Lipids being. Lipids (Fats). Substances of complex structure

Fat has always been regarded as a harmful component of food for the body, and some nutritionists are of the opinion that it is better to limit the intake of fats. But are fats really bad for us?

In fact, fats perform several very important functions for our body, and first of all, fat is an important energy supplier for us. We can highlight the fact that 1g of fat supplies more calories than proteins and carbohydrates in double quantity. The body does not burn all the fats at once, but puts a part in the depot as a reserve in order to use it in the future as needed. We have provided you with information about fats that will help you look at fats in a new way.

Why does our body need fat?

Fats supply fatty acids that are important for the life of our body, which are involved in metabolism and are energy suppliers. In addition, fats are part of the cell membranes, for example, nerve cells have membranes that are 60% fat. Thus, several important functions of fats can be distinguished:

Fats are suppliers of energy material - approximately 30% of energy comes from fats,

Forming subcutaneous fat, they protect organs and tissues from mechanical damage, and also prevent heat loss,

They are carriers for vitamins A, D, E, K, as well as for minerals, since their absorption in the body is impossible without fats,

They are part of the cell membranes (mainly cholesterol). Without them, the cell loses its function and collapses,

Fats produce female sex hormones, which is especially important in postmenopause, when ovarian function has almost died out. They also play an important role in the reproductive period, as they maintain the hormonal background at the proper level. If the level of adipose tissue in the body is below 10-15%, then a hormonal imbalance occurs up to the cessation of the menstrual cycle,

Omega-6 unsaturated acid (aka arachidonic acid) is involved in the activation of blood coagulation and anticoagulation systems.

Almost 35% of the daily diet should consist of fat. In this case, the type of fat plays a significant role.

Which fats are healthy and which are not?

Depending on the chemical structure, fats are divided into saturated and unsaturated fatty acids. Saturated fatty acids contain large amounts of hydrogen ions and are found in foods of animal origin. These are the fats that are deposited on the abdomen, thighs, buttocks. This is a kind of energy reserve of the body. Saturated fats inhibit muscle growth by reducing the action of insulin. But at the same time, they are the basis for the production of testosterone. When they are excluded from food, the level of this important hormone for men also decreases. The same can be obtained with excessive consumption of them. Therefore, they are also important for the body, but in moderation.

Unsaturated fatty acids (omega-3 and omega-6) contain few hydrogen ions and are found mainly in animal products, such as olive or vegetable oil, fish oil. These fats are not deposited in the body, but are completely burned. They are a nutritional component useful for the body, a raw material for the production of hormones.

There are also so-called trans fats, or artificial fats. They are stuffed with hydrogen ions and are found in candy and cookies, as well as in fast food (fast food). They are used mainly for food storage and they increase the risk of developing cancer and diseases from the cardiovascular system.

Omega-3 and Omega-6 unsaturated fatty acids.

Of all the types of fats, these fatty acids are the most valuable for our body. They are found in sunflower and corn oils, and rapeseed oil contains them in an ideal ratio.

Healthy omega-3 fatty acids are also found in flaxseed, walnut and soybean oils. Salmon, mackerel and herring also contain them in sufficient quantities.

Omega-3 and Omega-6 fatty acids:

Reduce the risk of atherosclerosis, thus preventing the development of cardiovascular diseases

Reduce cholesterol levels

Strengthen the walls of blood vessels

Reduce blood viscosity, thus preventing the development of blood clots,

Improve blood supply to organs and tissues, restore nerve cells.

Ideally, you should mix saturated and unsaturated fats, for example, meat dishes and salads dressed with rapeseed oil.

Which is better, margarine or butter?

Unlike butter, margarine contains more unsaturated fatty acids. But according to the new teachings, this does not mean that the oil is more harmful. In terms of calories, both products are almost equal. But margarine contains harmful trans fats that contribute to the growth of a number of diseases.

If you are a fan of margarine, then it is better to choose high-quality varieties with a low content of solid fats.

Do fats lead to obesity?

Despite the fact that fats contain more calories, there is no proven link between fat intake and increased weight.

An excess of calories leads to obesity: those who consume more calories than they burn, gain weight. A diet rich in fat leads to long-term satiety and allows us to eat less.

Who, on the contrary, tries to save on fats, often eats more carbohydrates. Grain foods such as white bread and pasta increase blood sugar levels, and with it, insulin, which leads to an increase in adipose tissue. In addition, the saturation of the body occurs quickly, but not for a long time, as a result of which it leads to more frequent consumption of food.

Lipids are the most important source of energy in the body. The fact is obvious even at the nomenclature level: the Greek "lipos" is translated as fat. Accordingly, the category of lipids combines fat-like substances of biological origin. The functionality of the compounds is quite diverse, which is due to the heterogeneity of the composition of this category of bio-objects.

What are the functions of lipids

List the main functions of lipids in the body, which are the main ones. At the introductory stage, it is advisable to highlight the key roles of fat-like substances in the cells of the human body. The basic list is the five functions of lipids:

reserve energy;
structure-forming;
transport;
insulating;
signal.

The secondary tasks that lipids perform in combination with other compounds include regulatory and enzymatic roles.

The energy reserve of the body

This is not only one of the important, but the priority role of fat-like compounds. In fact, part of the lipids is the source of energy for the entire cell mass. Indeed, fat for cells is an analogue of fuel in a car tank. The energy function of lipids is realized as follows. Fats and similar substances are oxidized in the mitochondria, breaking down to the level of water and carbon dioxide. The process is accompanied by the release of a significant amount of ATP - high-energy metabolites. Their reserve allows the cell to participate in energy-dependent reactions.

