Knocking down all myths about cholesterol
Knocking down all myths about cholesterol … Cardiovascular disease is the leading cause of death in the world.
Its direct relationship with cholesterol has given way to an intense concern about this risk factor. Hence the importance of correctly understanding what cholesterol is, where it comes from, what it is for, etc. And, of course, to knock down certain myths that don’t help in the fight against heart disease.
WHAT IS CHOLESTEROL?
The first thing that needs to be made clear, is that cholesterol is an essential substance for life. It is required by the body to perform various biological functions, from the manufacture of hormones to the synthesis of vitamins. Moreover, it is an essential structural component of every cell membrane of animal origin.
It is an organic molecule, a type of lipid or fat. Most cholesterol present in the body is endogenous. That is, it is produced internally, specifically in the liver. The rest is exogenous, meaning that it comes from external sources, such as food.
To incorporate cholesterol into the biological processes, our bodies must transport these molecules to each cell. That’s what Lipoproteins are for.
WHAT ARE LIPOPROTEINS?
Lipoproteins are complex molecules, composed of proteins and lipids. Their function is to transport fat molecules throughout the body. Since our blood is a watery medium, incompatible with fats, lipoproteins are essential to remove lipids from the bloodstream and stabilize the medium.
Lipoproteins are often confused with cholesterol types, which is not correct. This idea has given rise to one common myth related to the subject, which now must be brought down.
THERE ARE FOUR LIPOPROTEINS
These are responsible for the transport of cholesterol: CMs, VLDL, LDL and HDL. All play a different, but equally important, role.
Chylomicrons are the less dense cholesterol transport molecules. Their function is to bring fats from the intestine to the muscle and other tissues that need fatty acids to produce energy or fat deposits.
VLDL (VERY LOW DENSITY LIPOPROTEIN)
The VLDL molecules are produced by the liver. VLDL’s function is to distribute triglycerides (a type of fat) to all the cells of the body. A part of this type of lipoprotein is converted to LDL.
LDL (LOW DENSITY LIPOPROTEIN)
They are the main carriers of cholesterol in the blood. A cell with abundant cholesterol will have blocked its synthesis of LDL receptors, to prevent the new cholesterol in the LDL molecules from being absorbed. In contrast, LDL receptor synthesis proceeds when a cell is deficient in cholesterol. When this process becomes unregulated, LDL molecules without receptors begin to appear in the blood. These non-absorbed LDL molecules are highly oxidative, which then results in their accumulation in blood vessels, causing the known “blocked” veins or arteries.
HDL (HIGH DENSITY LIPOPROTEIN)
The HDL Lipoprotein has the function of transporting cholesterol back to the liver. From there they can either be excreted or used for other tissues that synthesize hormones, in a process known as reverse cholesterol transport (RCT). A large number of HDL particles correlates with better health outcomes.
THERE IS NO GOOD OR BAD CHOLESTEROL, ONLY AN EXCESS OF IT
The second misconception about cholesterol, deeply rooted in the population, is the idea that there is good cholesterol and bad cholesterol.
This relationship originates from lipoproteins and medical tests designed to diagnose cardiovascular diseases.
The main indicators measured to assess the risk of suffering from this type of disease are the presence of lipoprotein LDL and HDL. The greater the presence of LDL in the body, the greater the risk of cardiovascular disease.
On the other hand, a greater presence of HDL is associated with a favourable scenario. Hence the “good” and “bad” cholesterol. However, both lipoproteins are equally important for the body’s proper functioning.
Neither is bad or good in itself, but they both should be assessed in relation to the right health promoting proportion.
To better understand this idea it is necessary to dig deeper into the metabolic process of cholesterol.
We already said that as a fatty molecule, cholesterol is not soluble in water, so it needs another way to be transported by the blood (a watery medium). This is where liproproteins come into play, as a means of transporting cholesterol.
Lipoprotein particles can be recognized and bound to the cells by specific receptors in the cell membranes, thus being able to “transfer” their cholesterol load to the specific cells and tissues that require these particles.
Dr. Carlos Zavala explains it in detail in an article published by the Las Condes Clinic.
“This pathway starts in the liver where they are first assembled and then very low density lipoproteins (VLDL) are secreted. The hepatic synthesis of these lipoproteins increases with the ingestion of fat and carbohydrates. VLDL transport triglycerides to peripheral tissues (adipose tissue and muscle), and cholesterol to the suprarenal glands and plasma membranes.
LDLs are the main transporters of plasma cholesterol to tissues. However, 75% of the uptake of LDL occurs in the liver, the rest in the suprarenal and adipose tissue. Once inside the cell the particle is disarmed in its protein and lipid components “.
As long as there is a normal amount of cholesterol, it is healthy, necessary and functional as a cellular builder and source of energy. This energy, if used, leaves room for cells to metabolize more cholesterol.
However, when there is an excess of cholesterol the cellular receptors of lipoproteins are not enough, or they are full. Therefore, in simple terms, the cell “rejects” the lipoprotein by forcing it to remain in the blood.
Once the LDL lipoprotein is forced to circulate in the bloodstream, it begins a process of oxidation, sticking to the walls of veins and arteries.
This accumulation ends up causing the dreaded arterial congestion, which causes cardiovascular diseases and high risk of suffering a cardiac infarction.
HOW CAN WE ALWAYS KEEP OUR CHOLESTEROL AT “GOOD” LEVELS?
As we could see, the problem is not cholesterol, but the excess of it. Therefore the task should be to focus on how to keep cholesterol within healthy boundaries.
The main source of cholesterol rise is an unbalanced diet. According to the Heart Foundation, “Inadequate diets among the population are a determining factor of hypercholesterolemia. There are many people who include many unhealthy fats and alcohol in their diet, in addition to foods that are processed and high in sugars”.
On the other hand, a sedentary lifestyle means that this energy stored in the form of lipids is not spent. This saturates the cells and does not allow for a correct absorption of that cholesterol that continues to be generated in the body, or keeps entering through the diet.
Therefore, the good news is that most people with cholesterol problems should only make modifications to their eating habits and physical activity.
THE FOUR LIFESTYLE CHANGES THAT ARE REQUIRED
According to the Chilean Society of Cardiology, four changes in lifestyle should be made:
EAT HEART-HEALTHY FOODS
Decrease your intake of mainly trans fats and sugar; and increase the consumption of vegetables, whole grains, nuts and fruits.
Vegetables, virgin vegetable oils and nuts, among others, contain phytosterols. Phytosterols are vegetable “cholesterol”. This molecule is similar but not the same as that coming from the animal kingdom, and its consumption prevents the absorption of approximately 50% of the cholesterol ingested through food.
It is estimated that in a typical diet, approximately 250 mg of phytosterols are consumed daily. Those following a vegetarian diet probably get double that amount. However, the recommendation is for a daily intake of at least 2 g. of phytosterols.
An increase in consumption may be made easier by taking supplements, such as Cardiosmile, and always in the context of a healthy diet.
BE PHYSICALLY ACTIVE
Physical activity favours the production of HDL lipoprotein, which in turn helps the excretion of cholesterol from the body, in addition to regulating blood pressure.
Smoking also decreases HDL production. Cigarette compounds also increase other risk factors such as hypertension and Diabetes.
LOSE WEIGHT (IF YOU ARE OVERWEIGHT OR OBESE)
People who are overweight and obese tend to have increased LDL levels and decreased HDL levels.
Cardiovascular disease, and with it cholesterol problems as a risk factor, must be addressed correctly. Putting the focus on education and changing habits is essential to avoid the millions of deaths that this pathology causes each year.