Prevention of hypercholesterolemia

Cholesterol is a water-insoluble organic substance found in the plasma membrane and body tissues of all animals and in the blood plasma of vertebrates. In the human organism it fulfills essential functions such as the following:

• It constitutes an important component of cell membranes.

• It is essential for cell division.

It is the precursor in the synthesis of substances such as:

• Vitamin d, an essential element in calcium metabolism.

• Sex hormones and corticoids.

• Lipid rafts.

However, the increase of cholesterol in the blood and its deposit in the arteries is associated with an increased risk of cardiovascular diseases, such as coronary arteriosclerosis, the most common form of cardiovascular disease, which can remain silent, or manifest itself as acute myocardial infarction, angina pectoris or sudden death.

How does the body obtain cholesterol?

The body obtains cholesterol from two sources:

• The endogenous source: the liver is the main producing organ, although it is also produced by the intestine, adrenal cortex, testicles and ovaries. The level of cholesterol production by this route depends fundamentally on the diet. This source covers approximately 50% of the body's cholesterol requirements.

• The exogenous source: this includes cholesterol obtained from food, the amount of which varies depending on the type and quantity of food in the diet. Only foods of animal origin contain cholesterol, being more abundant in those with a high saturated fat content, such as red meat, seafood, egg yolks and dairy products.

How is cholesterol transported in the body?

Cholesterol circulates permanently in the body between the tissues and the liver, where it is stored or can be eliminated. Because it is not very soluble in water, it cannot be transported independently in the blood, but is bound to proteins forming lipoproteins.

Lipoproteins are very complex particles that transport other lipids in addition to cholesterol, such as triglycerides, phospholipids and fat-soluble vitamins (a, d, e, k). According to their physical properties there are four different categories, however, from the point of view of cholesterol transport the most important are two, named:

• Low density lipoproteins ( LDL): they are in charge of carrying cholesterol and depositing it in the tissues; when cholesterol levels are in excess, they also deposit them on the walls of the arteries, causing over time, fat deposits to become increasingly larger plaques, which obstruct blood circulation, posing a high risk to health, that is why they are commonly referred to as "bad cholesterol".

• High-density lipoproteins (HDL): they are mainly composed of proteins. They are responsible for transporting excess cholesterol from the tissues to the liver for excretion, helping to reduce blood cholesterol levels, thus having a beneficial effect on health, which is why they are colloquially referred to as "good cholesterol".

Recommended blood cholesterol levels

Total cholesterol: " 200 mg/dl (less than 200 milligrams per deciliter). Total cholesterol includes both low-density lipoprotein (LDL) cholesterol and high-density lipoprotein (HDL) cholesterol.

Low-density lipoprotein (LDL) (bad cholesterol): " 130 mg/dl (less than 130 milligrams per Deciliter).

High-density lipoproteins (HDL) (good cholesterol): 35 mg/dl (more than 35 milligrams per deciliter).

Factors that increase the risk of suffering from high blood cholesterol levels

Genetic factors: some individuals inherit defective genes for the production of LDL receptor proteins, so their cells have difficulties in capturing cholesterol from the blood, increasing LDL and total cholesterol levels. Most of these people present coronary artery disorders at an early age.

Family history: in general, family members have similar cholesterol levels. The existence in the family of several people with high cholesterol levels increases the risk of the other members of the family also having high cholesterol levels.

Age: unhealthy cholesterol levels can affect individuals of all ages, including young children; however, high cholesterol levels in both sexes are most commonly diagnosed between the ages of 40 and 59.

Gender: men have a higher risk of presenting high cholesterol levels than women at younger ages (between 20 and 50 years). In women from the age of 45, coinciding with the onset of menopause, cholesterol levels tend to increase.

Body weight: overweight and obesity increase the risk of an increase in blood cholesterol levels. Weight loss contributes to lower levels of (LDL) and total cholesterol; and also helps to increase (HDL).

Diet: saturated fat, trans fatty acids (trans fats) and cholesterol contained in dietary foods increase the levels of (LDL) and total cholesterol.

Sedentary lifestyle: people who are sedentary are at greater risk of suffering higher levels of LDL and total cholesterol. Regular physical activity contributes to the reduction of body weight and lDL levels, and also increases HDL levels.

Consumption of toxic substances: the consumption of anabolic steroids and excessive alcohol consumption increase blood cholesterol levels.

Smoking: regular smokers have higher blood cholesterol levels than the general population. Quitting smoking contributes to an increase in HDL levels, which favors the reduction of the total cholesterol index. However, quitting smoking increases the risk of becoming overweight or obese, so actions should be implemented to reduce this possibility.

Presence of pathological situations: the following conditions can also increase LDL and total cholesterol levels or reduce HDL levels:

• Diabetes mellitus.

• Chronic kidney disease.

• Hypothyroidism.

• Anorexia nervosa.

• Lupus erythematosus.

Disorders of blood cholesterol levels.

Hypercholesterolemia: Hypercholesterolemia is an increase in total blood cholesterol levels above 240 milligrams per deciliter. If the value exceeds 250 milligrams per deciliter, it is considered pathological and a risk factor for the development of cardiovascular diseases.

Hypercholesterolemias are classified into two types:

• Primary.

• Secondary.

Primary hypercholesterolemias are those that are not associated with any disease. They are due to genetic alterations that affect one or more genes of the cholesterol transporter systems or of the proteins involved in cholesterol metabolism. In primary hypercholesterolemias that affect several genes, in addition to genetic factors, external elements collaborate, mainly related to diet, such as foods rich in saturated fats, trans fats. And cholesterol, for example: red meat, crustaceans and cephalopods, egg yolk and fatty dairy products.

Secondary hypercholesterolemia: are those related to the following causes:

• Diseases: the diseases that most frequently cause hypercholesterolemias are the following.

• Renal: chronic renal insufficiency and nephrotic syndrome.

• Endocrine: hypothyroidism, diabetes mellitus and anorexia nervosa.

• Hepatic: hepatitis and liver cirrhosis.

• Consumption of toxic substances: consumption of anabolic steroids and alcohol when excessive amounts are taken.

Consequences of hypercholesterolemia: high blood cholesterol levels, diabetes mellitus, and arterial hypertension are the main risk factors for arteriosclerosis. Atherosclerosis is a complex disorder characterized by the accumulation of lipids in the walls of the arteries; these can begin after the second decade of life and progress slowly over the years.

The fatty deposits eventually become larger and larger plaques that obstruct blood circulation and cause reduced blood and oxygen flow (ischemia) to the various organs and tissues of the body. If the obstructed artery is in the heart, it causes angina pectoris or myocardial infarction, if it is in the brain, it causes stroke, and if the obstruction is located in the extremities, it causes peripheral arteriopathies.

Treatment of hypercholesterolemia

The treatment of hypercholesterolemia should be based on the combined action of drugs and the management of the following risk factors:

• Following a balanced diet, aimed at reducing high cholesterol levels. Stop smoking and avoid staying in enclosed spaces when other people smoke.<