Cholesterol is a type of steroid, that is, it is part of a group of lipids characterized by having a carbon skeleton formed by four fused rings. Despite being fundamental for the functioning of our body, its excess is related to a series of health problems.
Next, we'll learn more about this important steroid, better understanding its importance, how it is transported by the body, the relationship between LDL, HDL and atherosclerosis, and knowing the proper levels of cholesterol that our bodies should to introduce.
See too: Chemical composition of cholesterol
Cholesterol Function
Unlike what many people think, cholesterol is essential for the proper functioning of our body and without it our survival would not be possible. It is an important component of the plasma membrane of cells, membranes of cell organelles and the myelin sheath of neurons, acts as a precursor of bile salts and vitamin D and is also used in the synthesis of some hormones.
Cholesterol transport: lipoproteins
Cholesterol is transported in the blood by means of lipoproteins, which are particles formed by lipid molecules linked to a protein.
Lipoproteins can be classified into five distinct groups: chylomicrons (Qm), very low density lipoproteins (VLDL), intermediate density lipoproteins (IDL), low density lipoproteins (LDL) and high density lipoproteins (HDL). The two main lipoproteins are the LDL and HDL, which will be discussed below:
LDL
LDL (low-density lipoprotein) is a lipoprotein that guarantees the transport of cholesterol from the liver and intestine to the membranes or site of synthesis of other steroids. When in excess, LDL can deposit on the vessel wall and be oxidized. This oxidation modifies its structure, which is not recognized by the endothelial cells, triggering an action of the Imune system.
This process may be responsible for leading to the formation of atherosclerotic plaque. This plaque causes the artery to become rigid and its lumen to be narrowed, which may obstruct the blood vessel and, consequently, the development of problems, such as heart attack and strokes.
Know more:Difference between artery, vein and capillary
According to the Brazilian Society of Endocrinology and Metabolism, for every 40mg/dL of LDL cholesterol reduced, infarction mortality is reduced by 20%. Due to these characteristics, LDL is popularly called “bad cholesterol”.
HDL
HDL (high density lipoprotein) is a lipoprotein that captures excess cholesterol in tissues and takes it towards the liver, so that it can be excreted. In addition, studies in vitro and in animals demonstrated that HDL has antioxidant, anticoagulant, anti-inflammatory and endothelial protection properties.
Regarding atherosclerotic disease, there is an inverse relationship between HDL levels and disease development. Due to these characteristics, HDL is popularly called “good cholesterol”.
High concentrations of LDL and low concentrations of HDL in the blood are related to the development of atherosclerotic disease. However, in addition to cholesterol, it is important to be aware of blood pressure, smoking, weight and glucose control. Understand more about this topic by accessing the text: atherosclerosis. |
Cholesterol and food
Most of the cholesterol present in the body is produced in the body, while a small portion is provided by our food. Despite that, control of ingested food is critical for levels of LDL and HDL in the body are in balance. Keeping lipoproteins at adequate levels is essential, since an increase in LDL and a reduction in HDL is associated with the development of cardiovascular problems.
Cholesterol levels can be controlled through an adequate diet, with emphasis mainly on the levels of fat. Second the Ministry of Health, one of the reasons for changes in cholesterol levels is the excessive intake of saturated fats and trans fats, which are present in foods of animal origin and ultra-processed.
Thus, foods such as fatty meats, whole milk, yellow cheeses, bacon, cracklings, ice cream, potato chips, snacks and biscuits should be avoided. It must be inserted in the diet healthy food, like fruits, vegetables and greens, and give preference to lean white meats such as fish. Fried foods should be reduced, with grilled and roasted foods being the best choice.
It is also worth noting that, for cholesterol levels to be balanced, a balanced diet is not enough, it is essential to practice physical activity. THE physical exercise it is related to the reduction of bad cholesterol (LDL) and the increase of good cholesterol (HDL). It is recommended that at least 30 minutes of physical activity be completed, four to five days a week.
A balanced diet and physical activity are two basic requirements to maintain adequate cholesterol levels. |
Read too:Recommendations for healthy eating
Normal Cholesterol Values
Changes in values normal cholesterol levels may be related to development of cardiovascular problems. Therefore, it is important to perform preventive exams to assess the individual's lipid profile. It is important to make it clear that cholesterol levels can also be high in thin people, and this is not a problem that only occurs in overweight or obesity. Thus, the only way to identify it is to perform exams.
Check a table with reference values for the lipid profile for adults over 20 years old, according to with the V Brazilian Guideline on Dyslipidemias and Prevention of Atherosclerosis, of the Brazilian Society of Cardiology:
Lipids |
Values (mg/dl) |
Category |
CT (Total Cholesterol) |
< 200 |
Desirable |
200-239 |
borderline |
|
≥ 240 |
High |
|
LDL-C (LDL Cholesterol) |
< 100 |
Excellent |
100-129 |
Desirable |
|
130-159 |
borderline |
|
160-189 |
High |
|
≥190 |
Very high |
|
HDL-C (HDL Cholesterol) |
> 60 |
Desirable |
< 40 |
Low |
|
TG (Triglycerides) |
< 150 |
Desirable |
150-200 |
borderline |
|
200-499 |
High |
|
≥ 500 |
Very high |
|
non-HDL cholesterol |
< 130 |
Excellent |
130-159 |
Desirable |
|
160-189 |
High |
|
≥ 190 |
Very high |
Curiosity: The blood test capable of determining the amount of lipids in the bloodstream is called: lipid profile or lipid profile.
See too:Cardiovascular system - responsible for ensuring blood circulation
By Ma. Vanessa Sardinha dos Santos
Source: Brazil School - https://brasilescola.uol.com.br/saude-na-escola/colesterol.htm
