Biological substances such as carbohydrates, fats, proteins and nucleic acids play an important role for proper metabolism in all living organisms. Carbohydrates are the main source of energy. They are polymeric forms of monosaccharides. Depending on the taste, they are classified as sugar-like and non-sugar-like. Sugar molecules are usually sweet and well divorced in water. This is glucose, fructose. In contrast, non-sugar is not able to dissolve and is not sweet. Starch, fiber and other similar substances belong to this type. Depending on the amount of simple elements in the carbohydrate, monosaccharides, oligosaccharides and polysaccharides are distinguished. One example of oligosaccharides is lactose.

What is lactose?

Lactose is one of the most important classes of carbohydrates; they are optically active compounds with hydroxyl and carboxyl groups.

There are mono-, oligosaccharide carbohydrates (oligo - "several") and polysaccharides. Oligosaccharides, in turn, are classified as disaccharides, trisaccharides, tetrasaccharides.

Lactose (chemical formula - С12Н22О11), together with sucrose and maltose, is one of the disaccharides. As a result of hydrolysis, it is transformed into two saccharides - glucose and galactose.

For the first time, they started talking about lactose in 1619, when the Italian Fabrizio Bartoletti discovered a new substance. But only in 1780, a chemist from Sweden Karl Wilhelm Scheel defined the substance as sugar. This disaccharide is present in cow's milk (about 4-6 percent) and in female milk (from 5 to 8 percent of the composition). Milk sugar is also formed during the production of cheese - as a by-product, and is a white solid.

In nature, in particular in milk, this sugar is presented as lactose monohydrate - a carbohydrate with an attached water molecule. Pure lactose is an odorless white crystalline powder that dissolves well in water but is slightly reactive with alcohols. During heating, the disaccharide loses one molecule of water and thus anhydrous lactose is created.

Lactose breakdown

As already noted, in milk, the proportion of this carbohydrate is approximately 6 percent of the total composition. Once in the body along with dairy products, lactose is amenable to enzymes and then into the bloodstream. Nevertheless, there are cases when the body is not able to digest milk sugar, because it cannot produce the enzyme lactase necessary for the breakdown. And with age, as scientific experience shows, people are more and more at risk of a lack or complete absence of lactase, which causes a complete intolerance to dairy products.

It is believed that humanity has domesticated cattle about 8 thousand years ago. And only after that dairy products appeared in the diet of an ancient person. More precisely, not so. Since that time, dairy products have appeared in the diet of adults. Since earlier exclusively infants fed on milk and exclusively on mothers. That is why it is inherent in nature that babies have practically no problems with the assimilation of milk food, since lactase is produced regularly and correctly in their organisms. Ancient people in adulthood were completely devoid of lactase and did not feel any discomfort from it. And only after introducing milk into the diet, most people experienced a kind of mutation - the body began to produce the enzyme necessary for digesting lactose in adulthood.

Biological role

Despite scientific debate about the benefits of lactose for an adult, this saccharide plays an important role in the functioning of the body. Only getting into the oral cavity, affects the consistency of saliva - gives it a characteristic viscosity. In addition, it promotes more active absorption of B-group vitamins, ascorbic acid and calcium. And getting into the intestine, activates the reproduction of bifidobacteria and lactobacilli, which are important for the proper functioning of the body.

Effect on the body: harm and benefits

Lactose is a disaccharide that can affect the human body in different ways.

He harms someone, and someone benefits.

Lactose for ...

... energy

All carbohydrates are sources of energy. Lactose also serves as a kind of fuel for humans. After ingestion, it is metabolized and promotes the release of energy. In addition, the consumption of milk sugar, so to speak, saves protein in the body. In the presence of a sufficient amount of carbohydrates, including lactose, the body does not use proteins as fuel, but accumulates them in the muscles. It also allows proteins to perform other equally important functions in the body.

... weight gain

If the amount of calories consumed exceeds the amount of calories burned, excess is stored as fat. When lactose is consumed in larger quantities than necessary, the body transforms sugar into adipose tissue, which subsequently leads to weight gain. This ability of milk sugar is used when it is necessary to adjust the body weight in the direction of increase.

... digestion

Before lactose is converted into energy, it must enter the food tract, where it decomposes into monosaccharides under the influence of the enzyme. However, if the body does not produce enough lactase, digestive problems may occur. Undigested milk sugar causes an upset stomach, including abdominal pain, bloating, nausea, and diarrhea.

Lactose intolerance

Lactose intolerance is the inability of the body to absorb milk sugar.

Primary symptoms of intolerance:

  • diarrhea;
  • flatulence;
  • stomach pains;
  • nausea.

There are several options for laboratory testing that will help determine the presence of intolerance to this type of carbohydrate. Of course, in this case, it is easiest to refuse dairy food. But a complete rejection of milk can cause a deficiency of calcium and vitamin D, which in turn will cause bone disease. Therefore, there are various dietary supplements that allow you to consume at least the smallest portions of milk.

Causes of Intolerance

Lactase deficiency can be congenital. Usually this happens in people due to changes at the gene level.

