Can you become lactose intolerant overnight?

ou have noticed discomfort or discomfort during digestion after consuming dairy products. These symptoms may be a sign that you are lactose intolerant. However, before you go for medical tests, it is important to know what lactose intolerance is. Can it occur in adulthood or even appear overnight? Here are some answers to guide you.

What is lactose intolerance?

Lactose intolerance is the inability of the body to digest lactose, the carbohydrate in milk. This is because the body does not produce enough lactase, an enzyme found in all mammals that converts lactose into simple sugar.

Milk contains sugar, a so-called "complex" sugar that our body must break down into two simple sugars: glucose and galactose. In order to transform milk into these two simple sugars, lactase must be involved. Without it, the milk is not broken down and becomes difficult to digest.

Scientifically, lactose intolerance is called "alactasia". It is possible to have partial alactasia, i.e. the body still produces some lactase, or total alactasia, i.e. the body does not produce lactase at all.

What are the symptoms of lactose intolerance?

The symptoms of lactose intolerance can vary from person to person, but also according to the degree of intolerance. As you can see, some people continue to produce lactase, while others no longer produce it at all.

In general, the symptoms are listed as follows: borborygma, abdominal pain, bloating, flatulence, diarrhoea, but also in some cases nausea and vomiting, or more rarely migraines and constipation.

Disorders may appear between 15 minutes and 4 hours after ingesting lactose. Some people may experience symptoms up to 24 hours after consuming dairy products containing lactose.

Why are babies not lactose intolerant?

In mammals, lactase is produced in the small intestine. During the first few weeks of our lives, lactase activity is at its highest. However, as we grow, lactase activity gradually decreases. After adolescence, it is considered that lactase can reach a residual level of between 5 and 10%.

It can be noted that lactose intolerance can exist in infants up to the age of 3 months, i.e. until the digestive system is mature.

So why are some people not lactose intolerant?

Let's go back to the origins of lactose intolerance. As we have just explained, already in our prehistoric ancestors, the lactase gene was activated at the moment of birth and disappeared at the moment of weaning. So when we grow up and no longer need our mother's milk, we all naturally become lactose intolerant.

One people, however, changed all that. In the Caucasus, 10,000 years ago, a people began to breed and consume milk regularly. The body of these people adapted and naturally produced more lactase, even in adulthood. The body simply adapted to a new way of life! This adaptation was passed on to subsequent generations and people in these regions became (to some degree) lactose tolerant.

However, this tolerance remains marginal in the world. Lactose intolerance is still the norm.

Can you become lactose intolerant as an adult?

Yes, it is even natural and normal. Worldwide, there are 75% people with lactose intolerance. In Europe, the figures are lower, with 40% people with moderate intolerance. In France, 5 million people experience symptoms of intolerance on a daily basis.

It should also be noted that lactose intolerance is often hereditary. If your parents are lactose intolerant, there is a chance that your body will no longer produce enough lactase as you get older.

How can lactose intolerance develop? Can you become intolerant overnight?

The likelihood of becoming lactose intolerant at a young age is low. However, lactose intolerance increases over time. This process varies from person to person, from being born with lactase deficiency to developing intolerance much later in life as an adult.

Furthermore, the symptoms of intolerance vary greatly at different times of life and at different ages. In addition, some people may experience symptoms after consuming large amounts of dairy products, while others are bothered even after consuming small amounts.

There are three possible explanations for the development of lactose intolerance: ageing, genetic factors or gastrointestinal disease. Most of the time, it is simply the genes that are involved, coupled with the fact that as we age we naturally produce less lactase.

Note that in regions where there is less consumption of dairy products, individuals are more likely to be lactose intolerant. Worldwide, Asians, Africans and Spaniards are considered to be the populations most commonly affected by lactose intolerance. Milk is not part of their dietary habits.

How do you know if you are lactose intolerant?

There are several tests you can do to find out if you are lactose intolerant:

• the eviction test
• the breath test
• genetic testing

We recommend that you first carry out an eviction test and then, if the result is positive, have another test prescribed by your doctor or gastroenterologist. Please note that no CT scan or MRI scan is likely to show lactose intolerance.

Can lactose intolerance be cured?

Lactose intolerance is not a disease and there is no cure for (re)becoming lactose tolerant. The only way to get rid of the symptoms is to stop consuming lactose or to help the body digest this complex sugar. For this, there are food supplements based on the enzyme lactase that you can take before consuming lactose, as well as specific probiotics to be taken daily in order to be able to eat normally and to facilitate meals taken outside the home.