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, and 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 industrial production of vegetable oil.
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.
They are organic compounds insoluble in water. They are composed of fatty acid molecules linked in a chain of hydrogen and carbon atoms. If the carbon atoms are connected to each other 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.
The separation according to the chemical formula into saturated and unsaturated acids has been developed for a long time. Unsaturated, in turn, are subdivided 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 found 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 other hand, are hard and contain a lot of saturated acids.
Lipids fall into two main categories depending on their origin:
- Vegetable fats (olive oil, nut oil, margarine, etc.).
- Animal fats (found in fish, meat, cheese, butter, cream, etc.).
When fats are combined with "bad" carbohydrates, the metabolism is disrupted, and as a result, most of them are deposited in the body by fat layers.
As a rule, in our diet, an excess of fat - fried fatty foods, in particular - fast food, is becoming more popular and habitual. At the same time, food may well be tasty, even if you give up 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. And insufficient blood supply, in turn, leads to 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 body by the blood stream. His blood clot will clog the blood vessels of the heart, the person will be instantly fatal. 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 raise 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, and poultry meat (without skin).
- The fats that help lower cholesterol are vegetable oils: olive, rapeseed, corn, sunflower.
Saturated
Frequent consumption of saturated fat is harmful to health. Sausages, lard, butter and cheese should not form the basis of the diet. By the way, palm and coconut oils also contain saturated fatty acids. When buying groceries 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 large quantities for the body. The amount of fat in the daily diet should not exceed 50 grams. An optimal nutritional balance should be 50% monounsaturated fatty acids, 25% polyunsaturated, and 25% saturated.Most people consume too much saturated fat to the detriment of unsaturated fats. Of these, about 70% are "invisible" (sausages, sets for aperitifs, cheeses, chips, and, of course, meat), and 30% are "visible" (this is all that can be used for frying dishes and 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 excess weight. And only physical activity and a balanced diet can correct this situation. Therefore, it is imperative to adjust the intake of fatty acids in accordance with their expenditure.
Monounsaturated
This type of fat is found in vegetable oils, and its main component is monounsaturated oleic 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 excellent for cooking, as it can withstand quite high temperatures (in fact, up to 210 ° C), and at the same time retains a significant part of its valuable properties. It is advisable to buy unrefined first cold-pressed oil, and the darker the color, the better. Store it in a dark and cold place.
To get one liter of oil, you need 5 kg of black olives. The cold pressing method preserves most of all vitamins and mineral salts in the oil: copper, phosphorus, magnesium, calcium, potassium, copper, iron. Fun fact: The lipid balance in olive oil is almost the same as in breast milk.
Of all the oils, olive is the best absorbed, besides, it is great for constipation and liver failure. Another useful property is that it can neutralize the intoxication of the body after drinking alcohol. Recent studies have shown that olive oil increases the absorption of calcium. This means that it is indispensable in the diet of children, at the age when their bone apparatus is being formed and developed.
Oleic acid is contained in olive oil (77%), rapeseed oil (55%), peanut oil (55%), grape seed oil (41%), soybean oil (30%), sunflower oil (25%), in wheatgrass oil (25%), in walnut oil (20%).
Polyunsaturated
They consist of two groups, in which the active ingredient is the so-called basic fatty acid. Since the body cannot produce it on its own, this acid must come with food.
Main sources: cereal sprouts (up to 50% fatty acid content), corn, oatmeal, brown rice, and oils.
Linoleic acid (Omega-6) is found in: sunflower oil (57%), soybean oil (55%), grape seed oil (54%), walnut oil (54%), wheatgrass oil (53%) , in pumpkin (45%), sesame (41%), peanut (20%), rapeseed (20%), olive (7%).