In addition, intolerance can occur as a result of diseases, including those accompanied by destruction of the small intestine mucosa. Signs of intolerance may also appear with age or against a background of serious bowel disease, such as Crohn's disease.

One of the most common causes of lactase deficiency is the result of genetic programming. Nature has laid down a “program” according to which the amount of lactase produced decreases with age. And by the way, in different ethnic groups, the intensity and speed of this decrease is different. The highest indicator of lactose intolerance is recorded among residents of Asia. Nearly 90 percent of Asians adults cannot tolerate milk. But for residents of the northern part of Europe, hypolactasia is a very rare problem: only 5 percent of adults feel a lack of enzyme.

And one more thing: two concepts should be distinguished - lactose intolerance and lactase deficiency. People with moderate enzyme deficiency, as a rule, do not even notice discomfort after consuming dairy foods. With a deficiency of lactase, the concentration of the enzyme in the intestine decreases, without causing side effects. But intolerance is accompanied by pronounced symptoms of non-perception of milk by the body. They occur after the unsplit disaccharide enters the small intestine and intestines. But, unfortunately, the symptoms of intolerance can resemble other gastrointestinal diseases, therefore it is difficult to make a diagnosis of lactose non-perception solely by these signs.

There are three main types of lactose intolerance:

  1. Primary This is the most common type. It occurs with age. It is explained by the physiological characteristics of the body. People over the years consume less dairy food, which means that the need for the production of lactase disappears. This type of intolerance is most common among people in Asia, Africa, the Mediterranean and the Americas.
  2. Secondary It arises as a result of illness or injury. Most often after celiac disease, inflammation of the intestines, surgical operations on the small intestine. Other root causes of intolerance include Crohn's disease, Whipple's disease, ulcerative colitis, chemotherapy, and even flu with complications.
  3. Temporary. This type of intolerance occurs in children born prematurely. It is explained by the fact that only after 34 weeks of pregnancy does the fetus have the function of producing the lactase enzyme.

How to determine the presence of lactose intolerance

Self-determination of lactose intolerance is not so simple. Many people think that it is enough to abandon dairy products to avoid unpleasant consequences. In fact, in modern food products, lactose is not only found in milk. Some people completely refuse milk, but the symptoms of indigestion do not go away. Therefore, it is not surprising that they mistakenly delete lactose intolerance from the list of possible causes of indigestion.

At home, you can check tolerance / intolerance with the help of a test. So, the day before the study, the last meal is no later than 18 hours. Then in the morning on an empty stomach drink a glass of milk and again do not eat anything for 3-5 hours. If there is lactose intolerance, symptoms should appear within 30 minutes after taking the product or for a maximum of 2 hours. And further. It is better to take skim milk for testing to rule out the possibility that fats cause indigestion.

Products containing lactose

The most obvious sources of lactose are dairy products. You can be sure that by consuming milk, yoghurts, sour cream, cheeses, you will definitely get lactose.

But there is a list of less obvious sources. And to be more precise - very unexpected. Now let's analyze the list of products that contain milk sugar.

Dairy food

Dairy products are not only the most obvious sources of lactose, but also the most concentrated with this carbohydrate. A glass of milk, for example, contains about 12 grams of lactose. But cheese, one serving of which is filled with less than 1 g of milk sugar, is already considered a product with a low content of substance (cheddar, parmesan, ricotta, Swiss). In fermented dairy products, such as yoghurts, the concentration of lactose is also not the lowest. But due to the presence in their composition of enzymes that destroy the disaccharide, they are more easily tolerated.

An alternative to cow can be lactose-free soy milk and other plant-based analogues of milk. Also, with hypolactasia, milk can be replaced with dairy products. In kefir, for example, the concentration of carbohydrate is reduced due to the presence of the right enzyme in its composition.

Other products

A small amount of milk sugar can be found in baked goods, breakfast mixes. This substance is also found in crisps and dry soups. In addition, when buying margarines, dressings for salads, you should be ready to consume lactose, albeit in small portions. Determine the presence of saccharide in a particular product will help answer the question: "How was this product prepared?".

Processed products

Many food products are treated with milk and dairy products to extend their shelf life. Therefore, it is important for people with lactose intolerance to carefully read labels on food. The presence of milk, whey, cottage cheese, dairy by-products, milk powder, skim milk among the ingredients indicates the presence of lactose.

Hidden sources of milk sugar:

  1. Medications.

Many drugs contain lactose as a filler, which improves the bioavailability of the drug and its taste. In particular, milk sugar is found in birth control pills and in vitamin D. But, as a rule, carbohydrates are present in very small portions in these preparations. So even people with intolerance to the substance will normally respond to medications.

  1. Processed Grains.

Waffles, cookies, crackers, bread, potato chips, granola, cereals also often include lactose. And you have to be prepared for that, in whose body there is no lactase enzyme.

  1. Processed meat.

Meat is perhaps the last product that one would think of as a source of lactose. But, nevertheless, processed meat in the form of bacon, sausages, sausages and other products is not without milk sugar.

