Lipids - what are they? Translated from Greek, the word "lipids" means "small particles of fat". They are groups of natural organic compounds of an extensive nature, including fats themselves, as well as fat-like substances. They are part of all living cells without exception and are divided into simple and complex categories. The composition of simple lipids includes alcohol and fatty acids, while complex lipids contain high molecular weight components. Both are associated with biological membranes, have an effect on active enzymes, and also participate in the formation of nerve impulses that stimulate muscle contractions.
Fats and hydrophobia
One of them is the creation of the body's energy reserve and the provision of the water-repellent properties of the skin, coupled with thermal insulation protection. Some fatty acid-free substances are also classified as lipids, such as terpenes. Lipids are not susceptible to the action of an aqueous medium, but they easily dissolve in organic liquids such as chloroform, benzene, acetone.
Lipids, which are periodically presented at international seminars in connection with new discoveries, are an inexhaustible topic for research and scientific research. The question "Lipids - what are they?" never loses its relevance. However, scientific progress does not stand still. Recently, several new fatty acids have been identified that are biosynthetically related to lipids. The classification of organic compounds can be difficult due to the similarity in certain characteristics, but with a significant difference in other parameters. Most often, a separate group is created, after which the general picture of the harmonious interaction of related substances is restored.
Cell membranes
Lipids - what is it in terms of functional purpose? First of all, they are an essential component of living cells and tissues of vertebrates. Most of the processes in the body occur with the participation of lipids, the formation of cell membranes, interconnection and exchange of signals in the intercellular environment are not complete without fatty acids.
Lipids - what are they when viewed from the perspective of spontaneously emerging steroid hormones, phosphoinositides and prostaglandins? This is, first of all, the presence in blood plasma, which, by definition, are separate components of lipid structures. Because of the latter, the body is forced to develop the most complex systems for their transportation. Fatty acids of lipids are mainly transported in a complex with albumin, while lipoproteins, soluble in water, are transported in the usual manner.
Lipid classification
The categorization of biological compounds is a process that has some controversial issues. Lipids, due to their biochemical and structural properties, can be equally assigned to different categories. The main classes of lipids include simple and complex compounds.
Simple ones include:
- Glycerides are esters of glycerol alcohol and fatty acids of the highest category.
- Waxes are an ester of a higher fatty acid and a 2-atom alcohol.
Complex lipids:
- Phospholipid compounds - with the inclusion of nitrogenous components, glycerophospholipids, ophingolipids.
- Glycolipids are located in the outer biological layers of the body.
- Steroids are highly active substances of the animal spectrum.
- Complex fats - sterols, lipoproteins, sulfolipids, aminolipids, glycerol, hydrocarbons.
Functioning
Lipid fats act as a material for cell membranes. Participate in the transport of various substances along the periphery of the body. Fatty layers based on lipid structures help protect the body from hypothermia. They have the function of energy storage "in reserve".
Fat reserves are concentrated in the cytoplasm of cells in the form of droplets. Vertebrates, including humans, have special cells - adipocytes, which are capable of containing a lot of fat. The placement of fat accumulations in adipocytes is due to lipoid enzymes.
Biological functions
Fat is not only a reliable source of energy, it also has thermal insulating properties, aided by biology. At the same time, lipids allow achieving several useful functions, such as natural cooling of the body or, conversely, its thermal insulation. In the northern regions, characterized by low temperatures, all animals accumulate fat, which is deposited evenly throughout the body, and thus a natural protective layer is created that performs the function of heat protection. This is especially important for large marine animals: whales, walruses, seals.
Animals living in hot countries also accumulate fat deposits, but they are not distributed throughout the body, but are concentrated in certain places. For example, in camels, fat is collected in humps, in desert animals - in thick, short tails. Nature carefully monitors the correct placement of both fat and water in living organisms.