Linolenic acid (Omega-3): in flaxseed (55%), in walnut oil (13%), rapeseed (8%), in wheatgrass oil (6%), soybean (6%), sesame (1 %), olive (0.8%). Omega-3 is 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, and stimulates the production of hormones. It must not be heated or cooked with it. Linseed oil is added exclusively to a ready-made cooled dish: soups, cereals, salads, vegetables.
Fish and fish oil are the most valuable sources 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 advisable for a child to be given 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, flaxseed 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.
- Primrose and borage oils (can be found in capsules in pharmacies).
- Soy lecithins.
In addition to some oils
The table presents 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.Light and heat sensitive oils
- Walnut oil.
- Pumpkin.
- Linseed.
| Oils | Mg per 100g butter |
| Wheatgrass | 300 |
| Walnuts | 170 |
| Soybean | 94 |
| Corn | 28 |
| Olive | 15 |
It is best not to eat coconut oil. It contains too many fatty acids. Nevertheless, many people, especially those living in the places where coconut oil is obtained, consider it literally a panacea for all diseases. It is one of the oldest types of oils produced by humans. It is obtained from compressed dried coconut fruits. On the other hand, the advantage of coconut oil is that the saturated fat it contains has a completely different structure than the saturated fat used for preparing fast food. That is why there is still debate 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 beneficial, 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 cannot fry food on it. On contact with the hot surface of the frying pan, the oil immediately begins to release carcinogens that affect the intestines and stomach.
Margarine is an intermediate 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 wheatgrass oil, while others contain only saturated fatty acids or are hydrogenated.
If you carry out a minimum of processing, that is, do not hydrogenate the margarine, then some vitamins are preserved in it. But it must be remembered that the hardness of a margarine depends on the amount of palm and coconut oils added to it. Therefore, those who have a tendency to cardiovascular diseases are not advised to consume margarine.
Paraffin oil is a petroleum derivative and should be avoided. With food use of paraffin oil, the absorption of fat-soluble vitamins worsens. Moreover, when the oil is removed from the intestines, it binds to the already dissolved vitamins and comes out together 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 the precursors of prostaglandins. Prostaglandins are hormones that maintain a liquid state of cell lipids, and also prevent the development of atherosclerotic plaques, prevent cholesterol and other lipids from adhering 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 are, by nature, an excellent solvent. Those substances that do not dissolve in water dissolve well in fats. Most of the fat is stored in the cells of the adipose tissue, which are the fat depot. 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 keeps you warm, particularly during childhood. Lipid metabolism is closely related to protein and carbohydrate metabolism. With an excessive 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 energetic function consists in the fact that lipids of all nutrients give the body the greatest amount of energy. It has been proven that the oxidation of 1 gram of fat releases 9.3 kilocalories of heat, which is two times more than the oxidation of 1 gram of proteins or carbohydrates. When 1 g of proteins and carbohydrates are oxidized, 4.1 kcal of heat is released.
Food fats
Triacylglycerols predominate among them. There are vegetable and animal fats, and vegetable fats are more complete, since they contain much more unsaturated acids. Along with food, a small amount of free fatty acids is also ingested. Normally, up to 40% of all calories consumed by our body are lipids.Absorption and digestion of fats
Digestion of fats is a process of enzymatic hydrolysis that takes place in the small intestine and duodenum under the influence of enzyme substances found in the juices of the pancreas and intestinal glands.For fats to be digested, the body must produce bile. It contains detergents (or bile acids) that emulsify lipids so that enzymes break them down better. The products that are formed as a result of digestive hydrolysis - fatty, bile acids and glycerin - are absorbed from the intestinal cavity into the cells of the mucous membrane. In these cells, the fat is resynthesized again and forms special particles called "chylomicrons", which are sent to the lymph and lymphatic vessels, and then through the lymph into the blood. At the same time, 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 products of hydrolysis of dairy fats) are absorbed and enter the blood of the portal vein, and then into 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 in conjunction with bile acids come from the digestive tract through the portal vein with blood flow to the liver. These fatty acids are not involved in lipid synthesis and are oxidized by the enzyme systems of the liver. In adults, they generally do not play an important role in metabolism. The only exceptions are children, in their diet the most fat in milk.Other lipids enter the hepatic artery as lipoproteins or chylomicrons. They are oxidized in the liver, 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 necessarily go inside along with food. The total process of fatty acid biosynthesis is called "lipogenesis", and it is the liver that participates most intensively in this process.
