The importance of fats in human nutrition. Functions of fats in the cell

Fats are primarily a source of energy. But fats are also necessary to perform plastic functions, to protect the body, to carry out metabolic and many other processes.

IN general case fats are complexes of organic compounds, the main components of which are fatty acids. They also determine the properties of fats.

It should be noted that food fats do not directly “transition” into human fats. This is often ignored, which leads, for example, to a misunderstanding of the processes associated with losing weight.

Human fats belong to the group of lipids (from the Greek lipos - fat) - fat-like organic compounds, including fats and fat-like substances that are insoluble in water. Fats are necessary for a number of physiological processes essential for the existence of the body.

Simple lipid molecules are composed of glycerol and fatty acids, complex - from glycerol, high molecular weight fatty acids and other components. Glycerol makes up about 10% of fats and is broken off during digestion in the gastrointestinal tract. Fatty acids determine the properties of fatty acids.

Lipids are part of all living cells and, along with proteins and carbohydrates, play a decisive role in the existence of living organisms. Almost impossible to detect in human body tissue, wherever the process of formation and decomposition of fats takes place. IN large quantities lipids are found in the brain and spinal cord, liver, heart and other organs. Lipid concentration in nerve tissue reaches 25%, and in cellular and sub cell membranes ah - 40%. It should be noted that lipids are part of not only human and animal tissues, but also plants.

Lipids are divided into triglycerides, phospholipids, sphingolipids, glycolipids, sterols (sterols), waxes.

Triglycerides (neutral fats) are the simplest and most widespread lipids. The fatty acids they contain are neutralized by the ester bond and acidic properties do not show.

Phospholipids, which include phosphoric acid, play a key role in the structure and function of cell membranes, being, as is currently believed, the most important regulator of cell activity. IN food products phospholipids very often accompany triglycerides. About 25 subclasses of phospholipids are known and, perhaps, the most important of them is lecithin, which, along with other phosphatides, is part of the nervous (in particular, brain) tissue, including the nerve membranes.

Sterols include bile acids, cholesterol, sex hormones, vitamin D, etc.

Lipids also include terpenes (plant growth substances - gibberellins, carotenoids, essential oils plants, as well as wax).

Waxes are formed by fatty acids and polyhydric alcohols. In particular, they cover the skin, wool, and feathers of animals, softening them and protecting them from the action of water. A waxy protective layer also covers the stems, leaves and fruits of many plants.

Fats (or lipids) are synthesized by all living organisms. In a narrow, everyday sense, the term “fats” is equivalent to the term “triglycerides” and implies substances consisting of glycerol and fatty acids connected by ester bonds. In the body, fat is contained in the form of individual fat cells and structural elements all cells.

It is necessary to distinguish between fats that come directly from food and fats synthesized in the human body. It is necessary to emphasize once again that food fats do not directly “transition” into human fats.

As for quantitative characteristics, the overwhelming amount of fat is concentrated in adipose tissue, cells contain a small amount of it. On average, fat makes up 10-20% of total mass body, but with morbid obesity this percentage can increase to fifty or more. The fat content in the body depends on gender, age, nutrition, etc., but the fat content in the protoplasm of cells is always the same.

Functions of fats

Fats are one of the cornerstones vital functions of the body, perform numerous functions in it and it is difficult to divide them into main and secondary ones. Let us list below the main ones.

1. Being a material for cell membranes, fats perform fundamental structural function. Along with this, fats are also building materials for the brain and tissues nervous system(plastic function).

2. Fats are part of hormones, vitamins, and are involved in the passage nerve impulses- regulatory function.

3. Fats, with the help of lipoproteins, transport substances throughout the body - a transport function.

4. Fats carry out protective function, protecting both internal organs and the entire body as a whole from mechanical influences. Each internal organ contains in its membrane a certain amount of adipose tissue, and a number internal organs have a special fatty shell that protects them from mechanical damage.

In particular, the kidneys are surrounded by a double capsule with a layer of fat between them. A large number of fat is contained in the fatty lining of the intestines, and fat cells are in cells from connective tissue, which give the fat layer greater strength. Adipose tissue, located under the skin, also serves to protect against mechanical damage.

Fat forms the basis of the vascular-nerve bundles, in which large nerves and vessels are located, including filling the space between the nerves and vessels.