Structural function of lipids
All processes associated with the vital activity of the body are subject to certain laws. Phospholipids are the basis of the biological layer of cell membranes, and cholesterol regulates the fluidity of these membranes. Thus, most living cells are surrounded by plasma membranes with a double layer of lipids. This concentration is essential for normal cellular activity. One microparticle of a biomembrane contains more than a million lipid molecules that have dual characteristics: they are simultaneously hydrophobic and hydrophilic. As a rule, these mutually exclusive properties are of a non-equilibrium nature, and therefore their functional purpose looks quite logical. Cell lipids are an effective natural regulator. The hydrophobic layer usually dominates and protects the cell membrane from the penetration of harmful ions.
Glycerophospholipids, phosphatidylethanolamine, phosphatidylcholine, cholesterol also contribute to cell impermeability. Other membrane lipids are located in tissue structures, these are sphingomyelin and sphingoglycolipid. Each substance has a specific function.
Lipids in the human diet
Triglycerides - nature, are an effective source of energy. acids are found in meat and dairy products. And fatty acids, but unsaturated, are found in nuts, sunflower and olive oil, seeds and corn grains. To prevent an increase in cholesterol in the body, it is recommended to limit the daily intake of animal fat to 10 percent.
Lipids and carbohydrates
Many organisms of animal origin "store" fats at certain points, subcutaneous tissue, folds of the skin, and other places. The oxidation of lipids of such fat deposits is slow, and therefore the process of their transition to carbon dioxide and water allows you to get a significant amount of energy, almost twice as much as carbohydrates can provide. In addition, the hydrophobic properties of fats eliminate the need for large amounts of water to stimulate hydration. The transition of fats to the energy phase occurs "dry". However, fats act much more slowly in terms of energy release and are more suitable for hibernating animals. Lipids and carbohydrates, as it were, complement each other in the process of the body's vital activity.
One of the biggest myths of modern mankind is the harmfulness of fats. Fat has become enemy number one. People spend dollars, rubles, euros and so on to buy fat-free cookies, fat-free cola, pills that can inhibit the absorption of fat, pills that dissolve fat. People are on all kinds of fat-free diets.
But ... In countries that are prosperous in all respects, the number of obese people is steadily growing. The number of people suffering from cardiovascular diseases and diabetes mellitus, that is, diseases largely associated with excess weight, is growing. The war on fats continues ...
So what's wrong?
Fact 1: fats are good for you
The first and main mistake is to assume that all fats are the same, rejecting all fats is a blessing. However, the education of the population is quite high, now many people know that unsaturated fats (mainly vegetable) are useful. And saturated (mainly animals) are harmful.
Let's figure it out.
Saturated fats are structural components of cell membranes and are involved in the biochemistry of the body. Therefore, a complete rejection of them will lead to irreversible changes in health. Another thing is that their consumption should correspond to age indicators. Children and adolescents need them in sufficient quantities, their consumption can be reduced with age.
Unsaturated fats - reduce the level of "bad" cholesterol, are necessary for the assimilation of certain vitamins (fat-soluble) by the organisms, and are involved in metabolism. That is, these fats are also necessary for the body.
A little observation: saturated fats are solid, unsaturated fats are liquid.
According to physiological indicators, for an average person, the ratio of saturated - unsaturated fats should be 1/3: 2/3. Eating healthy fats is essential!
Trans fats are definitely harmful. They are also found in nature (for example, in natural milk), but for the most part they are formed from other (vegetable) fats, by hydrogenation (a method of processing fats to give them a solid form).
Fact 2: body fat is not the result of eating fat
What?! Of course, if you simply increase your fat intake without reducing other foods, you will gain weight. The basis for maintaining a healthy weight is balance. You should be spending as many calories as you consume.
But diets with a sharp calorie restriction can lead to a sharp increase in weight after cancellation. Why? The body received the installation: hunger. Hence, it is necessary to accumulate fats in reserve. Therefore, all food is processed and goes to the "depot" - fat deposits. In doing so, you can faint hungry. Processed carbohydrates are stored in fat stores.
Studies show that if a person is on a low-calorie, fat-free diet, then with great difficulty shed a few pounds will return, even if you continue to "sit" on this diet.
In addition, people who eat a small amount of fat are prone to obesity.
And observation of patients in the United States revealed a picture that a decrease in the amount of fat from 40% (which is considered the norm) to 33% in the diet is accompanied by an increase in overweight people.