Structural blocks

At the same time, lipids perform a building function: with their help, the cell membrane is formed. The following groups of fat-like substances are involved in the process:

cholesterol - lipophilic alcohol;
glycolipids - compounds of lipids with carbohydrates;
Phospholipids are esters of complex alcohols and higher carboxylic acids.

It should be noted that in the formed membrane, fats are not directly contained. The resulting wall between the cell and the external environment is two-layered. This is achieved due to biphilia. A similar characteristic of lipids indicates that one part of the molecule is hydrophobic, that is, insoluble in water, the second, on the contrary, is hydrophilic. As a result, the bilayer of the cell wall is formed due to the ordered arrangement of simple lipids. Molecules turn their hydrophobic regions towards each other, while hydrophilic tails are directed inside and outside the cell.

This determines the protective functions of membrane lipids. First, the membrane gives the cell its shape and even maintains it. Secondly, the double wall is a kind of passport control point that does not allow unwanted visitors to pass through.

Autonomous heating system

Of course, this name is rather conditional, but it is quite applicable if we consider what functions lipids perform. The compounds do not so much heat the body as they keep the heat inside. A similar role is assigned to fatty deposits that form around various organs and in the subcutaneous tissue. This class of lipids is characterized by high heat-insulating properties, which protects vital organs from hypothermia.

Have you booked a taxi?

The transport role of lipids is considered a secondary function. Indeed, the transfer of substances (mainly triglycerides and cholesterol) is carried out by separate structures. These are linked complexes of lipids and proteins called lipoproteins. As you know, fat-like substances are insoluble in water, respectively, in blood plasma. In contrast, the functions of proteins include hydrophilicity. As a result, the core of a lipoprotein is an accumulation of triglycerides and cholesterol esters, while the shell is a mixture of protein molecules and free cholesterol. In this form, lipids are delivered to the tissues or back to the liver for removal from the body.

Secondary Factors

The list of already listed 5 functions of lipids complements a number of equally important roles:

enzymatic;
signal;
regulatory

Signal function

Some complex lipids, in particular their structure, allow the transmission of nerve impulses between cells. Glycolipids act as an intermediary in this process. No less important is the ability to recognize intracellular impulses, which is also realized by fat-like structures. This allows you to select from the blood the substances necessary for the cell.

Enzymatic function

Lipids, regardless of their location in the membrane or outside it, are not part of enzymes. However, their biosynthesis occurs with the presence of fat-like compounds. Additionally, lipids are involved in protecting the intestinal wall from pancreatic enzymes. The excess of the latter is neutralized by bile, where cholesterol and phospholipids are included in significant quantities.

They are organic compounds that are insoluble in water. They are composed of fatty acid molecules connected in a chain of hydrogen and carbon atoms. If carbon atoms are interconnected by a stable bond, then such fatty acids are called "saturated". Accordingly, if the carbon atoms are loosely bound, then the fatty acids are unsaturated. For the human body, the most important are arachidonic, linoleic, and oleic fatty acids.

Separation according to the chemical formula into saturated and unsaturated acids was developed a long time ago. Unsaturated, in turn, are divided into polyunsaturated and monounsaturated. Today it is known that saturated acids in our food can be found in pates, meat, milk, eggs. And unsaturated ones are in olive, peanut, sunflower oil; fish, goose and duck fat.

The term "lipids" refers to the entire spectrum of fat-like substances extracted by fat solvents (chloroform, ether, gasoline).

Lipids include esters of triacylglycerols. These are substances in which glycerol binds to three fatty acid residues. Lipids include oils and fats. Oils contain a large amount of unsaturated acids, and have a liquid consistency (with the exception of margarines). Fats, on the contrary, have a solid structure and contain a large amount of saturated acids.

Depending on their origin, lipids are divided into two main categories:

Vegetable fats (olive oil, nut butter, margarine, etc.).
Animal fats (found in fish, meat, cheese, butter, cream, etc.).

Lipids are very important for our nutrition, because they contain many vitamins, as well as fatty acids, without which it is impossible to synthesize many hormones. These hormones are an indispensable part of the nervous system.

When fats are combined with "bad" carbohydrates, the metabolism is disturbed, and as a result, most of them are deposited in the body in fatty layers.

As a rule, in our diet, excess fat - fried fatty foods, in particular - fast food, is becoming more and more popular and familiar. At the same time, food may well be tasty, even if you refuse sunflower and butter when cooking it.

Some of the lipids directly affect the increase in blood cholesterol levels. Cholesterol can be roughly divided into "good" and "bad". The goal of a healthy diet is the dominance of "good" cholesterol over "bad". The total blood level of this substance should be normal. If there is too much cholesterol, then it is deposited on the walls of our blood vessels and disrupts blood circulation, which disrupts the trophism of organs and tissues. A lack of blood supply, in turn, leads to a serious disruption of the functioning of organs. The main danger is the possibility of tearing off a blood clot from the wall and spreading it through the blood flow throughout the body. His blood clot will clog the vessels of the heart, a person is waiting for an instant death. Everything happens so instantly that it is simply impossible to help and save a person.

Not all fats increase the amount of "bad" cholesterol in the blood, some of them, on the contrary, lower its level.

Fats that increase cholesterol levels are found in butter, lard, meat, cheese, smoked and dairy products, and palm oil. These are saturated fats.
Fats, which almost do not contribute to the formation of cholesterol, are found in eggs, oysters, poultry meat (without skin).
Fats that help lower cholesterol are vegetable oils: olive, rapeseed, corn, sunflower.