5. Fats perform an energy function by storing energy in fat cells. If necessary, fat, when oxidized, releases energy more than twice as much as the energy released by proteins and carbohydrates - fat, when oxidized, releases 9.3 kcal, while proteins and carbohydrates release 4.1 kcal.

6. Fat is a good heat insulator, protecting the body from temperature changes. Important feature is that fat exhibits heat-insulating properties both as a protective layer and through the release of fatty acids formed during the breakdown of fats contained in subcutaneous fat depots. In turn, fatty acids undergo oxidation in the liver with the release significant amount heat, sharply increase basal metabolism.

7. Fats promote absorption fat-soluble vitamins(retinol, calciferols, tocopherols, phylloquinones). Some of the fats are sources of these vitamins.

8. Fats stimulate intestinal motility, bile secretion and exocrine activity of the pancreas; fats also contribute to the absorption of proteins.

Fats, scientifically called triglycerides, perform very important function For human body and for many other living beings. The importance of fats for the body is difficult to overestimate, since without them not a single mammal (including, of course, humans) simply could exist.

Functions of fats in the body

The main function of triglycerides is, of course, energy production. Only having sufficient quantity fat in the body, a person can exist normally. The energy value of fats is twice as high as the energy value of carbohydrates, but many consider carbohydrates to be the main elements for energy production. However, triglycerides are significantly ahead of them in this indicator. It is fats that we need primarily in order to walk and move. True, one condition must be met, namely: their normal absorption in the intestine must occur with the help of acids contained in bile. If this does not happen, then fats cease to be absorbed by the body and gradually form harmful fats for the body. body fat. That is why for normal fat synthesis you need to try to eat enough moving image life, in which all triglycerides will be processed into the energy we need so much.

The meaning of fats

What functions do fats perform? As you know, fats have one more important for any animal organism. It is triglycerides that create the so-called fat layer, which does not allow cold to penetrate the body. This is explained by the extremely low thermal conductivity of fats. Of course, this is most important for those species of animals and birds that live in the far north or at the south pole - in Antarctica. Seals, whales, walruses, and penguins have a fat layer sufficient to withstand the most severe cold without any damage to their life and health. As for people, we, of course, do not need such protection from triglycerides, but a certain amount is still necessary - as they say, in reserve. But excess fat, as we said above, is very harmful to the human body, since it can lead to diseases of the nutritional organs, and even to various cardiovascular diseases. Therefore, it is not for nothing that they say: “movement is life.” It will save us from the cold warm clothes, and humans require fats only as a source of energy. As for the use of fats, in addition to the fact that they are actively used in Food Industry and soap making, triglycerides are actively used in medicine, as well as in the production of various lubricants.

Content:

Fats (chemically lipids), like proteins and carbohydrates, are essential for normal functioning body. Without their participation, the majority of metabolic (metabolic) processes, the construction of cell membranes and the storage of energy by the body are impossible.

In the human body, the main part of fats is triglycerides. In addition to them, phospholipids and sterols (including cholesterol) are called fats. It is customary to divide food lipids according to their state of aggregation (at room temperature): solids- fats; liquid substances- oils.

Lipids - group organic compounds insoluble in water, including fats and fat-like substances.

Saturated fats are broken down in the body by 25-30%, and unsaturated fats completely split.

Polyunsaturated fatty acids should be an essential part of the diet, since they are necessary material for the synthesis of biologically important active substances. Treatment vegetable oils containing polyunsaturated acids, can lead to their trans-isomerization with loss of biological function.

Basic functions involving the use of fats by the body

Energy– Main function. Although carbohydrates are the main source of energy, fat is used as a source of reserve energy in cases where carbohydrates are not available. Has a high energy value(approximately 9.1 kcal per 1 g), therefore fats can be considered one of the main energy sources for the functioning of the body.

Transport– Necessary for absorption (dissolution, assimilation) and movement of fat-soluble vitamins (A, D, E and K).

Storage– Storage of energy reserves in the form of subcutaneous fat, which will be used in case of deficiency nutrients.

Thermal insulation– Fats have poor heat conductivity. Acting as a heat insulator, they help maintain a constant body temperature and counteract hypothermia.

Protective– Layers of fat and fat capsules provide cushioning for the main organs and protect against mechanical damage.

