Lactose is a sugar present in mammalian milk and in many foods prepared from it like yogurt, custards, puddings, creams and ice creams. Some prepared dishes and certain foods may contain lactose. It is composed of two bound sugars, glucose and galactose. In order to be absorbed by the small intestine these molecules must be separated.
On the other hand, lactase is an enzyme produced in the small intestine that separates the lactose in its two basic components (glucose and galactose) for digestion by the intestine.
What is lactose intolerance
When sufficient lactase enzyme is not available in the intestine, lactose, which is not decomposed in its basic components, passes into the large intestine and is fermented by intestinal bacteria producing abdominal distension (swelling), abdominal cramps (spasmodic pain and abdominal tension) Gas or flatulence), nausea and in patients with high intolerance or ingestion of large quantities of lactose, is associated with diarrhea.
When lactose intolerance can occur
It can occur in premature babies due to immaturity of the digestive tract and even in children before the age of 3. It can also be produced transiently by digestive infections or alteration of the intestinal flora by ingestion of antibiotics. And in diseases that damage the small intestine such as celiac disease or Crohn's disease.
In adults it is quite common and presents with different degrees permanently. It is more frequent in Asian, African and Native American adults. In northern Europe it is less frequent due to the introduction of milk into the diet 11,000 years ago, when humanity began to be cattle and milk the animals.
Diagnosis of lactose intolerance
It can be diagnosed clinically by withdrawing milk and dairy products for two weeks and observing if symptoms improve. There are also two methods but they do not always confirm the diagnosis: the breath hydrogen test and the blood test for lactose intolerance.
The most commonly used method is the hydrogen breath test, which measures the amount of hydrogen in the air being exhaled. The patient will breathe on a balloon that measures the expelling hydrogen. Normally there is very little nitrogen in our breath. You will then ingest a liquid that contains lactose and make exhalation samples to see the exhaling hydrogen. If the intestine can not break down lactose, hydrogen levels in the breath increase and is considered positive when the hydrogen content is increased by 12 parts per million above the initial level.
The blood test for lactose intolerance observes the increase in glucose after lactose intake. If it increases more than 30 mg / dL (1.6 mmol / L) within two hours after lactose intake is considered normal (lactose has been separated by lactase in glucose and galactose, and therefore glucose Rises in blood). Increases below 20 mg / dL indicate lactose intolerance. Intermediate increases between 20-30 mg / dL are inconclusive.
Reducing lactose-containing dairy products relieves symptoms. But it is not advisable to eliminate the consumption of dairy from the nutritional point of view, being the foods that contain more calcium. 1000-1200 mg of calcium is needed to maintain bone health in an adult. It is necessary to eliminate the dairy foods that produce annoying symptoms and to look for the tolerated dairy to consume them within the feeding.
It is advisable to read the labeling of prepared or precooked foods because they may contain in their composition, lactose, milk powder, milk, whey or cream. Some yoghurts, especially skim, have added powdered milk to improve the texture, these yogurts contain more lactose.
In the following section the values of lactose per 100 gr of food are shown:
- Skimmed milk powder 53
- condensed milk 12,3
- Yogurt containing milk powder 4.7 - 5
- Sheep's milk 5,1
- Goat's milk 4,5
- Cow's milk 4.3 - 5
- Yogurt 2,7
- Fresh cheese 27
- Cream 2,4
- Cured cheeses less than 1 or traces
- Butter 0 - 0.5
Products containing less lactose
Milk butter, ice cream, milkshakes and cured or hard cheeses, some yogurts that do not contain milk powder, milk and lactose-free dairy products, lactase-treated cow's milk for older children and adults, baby soy formulas Children under two, soy or rice milk for young children.
What can a person do if they take lactose products even if they do not feel well
Lactase enzymes can be added to normal milk or can also be taken in capsules. They are sold in pharmacies and a strong lactase tablet is equivalent to tolerating the intake of a glass of milk with lactose.