Cholesterol chemical properties. What does cholesterol consist of: composition, properties, formula, structure. Cholesterol levels are normal and in various diseases

Cholesterol (CS) is a substance from which the human body forms atherosclerotic plaques. They are the cause of the manifestation, which is a very dangerous disease.

What cholesterol is can be judged by the meaning of this word, which Greek language translated as “hard bile.”

Substance belonging to the class lipids , comes with food. However, in this way, only a small part of the cholesterol enters the body - approximately 20% of the cholesterol a person receives mainly from products of animal origin. The remaining, more significant part of this substance (approximately 80%) is produced in the human liver.

In the human body, pure Chl is present only in small quantities, being part of lipoproteins. These compounds may have low density (so-called bad LPN cholesterol ) and high density (the so-called good cholesterol LPV ).

What should be the normal cholesterol level, as well as good and bad cholesterol - what it is, you can find out from this article.

Cholesterol: good, bad, total

The fact that if cholesterol levels are higher than normal is harmful is said very often and actively. Therefore, many people are under the impression that the lower the cholesterol, the better. But in order for all systems in the body to function normally, this substance is very important. It is important that a person’s cholesterol remains normal throughout his life.

It is customary to distinguish between so-called bad and good cholesterol. Low cholesterol (bad) is the one that settles on the walls inside the blood vessels and forms plaques. It has low or very low density and binds to special types of protein - apoproteins . As a result, VLDL fat-protein complexes . It is when the LDL level increases that a dangerous health condition occurs.

VLDL - what it is, the norm of this indicator - all this information can be obtained from a specialist.

Now the LDL norm in men and the LDL norm in women after 50 years of age and at a younger age are determined by conducting cholesterol tests and are expressed by different laboratory methods, the units of determination are mg/dl or mmol/l. You need to understand when determining LDL that this is a value that should be analyzed by a specialist and appropriate treatment prescribed if LDL cholesterol is elevated. What this means depends on the metrics. Thus, in healthy people, this indicator is considered normal at a level below 4 mmol/l (160 mg/dl).

If a blood test shows that cholesterol is high, you should ask your doctor what to do. As a rule, if the value of such cholesterol is elevated, this means that the patient will be prescribed, or this condition should be treated with medications.

The question of whether you should take cholesterol pills is controversial. It is important to note that statins do not eliminate the causes of high cholesterol. It's about o , low mobility, . only suppress the production of this substance in the body, but at the same time they provoke numerous side effects. Sometimes cardiologists say that the use of statins is more dangerous for the body than elevated levels.

• In people suffering from ischemic heart disease, who have had or, cholesterol levels must be below 2.5 mmol/l or 100 mg/dl.
• Those who do not suffer from heart disease, but have more than two risk factors, need to maintain cholesterol level at 3.3 mmol/l or below 130 mg/dl.

Bad cholesterol is counteracted by so-called good cholesterol, HDL cholesterol. What is high-density lipoprotein cholesterol? It is an essential substance for the body, as it collects bad cholesterol from the walls of blood vessels, after which it promotes its removal to the liver, where it is destroyed. Many people are interested: if HDL is lowered, what does this mean? It should be borne in mind that this condition is dangerous, since atherosclerosis develops not only against the background high cholesterol low density, but also if LDL is reduced. If HDL cholesterol is elevated, what does this mean, you need to ask a specialist.

That is why the most undesirable option in adults is when the level of bad cholesterol is increased and the level of useful cholesterol is decreased. According to statistics, approximately 60% of mature people have this combination of indicators. And the earlier such indicators can be determined and treatment carried out correctly, the lower the risk of developing dangerous diseases.

Good cholesterol, unlike bad cholesterol, is produced only by the body, so it will not be possible to increase its level by consuming certain foods.

The normal level of good cholesterol in women is slightly higher than normal HDL cholesterol in men. The most important recommendation on how to increase its level in the blood is the following: it is necessary to practice physical activity, during which its production increases. Even if you do ordinary exercises at home every day, this will help not only increase HDL, but also reduce levels of bad cholesterol, which the body gets from food.

If a person has eaten food that contains very high cholesterol, to activate its removal, it is necessary to ensure the active work of muscles of all groups.

Thus, those who want the LDL and HDL levels to be restored need to:

• move more (especially for those who have suffered a heart attack or stroke);
• exercise moderately;
• practice intense physical activity (in the absence of contraindications).

You can also increase the level of good cholesterol by taking a small dose of alcohol. However, in no case should it be more than one glass of dry wine per day.

It is important to take into account that excessive load threatens to suppress the synthesis of cholesterol.

To correctly decipher a blood test, you should take into account the level of cholesterol in a person’s blood.

There is a table of cholesterol norms for women by age, from which, if necessary, you can find out what the cholesterol norm is for women after 50 years of age, and what the norm is considered to be for women at a young age. Accordingly, the patient can independently determine whether her cholesterol is high or low and consult a doctor who will help find out the reasons for low or high cholesterol levels. It is the doctor who determines what treatment and diet should be.

• The normal level of cholesterol in the blood for women and men based on HDL, if the condition of the heart and blood vessels is normal, is above 1 mmol/l or 39 mg/dl.
• In people with coronary artery disease who have had a stroke or heart attack, the indicator should be 1-1.5 mmol/l or 40-60 mg/dl.

The analysis process also determines the norm of total cholesterol in women and men, that is, how good and bad cholesterol correlate.

Total cholesterol in the blood should be no more than 5.2 mmol/l or 200 mg/dl.

If the norm in young men is even slightly exceeded, then this must be considered a pathology.

There is also a table of cholesterol norms in men by age, which can easily be used to determine the cholesterol norm in men and its indicators at different ages. From the corresponding table you can find out what norm of hdl-cholesterol is considered optimal

However, in order to determine whether the level in men and women is actually normal for this indicator, first of all, you need to do a blood test, which makes it possible to find out the content of total cholesterol, as well as the content of other indicators - low or high sugar, etc.

After all, even if the norm of total cholesterol is noticeably exceeded, it is impossible to determine the symptoms or special signs of such a condition. That is, a person does not even realize that the norm has been exceeded, and his blood vessels are clogged or narrowed, until he begins to notice that he has pain in the heart, or until a stroke or heart attack occurs.