Fish oil prevents the occurrence of cardiovascular diseases, and at the same time does not play any role in cholesterol metabolism. In addition, it lowers triglyceride levels and therefore prevents blood clots. As a source of fish oil, those varieties of fish that are the most fatty are recommended: tuna, herring, chum and salmon, sardines, mackerel. In pharmacies, you can also find fish oil in capsules as a dietary supplement.

Saturated

Eating too much saturated fat can be detrimental to your health. Sausages, lard, butter and cheese should not form the basis of the diet. By the way, saturated fatty acids are also found in palm and coconut oils. When buying products in the store, pay attention to the composition of the ingredients included in them. Palm oil is a frequent "guest" in our diet, although we do not always know about it. However, some housewives will use it for baking, instead of margarine. Meat contains stearic acid, which is contraindicated in the body in large quantities. The amount of fat in the daily diet should not exceed 50 grams. The optimal nutritional balance should consist of 50% monounsaturated fatty acids, 25% polyunsaturated fatty acids and 25% saturated fatty acids.

Most people eat too much saturated fat at the expense of unsaturated fat. Of these, about 70% are “invisible” (sausages, aperitif sets, cheeses, chips, and, of course, meat), and 30% are “visible” (this is all that can be used for frying dishes and for spreading on bread) .

Those fats that the body did not use remain in reserve in the body and, when combined with sugars, become the main cause of overweight. And only physical activity and a balanced diet can correct this situation. Therefore, it is extremely important to adjust the intake of fatty acids in accordance with their costs.

monounsaturated

This type of fat is found in vegetable oils, and its main component is oleic monounsaturated acid. Monounsaturated fats are neutral in relation to the body, and do not affect either the tendency to thrombosis or the level of cholesterol in the blood.

Olive oil is great for cooking, as it can withstand fairly high temperatures (in fact, up to 210°C), while retaining a significant part of its valuable properties. It is advisable to buy unrefined oil of the first cold pressing, and the darker it is, the better. It must be stored in a dark and cold place.

To obtain one liter of oil, you need 5 kg of black olives. The method of cold pressing preserves in the oil most of all vitamins and mineral salts: copper, phosphorus, magnesium, calcium, potassium, copper, iron. An interesting fact: the balance of lipids in olive oil is almost the same as in breast milk.

Of all the oils, olive oil is the best absorbed, besides, it is wonderful for constipation and liver failure. Another of its useful properties is that it can neutralize the intoxication of the body after drinking alcohol. Recent studies have shown that olive oil improves calcium absorption. And this means that it is indispensable in the diet of children, at the age when their bone apparatus is formed and develops.

Oleic acid is found in: olive oil (77%), rapeseed (55%), peanut (55%), grape seed oil (41%), soybean (30%), sunflower (25%), in wheat germ oil (25%), in walnut oil (20%).

Polyunsaturated

They consist of two groups in which the active ingredient is the so-called essential fatty acid. Since the body cannot produce it on its own, this acid must be supplied with food.

Main sources: cereal sprouts (up to 50% fatty acids), corn, oatmeal, brown rice, and oils.

Linoleic acid (Omega-6) is found in: sunflower oil (57%), soybean (55%), grape seed oil (54%), walnut oil (54%), wheat germ oil (53%) , in pumpkin (45%), sesame (41%), peanut (20%), rapeseed (20%), olive (7%).

Linolenic acid (Omega-3): Flaxseed (55%), walnut oil (13%), rapeseed (8%), wheat germ oil (6%), soybean (6%), sesame (1 %), olive (0.8%). Omega-3s are also found in fish.

Flaxseed oil is very rich in omega-6 and omega-3 unsaturated fatty acids, which are essential for building cells. It softens the skin, helps the body fight allergies, protects the brain and nerve structures, stimulates the production of hormones. It must not be heated, it must not be cooked on it. Flaxseed oil is added exclusively to a ready-made cooled dish: soups, cereals, salads, vegetables.

Fish and fish oil are the most valuable source of omega-3 fatty acids. It is these acids that our body needs most of all. They are very useful for brain activity. However, the current ecology is such that it is desirable for a child to give sea fish, and not pure fish oil. It is made from cod liver, and the liver tends to accumulate various toxins in high doses. In addition, when eating cod liver, there is a high probability of an overdose of vitamins A and D. For people who eat vegetarian food, linseed oil will be a good substitute for fish oil.

Food supplements that are valuable sources of polyunsaturated fatty acids:

Pollen.
Sprouted wheat.
Brewer's yeast.
Oils of primrose and borage (they can be found in pharmacies in the form of capsules).
Soy lecithins.

In addition to some oils

The table provides data on the critical temperatures of some oils (in degrees Celsius), at which they decompose and release carcinogenic toxic substances that primarily affect the liver.

Oils sensitive to light and heat

Walnut oil.
Pumpkin.
Linen.

Table of vitamin contentE

Oils	mg per 100g butter
From wheat germ	300
From walnuts	170
soybean	94
corn	28
olive	15

Palm oil is a solid mass containing almost 50% saturated acids. The oil is obtained without heating, mechanically, from the pulp of the oil palm fruit. Unlike margarine, it turns out to be a solid consistency without hydrogenation. Contains vitamin E. Often used in place of margarine or butter in baked goods. In large quantities, it is harmful to health.

Coconut oil is best avoided. It contains too many fatty acids. However, many people, especially those who live in areas where coconut oil is extracted, consider it to be literally a panacea for all diseases. It is one of the oldest types of oils extracted by people. It is obtained from pressed dried coconut fruits. On the other hand, the good thing about coconut oil is that the saturated fat it contains has a completely different texture than the saturated fat used in fast food. That is why they are still arguing about whether this oil is harmful or not.