In the liver, enzymatic processes of transformation of phospholipids and cholesterol are carried out. 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 in the blood. Their own fractions during centrifugation are separated according to their relative density.The first faction is called the "chylomicrons"; they are composed of a thin protein coat and fats. The second fraction is very low density lipoproteins. They contain a large amount of phospholipids. The third fraction is lipoproteins, which contain a lot of cholesterol. The fourth fraction is high-density lipoproteins, they contain the most phospholipids. The fifth fraction is lipoproteins with high density and low content.
The function of lipoproteins in the blood is to carry lipids. Chylomicrons are synthesized in the intestinal mucous cells and carry fat that has been resynthesized from the products of fat hydrolysis. The fats of the chylomicrons 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.
Lipoproteins with a very low density carry only 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 enzymatic breakdown of fat contained in adipose tissue. This faction has a kind of 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 of high and low density lipoprotein fractions 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 cleaved under the influence of various lipases, and the formed fatty acids are attached to other formations: phospholipids, cholesterol esters, etc .; or they are oxidized to final products. Oxidation processes take place in several ways. One part of fatty acids, during oxidative processes in the liver, produces acetone. With a severe form of diabetes mellitus, with lipoid nephrosis and some other diseases, the amount of acetone bodies in the blood sharply increases.
Regulation of fat metabolism
The regulation of lipid metabolism is carried out by a rather complex neuro-humoral pathway, while the mechanisms of precisely humoral regulation prevail in it. If the functions of the gonads, pituitary gland, thyroid gland decrease, then the processes of fat biosynthesis are enhanced. The saddest thing is that not only lipid synthesis increases, but also their deposition in adipose tissue, and this leads to obesity.Insulin is a pancreatic hormone and is involved in the regulation of lipid metabolism. Since there is a cross-over possibility of transforming carbohydrates into fats, and then fats into carbohydrates, with a deficiency of insulin, the processes of carbohydrate synthesis are intensified, which is accompanied by an acceleration of lipid breakdown processes, during which intermediate metabolic products are formed that are used for the biosynthesis of carbohydrates.
Phospholipids are similar in structure to triacylglycerols, only their molecules contain phosphorus-containing groups. Steroids are cholesterol derivatives and have a different structure. Lipids also include a large group of fat-soluble substances, which include 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.
Disruption of the normal concentration of lipids in the blood
If there is an abnormally high lipid level in the blood, then this pathological condition is called hyperlipemia. With hypothyroidism, nephrosis, diabetes and disorders, doctors are faced with a secondary form of hyperlipemia. In these diseases, there is a high content of cholesterol and triglycerides. Primary hyperlipemia is a rather rare hereditary pathology that contributes to the development of arteriosclerosis and coronary heart disease.
With hypoglycemia, fasting, after injections of growth hormone, adrenaline, the amount of free fatty acids in the body sharply increases 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 interviewing the closest relatives in the anamnesis, cases of early atherosclerosis are necessarily identified. Hypercholesterolemia, even at an early age, can contribute to the development of myocardial infarction. As a rule, there are no external symptoms. If a disease is detected, treatment is carried out with diet therapy. Its essence consists in the substitution of saturated acids by unsaturated acids. Correct correction of the diet significantly reduces the likelihood of developing pathologies of the vascular system.
