Lactose is a sugar present in mammalian milk and in many foods prepared from it such as yogurt, custards, puddings, creams, creams and ice creams. Some prepared dishes and certain foods may contain lactose. It is composed of two linked sugars, glucose and galactose. In order to be absorbed by the small intestine, these molecules must be separated.
Lactase, on the other hand, is an enzyme produced in the small intestine that separates lactose into its two basic components (glucose and galactose) for digestion by the intestine.
What is lactose intolerance
When there is not enough lactase enzyme in the intestine, lactose not broken down into its basic components passes into the large intestine and is fermented by intestinal bacteria producing abdominal distension (bloating), abdominal cramps (spasmodic pain and abdominal tension), meteorism (gas or flatulence), nausea and in patients with high intolerance or ingestion of large amounts of lactose, it is associated with diarrhea.
When can lactose intolerance occur?
It can occur in premature babies due to immaturity of the digestive tract and even in children before the age of 3 years. It can also occur temporarily due to digestive infections or alteration of the intestinal flora due to the intake 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 of permanent form. It is more common in Asian, African and Native American adults. In northern Europe it is less frequent due to the introduction of milk in the diet 11,000 years ago, when mankind began to be cattle breeders and to milk animals.
Diagnosis of lactose intolerance
It can be diagnosed clinically, by withdrawing the intake of milk and milk derivatives for two weeks and observing whether symptoms improve. There are also two methods, although they do not always confirm the diagnosis: the hydrogen breath test and the lactose intolerance blood test.
The most commonly used method is the hydrogen breath test, which measures the amount of hydrogen in the exhaled air. The patient will breathe into a balloon that measures the hydrogen expelled. Normally there is very little nitrogen in our breath. He will then swallow a liquid containing lactose and perform exhalation samples to see how much hydrogen he exhales. If the intestine cannot break down lactose, hydrogen levels in the breath increase and it is considered positive when an increase in hydrogen content of 12 parts per million over the initial level is observed.
The blood test for lactose intolerance looks at the increase in glucose following lactose ingestion. If it rises more than 30 mg/dL (1.6 mmol/L) within two hours of lactose ingestion it is considered normal (lactose has been cleaved by lactase into glucose and galactose, and therefore glucose rises in the blood). Increases below 20 mg/dL indicate lactose intolerance. Intermediate increases between 20-30 mg/dL are inconclusive.
Lactose-containing foods
Reduction of lactose-containing dairy products relieves symptoms. However, it is not advisable to eliminate the consumption of dairy products from a nutritional point of view, since they are the foods that contain the most calcium. It takes 1000-1200 mg of calcium to maintain bone health in an adult. It is necessary to eliminate dairy foods that produce bothersome symptoms and look for tolerated dairy foods to be consumed as part of the diet.
It is advisable to read the labeling of prepared or precooked foods because they may contain lactose, milk powder, milk, whey or cream. Some yogurts, especially skimmed yogurts, have powdered milk added to improve the texture; these yogurts contain more lactose.
The following section shows the lactose values per 100 g of food:
– Skimmed milk powder 53
– Condensed milk 12.3
– Yoghurt containing powdered milk 4.7 – 5
– Sheep’s milk 5.1
– Goat milk 4.5
– Cow milk 4.3 – 5
– Yogurt 2.7
– Fresh cheeses 27
– Cream 2,4
– Cured cheeses less than 1 or traces
– Butter 0 – 0,5
Products containing less lactose
Milk butter, ice cream, malted and hard cheeses, some yogurts that do not contain milk powder, lactose-free milk and milk products, lactase-treated cow’s milk for older children and adults, soy formulas for infants under 2 years old, soy or rice milk for toddlers.
What a person can do if he or she drinks lactose products even if they do not agree with him or her.
Lactase enzymes can be added to regular milk, or you can also take them in capsules. They are sold in pharmacies and one tablet of strong lactase is equivalent to tolerating one glass of lactose milk.