Remember that unsaturated fats are involved in the metabolism. The ratio of protein: fat: carbohydrates for an adult should be approximately 14%: 33%: 53%.
Output: an increase in unsaturated fats in food with a constant calorie content will not lead to weight gain, but will contribute to improving health through metabolism.
LIPIDS - This is a heterogeneous group of natural compounds, completely or almost completely insoluble in water, but soluble in organic solvents and in each other, giving high molecular weight fatty acids during hydrolysis.
In a living organism, lipids perform a variety of functions.
Biological functions of lipids:
1) Structural
Structural lipids form complex complexes with proteins and carbohydrates, of which the membranes of the cell and cellular structures are built, and participate in a variety of processes in the cell.
2) Spare (energy)
Reserve lipids (mainly fats) are the body's energy reserve and are involved in metabolic processes. In plants, they accumulate mainly in fruits and seeds, in animals and fish, in subcutaneous adipose tissues and tissues surrounding internal organs, as well as in the liver, brain and nervous tissues. Their content depends on many factors (species, age, nutrition, etc.) and in some cases accounts for 95-97% of all lipids released.
Caloric content of carbohydrates and proteins: ~ 4 kcal / gram.
Caloric content of fat: ~ 9 kcal / gram.
The advantage of fat as an energy reserve, in contrast to carbohydrates, is hydrophobicity - it is not associated with water. This ensures the compactness of fat reserves - they are stored in anhydrous form, taking up a small volume. On average, a person's supply of pure triacylglycerols is approximately 13 kg. These reserves could be enough for 40 days of fasting in conditions of moderate physical activity. For comparison: the total reserves of glycogen in the body is about 400 grams; when starving, this amount is not enough even for one day.
3) Protective
Subcutaneous adipose tissue protects animals from cooling, and internal organs from mechanical damage.
The accumulation of fat in the body of humans and some animals is seen as an adaptation to irregular diets and to living in a cold environment. Especially large reserves of fat are found in animals that hibernate (bears, marmots) and are adapted to living in cold conditions (walruses, seals). The fetus has practically no fat, and appears only before birth.
Protective lipids of plants - waxes and their derivatives, covering the surface of leaves, seeds and fruits - constitute a special group in terms of their functions in a living organism.
4) An important component of food raw materials
Lipids are an important component of food, largely determining its nutritional value and taste. The role of lipids in various processes of food technology is extremely important. Spoilage of grain and its processing products during storage (rancidity) is primarily associated with a change in its lipid complex. Lipids isolated from a number of plants and animals are the main raw material for obtaining the most important food and industrial products (vegetable oil, animal fats, including butter, margarine, glycerin, fatty acids, etc.).
2 Classification of lipids
There is no generally accepted classification of lipids.
It is most expedient to classify lipids depending on their chemical nature, biological functions, as well as in relation to some reagents, for example, to alkalis.
According to their chemical composition, lipids are usually divided into two groups: simple and complex.
Simple lipids - esters of fatty acids and alcohols. These include fats , waxes and steroids .
Fats - esters of glycerol and higher fatty acids.
Waxes - esters of higher aliphatic alcohols (with a long carbohydrate chain of 16-30 C atoms) and higher fatty acids.
Steroids - esters of polycyclic alcohols and higher fatty acids.
Complex lipids - in addition to fatty acids and alcohols, they contain other components of various chemical nature. These include phospholipids and glycolipids .
Phospholipids - these are complex lipids in which one of the alcohol groups is associated not with FA, but with phosphoric acid (phosphoric acid can be combined with an additional compound). Depending on what kind of alcohol is included in the phospholipids, they are divided into glycerophospholipids (contain alcohol glycerin) and sphingophospholipids (contain sphingosine alcohol).
Glycolipids Are complex lipids, in which one of the alcohol groups is associated not with FA, but with a carbohydrate component. Depending on which carbohydrate component is included in the glycolipids, they are subdivided into cerebrosides (contain any monosaccharide, disaccharide or a small neutral homooligosaccharide as a carbohydrate component) and gangliosides (contain an acidic hetero-oligosaccharide as a carbohydrate component).