Structural– Participate in the formation of cell membranes (phospholipids, glycolipids and lipoproteins) and many other biologically important compounds, including the building material for the brain and tissues of the nervous system (plastic function).

Regulatory– Necessary in the formation of prohormones (preproinsulin, proinsulin, proopiomelanocortin, lipocortin, testosterone), the synthesis of prostaglandins from some essential fatty acids. Regulates the body's production of sex hormones. They produce peptide hormones - adipocytokines or adipokines.

Decrease in the total proportion of adipose tissue in female body below the level of 10-15% leads to hormonal imbalance. As a result, amenorrhea and sometimes infertility (usually reversible) may develop.

Unlike carbohydrates, all fats are very reluctant to come into contact with water (i.e. they are highly hydrophobic substances). This is due to the fact that any fat molecule contains three long hydrocarbon “tails” that do not have significant electrostatic charges and therefore avoid interaction with water. Typically, one fat molecule contains different hydrocarbon “tails”. They differ from each other in their sizes, as well as the number and arrangement of double covalent bonds C=C. However, despite these differences, all fats are structured quite uniformly, and therefore are capable of performing only a limited range of biological functions.

What functions do fats perform in the body?

The most important of these functions is the spare. Indeed, in many organisms the main supply of nutrients is formed by fats. For example, oily fruits and seeds of some plants (olive, sea buckthorn and sunflower) or fatty deposits in mammals.

The second function of fats is energy. The fact is that various fats, like glucose, can also undergo oxidation, as a result of which the necessary energy is released.

It is well known that fats have low thermal conductivity. Therefore, in warm-blooded animals (mammals and birds), fats also play a thermal insulating role. It is not surprising that fat deposits are mainly located not inside the body, but directly under the skin. This layer should be especially thick in animals that are constantly at risk of hypothermia (whales, seals, penguins, polar bears, etc.). In particular, at blue whale this layer reaches a thickness of 1 m.

Very important biological function performed by phospholipids related to fats. They form the basis of cell membranes. Instead of one of the three hydrocarbon “tails,” the phospholipid molecule contains a complex radical with a charged group. Due to the presence of strong electrostatic charges, this group is able to readily come into contact with water. Thus, in a phospholipid molecule two sections with different properties can be distinguished: a hydrophilic “head” and highly hydrophobic “tails”. Therefore, in an aqueous environment (for example, in the cytoplasm of a cell), phospholipid molecules are arranged so that their hydrophilic “heads” are in contact with water, and their hydrophobic “tails” are facing each other. As a result, the formation occurs various structures, including bilayer phospholipid membranes.

So, both carbohydrates and fats are important bioorganic compounds. Basically, they perform reserve and energy functions, and in some cases, some others. However, due to the monotony of its chemical structure neither carbohydrates nor fats are capable of providing all other functions necessary for life.

Ecology of consumption. Health: Understanding the importance of fats, you will not consciously avoid them by going on low-fat diets...

Fats and their functions in the human body

Fats perform 4 functions in the body:

2) restoration of the membranes of the body’s cells, and we have more than tens and hundreds of trillions of them,

3) fats are involved in the synthesis of hormones,

4) fats are an energy function of the body.

Understanding the importance of fats, you will not consciously avoid them by going on low-fat diets.

If you still have doubts and you don’t want to eat fat, then at least for protection, you will take fat-containing dietary supplements, the best of which are Omega 3/60 or Omega 3-6-9, as well as Lecithin.

It is especially important to know about fats for climbers and those people who work in conditions of low oxygen, as well as manicurists, hairdressers, builders, residents of megalopolises, and those who have sedentary image life and those who have diseases of the respiratory system.

Fats are involved in respiration

As soon as a child is born, the first thing he does is breathe. If the child's lungs do not receive oxygen, his life will immediately end. Therefore, the mechanism of the first breath is the most main point with which we begin our lives.

The body knows this very well and really wants to facilitate the mechanism for the supply of oxygen, which will then accompany us throughout our lives.

All cells in our body need oxygen. If oxygen is not supplied, then after 1 minute the cells begin to die, after 2-3 minutes they, in principle, cannot be brought back to life, even if we give them oxygen. In 5 minutes - it's already biological death, which is not reversible.