Therefore even healthy person of any age, it is important to get tested and monitor whether the permissible norm cholesterol. Also, each person should prevent an increase in these indicators in order to avoid the development of atherosclerosis and other serious ailments in the future.

Who needs to control cholesterol levels?

If a person is healthy, he does not show negative symptoms, he does not need to think about the state of blood vessels or check whether the level is normal Cholesterol takes place in the body. That is why it is often elevated level Patients are not even aware of this substance at first.

This indicator should be measured especially carefully and regularly for those who suffer from hypertension or have problems with the heart and blood vessels. In addition, indications for regular tests have the following categories:

• people who smoke;
• those who are sick hypertension ;
• overweight people;
• patients suffering from diseases of the cardiovascular system;
• those who prefer a sedentary life;
• women after ;
• men after reaching 40 years of age;
• elderly people.

Those who need a blood test for cholesterol should ask appropriate professionals about how to take a cholesterol test. The blood formula, including cholesterol content, is determined. How to donate blood for cholesterol? This analysis is carried out in any clinic; for this, approximately 5 ml of blood is taken from the ulnar vein. Those who are interested in how to donate blood correctly should note that before these indicators are determined, the patient should not eat for half a day. Also, in the period before blood donation, you should not engage in intense physical activity.

There is also a special test for use at home. These are disposable test strips that are easy to use. The portable analyzer is used by people with lipid metabolism disorders.

How to decipher a blood test

You can find out whether total cholesterol is elevated by conducting a blood test in the laboratory. If total cholesterol is elevated, what does this mean, how to act, and everything about treatment will be explained by your doctor. But you can try to decipher the test results yourself. To do this, you need to know that the biochemical analysis contains three indicators: LDL cholesterol, HDL cholesterol and total cholesterol.

Lipidogram is a comprehensive study that allows you to evaluate lipid metabolism in the body, which allows you to determine how lipid metabolism occurs and calculate the risk of atherosclerosis and coronary artery disease.

Correct interpretation of the blood lipid profile is also important from the point of view of assessing the need to take statins and the daily dose of such drugs. Statins are drugs that have many side effects, and their price is quite high. Therefore, based on what it is - a lipid profile, this analysis allows you to find out what a person’s blood consists of and prescribe the most effective therapy for the patient.

After all, total cholesterol is an indicator that in itself does not make it possible to clearly assess the likelihood of a patient developing atherosclerosis. If total cholesterol is elevated, what to do can be assessed using the full range of diagnostic indicators. Therefore, the following indicators are determined:

• HDL (alpha cholesterol) – it is determined whether high-density lipoproteins are increased or decreased. It is taken into account when determining the parameters of β-lipoproteins that this substance performs a protective function, preventing the development of atherosclerosis.
• LDL – low-density lipoproteins are increased or decreased. The higher the beta cholesterol level, the more activated the atherosclerotic process.
• VLDL – very low density lipoproteins, thanks to which exogenous lipids are transported in plasma. Synthesized by the liver, they are the main precursor of LDL. VLDL takes an active part in the production of atherosclerotic plaques.
• Triglycerides – these are esters of higher fatty acids and glycerol. This is a transport form of fats, therefore, their increased content also increases the risk of atherosclerosis.

What normal cholesterol should be is determined depending on age; it can be different for women and men. In addition, it is important to understand that there is no exact number that indicates the norm of cholesterol. There are only recommendations on what the index should be. Therefore, if the indicator is different and deviates from the range, then this is evidence of some kind of disease.

However, those who are planning to take the test should take into account that certain errors may occur during the analysis. The data from the study showed that in 75% of laboratories in the country such errors are allowed. What to do if you are trying to get exact result? It is best to do such analyzes in those laboratories that are certified by the VCS (Invitro, etc.)

Normal cholesterol levels in women

• Normally, in women, the total chol level is 3.6-5.2 mmol/l;
• Cholesterol, moderately elevated – 5.2 – 6.19 mmol/l;
• Hc, significantly increased - from more than 6.19 mmol/l.
• LDL cholesterol: normal – 3.5 mmol/l, elevated – from 4.0 mmol/l.
• HDL cholesterol: normal level is 0.9-1.9 mmol/l, a level below 0.78 mmol/l is considered dangerous to health.

№	Age (years)	Total Cholesterol (mmol/l)
1	under 5	within 2.90-5.18
2	5-10	within 2.26-5.30
3	10-15	within 3.21-5.20
4	15-20	within 3.08-5.18
5	20-25	within 3.16-5.59
6	25-30	within 3.32-5.75
7	30-35	within 3.37-5.96
8	35-40	within 3.63-6.27
9	40-45	within 3.81-6.53
10	45-50	within 3.94-6.86
11	50-55	within 4.20-7.38
12	55-60	within 4.45-7.77
13	60-65	within 4.45-7.69
14	65-70	within 4.43-7.85
15	from 70	within 4.48-7.25

Normal cholesterol levels in men

• Normally, the total Chol level in men is 3.6-5.2 mmol/l;
• Normal LDL cholesterol is 2.25-4.82 mmol/l;
• HDL cholesterol is normal - 0.7-1.7 mmol/l.

№	Age (years)	Total Cholesterol (mmol/l)
1	up to 5	within 2.95-5.25
2	5-10	within 3.13-5.25
3	10-15	within 3.08-5.23
4	15-20	within 2.93-5.10
5	20-25	within 3.16-5.59
6	25-30	within 3.44-6.32
7	30-35	within 3.57-6.58
8	35-40	within 3.78-6.99
9	40-45	within 3.91-6.94
10	45-50	within 4.09-7.15
11	50-55	within 4.09-7.17
12	55-60	within 4.04-7.15
13	60-65	within 4.12-7.15
14	65-70	within 4.09-7.10
15	from 70	within 3.73-6.86

Triglycerides

Triglycerides are a certain type of fat that is found in human blood. They are the main source of energy and the most abundant type of fat in the body. A complete blood test determines the amount of triglycerides. If it is normal, then these fats are beneficial for the body.

As a rule, triglycerides in the blood are elevated in those who consume more calories than they burn. When their levels are elevated, the so-called metabolic syndrome , in which there is high blood pressure, increased blood sugar, low levels of good cholesterin, and also a large amount of fat around the waist. This condition increases the likelihood of developing diabetes, stroke, and heart disease.

