Discover the four main food intolerances and their symptoms

Food intolerances are abnormal reactions that occur in the human body due to the consumption of certain foods. Some foods are not well digested, metabolised or assimilated by the body. It is estimated that 30% of the Spanish population suffers from an intolerance of this type.

Here we reveal the possible causes of this, the symptoms that can detect it and the four main intolerances, the most common ones that exist.

Intolerances, allergies and offending foods: how to tell them apart?

Before going into more detail on this subject, it should first be made clear that we should not confuse an intolerance with an allergy. Some symptoms may give rise to doubts, as they are the same. But there are differences, the clearest of which is that being intolerant to food affects the metabolism, whereas being allergic directly involves the immune system.

In addition, an allergic reaction can also cause inflammation and appear immediately. Intolerance, on the other hand, is more prolonged, as it occurs in the digestive tract. On the other hand, we have to add another differentiation regarding allergies and intolerances; we are referring to the so-called ‘aggressor’ foods. These are foods that alter blood glucose and insulin levels after consumption.

They are a problem because they tend to increase these substances in greater quantities than necessary. In other words, they provide an excess that accumulates in the form of fat, causing inflammation and addiction. You can find out which food causes this increase by measuring your blood sugar level after eating it.

Causes of food intolerances

There are non-specific causes because we do not know the origin of intolerances and their reactions. However, we do know that it is metabolic, i.e. we do not have the enzyme necessary for complete digestion of a particular food. Sensitivity to certain food additives (such as sulphites) can also trigger them.

Digestive problems also play a role and, in the long term, favour the development of intolerance. For example, if we follow an unhealthy diet, rich in ultra-processed or fatty products, which are more difficult to digest. Or if you suffer from irritable bowel syndrome, a chronic condition that causes cramps and constipation.

In the same vein, various diseases, from those of the gastrointestinal tract to those of the bile duct and pancreas, can lead to poor digestion. A body colonised by a high amount of the fungus candida albicans develops intolerances over time. Finally, psychological factors such as stress or anxiety can also play a role.

What are the symptoms of intolerance?

• Incomplete digestion of food, as explained above. Causes a feeling of bloating or a full stomach after eating.

• Disruption of the intestinal flora (or dysbiosis), occurs when the balance between beneficial and non-beneficial bacteria is disrupted. The consequence is an inadequate performance of their function, which hinders the absorption of nutrients.

• Diarrhoea is also caused precisely by this altered intestinal permeability.

• Gas is another symptom of poor digestion.

• Nausea.

• Cramps.

• Other respiratory (asthma), physical (fatigue), neurological (headache or vertigo) or dermatological (urticaria or acne) symptoms.

What types of intolerances are there?

Four food intolerances are the most common or frequent, although there are others that are less well-known:

Lactose

One of the best-known. It can be primary, secondary, congenital or developmental. Being lactose intolerant has its main origin in a type of sugar found in milk and other dairy products.

It occurs when we have too little of the enzyme lactase. As a result, our body cannot digest the nutrient as it should, and it remains in the colon.

Gluten

Also known as coeliac disease, it is suffered by people whose bodies cannot assimilate this protein. It is found naturally in wheat, rye, barley, spelt and oats, so foods produced from them are prohibited.

This intolerance can cause other symptoms such as anaemia, joint pain, loss of bone density and even mouth ulcers. We should remember that there are more and more products labelled “gluten-free” for those who are intolerant.

Fructose

A simple carbohydrate found in the natural sugar in fruits (hence the name) and other foods. Fructose intolerances make it necessary to limit or completely avoid fructose consumption.

Because the protein responsible for transporting it, in the digestive process, does not work properly. It then passes into the colon, where it is fermented by intestinal bacteria. This causes discomfort in the form of the symptoms mentioned above.

Sorbitol

Finally, sorbitol may also be present in certain fruits such as apples, pears, apricots and strawberries. It is also found in cauliflower and mushrooms. On the other hand, however, it is added as an artificial sweetener to many other foods. It is usually labelled E-420.

We have become accustomed to certain foods causing some mild symptoms in our daily lives: heartburn, gas, heaviness… It happens so much that we have even normalised it. The right food for us should not cause side effects after ingestion. Get to work on discovering what foods your body needs and tolerates correctly. Avoid generalised diets, as every body is different. Listen carefully to your body, it will give you all the information you need!