With dyslipidemia, the balance of various types of lipids is disturbed in the blood. In particular, the main lipids found 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 serious risk factors for cardiovascular complications in patients with diagnosed type 2 diabetes mellitus. Abnormal lipoprotein levels 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 influencing the development of dyslipidemia
The most significant causes of dyslipidemia are genetic disorders of lipid metabolism. They consist in mutations of genes responsible for the synthesis of apolipoproteins - constituent lipoproteins.The second important factor is a healthy / unhealthy lifestyle. Under unfavorable circumstances, in the absence of physical activity, with the use of alcohol, lipid metabolism is disrupted. Obesity is directly related to an increase in triglycerides, with a violation of cholesterol concentration.
Another factor in the development of dyslipidemia is psychoemotional stress, which, through neuroendocrine stimulation, contributes to disorders of lipid metabolism. By neuroendocrine stimulation is meant an increase in the activity of the autonomic nervous system.
The clinical classification of the types of dyslipidemia provides for their subdivision 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 parameters of lipoproteins (high and low density), total cholesterol, triglycerides. During the diurnal cycle, even in perfectly healthy people, fluctuations in cholesterol levels of the order of 10% are observed; and fluctuations in triglyceride levels - up to 25%. To determine these indicators, blood donated on an empty stomach is centrifuged.
Determination of the lipid profile is recommended 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, a history of ischemia in the next of kin).
Atherosclerosis
The main factor in the appearance of ischemia is the formation of many small atherosclerotic plaques, gradually increasing in the lumens 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 plaque and the simultaneous narrowing of the vessel duct can provoke the manifestation of signs of ischemia.
At first, they will begin to manifest themselves with intense physical exertion, when the myocardium requires more oxygen and this need cannot be provided by an increase in coronary blood flow.
The clinical manifestation of the ischemic state of the myocardium is a sharply arising attack of angina pectoris. It is accompanied by such phenomena as pain and a feeling of constriction behind the breastbone. The attack passes as soon as the load of an emotional or physical nature stops.
The main (but not the only main) cause of ischemia is considered by doctors to be lipid metabolism disorders, but in addition, significant factors are smoking, obesity, carbohydrate metabolism disorders and genetic predisposition. Cholesterol levels directly affect the occurrence of complications of diseases of the heart system.
Treatment for this disease is to normalize cholesterol levels. Correction of the diet alone is not enough for this. It is also necessary to deal with other risk factors for development: to reduce weight, increase physical activity, quit smoking. Correction of nutrition implies not only a decrease in the total calorie content of food, but also the replacement of animal fats with vegetable fats in the diet:
consumption of animal fats and a simultaneous increase in the consumption of vegetable fats, fiber. It must be remembered that a significant part of 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 agents, nicotinic acid acts most effectively against ischemia, but its use is limited due to concomitant side effects. The same applies to other medications.
In the 80s of the last century, know-how - drugs from the statin group - began to be used in lipid-lowering therapy. Currently, there are 6 drugs available on the pharmaceutical market that belong to this group. Pravastatin and lovastatin are drugs based on the waste products of fungi. Rosuvastatin, atorvastatin, fluvastatin are synthetic drugs, and simvastatin is semisynthetic.
These agents help lower low-density lipoprotein levels and 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 the replacement of myocardial connective tissue. The connective tissue is not elastic, unlike the myocardium, respectively, the elasticity of the entire organ, on which the inelastic "patch" has appeared, suffers, and the heart valves are deformed.Cardiosclerosis (or myocardiosclerosis) is a logical consequence of an untreated disease: myocarditis, atherosclerosis, rheumatism. The acute development of this disease occurs with myocardial infarction and coronary artery disease. When atherosclerotic plaques appear everywhere in the coronary arteries in the heart, the blood supply to the myocardium suffers, it does not have enough oxygen that is carried with the blood stream.
The acute form of ischemic disease is myocardial infarction. So an improper lifestyle, unbalanced diet and smoking can become an implicit cause of a heart attack, and acute psycho-emotional stress, against the background of 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 one. It is manifested by regularly occurring attacks of angina pectoris (that is, chest pain). You can relieve pain during an attack with nitroglycerin.