The normal triglyceride level is 150 mg/dl. The normal level of triglycerides in the blood of women, as well as men, is exceeded if the level is more than 200 mg/dl. However, the rate is up to 400 mg/dl. is designated as acceptable. A high level is considered to be 400-1000 mg/dl. very high – from 1000 mg/dl.

If triglycerides are low, what does this mean, you need to ask your doctor. This condition is observed in lung diseases, cerebral infarction, parenchymal damage, myasthenia gravis, when taken, etc.

What is the atherogenic coefficient

Many people are interested in what is the atherogenic coefficient in a biochemical blood test? Atherogenic coefficient It is customary to call the proportional ratio of good and total cholesterin. This indicator is the most accurate reflection of the state of lipid metabolism in the body, as well as an assessment of the likelihood of atherosclerosis and other ailments. To calculate the atherogenic index, you need to subtract the HDL cholesterol value from the total cholesterol value, and then divide this difference by the HDL cholesterol level.

The norm for women and the norm for men of this indicator is as follows:

• 2-2.8 – young people under 30 years old;
• 3-3.5 is the norm for people over 30 years old who do not have signs of atherosclerosis;
• from 4 – an indicator typical for people suffering from coronary artery disease.

If the atherogenic coefficient is below normal, then this is not a cause for concern. On the contrary, if the coefficient is reduced, then the person’s risk of atherosclerosis is low.

It is important to pay attention to the patient's condition if the atherogenicity coefficient is increased. A specialist will tell you what it is and how to act in this case. If a patient’s atherogenic coefficient is increased, the reasons for this are due to the fact that bad cholesterol is increased in the body. What to do in such a situation? First of all, you need to contact a qualified doctor who will adequately assess the atherogenic index. What this means can only be clearly assessed and explained by a specialist.

Atherogenicity – this is the main criterion for monitoring how effective hypercholesterolemia therapy is. One should strive to ensure that lipoprotein levels are restored. It is important to ensure not only a decrease in total cholesterol, but also an increase in high-density lipoproteins. Therefore, decoding the lipid spectrum of the blood provides that β-lipoproteins, the norm for which is different in women and men, as already noted, are necessarily taken into account when assessing the patient’s condition.

Other studies for high cholesterol

If there is a risk of atherosclerosis, they are determined not only by lipoproteins (normal in the blood), but also by others important indicators, in particular, also the norm of PTI in the blood of women and men. PTI – this is the prothrombin index, one of the most important factors of a coagulogram, a study of the state of the blood coagulation system.

However, currently in medicine there is a more stable indicator - INR , which stands for international normalization ratio. If the level is elevated, there is a risk of bleeding. If the INR is elevated, a specialist will explain in detail what this means.

The determination of hgb () is also important, since with high cholesterol levels, hemoglobin levels can be very high, and this increases the risk of heart attack, stroke, thrombosis, etc. How much hemoglobin should be normal can be found out from a specialist.

Other indicators and markers (he4), etc. are determined in people with high cholesterol if necessary.

What to do to normalize cholesterol?

Many people, having received test results and learned that they have cholesterol 7 or cholesterol 8, simply have no idea what to do. The basic rule in in this case the following: a clinical blood test must be deciphered by a specialist, whose recommendations should be followed. That is, if low-density lipoproteins are elevated, the doctor should explain what it is. In the same way, if there is low cholesterol in the blood, what does this mean, you should ask a specialist.

As a general rule, it is important to be strictly followed in men as well as in women. Its conditions are not difficult to understand. It is enough just not to consume foods with saturated fats and dangerous dietary cholesterol. There are some important tips to keep in mind:

• significantly reduce the amount of animal fats in the diet;
• reduce portions of fatty meat, remove skin from poultry before consumption;
• reduce portions of butter, mayonnaise, sour cream with high fat content;
• prefer boiled rather than fried foods;
• You can eat eggs without overdoing them;
• the diet should contain a maximum of healthy fiber (apples, beets, legumes, carrots, cabbage, kiwi, etc.);
• useful to consume vegetable oils, fish.

If cholesterol is elevated with, it is important to strictly adhere to the doctor’s recommendations - it is he who will tell you which diet plan is most relevant in this case.

Seeing cholesterol 6.6 or cholesterol 9 in test results, what to do, the patient should ask a specialist. It is likely that the doctor will prescribe treatment based on the patient’s individual characteristics.

You should clearly remember that normal Chl levels are the key to the health of your blood vessels and heart, and do everything to improve these indicators

Normal fat metabolism occurs if the indicators are close to the following values.

Last edited by Alena; 22.11.2006 at 21:32.

Just Alena

Cholesterol-2

Just Alena

Fat and cholesterol

Almost all modern nutrition systems in bodybuilding call for avoiding fat and cholesterol like the plague.
Of course, it’s worth keeping an eye on your fat and cholesterol intake, but don’t turn caring for your health into psychosis - shaking over every extra yolk and every sip of milk. Moreover, one cannot automatically classify as “harmful and bad” all diets containing a lot of fat and cholesterol. Here everything is much more complicated: different factors must be taken into account.
If you get enough fresh dairy products and eggs, do not rely on smoked meat, sausage and canned foods I healthy foods, eat a lot of fiber, fresh fruits, greens and olive oil, don’t smoke, don’t inject yourself steroids, accept complex multivitamins c multiminerals,If you are not genetically predisposed to high blood cholesterol, then why should you exhaust yourself with the strictest, completely low-fat diets? And if you have already decided, in the interests of prevention, to reduce the fat content in your diet, it will be enough to switch from whole milk to low-fat milk, and instead of fatty cheeses, buy the so-called. "lightweight".
Another thing is a bodybuilder, who pours buckets into himself ts spruce milk, eats fifty eggs ts and a kilogram of fatty cheese a day, does not disdain smoked meats, canned food, sausages, etc., eats very little rough food l fiber and a lot of refined food. And on top of that, it also hits steroids. His liver can barely move: for such and such, fat and cholesterol are like a sharp knife.
With all this, I don’t want to say at all that you don’t have to watch fat and cholesterol at all. However, first we need to ts e-thread way of life, so to speak, in general. If it is clearly "unhealthy", then fat and cholesterol will indeed be harmful to health. But in a normal life, the risk is practically zero.
However, I strongly recommend that any bodybuilder periodically test their blood for cholesterol. If your cholesterol level is normal, then you are doing everything right. But even if it is elevated, this does not mean that there is too much fat in your diet. Don't take this popular "fashionable" opinion for granted until you've considered everything. possible reasons. And they can be very different, including liver diseases.
If you are for 35, Replace some animal fats with olive oil, nuts, fish, and seeds. You may get even more fat, but there will certainly be less cholesterol in your diet.
In any case, don't panic by thinking that elevated cholesterol automatically makes you a candidate for a heart attack. Heart diseases have many other causes, for example, smoking, bad heredity, high blood pressure, diabetes, etc. And cholesterol is just one, and not the most important, of the risk factors.
And one more important note. Professionals who massively use steroids, forced to adhere to the strictest diet with an extremely low fat content, otherwise their liver will simply “bend.” Titled champions promote their low-fat diets as a kind of rule bodybuilding. In fact, they simply cannot live without them. both

