What you need to know about cholesterol

What is cholesterol

Cholesterol, or cholesterol, is a fat-like substance that belongs to the lipid class. Cholesterol does not dissolve in water, so lipoproteins are used to transport it through the vessels – “trucks” for all types of lipids.

Cholesterol is essential for the body. It is a part of cell membranes and regulates their density, and also participates in the synthesis of many important substances: vitamin D, male and female sex hormones and bile.

The body of an adult contains about 140 g of cholesterol. On average, we get about 0.3-0.5 g from food, and the body synthesizes another 1 g on its own. Any cell can produce cholesterol if needed, but the liver and small intestine are primarily responsible for this.

Cholesterol deficiency is very rare. It is caused by hereditary diseases that interfere with the mechanisms of fat absorption, such as Tangier’s disease, malabsorption syndrome, or hyperthyroidism.

Its excess is much more common – hypercholesterolemia. Cholesterol that has not been utilized by the cells remains in the blood. Over time, it adheres to the walls of blood vessels and forms plaques that interfere with blood flow, and then completely block them. Blockage of blood vessels throughout the body is atherosclerosis.People with high cholesterol are at increased risk of:

• heart attack;
• stroke;
• ischemic heart disease;
• heart attack;
• heart failure;
• diseases of the central and peripheral vessels.

Bad and good cholesterol

Doctors often distinguish between “good” and “bad” cholesterol. This is not entirely true: cholesterol is one substance, and its quality determines which type of lipoprotein transports it.

LDL – “bad” cholesterol

“Bad” is the name given to cholesterol, which is carried by low-density lipoprotein (LDL) cholesterol. It is they who adhere to the walls of blood vessels, creating cholesterol plaques.

HDL – “good” cholesterol

“Good” cholesterol is one that is transported by high-density lipoprotein (HDL). They not only deliver it to the cells, but also collect excess cholesterol, including the one that sticks to the vessels along with LDL, and carry it back to the liver. From where it is excreted with feces. A large amount of good cholesterol is beneficial in the long run.

The ratio of types of lipoproteins in the blood is no less important for the control of the state of the cardiovascular system than the total level of cholesterol.

What foods raise cholesterol levels

Man gets cholesterol from animal food. A certain amount of it is found in any type of meat or dairy product. Cholesterol analogs from plant foods are not absorbed.

The level of cholesterol in the blood depends not only on its content in food but also on many other factors. Some foods contain cholesterol along with saturated fats, which themselves raise blood levels. A diet for people with high cholesterol involves refusal, first of all, from just such food.

Foods high in cholesterol and saturated fat:

• fat meat;
• bacon, lard;
• fatty milk and dairy products;
• butter, margarine;
• semi-finished meat products, sausages, sausages;
• coconut oil and palm oil (they are cholesterol-free, but are often used with foods that have a lot of it).

Other cholesterol-rich foods are low in saturated fat. They are not so dangerous, and people with slightly high cholesterol can eat them occasionally. These products include:

• lean meat;
• hen;
• offal: liver, kidney, heart, scar;
• seafood: shrimps, crabs, squids;
• egg yolk.

Scientists are not yet sure exactly how saturated fats raise cholesterol levels. According to a 2021 study [1] , this mechanism works as follows: when a cell receives a lot of saturated fats from the blood (saturated fats are solid, they are part of the cell membrane), its membrane hardens. Cholesterol plays the role of a regulator of membrane density – if it becomes solid, then the need for it decreases, and the cell reduces its consumption. Therefore, the proportion of cholesterol that remains in the blood and can be deposited in atherosclerotic plaques increases.

Unsaturated fats, on the other hand, make the membrane more elastic. This forces the cell to absorb more cholesterol (it does not harm her) and reduces its concentration in the blood.

According to another version, saturated fats inhibit LDL receptors and increase their content in the blood [2] .

Foods high in unsaturated fat:

• avocado;
• vegetable oils;
• fatty fish;
• fish fat;
• pine and walnuts;
• pistachios;
• grape seeds;
• seeds.

Also, cholesterol levels and total blood lipid saturation greatly increase trans fats. They are considered the worst type of lipids and one of the most damaging macronutrients for the cardiovascular system [3] .

Trans fats are a by-product of the hydrogenation process of unsaturated fats, during which vegetable oils are hardened by adding a hydrogen molecule to their structure. This is how spreads are produced. Also, trans fats are formed when frying in oil – so you need to change it as often as possible. Many countries today impose severe restrictions on the amount of trans fat. Since 2018, in Russia, they can make up no more than 2% of the total fat in a product [4] .

Most trans fats are found in the following foods:

• margarine;
• cream substitutes;
• ice cream;
• factory baked goods;
• fast food;
• frozen ready-made semi-finished products;
• deep-fried food.

“In 2015, the US Food Safety Administration (FDA) legally obliged all manufacturers to remove industrial trans fats from formulations within three years,” says nutritionist Maria Volchenkova. “There is no such ban in Russia, and the level of consumption of products with industrial trans fats remains extremely high.”

Causes of increased cholesterol

An excess of cholesterol has no symptoms until it develops into a disease of the cardiovascular system. Therefore, he is doubly dangerous.

