Biochemically, the cholesterol belongs to the class of lipids, together with triglycerides, fatty acids etc. and is an essential component of all cell membranes, playing an important role in the modulation of their permeability for various compounds.
Furthermore, a number of other important substances in the body are synthesized from it, such as bile acids that are involved in the digestion of the fat we eat, sex hormones and vitamin D.
The liver holds the leading role in regulating cholesterol in the body and is the place where the cholesterol ingested from food and synthesized in various tissues reaches, and from here it is removed as such or in the form of bile salts, through the bile, in the intestinal lumen.
The absorption of a certain percentage of the cholesterol from food and the one produced by the liver, in the form of biliary cholesterol, takes place in the intestine, and the rest is eliminated through feces.
Keep in mind that not every type of cholesterol is harmful to the body! There are two types – HDL (high-density lipoprotein or good cholesterol) and LDL (low-density lipoprotein or bad cholesterol).
While LDL causes blockages in the arteries, HDL helps in the transportation of triglycerides in the liver, for excretion.
LDL is a type of fat in the blood, whose high values can cause health problems, as it tends to accumulate in the arteries (atherosclerosis) and hinder the blood flow.
HDL includes high-density lipoproteins, also found in the bloodstream, which help transport the triglycerides to the liver for excretion or reuse.
Total <200 mg / dL
LDL <100 mg / dL
HDL > 60 mg / dL
LDL is found in foods that are rich in trans fats, refined carbohydrates (like sugar and white flour), cholesterol-rich foods (such as egg yolks, liver, and kidney of animals, dairy products and alcohol).
HDL sources include onions, foods rich in omega-3 fatty acids and fiber-rich foods (grains, oatmeal, bran, etc.).
Structural and functional differences
Lipoproteins are a complex of apolipoproteins and phospholipids. HDL contains the smallest of all lipid molecules, which are high-density molecules due to their protein content. The cholesterol transported to the liver is secreted in the bile and then in the intestines. It is transported to other organs is used by the body for the synthesis of steroid hormones. Other functions of the good cholesterol include inhibition of cell oxidative process, fighting inflammation, endothelial activation and balancing blood clotting function.
It consists of a single molecule of apolipoprotein that helps the circulation of fatty acids and the only function of these less dense molecules is to carry cholesterol to the tissues and arteries.
What causes high cholesterol levels?
Harmful fats are saturated fats, hydrogenated fats, and trans fats. Their excess in the diet increases the risk of cardiovascular diseases, by increasing total cholesterol and LDL.
Saturated fats are found in animal products, such as pork, lamb, chicken/turkey skin, butter, fat, eggs, milk, fatty cheeses. Other foods rich in saturated fats are the coconut oil, palm oil and other tropical oils.
Saturated fats are responsible for increasing blood cholesterol levels and the risk of developing coronary diseases. For this reason, it is recommended to limit them to a maximum of 10% of the total kilocalories consumed in a day, in other words to a maximum of 20 grams per day for women and 24 grams per day for men.
Hydrogenated fats, trans fatty acids (trans-unsaturated fats) are a type of “bad” unsaturated fats. They often form during industrial processing of food, when some fats suffer a process called hydrogenation, which modifies their chemical structure.
Trans-unsaturated fats increase total cholesterol, LDL and lower HDL. They are usually abbreviated and listed on food labels as TFA.
The effects of high LDL our body’s health
The higher the LDL levels are in the blood, the greater the risk of developing heart diseases. When the level in the blood decreases, the risk of heart diseases drops as well.
Coronary diseases are caused by the buildup of plaque inside the coronary arteries. Plaque formation in the arteries restricts the flow of oxygen-rich blood to the heart.
Eventually, a part of the plaque can break off from the artery walls, causing the formation of a blood clot. If the clot is large enough, blood flow may partially or totally block. In this case, the person in question may develop angina or even suffer a heart attack.
How does hypercholesterolemia manifest?
Hypercholesterolemia has no clinical manifestation. Its consequence – the atheromatous plaque, underlies the occurrence of cardiovascular disease. This process is slow and can take years.
Hypercholesterolaemia affects all age groups, including children.
There are young people between 30-40 years of age, usually men, heavy smokers, with relatively low cholesterol levels above normal, working in a stressful environment, with or without a family history of cardiovascular disease, who suffer an acute heart attack in an apparent good health condition.
However, at a closer look, there are more cardiovascular risk factors present. Some of them are unchangeable, like gender and personal history, others (most) are subject to change: smoking, hypercholesterolemia, stress.
Therefore, annual medical checkup from your family doctor is important regardless of age. Its purpose refers to an early identification of general risk factors and cardiovascular risk factors in particular. Once identified, the risk factors can be removed by simple means.
This can save us from many diseases, some of which very serious, requiring costly medication, on long-term or even for life. We may state that hypercholesterolemia is a hidden enemy, which can do much harm if not properly approached.