Butter is, on the one hand, an excellent source of vitamins A and D, and on the other hand, cholesterol. But for young children, a small amount of butter will be useful, because when the body is actively growing, it needs saturated fats for the harmonious and complete development of the brain.

What you should definitely know about butter: it absolutely does not tolerate heating above 120 °. This means that you can not fry food on it. Upon contact with the hot surface of the pan, the oil immediately begins to release carcinogens that affect the intestines and stomach.

Margarine is an intermediate product between vegetable oil and butter. It was created as a substitute for butter. The composition of margarines may vary from manufacturer to manufacturer. Some are fortified with wheat germ oil, while others contain only saturated fatty acids or are hydrogenated.

If a minimum of processing is carried out, that is, margarine is not hydrogenated, then some vitamins are preserved in it. But it must be remembered that the hardness of margarine depends on the amount of palm and coconut oils added to it. Therefore, those who have a tendency to cardiovascular diseases are not recommended to use margarine.

Paraffin oil is a petroleum derivative and should be avoided. With the food use of paraffin oil, the absorption of fat-soluble vitamins worsens. Moreover, when removing oil from the intestines, it binds to the already dissolved vitamins and goes out with them.

Functions of fats

Lipids in our body perform energy and plastic functions. Unsaturated fatty acids are essential because not all of them are synthesized in the body. They are precursors of prostaglandins. Prostaglandins are hormones that maintain the liquid state of cellular lipids, and also prevent the development of atherosclerotic plaques, prevent cholesterol and other lipids from sticking to the walls of blood vessels.

Phospholipids are the fundamental structures of most cell membranes. They are part of the white and gray matter of the nervous tissue.

Fats, by their very nature, are excellent solvents. Those substances that do not dissolve in water are well soluble in fats. Most of the fat accumulates in the cells of adipose tissue, which are fat depots. Depot can be up to 30% of body weight. The function of adipose tissue is to fix the neurovascular bundles and internal organs. Fat is a heat insulator that retains heat, in particular in childhood. Lipid metabolism is closely related to protein and carbohydrate metabolism. With an excess intake of carbohydrates in the body, they can turn into fats. In unfavorable conditions for the body, during starvation, fats are converted back into carbohydrates.

The energy function is that of all nutrients, lipids give the body the most energy. It has been proven that the oxidation of 1 gram of fat releases 9.3 kilocalories of heat, which is twice as much as the oxidation of 1 gram of proteins or carbohydrates. During the oxidation of 1 g of proteins and carbohydrates, 4.1 kcal of heat is released.

Food fats

Among them, triacylglycerols predominate. There are vegetable and animal fats, and vegetable fats are more complete, since they contain much more unsaturated acids. With food, a small amount of free fatty acids also enters. Normally, up to 40% of all calories consumed by our body come from lipids.

Absorption and digestion of fats

Digestion of fats is a process of enzymatic hydrolysis, which is carried out in the small intestine and duodenum under the influence of enzyme substances found in the juices of the pancreas and intestinal glands.

In order for fats to be digested, the body must produce bile. It contains detergents (or bile acids) that emulsify lipids so that enzymes can better break them down. Products that are formed as a result of digestive hydrolysis - fatty, bile acids and glycerol - are absorbed from the intestinal cavity into the mucosal cells. In these cells, fat is resynthesized and forms special particles called chylomicrons, which are sent to the lymph and lymphatic vessels, and then through the lymph into the blood. In this case, only a small part of the fatty acids formed in the process of hydrolysis, which have a relatively short carbon chain (in particular, these are the products of hydrolysis of fats in dairy products) are absorbed and enter the blood of the portal vein, and then to the liver.

The role of the liver in lipid metabolism

The liver is responsible for the processes of mobilization, processing and biosynthesis of lipids. Short-chain fatty acids, combined with bile acids, travel from the digestive tract via the portal vein into the bloodstream to the liver. These fatty acids are not involved in the processes of lipid synthesis and are oxidized with the assistance of the enzyme systems of the liver. In adults, they generally do not play an important role in metabolism. The only exception is children, in their diet most of the milk fats.

Other lipids enter through the hepatic artery as part of lipoproteins or chylomicrons. In the liver, they are oxidized, as in other tissues. Most of the lipids, except for a few unsaturated ones, are re-synthesized in the body. Those of them that are not synthesized must be ingested along with food. The overall process of fatty acid biosynthesis is called "lipogenesis", and it is the liver that is most intensively involved in this process.

Enzymatic processes of transformation of phospholipids and cholesterol are carried out in the liver. The synthesis of phospholipids ensures the renewal of the structural units of its cell membranes in the liver.

blood lipids

Blood lipids are called lipoproteins. They are associated with different protein fractions of the blood. Their own fractions are separated by centrifugation according to their relative density.

The first fraction is called "chylomicrons"; they consist of a thin protein coat and fats. The second fraction is lipoproteins with a very low density. They contain a large amount of phospholipids. The third fraction is lipoproteins containing a lot of cholesterol. The fourth fraction is high-density lipoproteins, they contain the most phospholipids. Fifth fraction - lipoproteins with high density and low content.

The function of lipoproteins in the blood is to transport lipids. Chylomicrons are synthesized in the mucous cells of the intestine and carry fat, which is resynthesized from the products of fatty hydrolysis. Chylomicron fats enter, in particular, adipose tissue and the liver. Cells of all tissues of the body can use chylomicron fatty acids if they have the necessary enzymes.