Our body has developed the whole system protection so as not to leave us without oxygen for a single second. This system is located in the lungs. If we consider bronchial tree, it can be seen that the bronchi towards the periphery decrease to bronchioles, and each bronchiole at its tip has a vesicle called an alveolus. These are respiratory bubbles that contain air. They don't deflate. The lungs get their airiness due to the air bubbles that are located in the alveoli. The main thing is that these alveoli remain in a straightened state throughout our lives.

Surfactant

The amazing substance that provides us with this function covers inner side alveoli and it is called surfactant, which is 99% fat and 1% protein.

From the moment we take our first breath, we all breathe thanks to the presence of a layer of surfactant in our lungs. If we have him and he good quality, then we breathe easily, absorbing oxygen within a fraction of a second. As soon as the surfactant leaves the alveoli various reasons, then we cannot transport oxygen with such an alveoli and the respiratory surface of the lungs decreases.

When they began to study the processes of fat metabolism, they found out that the first thing that the dietary fat that we ate should provide is the function of surfactant synthesis and provide us with respiration.

How do we digest fats?

All the fats that we eat are foreign to our body, and they must be broken down in our intestines under the action of the enzyme lipase protein. This enzyme breaks down fat molecules into fatty acids.

The only trouble with fatty acids is that they are very large, their molecules are huge. These molecules should not get into blood vessels, because they can clog them and the vessels will not function. The result is a condition of fat embolism.

Wise Mother Nature has built a separate suction system called lymph. All large molecules are absorbed into our lymphatic system and then with the lymph flow they move to the place where they should be used.

The body remembers that bacteria can slip through along with large molecules. Therefore, along the path of lymph flow, the body builds blog posts, which are called lymph nodes, through which lymph is filtered. If there are bacteria, they linger in the nodes and cannot penetrate further into our internal environment.

Here are immune cells lymphocytes. All lymphatic vessels, which flow from the intestines, merge into the lymphatic system, it collects fats from our intestines into the general lymphatic duct, which flows into the left subclavian vein. In this place, fats are not dangerous for us. Because the subclavian vein has a constant lumen, it is fixed by the clavicle.

When a person dies from shock, all his veins collapse, and the only place that can be reached is the subclavian vein, which resuscitators puncture by placing a subclavian catheter.

The common lymphatic duct and all fats after absorption in the intestine flow into this place (only a small part is spent on The lymph nodes) enter the venous blood, and deoxygenated blood we go, first of all, to the lungs in order to give up oxygen and become arterial, and then spread throughout the entire body.

Venous blood entering the lungs is rich carbon dioxide and rich in fats. Together with oxygen, fats begin to penetrate the alveolocyte membrane and form a layer of surfactant.

It is no coincidence that our body sends fats to the lungs - the first place where we need them. The alveoli take up fats, synthesize surfactant from them, and after we have secured ourselves in terms of breathing, the remaining fats from arterial blood are already beginning to spread throughout the body.

If 100% of the alveoli are provided with surfactant, our breathing is ideal

• If 80% of the alveoli are provided with surfactant, then you can already feel the symptoms of hypoxia.
• If 60% is a problem (if we run, we will get short of breath)

The state of oxygen deficiency is called hypoxia

This condition is equated to diseases of civilization, because great amount people have a deficiency of surfactant structures. And these are all people who are on low-fat diets.

The reduction in surfactant levels is influenced by:

• nicotine,
• petrol,
• acetone,
• alcohol.

Surfactant is loved by bacteria, viruses, fungi, and protozoa.

Roundworms love surfactant (their development cycle begins with the lungs!).

A partial sign of hypoxia is low arterial pressure 105/65.

Hypotonics are people with impaired surfactant functions, with impaired breathing in the alveolar part of the lung.

The most vulnerable to surfactant are newborns

If a woman is deprived of fat during pregnancy, the child will definitely be born with a surfactant deficiency. This means that the lungs will breathe poorly and some kind of infection will set in.

If there is little oxygen, then the brain begins to suffer.

Sometimes we see that a person has a problem with all organs. This happens when there is not enough oxygen and all cells are starved. The only way To improve matters is to prescribe fats to a person. Ensure the absorption of fatty acids into the lymph, ensure the synthesis of surfactant, and then the person will begin to breathe correctly. Diseases will miraculously begin to recede.