  1. Instant coffee, "quick" soups.

Do you like coffee and soups or potatoes, for the preparation of which you just need to add boiling water? Then know that with them you get lactose. Why is milk sugar in these products? It provides texture to the product, prevents clumping, and of course gives a special aftertaste.

  1. Salads.

Many salad dressings contain lactose, which gives the product the necessary texture, taste. If you want to avoid extra servings of milk sugar, then it is better to use vegetable oil, such as olive oil, as a dressing. In addition, this is a more useful product than a ready-made dressing.

  1. Artificial Sweeteners.

Some of these sugar substitutes contain lactose. Thanks to it, sweeteners in the form of tablets or powder dissolve more quickly in food.

  1. Alcohol.

Certain types of alcohol also contain milk sugar. A particularly high concentration of the substance is in milk-based liquors. So alcohol is also one of the products whose composition may be of interest to people with intolerance to milk sugar.

  1. Margarines

Many people are absolutely sure that margarine is a completely vegetable substitute for butter, which means that there can be no dairy ingredients in it. In fact, most fats in this category contain lactose, which improves the taste of margarine.

Milk Sugar Table
Product Name (glass)Lactose (g)
Women's milk17,5
Ice cream14,5
Goat's milk12
Cow's milk11,7
Sour Cream (20 percent)8
Cottage cheese3,5

How to Avoid Lactose

So, the only way to avoid lactose in products from stores is to read the labels carefully. At the same time, you should not hope that on all products the manufacturer will write: "Contains lactose." In fact, this substance in the composition of food can hide under other names, for example: whey, casein, cottage cheese, milk powder. But at the same time, you need to know that similar names - lactate and lactic acid - are completely different ingredients that are not related to lactose.

Bodybuilders are also not immune from intolerance to milk sugar. But most protein shakes contain milk. Therefore, sports nutrition manufacturers have created lactose-free protein., which, however, can be consumed by all people with a lack of lactase.

A few arguments for milk sugar

Many people talk about lactose exclusively as a harmful substance.Meanwhile, it is worth remembering that these carbohydrates are contained in milk - in the product that mammals feed their newborns according to the idea of ​​nature. And logically, this food should have many beneficial properties.

Pluses of milk sugar:

  • galactose, which is part of lactose, is one of 8 essential sugars for the body;
  • supports immunity, promotes the production of antibodies;
  • galactose, an integral part of lactose, is called sugar for the brain, in particular it is important for infants;
  • galactose - prevention against cancer and cataracts;
  • improves wound healing;
  • accelerates the metabolism and absorption of calcium;
  • protects against x-rays;
  • important for people with arthritis and lupus;
  • prophylactic against cardiological diseases;
  • lactose is a low-calorie sweetener;
  • the glycemic index of lactose is more than 2 times lower than that of glucose, which is useful for patients with diabetes;
  • stimulates the nervous system;
  • lactose positively affects the intestinal microflora, stimulating the growth of beneficial bacteria.

Lactose Intolerance Treatment

Currently, there is no way to treat milk sugar intolerance, except for the consumption of the lactase enzyme in tablet form. The only thing that can help people with this disorder is to limit their intake of foods containing lactose. It is believed that approximately half a glass of milk (contains approximately 4.5 g of saccharide) does not yet cause consequences for intolerance. Also, when consuming dairy products, it is better to give preference to low-fat or low-lipid foods, since the concentration of lactose in them is usually lower. For babies with milk sugar intolerance, there is a lactose-free infant formula.

Sometimes people mistakenly call lactose intolerance an allergy to milk. In fact, these are two different diseases. The common thing for them is that unpleasant consequences, as a rule, are caused by dairy food. Meanwhile, allergies are accompanied by an eruption on the skin, itching, runny nose, which never happens with hypolactasia. The main difference between both diseases in the cause. Allergy speaks of problems with the immune system, lactose intolerance - an enzyme deficiency.

Lactose in the food industry

The modern food industry has learned to use lactose not only in the composition of dairy products. This type of carbohydrate is found in glaze, plays the role of a filler in bakery products, and is found in cookies, pancakes and cereals. It is used as a food supplement, and since it does not have a pronounced taste, they are used in many categories of food. This substance can be found in frozen and canned vegetables, as it prevents the loss of color. Lactose is found in dry soups, wholemeal flour and many other foods.

Other applications

Today, lactose is used not only in the food industry. In addition to preparing various products, including infant formula and breast milk substitutes, chemists use lactose in their work. Also, this saccharide serves as a feed vitamin, and in microbiology as a medium for the cultivation of various bacteria and cells.

Lactose is one of the representatives of a large carbohydrate family; the substance is very useful for both kids and adults.

And to say that this disaccharide is harmful to humans, only because in some individuals congenital intolerance to the substance, at least, is incorrect. Hypolactasia is just a disease that does not in any way deprive lactose of its beneficial properties. Although, however, you already know about this.

Watch the video: What is Lactose Intolerance? UCLA Digestive Diseases (January 2020).