Very low density lipoproteins carry exclusively fats that are synthesized in the liver. These lipids are usually consumed by adipose tissue, although they can be used by other cells as well. Fatty acids of high-density lipoproteins are products of the enzymatic breakdown of fat contained in adipose tissue. This faction has a peculiar mobility. For example, during a hunger strike, up to 70% of all energy costs of the body are covered by fatty acids of this particular fraction. Phospholipids and cholesterol fractions of high and low density lipoproteins are a source of exchange with the corresponding components of cell membranes, with which these lipoproteins can interact.

Transformation of lipids in tissues
In tissues, lipids are broken down under the influence of various lipases, and the resulting fatty acids are attached to other formations: phospholipids, cholesterol esters, etc.; or they are oxidized to end products. Oxidation processes take place in several ways. One part of the fatty acids during oxidative processes in the liver produces acetone. In severe diabetes mellitus, with lipoid nephrosis and some other diseases, the amount of acetone bodies in the blood increases sharply.

Regulation of fat metabolism

The regulation of lipid metabolism is carried out by a rather complex neuro-humoral pathway, while it is dominated by the mechanisms of humoral regulation. If the functions of the sex glands, pituitary gland, thyroid gland decrease, then the processes of fat biosynthesis increase. The saddest thing is that not only the synthesis of lipids increases, but also their deposition in adipose tissue, and this leads to obesity.

Insulin is a hormone of the pancreas and is involved in the regulation of lipid metabolism. Since there is a cross possibility of transforming carbohydrates into fats, and then fats into carbohydrates, with insulin deficiency, the processes of carbohydrate synthesis are enhanced, which is accompanied by an acceleration of the processes of lipid splitting, during which intermediate metabolic products are formed used for the biosynthesis of carbohydrates.

Phospholipids are similar in structure to triacylglycerols, only their molecules contain groups containing phosphorus. Steroids are derivatives of cholesterol and have a different structure. Lipids also include a large group of fat-soluble substances, which includes vitamins A, D, K, E. Lipids are needed not only to create the shell of our body - they are necessary for hormones, for brain development, for blood vessels and nerves, for the heart. It is known that lipids make up 60% of the brain.

Violation of the normal concentration of lipids in the blood

If there is an abnormally elevated level of lipids in the blood, then this pathological condition is called hyperlipemia. In hypothyroidism, nephrosis, diabetes, and disorders, physicians are faced with a secondary form of hyperlipemia. These diseases are characterized by high levels of cholesterol and triglycerides. Primary hyperlipemia is a rather rare hereditary pathology that contributes to the development of arteriosclerosis and coronary disease.

With hypoglycemia, starvation, after injections of growth hormone, adrenaline, the amount of free fatty acids in the body increases sharply and the mobilization of previously deposited fat begins. This form of the disease is called mobilization hyperlipemia.

With hypercholesterolemia in the blood serum, there is a high level of cholesterol and a moderate level of fatty acids. When questioning the next of kin in the anamnesis, cases of early atherosclerosis are necessarily detected. Hypercholesterolemia, even at an early age, can contribute to the development of myocardial infarction. As a rule, there are no external symptoms. When a disease is detected, treatment is carried out with diet therapy. Its essence is to replace saturated acids with unsaturated acids. Proper diet correction significantly reduces the likelihood of developing pathologies of the vascular system.

With dyslipidemia in the blood, the balance of various types of lipids is disturbed. In particular, the main lipids contained in the blood are cholesterol and triglycerides in different ratios. It is the violation of the ratio that leads to the development of diseases.
High levels of low-density lipids in the blood, as well as low levels of high-density cholesterol, are important risk factors for cardiovascular complications in patients diagnosed with type 2 diabetes mellitus. The abnormal level of lipoproteins in this case may be the result of improper glycemic control.

It is dyslipidemia that is considered the main cause of the development of atherosclerotic changes.

Factors affecting the development of dyslipidemia

The most significant causes of dyslipidemia are genetic disorders of lipid metabolism. They consist in mutations of the genes responsible for the synthesis of apolipoproteins - the constituents of lipoproteins.

The second important factor is a healthy/unhealthy lifestyle. Under adverse circumstances, in the absence of physical activity, while drinking alcohol, lipid metabolism is disturbed. Obesity is directly related to an increase in triglycerides, with a violation of the concentration of cholesterol.

Another factor in the development of dyslipidemia is psycho-emotional stress, which, through neuroendocrine stimulation, contributes to lipid metabolism disorders. Neuroendocrine stimulation refers to increased activity of the autonomic nervous system.

The clinical classification of the types of dyslipidemia provides for their division into the so-called primary and secondary. Among the primary ones, polygenic (acquired during life, but due to hereditary disposition), and monogenic (genetically determined family diseases) can be distinguished.

The cause of the secondary form of the disease can be: alcohol abuse, insufficient kidney function, diabetes, cirrhosis, hyperthyroidism, medications that give side effects (antiretroviral drugs, progestins, estrogens, glucocorticosteroids).

Diagnostic methods used to diagnose "dyslipidemia" are to determine the indicators of lipoproteins (high and low density), total cholesterol, triglycerides. During the daily cycle, even in perfectly healthy people, there are fluctuations in cholesterol levels of the order of 10%; and fluctuations in triglyceride levels - up to 25%. To determine these indicators, centrifugation of blood donated on an empty stomach is carried out.

Determination of the lipid profile is recommended to be carried out every five years. At the same time, it is desirable to identify other potential risk factors for the development of cardiovascular pathologies (smoking, diabetes mellitus, history of ischemia in the immediate family).