In the last 15 years, few healthy children have been born, because low-fat diets have been popular for 30 years. Girls naively believe that obesity depends on dietary fats.

Obesity does not depend on dietary fats. Obesity depends on carbohydrates.

After some of the fat has been used as a surfactant, the remainder that is not needed by our lungs begins to circulate. These fatty acid residues should not be free in our vessels, because they cause blockage, atherosclerosis and deposits on the walls of blood vessels.

Therefore, the body begins to bind them with transport proteins and complexes called lipoproteins begin to form. These are the substances that the doctor takes when studying our fat metabolism. This is a cholesterol test.

Cholesterol

Cholesterol is divided into 3 groups:

1. Lipoproteins high density HDL

2. Low-density lipoprotein LDL

3. Very low density lipoproteins

Lipoprotein is a fat-protein. It all depends on how much transport protein is in this molecule:

1. If there are 20-30% fat and 70-80% protein, then this is high density. The molecule is dense, the fat is well packed, so this fat will reach the place where it is needed, and doctors call this cholesterol “good.”

2. If a molecule contains 50-60% fat and 40-50% protein, then the density of this molecule decreases and the lipoprotein becomes low-density. And this is already dangerous.

3. But it is even more dangerous if the density becomes even lower, when fat became 80% and protein 20%. In this case, a situation is created when we are carrying 10 tons on a small cart and on every bump the cart bounces and the goods fall out of it. In the same way, fats from molecules of very low density begin to fall out at the place of transportation.

Missing out on these low-density fats is called bad cholesterol. The more of these fats, the higher the risk of atherosclerosis and the overgrowth of our vessels with coarse fats.

Is it the fats?

It's not all about fats, but about transport proteins in the blood. The more transport protein in the blood, the higher we have high-density lipoproteins, the more we have good cholesterol. And the higher the number of depleted molecules we have, the higher the bad cholesterol.

It's called promotion atherogenic coefficient (KA). This is the ratio of high and low molecules. If KA is more than 3 (for each of those molecules there are 3 of these and this is bad. But when there are 5 of these and 2 of these, then everything is perfect).

Therefore, atherosclerosis is not a problem fat metabolism. This is an area of ​​transport protein deficiency.

Fats and restoration of cell membranes in a constant mode

Proteins form a cell, all cells are protein structures, but the cell membrane is a layer of fat.

The body builds a double layer of lipids around each cell to protect the cell from threats from the external environment.

Since for our cell external environment is the intercellular space, respectively, the cell membrane protects it from the effects of aggressive factors located in the intercellular space, and in fact, the health of the cell, as a protein structure, depends on the function of membranes consisting of fats.

Now there is a huge number cardiovascular diseases, a huge number of arrhythmias. Many people take potassium, iodine, magnesium, vitamins and minerals, but they must understand that if we have little transport protein and our membranes do not function well, no trace elements will enter the cell. They will be deposited in other places, accumulate in the intercellular space, and the cell, as it was in a state of deficiency, will remain so.

To avoid such a disastrous situation, we must remember that the membrane is no less important than the function of the protein cell itself. If all membranes work well, we will never have a deficiency, and most importantly, we will never retain toxins or water in the tissue space.

What is water in the intercellular space? This is swelling that affects 60% of people. And many who consider themselves fat are actually edematous people.

AND fat people they begin to take drugs with a fat-burning effect, go on a low-fat diet, begin to breathe poorly and, instead of the desired weight loss, gain 2 times more.

Edema syndrome has nothing to do with obesity. The only thing people with edematous syndrome need to do is to normalize the condition of their membranes so that water leaves their tissues well.

Fats and hormone synthesis

The next function of fats is the synthesis of hormones.

People are divided into men and women, so let's divide them accordingly into estrogens and testosterone.

And these sex hormones are synthesized in us from the same fat - from cholesterol. If there is no cholesterol, no man will have normal level testosterone. One of the most extreme norms of cholesterol metabolism disorders, a decrease in the function of fats in the body, is a decrease in testosterone levels in men and the occurrence of diseases such as adenoma and prostate cancer, where oxidized testosterone appears, which causes tumor diseases.

In women, the same can be said about estrogen functions. Now there are many women with breast cancer, uterine cancer, etc. Almost all of these are considered disharmonious tumors.