The functions of cholesterol in the body have long been a subject of scientific interest. Research by scientists is aimed at preventing atherosclerosis, a dangerous disease in the development of which cholesterol plays a major role.

Despite the abundance of information, many people still consider cholesterol to be harmful. In fact, cholesterol helps maintain health by playing an important role in the body - ensuring metabolic processes.

The body's need for cholesterol is low. Only 10% of people have elevated concentrations of the substance. Previously, there was an opinion that all cholesterol is harmful and leads to atherosclerosis.

High cholesterol is harmful to the arteries, but its deficiency leads to increased fragility of blood vessels. In this case, the damaged areas are strengthened by cholesterol patches.

The main functions of cholesterol

In the correct concentration, cholesterol ensures many vital processes:

1. Maintains the shape and function of cell membranes: increases strength, regulates permeability. The membrane performs a barrier function between the cell contents and external environment. At the same time, this semi-permeable partition is capable of allowing water molecules and certain substances dissolved in it to pass through. Cell membranes are 95% made up of lipoproteins, which include glyco-, phospholipids, and cholesterol. Providing a stabilizing effect, it resists the destructive effects of free radicals.
2. Provides transportation of beneficial and harmful elements, regulation of the activity of enzymes that greatly accelerate biochemical reactions.
3. Takes part in the synthesis of sex hormones and maintains normal hormonal levels.
4. Participates in the synthesis of bile acids.
5. Supports the structure and growth of fetal cells. To bear a fetus during pregnancy, the female body requires an increased amount of cholesterol. Mother's milk, rich in cholesterol, has a positive effect on the baby's health.
6. Ensures normal brain functioning and protects against Alzheimer's disease. Scientific research indicate a direct effect of cholesterol on mental abilities.

The human body contains 140-350 g of cholesterol, 90% of which is found in tissues, and 10% in the blood. Insoluble in water, cholesterol dissolves in fatty environments. It is transported to all tissues of the body by lipoproteins - complexes of proteins and fats.

There are several types of lipoprotein complexes of different densities that determine the structure of cholesterol in the body:

• LDL - low density - 70%;
• VLDL - very low density - 9-10%;
• HDL - high density - 20-24%.

Low-density lipoproteins are called harmful or bad cholesterol. Their source is only animal fats. LDL ensures the delivery of cholesterol to cells that need it, replenishes them with vitamins, and has a neutralizing effect on toxins.

Our body needs bad cholesterol to keep it functioning immune system, including protection against cancer.

At the same time, LDL is the cause of the appearance of plaques deposited on the walls of blood vessels, which can cause blockage (atheroma).

As a result, atherosclerosis and a number of associated pathologies develop: peripheral arterial disease, ischemic attacks, angina pectoris, stroke, and heart attack. Illnesses caused by atheroma lead to deterioration of health and most often cause death.

The structure of HDL differs from LDL. They have an anti-atherosclerotic effect by removing LDL from the cell walls and delivering them to the liver for processing and removal from the body. As a result, the thickness of the plaque decreases and the risk of developing atherosclerosis decreases.

Obesity, diabetes mellitus, liver hepatosis are factors that increase the level of bad cholesterol and reduce the level of good cholesterol.

Eating certain foods helps optimize the ratio of cholesterol components in the blood:

• Carrots, Jerusalem artichoke, celery, cabbage, beets, bran, greens, citrus fruits, pears, apples containing insoluble fiber;
• Phytosterols that lower LDL levels: grains, pumpkin, eggplant, zucchini, ginger, hibiscus, sesame, strawberries;
• Legumes;
• Sea fish, fish oil, corn, olive, mustard oil;
• Red rice;
• Avocado and its oil;
• Onions, garlic.

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Everything you need to know about triglycerides

Fats are an important part of our lives from a biological point of view, since they provide us with a significant proportion of the energy that we then expend over time. But everything is good in moderation, and obese people will confirm this. Where does obesity come from? What causes fats from food to be deposited in different parts of the body? Of course, physical inactivity and overeating play a significant role. But there are also biochemical reasons that lie in the word “triglycerides”. So what are triglycerides? Let's try to figure it out.

Functions

And it won’t be easy to figure it out, because chemists and biologists have different opinions about triglycerides. Their opinions agree on two points: the “triglyceride formula” and the “triglyceride structure.” When it comes to function, chemists tend to completely ignore the complex biological roles that these substances play in the body.

Biologists, on the other hand, are not particularly interested in the “personal qualities” of triglycerides, and view them as part of the extremely complex metabolism of fats and energy in the body.

Such different points of view are partly due to the inflexibility of chemical terminology: when lipids (fats in the broad sense) were first discovered, they were described too strictly and unambiguously. Over time, lipids were found that did not fit the old definition, and chemists had to hastily come up with clarifications and exceptions.

Confused in the chaos of definitions, biologists began to consider lipids (including TGs) as part of metabolism, ignoring chemical terminology.