Atherosclerosis

The main factor in the appearance of ischemia is the formation of many small atherosclerotic plaques, gradually increasing in the lumen of the coronary arteries and narrowing the lumen of these vessels. In the early stages of the development of the disease, plaques do not impair blood flow, and the process does not manifest itself clinically. The gradual growth of the plaque and the simultaneous narrowing of the vessel duct can provoke the manifestation of signs of ischemia.
At first, they will begin to appear with intense physical exertion, when the myocardium needs more oxygen and this need cannot be met by an increase in coronary blood flow.

The clinical manifestation of the ischemic state of the myocardium is a sharp attack of angina pectoris. It is accompanied by such phenomena as pain and a feeling of constriction behind the sternum. The attack passes as soon as the load of an emotional or physical nature stops.

Doctors consider lipid metabolism to be the main (but not the only main) cause of ischemia, but in addition, smoking, obesity, carbohydrate metabolism disorders and genetic predisposition are significant factors. Cholesterol levels directly affect the occurrence of complications of diseases of the heart system.

Treatment of this disease is to normalize cholesterol levels. For this, dietary modification alone is not enough. It is also necessary to deal with other risk factors for development: reduce weight, increase physical activity, quit smoking. Nutrition correction implies not only a reduction in the total caloric content of food, but also the replacement of animal fats in the diet with vegetable fats:
consumption of animal fats and a simultaneous increase in the consumption of vegetable fats, fiber. It must be remembered that a significant part of the cholesterol in our body does not come with food, but is formed in the liver. Therefore, diet is not a panacea.

To reduce cholesterol levels, medications are also used - nicotinic acid, estrogen, dextrothyroxine. Of these drugs, nicotinic acid is the most effective against ischemia, but its use is limited due to associated side effects. The same applies to other medications.

In the 80s of the last century, know-how began to be used in lipid-lowering therapy - drugs from the statin group. Currently, 6 drugs belonging to this group are available on the pharmaceutical market. Pravastatin and lovastatin are drugs based on the waste products of fungi. Rosuvastatin, atorvastatin, fluvastatin are synthetic drugs, and simvastatin is semi-synthetic.

These agents help lower low-density lipoprotein levels, lower total cholesterol, and, to a lesser extent, triglycerides. Several studies have also shown a reduction in overall mortality among ischemic patients.

Cardiosclerosis

This disease is a complication of atherosclerosis and consists in replacing the myocardium with connective tissue. The connective tissue is not elastic, unlike the myocardium, respectively, the elasticity of the entire organ, on which the inelastic “patch” appeared, suffers, and the heart valves are deformed.

Cardiosclerosis (or myocardiosclerosis) is a logical consequence of an uncured disease: myocarditis, atherosclerosis, rheumatism. The acute development of this disease occurs with myocardial infarction and ischemic disease. When atherosclerotic plaques occur everywhere in the coronary arteries in the heart, the blood supply to the myocardium suffers, it lacks oxygen carried in the bloodstream.

An acute form of ischemic disease is a myocardial infarction. So an unhealthy lifestyle, unbalanced diet and smoking can become an implicit cause of a heart attack, and acute psycho-emotional stress, against which a heart attack appears, is a visible, but far from the main reason.

In addition to the acute form, there is also a chronic form. It is manifested by regularly occurring attacks of angina pectoris (that is, retrosternal pain). You can relieve pain during an attack with nitroglycerin.

The body is designed in such a way that it tries to decompensate for any violation. Connective tissue scars prevent the heart from expanding and contracting elastically. Gradually, the heart adapts to scars and simply increases in size, which leads to disruption of blood circulation through the vessels, disruption of the contractile activity of the muscle, and expansion of the cardiac cavities. All this together is the cause of insufficiency of heart function.

Cardiosclerosis is complicated by a violation of the heart rhythm (extrasystole, arrhythmia), protrusion of a fragment of the heart wall (aneurysm). The danger of an aneurysm is that the slightest stress can cause it to rupture, which leads to instant death.

Diagnosis of the disease is carried out using an electrocardiogram and ultrasound of the heart.

Treatment consists in the following: identification and treatment of exactly the disease that was the main cause of the development of cardiosclerosis; compliance with bed rest in the event that the disease has led to myocardial infarction (at rest, scarring and healing occurs without the formation of a dangerous aneurysm); rhythm normalization; stimulation of metabolic processes in the heart muscle, limiting any load; maintaining a properly balanced diet, in particular, reducing the amount of lipids in the diet.

The diet gives a good anti-allergic and anti-inflammatory effect, and is also considered an excellent preventive measure to prevent heart disease.

The basic rule of nutrition is moderation in the amount of food. It is also useful to lose extra pounds, which put a strain on the heart. The selection of food products should be carried out in terms of their value as energy and plastic materials for the heart. It is imperative to exclude from food spicy, sweet, fatty, salty. The use of alcoholic beverages in patients with vascular disorders is contraindicated. Food should be enriched with minerals and vitamins. Fish, boiled meat, vegetables, fruits, dairy products should be the basis of the diet.

Fat-like substances lipids are components that take part in vital processes in the human body. There are several groups that perform the leading functions of the body, such as the formation of hormonal levels or metabolism. In this article we will describe in detail what it is and what role it plays in life processes.

Lipids are organic compounds that include fats and other fat-like substances. They are actively involved in the process of cell structure and are part of the membranes. They affect the carrying capacity of cell membranes, as well as enzymatic activity. They influence the creation of intercellular bonds and various chemical processes in the body. They are insoluble in water, but they dissolve in organic solvents (such as gasoline or chloroform). In addition, there are species that dissolve in fats.