Sometimes in an independent group of lipids ( minor lipids ) secrete fat-soluble pigments, sterols, fat-soluble vitamins. Some of these compounds can be classified as simple (neutral) lipids, while others are complex.
According to another classification, lipids, depending on their relationship to alkalis, are divided into two large groups: saponifiable and unsaponifiable.... The group of saponifiable lipids includes simple and complex lipids, which, when interacting with alkalis, hydrolyze to form salts of high molecular weight acids, called "soaps". The group of unsaponifiable lipids includes compounds that do not undergo alkaline hydrolysis (sterols, fat-soluble vitamins, ethers, etc.).
According to their functions in a living organism, lipids are divided into structural, storage and protective.
Structural lipids are mainly phospholipids.
Storage lipids are mainly fats.
Protective lipids of plants - waxes and their derivatives, covering the surface of leaves, seeds and fruits, animals - fats.
FATS
The chemical name for fats is acylglycerols. These are esters of glycerol and higher fatty acids. "Acyl-" means "fatty acid residue".
Depending on the number of acyl radicals, fats are divided into mono-, di- and triglycerides. If the molecule contains 1 fatty acid radical, then the fat is called MONOACYLGLYCERIN. If there are 2 fatty acid radicals in the molecule, then the fat is called DIACYLGLYCERIN. In humans and animals, TRIACYLGLYCERINS predominate (contain three radicals of fatty acids).
The three hydroxyls of glycerol can be esterified either with just one acid, for example palmitic or oleic, or with two or three different acids:
Natural fats contain mainly mixed triglycerides, including residues of various acids.
Since the alcohol in all natural fats is the same - glycerin, the differences observed between fats are solely due to the composition of fatty acids.
More than four hundred carboxylic acids of various structures have been found in fats. However, most of them are present only in small quantities.
The acids found in natural fats are monocarboxylic, built from unbranched carbon chains containing an even number of carbon atoms. Acids containing an odd number of carbon atoms, having a branched carbon chain or containing cyclic moieties are present in minor amounts. The exceptions are isovaleric acid and a number of cyclic acids found in some very rare fats.
The acids most common in fats contain 12 to 18 carbon atoms and are often referred to as fatty acids. Many fats contain small amounts of low molecular weight acids (C 2 -C 10). Acids with more than 24 carbon atoms are present in waxes.
The glycerides of the most common fats contain significant amounts of unsaturated acids containing 1-3 double bonds: oleic, linoleic and linolenic. Arachidonic acid containing four double bonds is present in animal fats; acids with five, six or more double bonds are found in fats of fish and marine animals. Most of the unsaturated lipid acids have a cis-configuration, their double bonds are isolated or separated by a methylene (-CH 2 -) group.
Of all the unsaturated acids found in natural fats, oleic acid is the most abundant. In very many fats, oleic acid makes up more than half of the total mass of acids, and only a few fats contain less than 10%. The other two unsaturated acids, linoleic and linolenic, are also very widespread, although they are present in much lower quantities than oleic acid. Linoleic and linolenic acids are found in significant quantities in vegetable oils; for animal organisms, they are essential acids.
Of the saturated acids, palmitic acid is almost as widespread as oleic acid. It is present in all fats, with some containing 15-50% of the total acid content. Stearic and myristic acids are widespread. Stearic acid is found in large quantities (25% or more) only in the storage fats of some mammals (for example, in sheep fat) and in the fats of some tropical plants, for example, in cocoa butter.
It is advisable to divide the acids contained in fats into two categories: major and minor acids. The main acids of fat are acids, the content of which in fat exceeds 10%.
Physical properties of fats
As a rule, fats do not withstand distillation and decompose even when distilled under reduced pressure.
The melting point, and, accordingly, the consistency of fats depends on the structure of the acids that make up their composition. Solid fats, i.e. fats that melt at a relatively high temperature, consist mainly of glycerides of saturated acids (stearic, palmitic), and oils that melt at a lower temperature and are thick liquids contain significant amounts of glycerides of unsaturated acids (oleic , linoleic, linolenic).
