Cholesterol (cholesterol) is a fat-like substance that is vital to a person. It is a part of the shells of all cells of the body, a lot of cholesterol in the nervous tissue (60% of the brain consists of fatty tissue), many of the hormones are formed from cholesterol.
In most people, the word "cholesterol" is associated with the word "atherosclerosis". But cholesterol is a necessary substance for human life, which is contained in every cell of our body.
From the biography of cholesterol
In 1769 Pouletier de la Salle received from the gallstones a dense white substance ("zhivorovsk"), which had the properties of fats. In 1815, Michel Chevrel, dubbed this compound cholesterol ("chol" - bile, "sterin" - fat).
In 1859, Marcelin Berthelot proved that cholesterol belongs to the class of alcohols and, therefore, in accordance with the chemical nomenclature, it should be called cholesterol. In the West, he is called that.
A cholesteric theory was first proposed by the Russian scientist NN Anichkov at the beginning of the 20th century. In the twentieth century for the work on the study of cholesterol, 13 Nobel Prizes were awarded.
The role of cholesterol in the body
What kind of cholesterol is vital for us, and which one can be considered a sworn enemy of man?
The role of cholesterol in the human body is enormous and diverse.
Cholesterol is a part of sex hormones, is contained in the brain. He plays a crucial role in the activity of the body, but there are situations when cholesterol from a friend turns into a dangerous enemy.
It is necessary for the production of vitamin D, which is involved in the regulation of calcium and phosphorus metabolism in the body; for the development of the adrenal glands of various steroid hormones, including cortisol, aldosterone, female sex hormones estrogen and progesterone, the male sex hormone testosterone, and according to recent data - plays an important role in the activity of brain synapses and the immune system, including protection against cancer.
In the liver of cholesterol, bile acids are formed that help us digest fats. And cholesterol serves as a building material for cell membranes. It makes them strong and elastic. And to replace it in these important matters nothing else can.
80% of the cholesterol necessary for a person is produced directly in the body, in the liver and small intestine. The rest of the organism "imports". The main suppliers of cholesterol are offal (brain, liver, kidneys), fatty meat, butter, egg yolk.
WHO recommends that healthy people consume not more than 0.3 grams of cholesterol per day. This amount is contained, approximately, in 1 liter of milk of 3 percent fat content, 300 g of boiled chicken, 200 g of pork, 150 g of smoked sausage, 50 g of beef liver or one and a half chicken eggs. And on the average we eat 0.43 g of cholesterol, that is, almost 50% more than normal.
Low cholesterol in future mothers can lead to premature birth.
In 1991, the American medical journal The New England Journal of Medicine published an article by Professor Fred Kern, a respected expert in gastroenterology in the United States. It was called "Normal level of cholesterol in the blood plasma of an 88-year-old man who eats 25 eggs a day." The protagonist of this article ate 25 eggs a day for 15 years. That is, every day he consumed cholesterol 20 times more than the recommended quantities and at the same time was perfectly healthy. The cholesterol content in his blood was within normal limits.
Scientists have tried to find out where the excess of cholesterol disappears. It turned out that excess dietary cholesterol reduced the synthesis of cholesterol in the liver of a male by 20%. And in some people food cholesterol in the intestines is absorbed badly and is removed from the body together with the remnants of undigested food.
The French paradox! In France, traditionally consuming fatty, cholesterol-rich food, cardiovascular diseases are much less common than in other Europeans. The reason for this is moderate consumption of red dry wines.
In everyday life, we are accustomed to divide cholesterol into "good" and "bad." But in fact he is no, but whether it becomes good or bad depends on his "environment". The fact is that he can not independently travel the body and does it exclusively in the company with fats and transport proteins. Such compounds are called lipoproteins. There are several types. And all have the same shape - a ball. But the size, density and composition are different. The smallest are high-density lipoproteins (HDL). Here they are called "good cholesterol". A low-density lipoprotein (LDL) and very low density (VLDL) - "bad." That is, the lower the density of these compounds, the larger the size. And this division is connected with the various participation of lipoproteins in the development of atherosclerosis.