This substance can be of plant or animal origin. If we are talking about plants, then most of them are in nuts and seeds. Animal origin is mainly located in the subcutaneous tissue, nervous and cerebral.

Lipid classification

Lipids are present in almost all tissues of the body and in the blood. There are several classifications below, we give the most common, based on the features of the structure and composition. By structure, they are divided into 3 large groups, which are divided into smaller ones.

The first group is simple. They include oxygen, hydrogen and carbon. They are divided into the following types:

fatty alcohols. Substances containing from 1 to 3 hydroxyl groups.
Fatty acid. Found in various oils and fats.
fatty aldehydes. The molecule contains 12 carbon atoms.
Triglycerides. These are the fats that are deposited in the subcutaneous tissues.
The bases are sphingosine. They are located in plasma, lungs, liver and kidneys, they are found in nerve tissues.
Waxes. These are esters of fatty acids and macromolecular alcohols.
Limit hydrocarbons. They have exclusively single bonds, while the carbon atoms are in a state of hybridization.

The second group is complex. They, like simple ones, include oxygen, hydrogen and carbon. But, in addition to them, they also contain various additional components. In turn, they are divided into 2 subgroups: polar and neutral.

The polar ones are:

Glycolipids. They appear after the combination of carbohydrates with lipids.
Phospholipids. These are esters of fatty acids, as well as polyhydric alcohols.
Sphingolipids. They are derivatives of aliphatic amino alcohols.

Neutrals include:

Acylglycerides. Includes monoglycerides and diglycerides.
N-acetylethanolamides. They are fatty acid ethanolamides.
Ceramides. They include fatty acids in combination with sphingosine.
esters of sterols. They represent complex cyclic high-molecular alcohols. They contain fatty acids.

The third group is oxylipids. Substances appear as a result of oxygenation of polyunsaturated fatty acids. In turn, they are divided into 2 types:

cyclooxygenase pathway.
lipoxygenase pathway.

Significance for membrane cells

increase

The cell membrane is what separates the cell from the surrounding environment. In addition to protection, it performs a fairly large number of functions necessary for normal life. The importance of lipids in the membrane cannot be overestimated.

In the cell wall, the substance forms a double layer. This helps the cells to interact normally with the environment. Therefore, there are no problems with the control and regulation of metabolism. Membrane lipids maintain the shape of the cell.

Part of a bacterial cell

An integral part of the cell structure is bacterial lipids. As a rule, in the composition of waxes or phospholipids. But the amount of the substance directly varies in the range of 5-40%. The content depends on the type of bacterium, for example, in a diphtheria bacillus contains about 5%, but in a tuberculous pathogen it is already more than 30%.

A bacterial cell is different in that the substances in it are associated with other constituents, such as proteins or polysaccharides. In bacteria, they have many more varieties and perform many tasks:

energy storage;
participate in metabolic processes;
are a component of membranes;
the resistance of the cell to acids depends on them;
antigen components.

What functions do they perform in the body

Lipids are an integral part of almost all tissues of the human body. There are different subspecies, each of which is responsible for a specific function. Next, let's take a closer look at the importance of a substance for life:

Energy function. They tend to disintegrate and a lot of energy appears in the process. It is needed by the cells of the body to support processes such as air intake, the formation of substances, growth and respiration.
Reserve function. In the body, fats are stored in reserve, it is from them that the fatty layer of the skin consists. If hunger sets in, the body uses these reserves.
thermal insulation function. The fat layer does not conduct heat well, and therefore the body is much easier to maintain temperature.
structural function. This applies to cell membranes because the substance is their permanent component.
enzymatic function. One of the secondary features. They help cells form enzymes and help with the absorption of certain trace elements coming from outside.
transport function. Side and lies in the ability of certain types of lipids to carry substances.
Signal function. It is also secondary and simply supports some body processes.
regulatory function. This is another mechanism that has a side effect. By themselves, they almost do not participate in the regulation of various processes, but are a component of substances that directly affect them.

Thus, it is safe to say that the functional significance of lipids for the body is difficult to overestimate. Therefore, it is important that their level is always normal. Many biological and biochemical processes in the body are tied to them.

What is lipid metabolism

Lipid metabolism is a process of a physiological or biochemical nature that occurs in cells. Let's take a closer look at them:

Triaciglycerol exchange.
Phospholipid metabolism. They are distributed unevenly. There are many of them in the liver and plasma (up to 50%). The half-life is 1-200 days, depending on the type.
cholesterol exchange. It is produced in the liver and is taken in with food. Excess is excreted naturally.
Fatty acid catabolism. Occurs during β-oxidation, rarely α- or ω-oxidation is involved.
Included in the metabolic processes of the gastrointestinal tract. Namely, the breakdown, digestion and absorption of these substances that come with food. Digestion begins in the stomach with the help of an enzyme called lipase. Further in the intestine, pancreatic juice and bile come into action. The cause of failures may be a violation of the secretion of the gallbladder or pancreas.
Lipogenesis. Simply put - the synthesis of fatty acids. Occurs in the liver or adipose tissue.
This includes the transport of various fats from the intestines.
Lipolysis. Catabolism, which occurs with the participation of lipase and provokes the breakdown of fats.
Synthesis of ketone bodies. Acetoacetyl-CoA gives rise to their formation.
Interconversion of fatty acids. From the fatty acids in the liver, acids characteristic of the body are formed.

