological mechanisms, but they are sometimes confused because of some common symptoms such as hives, angioedema (significant swelling of the face and body to be treated with cortisone), or transit disorders.

What differentiates them at first glance is the time it takes for them to appear. It is also their degree of severity, which is higher in allergy.

Food intolerance is not a life-threatening condition. 

Some events are specific to food allergy. These include asthma, rhinitis, itching of the palate, and even anaphylactic shock that must be treated urgently. Beware, all these signs do not necessarily appear together in a person. Above all, food allergy has the particularity of occurring very quickly, from a few minutes to two hours, after ingestion of the food in question. The most frequent examples are fish, shellfish, eggs, peanuts, milk, and certain fruits such as bananas or strawberries.

Food intolerances do not present a vital risk. They often appear more than six hours after eating a variety of foods ranging from strawberries to dairy products, mussels, or certain preservatives such as tartrazine.

Different mechanisms in food allergy and intolerance. 

In allergy, there is an abnormal stimulation of the immune system: the immune system "overreacts" to certain substances that are ingested and are usually harmless. A substance called histamine is then released in reaction to proteins from allergenic foods entering the body. Allergies often run in the same family, and people who are allergic to certain foods may also be allergic to other environmental factors such as dust, fur, and pollen.

In food intolerance, there can be several phenomena. Either food containing pharmacologically active substances such as histamine (fish, tomato, sausage, fermented food...) or tyramine (chocolate, white wine, cheese...) is ingested in too large quantities. Or some people are sensitized from birth to dairy products, bread, tomatoes, potatoes ... without their knowledge. Originally, we often find a deficiency in certain digestive enzymes, for example, lactase, which digests milk. In general, it is in adulthood that food intolerance is suddenly triggered.

What to do in case of food intolerance or allergy?

If in doubt, consult an allergist who will know how to distinguish between intolerance and true allergy. For the latter, the only treatment is the strict avoidance of the food responsible (beware of hidden forms, case of peanut, egg ...). Knowing that the ingestion of even a small amount of food can be enough to trigger the allergic storm.

For food intolerances, the quantitative factor plays a role. For example, avoid combining histamine-rich foods and histamine-releasing foods in the same meal.