The body is designed in such a way that it tries to decompensate any violation. Connective tissue scars prevent the heart from stretching and contracting elastically. Gradually, the heart adapts to the scars and simply increases in size, which leads to a violation of blood circulation through the vessels, to a violation of the contractile activity of the muscle, to the expansion of the cardiac cavities. All this together is the cause of the failure of the 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; adherence to bed rest if the disease has led to myocardial infarction (at rest, scarring and healing occurs without the formation of a dangerous aneurysm); normalization of the rhythm; stimulating metabolic processes in the heart muscle, limiting any stress; adherence to a properly balanced diet, in particular, reducing the amount of lipids in the diet.
The diet provides good anti-allergic and anti-inflammatory effects, and is also considered an excellent preventive measure for preventing heart disease.
The basic rule of nutrition is moderation in the amount of food. It is also useful to lose those extra pounds that put stress 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 spicy, sweet, fatty, salty foods from food. The use of alcoholic beverages in patients with vascular disorders is contraindicated. Food should be fortified with minerals and vitamins. Fish, boiled meat, vegetables, fruits, dairy products should be the basis of the diet.
07.04.2009
In the diet, fat is approximately 44 percent. Recommendations on the right diet advise that this figure does not exceed 30 percent of the total calories, and 25 percent would be even better.
Your fat intake should lean towards polyunsaturated and monounsaturated fats with a maximum saturated fat of no more than 10 percent or less, of that total 25 percent fat.
* To reduce the fat content when making an omelet, remove the yolk of every other egg, this will reduce the fat and cholesterol levels, and you won't even feel the difference.
* Cottonseed oil is 25 percent saturated fat and is not the best to use.
* Soybean oil changes its taste during long-term storage due to changes in the levels of linolenic acid it contains.
* Sixty-four percent of the calories from caviar are from fat.
* Butter absorbs fridge odors and should be kept in a closed container.
* Butter, stored in the refrigerator for only two weeks. If you need to store it for a longer time, store it in the freezer.
* Eight ounces of potato chips equals 12 to 20 teaspoons of fat.
* Try using water instead of fat in some recipes. It is true that it makes dressings from fats, etc., the taste becomes even, but if you mix water with flour, with cornstarch (corn flour) or potato starch, it will save you extra calories.
* Oils should be stored in dark containers and stored in a dark, cool place to reduce the risk of rancidity.
* When carob is made into candy, fat is added for texture, which brings the fat level close to that of real chocolate. In fact, the cocoa butter used in chocolate is 60 percent saturated fat, while the fat in carob candies is, in most cases, 85 percent saturated fat.
* Using non-stick cookware and vegetable oil sprays will reduce your fat intake.
* Never eat salad dressings or mayonnaise-based salad until you are sure they were chilled before you are ready to eat them. Neglect is the culprit in thousands of food poisoning cases every year.
* Oils related to fish are healthier than those related to meat. Fish contains a high percentage of omega fatty acids.
* Any margarine containing coconut or palm oil will be very high in saturated fat. They are now called tropical oils (tropical plant oils) on labels.
* New fat substitutes continue to appear in our products. Do not forget that they are still synthetic, and not a natural product. They should not be seen as a panacea for fat replacement in our diet.
* The best butter is made from AA grade sweet cream.
* An ounce of seeds (sunflower) contains 160 calories and is not considered a diet food.
* A burrito with sour cream and guacamole (a sauce made from mashed avacado, spiced tomatoes, and mayonnaise) can contain up to 1,000 calories and 59 percent fat.
* Research has shown that stearic acid, one of the saturated fats, has little effect on raising cholesterol levels.
* New Low Fat Peanut Butter has the same calories per serving as regular peanut butter, approximately 190 calories per serving, sweeteners have been added instead of fat.