Again, from a nutritional point of view, everything depends on the amount of fats consumed in food, their quality and their sufficiency.

Energy function of fats

You can also talk about fats as a source of energy.

All daily carbohydrates that we cannot waste are carefully stored in humans. Our body lives by the principle: “I don’t know what will happen tomorrow, but I’ll save a little extra for a rainy day.”

And the excess carbohydrates go into fat cells, which are found in each of us, and are stored in the form of fats. Therefore, obesity, which everyone is afraid of, is precisely obesity from excess carbohydrates.

The most interesting thing is that fat exchanges have been practiced for a long time. Northern peoples (Chukchi, Evenks) consume a lot of fats. In the 70s, Americans began to study the theory of the dangers of fat using the example of the American Evenks. It was revealed that in their diet fats account for up to 60% (animal fat from seals, walruses, very fatty northern fish) and 40% protein. It seems that with such a ratio of fats and protein and with such a diet, the Evenks should die from atherosclerosis. However, it turns out that among northern peoples the lowest percentage of atherosclerosis.

“The further north and high altitude a person lives, the higher the percentage of fats should be in his diet.” Because the higher and the further north we live, the more we need surfactant to breathe cold air and provide ourselves with oxygen.

And most importantly, in the North, fats are quickly burned, providing energy. In this case, their consumption is so high that such ratios of dietary fats do not cause the phenomenon of atherosclerosis in humans. Provided, of course, that the transport proteins are not affected and protein deficiency No.

If we transfer this situation to the south, we will find out that southern people do not need so much fat. “The further south and closer to the equator we live, the less fat we need in our diet”. For southern people key factor is the provision of protein. If in warm regions well provided with protein, they will be fine with fat metabolism. If there is a deficiency in fats, they will begin to have an increase in low and very low density lipoproteins and fats will begin to precipitate.

Therefore, in terms of fats, atherosclerosis is a disease transport proteins and illness of people living in warm, comfortable conditions.

The second group of people most vulnerable to fat is growing children. The child grows and his need for oxygen increases. The more active a child grows, the more oxygen he should have, because all memory and brain functions depend on it.

Is your baby getting enough oxygen and does he have surfactant? For it to exist, we must ensure food sources fat First of all, these are eggs (protein + fats), in the optimal ratio fatty fish, caviar and all coarse cholesterol fractions (lard, fatty meat), since these structures provide us with good membrane formation nerve cells. This is almost pure cholesterol.

When the child grows up, you can reduce the amount of crude fats and switch to vegetable fats, which contain many unsaturated bonds that provide the molecule with chemical reactivity. And so that the fat molecule binds free radicals and rid our intercellular space of toxins and free forms oxygen, we must switch to vegetable fats. To those who havemore Omega-3.6 polyunsaturated fatty acids.Their source is fish fat And vegetable oils:

• oil grape seeds,
• soybean,
• sesame,
• nutty,
• the poorest - sunflower,
• corn contains more saturated fatty acids,
• palm contains only saturated fats.

In relation to fats, there is a principle of constant diversity. If it’s winter, we increase the amount of coarse fats. If by summer - vegetable.

Fat by itself will never increase quickly (3 kg in 2 months), and then decrease by May-June.

And the swelling - speed dial weight(today 86 kg, and tomorrow it’s already 87 kg - 2-3 kg of water flows back and forth). This is an unsustainable weight. A symptom of unstable scales is that the weight fluctuates all the time.

The second sign of edema is a flabby body.

Cellulite is swelling of adipose tissue, when in fat cells, in addition to the fats deposited there naturally, toxins begin to be deposited. Or the cells swell if some structures begin to change in them and lipomas grow. This is a disease of adipose tissue and you need to work with transport proteins.

I repeat, If we talk about fats, the best food supplements are fish oil:

• Omega-3/60,
• Shark liver oil,
• Omega 3-6-9,
• Coral Lecithin (this is a phospholipid, i.e. the residue phosphoric acid plus fat, in addition, lecithin provides cells with energy).

If you take 1 capsule 2 times a day with food, it will cover daily requirement in surfactant. It is ideal to take Omega 3/60 one day, Lecithin another day, especially in winter time and especially for children. published

Based on lectures by nutritionist Konstantin Zabolotny