Atherosclerosis and cholesterol
Atherosclerosis is the process underlying most diseases of the circulatory system (IHD, myocardial infarction, thrombosis, cerebral stroke, gangrene of the lower extremities, etc.). The mortality of cardiovascular diseases has long been the first in the world and, despite all the achievements of medicine, this sad statistics remains unchanged.
It is believed that this is caused by an increased level of cholesterol, which is deposited on the walls of blood vessels in the form of plaques, making it difficult to flow. But we will remember that the development of atherosclerosis is promoted by a large content of bad cholesterol. A good, on the contrary, clears the vessels from it.
Still, the connection between high cholesterol and atherosclerosis is ambiguous: on the one hand, an increase in cholesterol in the blood plasma is considered an indisputable risk factor for atherosclerosis, on the other hand, atherosclerosis often develops in people with normal cholesterol. In fact, high cholesterol is only one of many risk factors for atherosclerosis (obesity, smoking, diabetes, hypertension). The presence of these factors in people with normal cholesterol potentiates the negative effect of free cholesterol on the walls of the vessels and thereby leads to the formation of atherosclerosis with lower cholesterol concentrations in the blood.
There is also a different view on the problem of cholesterol. Cholesterol as a "repair" material accumulates in places of microdamage of blood vessels and blocks these damages, performing a homogeneous medicinal role. That is why atherosclerosis is observed in people with normal cholesterol levels. People with an elevated level of the problem appear faster, plus, the presence of an elevated cholesterol level is easier to statistically associate with atherosclerosis, which was done at the beginning of the research, because of which cholesterol was declared the culprit of all ills. Therefore, simply lowering cholesterol alone does not solve all the problems with blood vessels. The lack of cholesterol in this case can cause hemorrhages. It is necessary to further study the causes of vascular damage and the development of methods for their treatment.
Fats are also different
American researchers from Connecticut put forward a hypothesis about the relationship between low cholesterol and people's predisposition to cruel behavior and violence.
The level of cholesterol in the blood largely depends not only on its quantity in food, but also on the quantity and quality of the fats contained in it. Some fats are simply necessary for a person, because they lower the level of bad cholesterol, increasing the amount of good. These are monounsaturated fats. They are in almonds, avocados, cashew nuts, natural nut and olive oils, pistachios, sesame oil and its seeds. They should not be abandoned.
Corn oil, pumpkin seeds and sunflower seeds contain polyunsaturated fats. They do not clog arteries with harmful deposits. From them, too, you can not give up, but not zealous with their abundance.
Fatty varieties of fish and seafood, as well as flaxseed, hemp and soybean oil, walnuts - a source of polyunsaturated fatty acids Omega-3. The organism can not synthesize them on its own, they must come with food. At a lack of these acids in a delivery atherosclerotic plaques. On the walls of the vessels are formed at twice the rate.
But the consumption of saturated fats, which raise the level of cholesterol in the blood, should be limited. To do this, you have to eat less, adhering to a diet that lowers cholesterol. It is desirable to completely exclude from the diet pork, beef, butter, fatty cheeses, palm and coconut oils, cream, sour cream, ice cream and whole milk.
There is another potentially dangerous group of fats - trans fats. Most of them are made artificially from liquid vegetable oils - a special way of processing them, get solid oils, what we used to call margarine. Trans fats increase the level of bad cholesterol in the blood, while reducing the level of good. Unfortunately, most of the fats used in the production of confectionery, baking, semi-finished products - just from this group.
Cholesterol and age
The level of cholesterol increases with age. For newborns this is 1.3-2.6 mmol / l, for babies from one year to two - 1.8-4.9 mmol / l, for children from two to fourteen years - 3.7-5.2 mmol / l, for adults - 3.9-5.2 mmol / l. If the blood of an adult person contains from 5.2 to 6.5 mmol / l of cholesterol, doctors say a slight deviation from the norm; from 6.6 to 7.8 mmol / l - the deviation is moderate; above 7.8 mmol / l is already severe hypercholesterolemia. A disease that must be treated without fail.