Let us briefly list the terms that are needed to understand the role of triglycerides in the body:

• Lipids are fats in the broad sense of the word or fat-like substances. Present in all living cells.
• Triglycerides are simple lipids; among all fats, they are the main source of nutrition for cells. Synonym: “total fats.” They are divided into: short-chain TG, medium-chain triglycerides, long-chain TG.
• Lipoproteins are proteins that contain lipids. They are divided into high-density lipoproteins (“good” lipoproteins) and low-density lipoproteins (“bad” fats).
• Cholesterol is a fat-soluble alcohol. Normally, it is extremely important for the normal functioning of cell membranes, but in excess it is deposited on the inner walls of blood vessels in the form of crystals.

So, triglycerides are common fat that comes to us with food and performs several functions:

1. It is spent on the current energy needs of the body.
2. It is stored as fat reserves.
3. Transformed into lipoproteins.

There is no special explanation for the first point. Regarding the second, the following can be noted: a person has 3 main sources of energy - proteins, fats and carbohydrates. Why are fats deposited in peripheral tissues? First, 1 gram of fat gives a person the same amount of energy as 2 grams of carbohydrates or protein.

Secondly, fat conducts heat poorly, so during cold seasons a person loses less heat (which is also energy) due to fat deposits.

The third point, transformation into lipoproteins, deserves some attention. But first, let’s talk about the difference between short-, medium- and long-chain TGs. In fact, their general formula is the same, but the difference lies in the number of “fat blocks” per molecule. Short-chain triglycerides have 4-6, while long-chain triglycerides have about 20. So, the more fat blocks per fat molecule involved in the synthesis of lipoprotein, the lower the density of this lipoprotein.

What is the difference between high and low density lipoproteins? The structure of HDL is designed so that these molecules transfer cholesterol from peripheral tissues to the central bloodstream, where this cholesterol is used according to the situation.

LDL, on the other hand, does the opposite: it transfers cholesterol from the general bloodstream to peripheral tissues and small vessels, where (with an excess of LDL) crystalline deposits form.

It is very easy to get confused in metabolism (even doctors sometimes forget what comes from what and what turns into what), so we will provide a brief summary of all of the above:

1. fat in the form of TG enters the body with food;
2. part is spent on current needs, part on fat deposits, part on the production of lipoproteins;
3. the longer the triglyceride chain, the more fat the body needs to distribute;
4. the more fat needs to be distributed, the more goes into reserves and the more low-density lipoproteins are produced;
5. The more low-density lipoproteins there are, the more cholesterol ends up in small vessels.

Watch the video

Blood test

Triglycerides in the blood are determined using a biochemical blood test. This blood test should be done according to standard recommendations: on an empty stomach, in the morning, 2 days before the test, you should eat the same way as usual.

Triglycerides are shown mixed in the analysis, without separation by chain length (because this is very problematic from a technical point of view).

Scientific research on the relationship between triglyceride levels and body condition

Research on TG began in 1950, and since then the volume of data has been constantly increasing. For convenience, we will divide the studies into subcategories: triglyceride studies, triglycerides and nutrition, medium chain triglycerides as therapy.

Triglyceride studies

As mentioned above, TG were found in the blood in the middle of the last century, and in the next few decades, the primary task of scientists was to find out what kind of fat it is and what it is responsible for.

By and large, the results of these studies are described in the “More about triglycerides and their functions” section of this article. Short-chain MCTs (Medium Chain Triglycerides), long-chain MCTs and medium-chain TGs were detected. Much attention has been paid to their ability to transform into lipoproteins, as a result of which it was discovered that an excess of fatty foods in food provokes hypertriglyceridemia, which causes the production of large amounts of low-density lipoproteins, which lead to atherosclerosis and heart attacks.

Thus, a blood test for triglycerides has become a tool for the early diagnosis of atherosclerosis.

Triglycerides and nutrition

Triglycerides in food became a separate branch of research, because changing your diet is the best (and only) way to normalize this blood parameter.

The first interesting fact was that to normalize fat levels, you need to reduce your carbohydrate intake. The same sugar, for example, does not contain fat, but the more sugar in the daily diet, the more energy the body receives from it.

Fats, which would normally be used for the body’s current needs, remain unused and go “in reserve”.

Second interesting fact– Alcohol increases the level of fats in the blood. This is due to the fact that alcoholic drinks put a lot of stress on the liver, and it does not have time to process fats into energy. Therefore, frequent alcohol consumption leads to obesity.

And finally, “good” and “bad” foods. The most important discovery (and not only for TG) was the discovery of vitamin D, which is now called Omega-3. By itself, this vitamin does nothing for a person, but once in the blood, it accelerates the absorption of all other vitamins, as well as proteins, fats and carbohydrates. This vitamin is found in fish bones and joints, so getting it from food is not very easy. If you need to correct the balance of triglycerides (and other metabolic participants), it is better to take a course of vitamin D.

Other discoveries regarding products can be found in any manual on proper nutrition. Long-chain TGs predominate in fried foods, fast food and animal fats.

Short- and medium-chain triglycerides predominate in plant foods and oils.

Medium chain triglycerides as therapy

These TGs are of great interest to scientists because of their balance. The predominance of short-chain TGs in the diet leads to lack of nutrition and dystrophy, while long-chain TGs lead to atherosclerosis and obesity.

Medium chain triglycerides fall between these two extremes: they provide enough energy and do not lead to weight gain. Therefore, doctors began to develop individual diets with a predominance of “average” TG, and empirical studies have shown that such diets work.

Another use of medium-length triglycerides is in situations where the remaining triglycerides cannot be absorbed due to intestinal or liver pathologies (most often genetic).

For reasons that are not fully understood, a diet high in medium-chain triglycerides (more than 70% of total triglycerides) reduces the number of epileptic seizures in patients with epilepsy.

And finally, mid-chain TGs work effectively when the patient is unable to eat on his own (coma). Increasing these triglycerides in the diet of such patients reduces the risk of long-term complications from parenteral nutrition.

So, what are “triglycerides” in a blood chemistry test? This is the total fat that enters the body with food. TGs are part of a larger system of metabolism and energy production, distributed evenly throughout it. An increase or decrease in triglyceride levels is an extremely alarming sign, indicating either poor nutrition or metabolic problems.

How and why cholesterol is produced in the liver

The human body is a unique, complex machine that sometimes amazes with its capabilities. The biochemistry of the processes is so unusual that sometimes you can’t even imagine them. The liver is responsible for many processes; the production of cholesterol is one of its most important functions; the synthesis of steroid hormones, vitamin D, the transport of certain substances, and more depend on this. But how does this happen? Where does cholesterol come from in the liver, how is its biosynthesis carried out, and what happens in the body when it is disrupted?