Since natural fats are complex mixtures of mixed glycerides, they melt not at a certain temperature, but in a certain temperature range, and they are preliminarily softened. For the characterization of fats, as a rule, is used solidification temperature, which does not coincide with the melting point - it is slightly lower. Some natural fats are solids; others are liquids (oils). The solidification temperature varies within wide limits: -27 ° C for linseed oil, -18 ° C for sunflower oil, 19-24 ° C for cow and 30-38 ° C for beef lard.
The solidification temperature of fat is due to the nature of its constituent acids: the higher the content of saturated acids, the higher it is.
Fats dissolve in ether, polyhalogenated derivatives, carbon disulfide, aromatic hydrocarbons (benzene, toluene) and gasoline. Solid fats are difficult to dissolve in petroleum ether; insoluble in cold alcohol. Fats are insoluble in water, but they can form emulsions, which are stabilized in the presence of surfactants (emulsifiers) such as proteins, soaps and some sulfonic acids, mainly in a slightly alkaline environment. Milk is a natural emulsion of protein-stabilized fat.
Chemical properties of fats
Fats enter into all the chemical reactions characteristic of esters, but their chemical behavior has a number of features associated with the structure of fatty acids and glycerol.
Among the chemical reactions involving fats, several types of transformations are distinguished.
Lipids are fat-like organic compounds insoluble in water, but readily soluble in non-polar solvents (ether, gasoline, benzene, chloroform, etc.). Lipids belong to the simplest biological molecules.Chemically, most lipids are esters of higher carboxylic acids and a number of alcohols. The best known among them are fats. Each fat molecule is formed by a molecule of a triatomic alcohol of glycerol and attached to it ether bonds of three molecules of higher carboxylic acids. According to the accepted nomenclature, fats are called triacylglcherols.
The carbon atoms in the molecules of higher carboxylic acids can be connected to each other by both single and double bonds. Of the limiting (saturated) higher carboxylic acids, palmitic, stearic, arachidic acids are most often included in the composition of fats; from unsaturated (unsaturated) - oleic and linoleic.
The degree of unsaturation and the chain length of higher carboxylic acids (i.e., the number of carbon atoms) determine the physical properties of a particular fat.
Fats with short and unsaturated acid chains have a low melting point. At room temperature, these are liquids (oils) or greasy substances (fats). Conversely, fats with long and saturated chains of higher carboxylic acids become solid at room temperature. That is why, during hydrogenation (saturation of acid chains with hydrogen atoms along double bonds), liquid peanut oil, for example, becomes greasy, and sunflower oil turns into solid margarine. Compared to inhabitants of southern latitudes, animals living in cold climates (for example, fish from the Arctic seas) usually contain more unsaturated triacylglycerols. For this reason, their body remains flexible even at low temperatures.
In phospholipids, one of the extreme chains of the higher carboxylic acids of triacylglycerol is replaced by a group containing phosphate. Phospholipids have polar heads and non-polar tails. The groups forming the polar head are hydrophilic, while the non-polar tail groups are hydrophobic. The dual nature of these lipids determines their key role in the organization of biological membranes.
Another group of lipids are steroids (sterols). These substances are based on cholesterol alcohol. Sterols are poorly soluble in water and do not contain higher carboxylic acids. These include bile acids, cholesterol, sex hormones, vitamin D, etc.
Lipids also include terpenes (plant growth substances - gibberellins; carotenoids - photosynthetic pigments; essential oils of plants, as well as waxes).
Lipids can form complexes with other biological molecules - proteins and sugars.
The functions of lipids are as follows:
Structural. Phospholipids, together with proteins, form biological membranes. The membranes also contain sterols.
Energy. When fat is oxidized, a large amount of energy is released, which goes into the formation of ATP. A significant part of the body's energy reserves is stored in the form of lipids, which are consumed when there is a lack of nutrients. Hibernating animals and plants accumulate fats and oils and use them to maintain vital processes. The high content of lipids in plant seeds ensures the development of the embryo and seedling before their transition to independent feeding. The seeds of many plants (coconut palm, castor oil plant, sunflower, soybean, rapeseed, etc.) are used as raw materials for the production of vegetable oil industrially.