Lipids are an important substance that affects almost all spheres of life. The most common in the human diet are triglycerides and cholesterol. Triglycerides are an excellent source of energy, it is this type that forms the fat layer of the body. Cholesterol also affects the metabolic processes of the body, as well as the formation of hormonal levels. It is important that the content is always within the normal range, not exceeding or underestimating it. An adult needs to consume 70-140 g of lipids.

The body produces most of the lipids on its own, only essential fatty acids and soluble vitamins come from food.

Lipids are a large group of organic substances, consisting of fats and their analogues. Lipids are similar in characteristics to proteins. In plasma, they are in the form of lipoproteins, completely insoluble in water, but perfectly soluble in ether. The exchange process between lipids is important for all active cells, since these substances are one of the main components of biological membranes.

There are three classes of lipids: cholesterol, phospholipids, and triglycerides. The best known among these classes is cholesterol. The definition of this indicator, of course, has the maximum value, but nevertheless, the content of cholesterol, lipoproteins, triglycerides in the cell membrane should be considered only in a complex way.

The norm is the content of LDL in the range of 4-6.6 mmol / l. It should be noted that in healthy people this indicator can change depending on a number of factors: age, seasonality, mental and physical activity.

Peculiarities

The human body independently produces all major groups of lipids. The cell membrane does not form only polyunsaturated fatty acids, which are essential substances and fat-soluble vitamins.

The main part of lipids is synthesized by epithelial cells of the small intestine and liver. Individual lipids are characterized by a connection with specific organs, tissues, and the rest are found in all cells and tissues. Most lipids are contained in nervous and adipose tissue.

The liver contains from 7 to 14% of this substance. In diseases of this organ, the amount of lipids increases to 45%, mainly due to an increase in the number of triglycerides. Plasma contains lipids combined with proteins, this is how they enter organs, cells, tissues.

biological purpose

Lipid classes perform a number of important functions.

Construction. Phospholipids combine with proteins to form membranes.
Cumulative. When fats are oxidized, a huge amount of energy is produced, which is subsequently spent on the creation of ATP. The body accumulates energy reserves mainly in lipid groups. For example, when animals fall asleep for the whole winter, their body receives all the necessary substances from previously accumulated oils, fats, bacteria.
Protective, heat-insulating. The main part of the fat is deposited in the subcutaneous tissue, around the kidneys, intestines. Thanks to the accumulated layer of fat, the body is protected from the cold, as well as mechanical damage.
Water repellent, lubricating. The lipid layer on the skin maintains the elasticity of cell membranes and protects them from moisture and bacteria.
Regulatory. There is a link between lipid content and hormonal levels. Almost all hormones are made from cholesterol. Vitamins and other derivatives of cholesterol are involved in the exchange of phosphorus and calcium. Bile acids are responsible for the absorption and digestion of food, as well as the absorption of carboxylic acids.

metabolic processes

The body contains lipids in the amount determined by nature. Taking into account the structure, effects and conditions of accumulation in the body, all fat-like substances are divided into the following classes.

Triglycerides protect the soft subcutaneous tissues as well as organs from bacterial damage. There is a direct relationship between their quantity and the conservation of energy.
Phospholipids are responsible for the course of metabolic processes.
Cholesterol, steroids are substances needed to strengthen cell membranes, as well as to normalize the activity of the glands, in particular, the regulation of the reproductive system.

All types of lipids form compounds that support the life process of the body, its ability to resist negative factors, including the reproduction of bacteria. There is a connection between lipids and the formation of many extremely important protein compounds. Without these substances, the work of the genitourinary system is impossible. A failure of a person's reproductive capacity may also occur.

Lipid metabolism involves the relationship between all of the above components and their complex effects on the body. During the delivery of nutrients, vitamins and bacteria to membrane cells, they are transformed into other elements. This situation contributes to the acceleration of blood supply and, due to this, the rapid intake, distribution and assimilation of vitamins from food.

If at least one of the links stops, then the connection is broken and the person feels problems with the supply of vital substances, beneficial bacteria and their spread throughout the body. Such a violation directly affects the process of lipid metabolism.

Exchange disorder

Every functioning cell membrane contains lipids. The composition of molecules of this kind has one unifying property - hydrophobicity, that is, they are insoluble in water. The chemical composition of lipids includes many elements, but the largest part is occupied by fats, which the body is able to produce on its own. But irreplaceable fatty acids get into it, as a rule, with food.

Lipid metabolism is carried out at the cellular level. This process protects the body, including from bacteria, occurs in several stages. First, the splitting of lipids occurs, then they are absorbed, and only after that comes the intermediate and final exchange.

Any failures in the process of assimilation of fats indicate a violation of the metabolism of lipid groups. The reason for this may be an insufficient amount of pancreatic lipase and bile entering the intestine. And also with:

obesity;
hypovitaminosis;
atherosclerosis;
diseases of the stomach;
intestines and other painful conditions.

If the tissue of the epithelium of the villi is damaged in the intestine, fatty acids are not fully absorbed. As a result, a large amount of fat accumulates in the feces, which has not passed the splitting stage. Feces become a specific grayish-white color due to the accumulation of fats and bacteria.

You can correct lipid metabolism with the help of a dietary regimen and drug treatment prescribed to reduce LDL. It is necessary to systematically check the content of triglycerides in the blood. Also, do not forget that the human body does not need a large accumulation of fat.

In order to prevent disruptions in lipid metabolism, it is necessary to limit the consumption of oil, meat products, offal and enrich the diet with fish and seafood of low fat content. As a preventive measure, lifestyle changes will help - increasing physical activity, sports training, and abandoning bad habits.