Substance production

Many foods - meat, eggs, oils, processed foods and even fast food - contain cholesterol, and people consume them daily. It would seem that these sources can completely meet the body's needs, then why does the liver produce its low-density lipoprotein (LDL)?

Most often, cholesterol, which contains food “sources”, has a low density and is called “bad”, since due to a structural disorder the body cannot use it for synthesis or transport, so it settles in the form of atherosclerotic plaques on the walls of blood vessels or in the internal their parts.

The liver “takes care” of health; it also produces cholesterol, which has a normal density, but it filters its “harmful” analogue from the blood and gradually removes it from the body in the form of bile. This factor prevents the rapid development of atherosclerotic plaques.

Cholesterol biosynthesis

The formation of cholesterol molecules in the liver is an interesting process, which is not difficult to understand. It occurs in cells - hepatocytes. They have a well-developed endoplasmic reticulum - a cellular organelle responsible for the production of fatty and carbohydrate substances, as well as their modification. There is no need to delve into the jungle of biosynthesis, but rather proceed to the main points of the process.

The following compounds are synthesized step by step:

• mevalonate;
• isopentenyl pyrophosphate;
• squalene;
• lanosterol;
• and finally cholesterol.

Mevalonate synthesis

To synthesize mevalonate, the body requires a lot of glucose, which is found in sweet foods and cereals. Each sugar molecule is broken down in the body by enzymes into 2 molecules of acetyl-CoA. After which acetoacetyltransferase enters the reaction, which converts the latter product into acetoyl-CoA. From this compound, through other complex reactions, mevalonate is ultimately formed.

Isopentenyl pyrophosphate

When enough mevalonate is produced in the endoplasmic reticulum of hepatocytes, the synthesis of isopentenyl pyrophosphate begins. To do this, mevalonate is phosphorylated - it gives up its phosphate to several molecules of ATP - a nucleotide, which is the body’s universal energy store.

Squalene

Through successive condensations (release of water) of isopentenyl pyrophosphate, a squalene molecule is formed. If in the previous reaction the cell spends ATP energy, then to synthesize squalene it uses NADH, another source of energy.

Lanosterol

The penultimate reaction in the chain of cholesterol creation by the liver is the production of lanosterol. This occurs when water is removed from the lanosterol molecule, after which the molecular form of the compound, instead of being unfolded, becomes cyclic. Here NADPH becomes the energy donor for the reaction.

Cholesterol

The process of converting lanosterol into cholesterol occurs in the membranes of the endoplasmic reticulum of the hepatocyte. The molecule of the first substance, through several modifications, acquires a double bond in the carbon chain. This requires a lot of energy, the donors of which are NADPH molecules. After various transforming enzymes “work” on lanosterol derivatives, cholesterol is formed.

The synthesis pathway in the body is complex, occurring in 5 stages, which are controlled by various enzymes, energy donors and other factors. For example, the activity of some reaction catalysts is influenced by thyroid hormones and insulin.

How the body uses the substance

Synthesized cholesterol is necessary for very important processes. Several of its main functions:

• synthesis of steroid hormones;
• and vitamin D;
• transport Q10.

Hormone production

Steroids are: corticosteroids, glucocorticoids, mineralcorticoids and others that regulate metabolic processes, active substances, as well as female and male sex hormones. All of them are no longer formed in the liver, but in the adrenal glands. Cholesterol gets there due to the fact that all organs are connected by a network of blood vessels through which blood delivers it.

Vitamin D synthesis

There is a lot of cholesterol in skin cells, since vitamin D is produced from it under the influence of ultraviolet radiation, which regulates the absorption of calcium in the body. LDL is transported to the epidermis from the liver, but some of it is synthesized in skin cells.

Transport Q10

If we talk about the molecular function of cholesterol, it is worth mentioning Q10 transport. This enzyme protects membranes from the destructive action of enzymes. A lot of Q10 is synthesized in certain structures, and then released into the bloodstream. It cannot penetrate other cells on its own, so there is a need for a transporter. Cholesterol takes responsibility for the transport of Q10, “pushing” the enzyme inside.

Metabolic disorder

What happens if cholesterol synthesis changes? The consequences of the deviation depend on whether the reaction has shifted towards a deficiency or excess of produced molecules.

Lack of cholesterol

Due to diabetes, a thyroid disorder, heart failure, or a genetic predisposition, the body may produce less LDL than needed. When this happens in the human body, serious diseases appear:

• lack of sex and other steroid hormones;
• children develop rickets as a result of failure to absorb calcium;
• premature aging and cell death due to the destruction of their membranes without Q10;
• weight loss with insufficient fat breakdown;
• immune suppression;
• Pain in the muscles and heart appears.

The problem of cholesterol deficiency can be solved by following a diet that contains foods with healthy cholesterol (eggs, lean meat, dairy products, vegetable oils, fish), as well as by treating diseases that cause abnormalities in the production of LDL in the liver.

Excess cholesterol

If a person has too much cholesterol, then his health is also at risk. The reasons for this violation are:

• hepatitis and cirrhosis (the liver cannot utilize excess cholesterol in a timely manner);
• excess weight;
• lipid metabolism disorders;
• chronic inflammatory processes.

When cholesterol accumulates, atherosclerotic plaques form inside the vessels, a lot of bile is produced, which does not have time to leave the gallbladder and forms stones there, and the functioning of the heart and nervous system also suffers. If this condition is not treated, myocardial infarction, stroke, etc. will soon develop.

Conclusion

Cholesterol synthesis by the liver is a complex, energy-consuming process that occurs daily inside liver cells. The body produces its own high-density lipoproteins so that the blood vessels are not covered with cholesterol plaques, which are the site of deposition of harmful cholesterol from food. If this synthesis is disrupted, then atherosclerosis progresses.