Protective and heat-insulating. Accumulating in the subcutaneous tissue and around some organs (kidneys, intestines), the fat layer protects the animal body and its individual organs from mechanical damage. In addition, due to its low thermal conductivity, the layer of subcutaneous fat helps to retain heat, which allows, for example, many animals to live in cold climates. In addition, it plays another role in whales - it contributes to buoyancy.
Lubricating and water repellent. The wax covers the skin, wool, feathers, makes them more elastic and protects them from moisture. The leaves and fruits of many plants have a waxy coating.
Regulatory. Many hormones are derivatives of cholesterol, such as sex hormones (testosterone in men and progesterone in women) and corticosteroids (aldosterone). Cholesterol derivatives, vitamin D play a key role in calcium and phosphorus metabolism. Bile acids are involved in the processes of digestion (emulsification of fats) and absorption of higher carboxylic acids.
Lipids are also the source of metabolic water formation. Oxidation of 100 g of fat gives about 105 g of water. This water is very important for some desert inhabitants, in particular for camels, which can go without water for 10-12 days: the fat stored in the hump is used for this very purpose. Bears, marmots and other hibernating animals receive the water necessary for life as a result of fat oxidation.
In the myelin sheaths of the axons of nerve cells, lipids are insulators during the conduction of nerve impulses.
The wax is used by bees to build honeycombs.
The body produces most of the lipids on its own, only essential fatty acids and soluble vitamins come with food.
Lipids are a large group of organic substances, consisting of fats and their analogs. 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 most important components of biological membranes.
There are three classes of lipids: cholesterol, phospholipids, triglycerides. The best known among these classes is cholesterol. The determination 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 manner.
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 taking into account a number of factors: age, seasonality, mental and physical activity.
Peculiarities
The human body independently produces all major lipid groups. The cell membrane does not form only polyunsaturated fatty acids, which are irreplaceable substances and fat-soluble vitamins.
The bulk of lipids are synthesized by epithelial cells of the small intestine and liver. For individual lipids, communication with specific organs and tissues is characteristic, and the rest are in all cells and tissues. Most of the lipids are contained in the 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.
- Accumulative. When fat is oxidized, a huge amount of energy is generated, which is subsequently spent on the creation of ATP. The body accumulates energy reserves mainly by lipid groups. For example, when animals fall asleep for the whole winter, their body receives all the necessary substances from the previously accumulated oils, fats, and bacteria.
- Protective, heat-insulating. The bulk of fat is deposited in the subcutaneous tissue, around the kidneys and intestines. Thanks to the accumulated layer of fat, the body is protected from cold, as well as mechanical damage.
- Water-repellent, lubricating. The lipid layer on the skin retains the elasticity of the cell membranes and protects them from moisture and bacteria.
- Regulatory. There is a link between lipid content and hormonal levels. Almost all hormones are produced from cholesterol. Vitamins and other cholesterol derivatives are involved in the metabolism of phosphorus and calcium. Bile acids are responsible for the absorption and digestion of food, as well as for the absorption of carboxylic acids.
Exchange processes
- Triglycerides protect soft subcutaneous tissues, as well as organs from damage, bacteria. There is a direct connection between their quantity and energy conservation.
- Phospholipids are responsible for 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 ensure the maintenance of the body's vital activity, 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. The work of the genitourinary system is impossible without these substances. A person's reproductive capacity can also fail.
Lipid metabolism involves the relationship between all of the above components and their complex effect 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 supplied with food.
If at least one of the links stops, then the connection is disrupted and the person feels problems with the intake of vital substances, beneficial bacteria and their spread throughout the body. Such a violation directly affects the process of lipid metabolism.
Disruption of exchange
Each 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, takes place in several stages. First, lipids are broken down, then they are absorbed, and only after that an intermediate and final exchange occurs.
Any disruptions in the process of assimilating 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 epithelial tissue 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 breakdown stage. The feces become a specific grayish-white color due to the accumulation of fats and bacteria.
Lipid metabolism can be corrected with a dietary regimen and medication prescribed to lower the LDL value. 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 use of oil, meat products, by-products and enrich the diet with low-fat fish and seafood. As a preventive measure, a change in lifestyle will help - an increase in physical activity, sports training, and rejection of bad habits.
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