Begin to monitor the level of cholesterol doctors recommend years with 20-25. But if a family has a high cholesterol in its older members, then children should be monitored from adolescence.
Women of childbearing age are protected from atherosclerosis by nature: female sex hormones prevent the deposition of cholesterol on the walls of blood vessels. But during menopause, the cholesterol level usually rises. And with it the risk of cardiovascular diseases increases.
And cholesterol is important for the formation of serotonin - a substance involved in the transmission of nerve impulses. If there is little serotonin, a person faces depression. Scientists compared cholesterol levels in 149 patients with depression hospitalized after a suicide attempt, 149 depressed patients who did not attempt suicide, and 251 healthy controls. And they came to the conclusion that with low cholesterol, the risk of suicide increases. So to achieve a decrease in its level to zero is also not worth it - in the body, as a rule, nothing superfluous happens.
Analysis for cholesterol
An important analysis is a lipidogram, or fatty formula of blood, it is also an analysis for cholesterol. What does this analysis say and why is it important to know its meaning?
Total cholesterol (or cholesterol). Normally, this figure should not exceed 5.5 mmol / l.
What is dangerous for high cholesterol?
To begin with, the normal cholesterol is present in the body. Cholesterol acts as a transport molecule, or carrier of fats. He drags the fat either inside the vessel, or from the vessel. But when its concentration exceeds a certain permissible level, it is deposited in the vessels. Atherosclerotic plaques are formed. In simple terms, the vessels are clogged.
This is dangerous with the following condition: when a large amount of liquid cholesterol accumulates in the vessel wall, a small tear appears, in the place of which thrombocytes and red blood cells rush. So the thrombus is formed. The vessel overlaps: myocardial infarction, stroke or gangrene of the extremity may occur.
Triglycerides (TG). The norm for men is up to 2 mmol / l, for women - up to 1.5 mmol / l.
Triglycerides are fats that accumulate in the body, and when energy is needed, triglycerides come out of the adipose tissue and go to the muscles that burn them. If fats are not wasted, fat deposits inside the abdomen, on the hips, etc. are formed. Obesity is developing.
The ratio of HDL to LDL is calculated in the analysis. It turns out the final formula for the risk of atherosclerosis. If the LDL is greater, then they settle on the walls of the vessels, are oxidized, thus forming an atherosclerotic plaque. When we are dominated by HDL, then they go to the liver and there are recycled.
Remember that bad cholesterol is not taken from nowhere, it enters your body with food. Do not eat anything, choose vegetables and fruits instead of fatty foods, and then you will live a long and happy life without atherosclerosis.
Treatment of disorders of cholesterol metabolism
A healthy lifestyle: reducing excess weight, regular exercise and a diet low in saturated fats and low cholesterol.
Drugs that reduce the levels of "bad" cholesterol are prescribed when positive lifestyle changes do not have a significant effect on the levels of "bad" cholesterol.
The most effective and widely used drugs to reduce the level of "bad" cholesterol are statins. Studies have shown that statins can reduce levels of "bad" cholesterol and thereby prevent heart attack and stroke. Other drugs that are used to reduce the level of "bad" cholesterol include: polycosanol, nicotinic acid (niacin, niacin + laropiprant), cholesterol absorption inhibitor in the intestine - ezetimibe (zetia, ezetrol), combinations (inegi, vitorin), fibrates like , for example, gemfibrozil (lopid) and resins, such as cholestyramine (quistra).
And finally, three simple tips:
It is impossible to refuse from fat at all: it is a source of energy, a building material for cell membranes, a protective material;
The American Heart Association notes that the number of calories from fat should not exceed 30% of the daily allowance (for urban dwellers not engaged in manual labor, this is approximately 600-800 kcal);
There is only necessary natural fats. Remember: the most useful fats are those that remain liquid at room temperature.