Milk allergy and lactose intolerance: what are the differences?

Surely you have heard about dairy and some diseases that are related to its consumption. The most mentioned, probably, are milk allergy and lactose intolerance. Differences exist?

It is essential to keep in mind that, although both conditions share some symptoms, produce different effects in the body. Therefore, it is essential to know how to distinguish them.

Milk allergy is actually an allergy to cow's milk protein, while lA lactose intolerance is the difficulty in absorbing the sugar present in milk called lactose.

What does the milk contain?

Milk contains several nutrients that are:

  • Proteins: casein and whey
  • Carbohydrates: lactose (composed of glucose and galactose)
  • Fats and vitamins

In addition to these nutrients, milk has water.

Discover: Are dairy bad for your health?

Milk contains important nutrients such as protein, carbohydrates, fats and vitamins.

Milk allergy or lactose intolerance?

Milk allergy is a condition that is usually caused by the protein fraction of milk. Cow's milk is the usual cause of milk allergy, But sheep, goat, buffalo and other mammals can also cause this reaction.

Intolerance, meanwhile, It is given directly by carbohydrate or milk sugar, called lactose, which in turn is composed of glucose and galactose (they are simple molecules).

What happens in lactose intolerance is that the body does not produce an enzyme called lactase that is responsible for allowing its breakdown and absorption.

The fundamental difference is that allergy is a reaction mediated by the body's immune system and in intolerance the immune response does not exist. Allergy being less common than intolerance.

The other basic difference is that each of these diseases are caused by a different fraction of the milk. One is for protein and another for sugar or hydrate. Milk intolerance requires a different treatment than an allergy.

Be sure to read: The risks of eating a high protein diet

Milk allergy and lactose intolerance: most common symptoms

Between milk allergy and lactose intolerance, are there differences in symptoms? Common signs and symptoms of milk protein intolerance or lactose intolerance They include digestive problems, such as bloating, gas or diarrhea after consuming milk or dairy products.

In allergy the consequences can even be fatal, depending on the sensitivity and response of the immune system. To determine the diagnosis of one or the other, it is necessary to perform a correct interrogation of the patient and specific tests to observe the reaction to the consumption of milk and dairy products.

There are some similarities between the symptoms of allergy and lactose intolerance. However, in the case of allergy they can become fatal, depending on the level of sensitivity.


It is important that, if you already have a medical diagnosis of any of these diseases, Check labels not only for food but also for the medications you take.

There are many foods that can say "free of" or «Vegan«, But in the list of ingredients we find the surprise that indicate that they may contain traces of milk or lactose.

Similarly, some medicines contain lactose as an excipient for their manufacture. To know what they are, consult this list published in the SVR magazine.

Now, in both conditions it is important to get a proper diet. For that reason, Part of the treatment should be indicated by a nutritionist. This professional will be in charge of determining the diet based on the individual characteristics of each one. Keep that in mind!