Cholesterol is a waxy substance that is produced in the liver and then enters the blood. It gives cell membranes fluidity and permeability. In addition, cholesterol is involved in the production of hormones and vitamins in the body. In addition to the fact that cholesterol is secreted in the liver, it also enters the body through the meat we eat. High levels of saturated and trans fats in the diet cause the liver to produce excess cholesterol, which increases the risk of heart attack or stroke. To find out potential health hazards, your doctor may order a blood test to determine the ratio of good cholesterol to bad cholesterol. High level cholesterol usually causes narrowing or blocking of the arteries due to the accumulation of cholesterol plaques in them.

Steps

Part 1

Cholesterol level determination

Prepare for analysis. Do not eat or drink anything for 9-12 hours before your test. As a rule, you can drink water the day before the test, but you should refrain from coffee, tea, alcoholic and carbonated drinks.

1. Select the location for the test. It is recommended that you get your cholesterol tested by your family doctor because he or she knows your age, family history and other factors related to your health better than anyone else. This information plays an important role in interpreting the results obtained during the analysis. Because your family doctor knows you well, if you have high cholesterol, he will be able to draw up a suitable treatment plan for you.

   • There are many different tests that are designed for home use, but they have not been approved by most health organizations. When using such tests, please read the included instructions carefully and use caution. These tests may give incorrect results.
   • Clinical examination tests are usually inexpensive, but they are not recommended for children and adolescents. Adults should also be careful about such tests, as they may not be accurate enough. Proper analysis requires appropriate equipment, supervision and trained personnel.
   • A number of organizations and companies conduct medical examinations of employees. In this case, you should pay attention to which medical institutions conduct medical examinations and whether they are trustworthy.

2. Calculate cholesterol ratio. A cholesterol test measures high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, and triglyceride levels. This involves taking a small amount of blood from your arm, which is then analyzed in a laboratory. The result is a cholesterol level in millimoles per liter of blood, and your doctor interprets this value based on your age, family history and blood pressure.

   Part 2

   Preventing High Cholesterol

   1. Monitor your blood pressure. High blood pressure is a major risk factor for heart disease and stroke. High blood pressure means increased stress on the heart and arteries, as well as kidney problems, and can be caused by high cholesterol levels.

      • Blood pressure can be reduced by eating a healthy diet, exercising regularly, reducing stress, maintaining an optimal body weight, and avoiding smoking and drinking alcohol. Changing your lifestyle can be difficult. It may be worth asking your doctor to recommend a competent specialist who can help you do this.
      • In case of high blood pressure, you need to be aware of this problem. There are very few (or even none) symptoms of high blood pressure, so be sure to measure it regularly. You can check your blood pressure at every doctor's visit, but if you do have high blood pressure, your doctor may recommend that you purchase a blood pressure monitor and measure your blood pressure regularly at home.

   2. Lower your blood sugar levels. High blood sugar can cause health problems and lead to diabetes. Diabetes is known to lower HDL cholesterol (good cholesterol) and increase LDL cholesterol (bad cholesterol), which increases the risk of heart disease and stroke.

      • This phenomenon is called diabetic dyslipidemia. Her side effect is atherosclerosis, in which cholesterol clogs the arteries.
      • If your family history or other factors indicate you are at high risk for developing diabetes, lose excess weight, eat a healthy diet, and increase your physical activity. These measures will help significantly reduce the risk of developing diabetes.
      • There are also medications that can help lower blood glucose levels and prevent heart attack or stroke.

   3. Lead an active lifestyle. Not only is this good in itself, but it can also help prevent many of the health problems that are associated with high cholesterol. Try to exercise daily. By doing so, you will strengthen your heart and increase the length and quality of your life.

      • Any exercise that gets you sweating and breathing faster strengthens your heart and helps lower cholesterol. For example, you can do walking, swimming, cycling, jogging, skiing or mountain climbing.
      • Choose what you like and is convenient for you. This could be a specific training program in a group, individual sports, or doing exercises together with a partner. Keep in mind that if training brings you pleasure, you are unlikely to give it up.

   4. Stick to it healthy diet nutrition. A healthy diet is the most important factor in promoting health and reducing the risk of a wide range of diseases and problems, including reducing cholesterol levels. Try to eat a healthy diet.

      • Learn how calories affect your health and how many calories you should eat daily. Most food labels recommend a daily intake of 2,000 calories, and you need to know how that number compares to your daily value, which depends on your age, gender, and level of physical activity. Talk to your doctor or professional nutritionist about a healthy eating plan that is right for you.
      • Regular exercise helps maintain optimal weight and lower cholesterol levels.
      • It is best to have a varied and well-balanced diet. Make sure you get the nutrients you need from all the major recommended food groups. Foods rich in micronutrients, proteins and whole grains contain few calories and help maintain optimal body weight.
      • Limit your intake of saturated and trans fats, sodium, red meat and sugar, all of which contribute to high cholesterol levels.
      • Try not to add salt, sauces or creams to your food.
      • Drink low-fat (skim) and low-fat (1%) dairy products, eat enough whole grains that are high in fiber, and eat 2-3 servings of vegetables and fruits daily.
      • Eat fish rich in omega-3 fatty acids twice a week, or eat other foods high in these acids, such as avocados. olive oil and nuts.
      • Drink alcohol in moderation. Women should drink no more than 1 serving, and men - 2 servings per day. One serving corresponds to 30 milliliters of strong drink, 120 milliliters of wine or 250 milliliters of beer.

   5. Lose weight. Maintaining an optimal body weight will reduce the load on internal organs, especially the heart. Lead an active lifestyle and watch your weight to lower your blood pressure and normalize your cholesterol levels.

      • A simple way is to reduce your calorie intake to the amount your body burns. If you consume more calories than you burn, your body will store the extra energy as fat and you will gain weight.
      • A pound of fat is equivalent to about 3,500 calories. To lose half a kilogram in a week, you need to reduce the daily amount of calories by about 500 units, which can be achieved through a combination of diet and exercise.
      • Find out how many calories are in the food you eat and either eliminate unhealthy foods from your diet completely or reduce the amount to an acceptable level.
      • Calorie counts are difficult to calculate when you're at the grocery store, so make a short list of typical foods and how many calories they contain. This will make it easier for you to keep calories in mind when purchasing and eating food.

   Part 3

   Why is cholesterol dangerous?

   1. Consider your risk factors. High cholesterol can be deadly because it rarely causes any symptoms. When deciding whether to get your cholesterol levels checked, you should also consider the associated risk of heart attack and stroke.