The level of “bad” cholesterol depends on many factors. Here are the main ones:

• unhealthy diets, which are high in animal fats and simple carbohydrates;
• overweight;
• high blood pressure;
• hereditary predisposition to cardiovascular disease;
• elderly age;
• gender (men have a higher risk);
• smoking;
• alcohol;
• genetic predisposition to high cholesterol;
• diseases of the liver, kidneys, intestines, thyroid gland;
• diabetes.

Hereditary (familial) hypercholesterolemia is one of the most common genetic diseases. According to the Ministry of Health, 1 out of 200 people in the world has genetic damage that causes familial hypercholesterolemia .

Also, some medications can raise the level of bad cholesterol:

• drugs for HIV;
• arrhythmia medications;
• beta-blockers, which treat angina pectoris or high blood pressure;
• chemotherapy drugs;
• diuretics;
• immunosuppressants;
• retinoids;
• steroids.

Studies show that the oils found in coffee can raise blood cholesterol levels by 5% of normal. At the same time, the content of oils in the drink depends on the brewing method – most of them are in coffee prepared in a funnel or a French press, and least of all in instant coffee or from a drip coffee maker. Some people have a genetic mutation that slows down the breakdown of coffee oils and enhances this negative effect .

When to start monitoring your cholesterol

There is no exact data on how often the acquired excess of cholesterol is found among Russians. However, cardiovascular diseases, which most often develop against the background of high cholesterol, are considered the first most common cause of death in Western countries and Russia. According to the Ministry of Health, in 2020 the share of diseases of the cardiovascular system in the structure of the total mortality rate of Russians was 46%.

There is a popular myth that high cholesterol is a problem for the elderly and should not be thought of until at least 50 years of age. This is not the case: high cholesterol can be diagnosed in young people and even in children.

The American Heart Association recommends checking cholesterol levels every 4–6 years starting at age 20  . The American Center for Disease Prevention recommends taking a cholesterol test every five years from childhood . The Russian Ministry of Health instructs people with a predisposition to high cholesterol to take a child to a doctor and have a test done before he turns eight.

Cholesterol norms

Cholesterol levels are checked with a blood test. A simple test shows only the total blood cholesterol, and the detailed test also includes data on the proportions of LDL and HDL, as well as triglyceride levels.

It is not easy to understand the results of the analysis – it is better to see a doctor. There is no universal norm for types of cholesterol – it differs depending on how high a person’s risk of developing cardiovascular diseases is. The more it is, the lower it is recommended to keep the cholesterol level. The doctor will help to determine the risk group.

How to lower cholesterol

To lower LDL cholesterol and increase the proportion of HDL cholesterol, doctors recommend a diet low in animal fats and carbohydrates, exercise, and quitting smoking and alcohol. Cholesterol is also lowered with medication – using a class of drugs called statins. Only a doctor can choose the right treatment.

Does cholesterol rise during pregnancy and lactation? How to control it during these periods?

Cholesterol levels rise during pregnancy. It is necessary for the formation of cell membranes, the proper functioning of the hormonal system, including the production of vitamin-hormone D. That is, it is necessary for the proper development of the child. Further, during breastfeeding, the cholesterol level remains elevated for some time.

How long will this increase last?

Scientific publications describe different terms. On average, three to six months. If a woman has been diagnosed with violations of the lipid spectrum of the blood (especially an increase in LDL and triglycerides) even before pregnancy, she should definitely consult a doctor.

The main control method for women with initially normal cholesterol levels is to monitor the ratio of carbohydrates to fat in the diet. It is especially important to completely eliminate industrial trans fats in combination with sugar. However, the rejection of such products is needed by everyone, not just pregnant and lactating women. Trans fatty acids combined with sugar have a profound effect on the risk of atherosclerosis.

But the question of the effect of natural foods rich in saturated fatty acids and cholesterol (butter, eggs) on the lipid spectrum of the blood remains controversial today. However, all official guidelines indicate the need to reduce the consumption of saturated fat, especially red meat. It is important to understand that this does not apply to oily fish. It contains unsaturated fatty acids.

If a woman has had lipid spectrum disorders before pregnancy and has been prescribed statins, it is imperative to consult a doctor about controlling cholesterol levels during pregnancy and lactation.

How to regulate the consumption of eggs and other foods that are high in cholesterol but low in saturated fat?

Eggs are a very healthy but still controversial product. They contain choline, a substance that is essential for the normal functioning of the brain. According to the Harvard School of Public Health, pregnant women are at risk for this substance deficiency.

One egg yolk contains 200 mg of dietary cholesterol, but it is important to understand here: the cholesterol that we see in blood tests and the cholesterol that we get with food is rather weakly linked in most healthy people, although it was considered differently for a long time. For example, in two huge studies on 120 thousand people, it was found that one egg per day does not increase the risk of developing cardiovascular diseases, which means it will not do harm.

However, there are exceptions to any rule. Some people are sensitive to dietary cholesterol. Its blood level is closely related to dietary cholesterol. Therefore, medical authorities do not yet approve of a three-egg omelet for breakfast.

What physical activity is best for lowering cholesterol levels?

Regular cardio activities – brisk walking, aerobics, jogging. The minimum period for which you can see changes is three months. Do not forget that no load will work if the person does not adjust the diet. Too many carbohydrates combined with excess fat should be avoided and commercial trans fats should be avoided altogether.