* When you store some oils in the refrigerator, they may become hazy (opaque, light hazy) due to the formation of harmless crystals. Manufacturers sometimes chill the oils before they are released for sale and remove these crystals in a process called winterizing. These oils will now remain clear when cooled.
* Pork fat has large crystals, while butter is small. This is highly dependent on the texture of the fat and can be controlled during processing. The size of the crystals can be changed by stirring (shaking) the oil while it is cooling.
* Studies have shown that people on a diet miss fat more than sweet.
* People on a high-fat diet are more prone to colon cancer, prostate cancer, or breast cancer. Future research may show that it also has a detrimental effect on the immune system.
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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 a 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 most common acids 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 accounts for 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, that is, 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 widely: -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: it is the higher, the higher the content of saturated acids.
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 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.
Fat is considered the culprit of many troubles. Doctors and scientists advise cutting down on fat or eliminating it altogether. Of course, for those who are obese or have chronic diseases, it is better to heed this advice. However, the rest would be foolish to give up fat. Let's find out more about them from the facts below.
1. Consumption of fats does not necessarily lead to their storage in the body
Many people think that fat consumption will definitely affect the figure in the form of deposits on the waist, hips and abdomen. If you eat more than your body requires, then yes, such a problem may arise. For example, if you consume an unlimited amount of starchy carbohydrates, then you can expect an increase in insulin levels, and then fat will be deposited. But if you eat, consuming fat and protein evenly, then this problem can be avoided. In everything you need to know when to stop.
2. No need to avoid eating nuts
Nuts contain healthy forms of fat, monounsaturated fats, which help you feel full faster, but also raise your good cholesterol. Nuts do not affect weight gain in any way, because you cannot eat a lot of them due to their satiety, and besides, they are poorly digested by the body. Consequently, the cell walls of nuts are not easily destroyed when chewed. This means that they pass through the body in transit and do not excrete all of their fat.
3. It is not necessary to completely eliminate saturated fat from the body.
Saturated fats have always been thought to be the enemy of health, so they were advised to be eliminated from the diet. But today it has become clear that moderate consumption of saturated fat does no harm. And some of them even need to be included in a healthy eating program.
Extra-virgin coconut oil is one of the healthy sources of saturated fat. It contains lauric acid which is found nowhere else except in breast milk. It is a powerful immune stimulant. It is advised to fry foods in coconut oil.
4. If the product label says "no trans fats" does not mean that they are not there.
Many manufacturers believe that if a product contains a very small amount of an ingredient, then it is not necessary to indicate it on the label. It happens that a product contains only 0.5 g of trans fat, but you will not find it among the ingredients on the package. After eating several servings of such a product, you will not even know that you have eaten enough of this harmful ingredient.
5. Nutrients from vegetables without fat are absorbed worse
Studies have shown that lettuce seasoned with fat or a sauce with fats is significantly better absorbed by the body and receives more of the necessary nutrients - carotenoids. If you constantly eat salads without fats, then carotenoids will not be absorbed by the body at all. They are responsible for the red, yellow, orange and green colors and are important in the prevention of many diseases. To help your body absorb all the nutrients from vegetables, consume them with healthy fats.
6. Extra virgin olive oil is not suitable for frying.
Although it contains healthy monounsaturated fats, it loses its properties at high temperatures. Better to use it for dressing salads or marinating meat. Olive oil is very delicate and quickly deteriorates, so it should be stored in a dark glass container with a tightly closed lid to avoid oxidation and retain all its beneficial properties.
7. Fats have many functions in the body
Without fat, our body and our body cannot live. There are several reasons for this:
The brain needs fats. About 60% of the dry weight of the human brain is fat. Healthy nerve cells contain fats - docosahexanoic acid;
Sex hormones are formed with the help of fats;
Fatty acids are essential for healthy skin and hair;
Fats are involved in metabolism, functions of the immune system, and help stabilize blood sugar.
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