      • With the help of your doctor, creating and following a healthy lifestyle plan will help lower your cholesterol levels and improve your overall health. Listen to your doctor's advice because he or she will know your medical history and risk factors.
      • High cholesterol levels are usually directly related to poor diet, excess weight, insufficiently active lifestyle and smoking. Change your diet to lower your cholesterol levels. Try to eat less meat and more fresh vegetables and fruits.

Cholesterol

Cholesterol or cholesterol is a steroid found only in animal organisms. Belongs to the class of sterols (steryls). Sterols are characterized by the presence of a hydroxyl group at position 3, as well as a side chain at position 17. In cholesterol, all rings are in the trans position; in addition, it has a double bond between the 5th and 6th carbon atoms. Therefore, cholesterol is an unsaturated alcohol:

Core formed by hydrogenated phenanthrene (rings A, B and C) and cyclopentane (ring D). Cyclopentaneperhydrophenanthrene (common structural basis of steroids)

The ring structure of cholesterol is characterized by significant rigidity, while the side chain is relatively flexible. So, cholesterol contains an alcohol hydroxyl group at C-3 and a branched aliphatic chain of 8 carbon atoms at C-17. The chemical name for cholesterol is 3-hydroxy-5,6-cholestene. The hydroxyl group at C-3 can be esterified with a higher fatty acid, resulting in the formation of cholesterol esters (cholesterides)

More than 50% of cholesterol is synthesized in the liver, 15-20% is synthesized in the small intestine, the rest of the cholesterol is synthesized in the skin, adrenal cortex, and gonads. In the cytoplasm, cholesterol is found predominantly in the form of esters with fatty acids, forming vacuoles. In blood plasma, both unesterified and esterified cholesterol are transported as part of lipoproteins. About 1 g of cholesterol is synthesized in the body per day; 300-500 mg comes with food. It is a component of cell membranes, a precursor in the synthesis of bile acids, steroid hormones, and vitamin D.

History of discovery. In 1769, Pouletier de la Salle obtained from gallstones a dense white substance (“adipose wax”) that had the properties of fats. Cholesterol was isolated in its pure form by the chemist, member of the National Convention and Minister of Education Antoine Fourcrouw in 1789. In 1815, Michel Chevreul, who also isolated this compound, called it cholesterol (“chole” - bile, “sterol” - fatty). In 1859, Marcelin Berthelot proved that cholesterol belongs to the class of alcohols, after which the French renamed cholesterol “cholesterol.” In a number of languages ​​(Russian, German, Hungarian, etc.), the old name - cholesterol - has been preserved.

Cholesterol synthesis starts with acetyl-CoA. Cholesterol biosynthesis can be divided into four stages. In the first step (1), mevalonate (C6) is formed from three molecules of acetyl-CoA. In the second step (2), the mevalonate is converted into “active isoprene,” isopentenyl diphosphate. In the third step (3), six isoprene molecules polymerize to form squalene (C30). Finally, squalene cyclizes with the elimination of three carbon atoms and is converted to cholesterol (4). The diagram shows only the most important intermediate products of biosynthesis.

1. Formation of mevalonate. The conversion of acetyl-CoA to acetoacetyl-CoA and then to 3-hydroxy-3-methylglutaryl-CoA (3-HMG-CoA) corresponds to the pathway of ketone body biosynthesis (for details, see Fig. 305), however, this process does not occur in mitochondria, but in the endoplasmic reticulum (ER). 3-HMG-CoA is reduced with the elimination of coenzyme A with the participation of 3-HMG-CoA reductase, a key enzyme in cholesterol biosynthesis (see below). At this important stage, by repressing the biosynthesis of the enzyme (effectors: hydroxysterols), as well as due to the interconversion of the enzyme molecule (effectors: hormones), regulation of cholesterol biosynthesis is carried out. For example, phosphorylated reductase is an inactive form of the enzyme; insulin and thyroxine stimulate the enzyme, glucagon inhibits; Dietary cholesterol also inhibits 3-HMG-CoA reductase.

2 . Formation of isopentenyl diphosphate. Mevalonate, due to decarboxylation with the consumption of ATP, is converted into isopentenyl diphosphate, which is the structural element from which all isoprenoids are built.

3 . Formation of squalene. Isopentenyl diphosphate undergoes isomerization to form dimethylallyl diphosphate. Both C5 molecules condense into geranyl diphosphate and, as a result of the addition of the next isopentenyl diphosphate molecule, form farnesyl diphosphate. When the latter dimerizes in a head-to-head manner, squalene is formed. Farnesyl diphosphate is also the starting compound for the synthesis of other polyisoprenoids, such as dolichol and ubiquinone.

4. Cholesterol formation. Squalene, a linear isoprenoid, cyclizes with the consumption of oxygen into lanosterol, a C30-sterol, from which three methyl groups are cleaved in subsequent steps catalyzed by cytochrome P450, resulting in the formation of the final product - cholesterol. The described biosynthesis pathway is localized in the smooth ER. The synthesis occurs due to the energy released during the breakdown of coenzyme A derivatives and energy-rich phosphates. The reducing agent in the formation of mevalonate and squalene, as well as in the last stages of cholesterol biosynthesis, is NADPH + H+. This pathway is characterized by the fact that intermediate metabolites can be divided into three groups: coenzyme A derivatives, diphosphates, and highly lipophilic compounds (from squalene to cholesterol) associated with sterol transporters.

.

Esterification of cholesterol. In some tissues, the hydroxyl group of cholesterol is esterified to form more hydrophobic molecules, cholesterol esters. The reaction is catalyzed by the intracellular enzyme ACHAT (acylCoA: cholesterol alyltransferase). The esterification reaction also occurs in the blood in HDL, where the enzyme LCAT (lecithin: cholesterol acyltransferase) is located. Cholesterol esters are the form in which they are stored in cells or transported in the blood. In the blood, about 75% of cholesterol is in the form of esters.

Literature used

Berezov. Korovkin.

http://www.xumuk.ru/biochem/174.html

http://biokhimija.ru/lipidny-obmen/cholesterin.html

http://ru.wikipedia.org/wiki/%D0%A5%D0%BE%D0%BB%D0%B5%D1%81%D1%82%D0%B5%D1%80%D0%B8%D0 %BD