Cholesterol… The good and the bad
In this article we are going to see which are the two types of cholesterol that exist.
Both sides of dreaded cholesterol
- It is a molecule essential for life, without control causes deleterious effects
- We must balance the levels of HDL and LDL
- It is essential also to control triglycerides
- Dietary habits are essential
There is no doubt that cholesterol is bad press, and no wonder. The heavy presence of this substance in the blood, which scientists called hypercholesterolemia-is a major cardiovascular risk factors and stroke.
It is, or more precisely, the starting point of atherosclerosis, with the Over the years leads to a heart attack or stroke.
But what few know is that humans could not live even one minute without a proper share of cholesterol in our veins.
"This type of fat molecule is essential for life," says Dr. Alejandro Ugarte, head of the Diabetes and Nutrition Section of the Center for Clinical Medical Education and Research (CEMIC) and co-author of "Cholesterol: What it is and how to control it" -. It is part of the membranes of cells, the basic structure of many hormones and bile salts that are involved in digestion.
The problem, as we advance, is the excess: "When there are excessive levels of cholesterol in blood, and it cannot find the normal target, which are the cells that require it to function, the excess is deposited in layer inside of the arteries or arterial endothelium", explains Dr. Ugarte.
There, hidden cholesterol molecules generate an inflammatory process that brings together elements that circulate in the blood, and that leads to the formation of a plaque atheroma thay is gradually closing the light of the arteries, according to the specialist.
Everything goes silent until a hypertensive crisis or an effort, for example, breaking the wall of the atheroma and dumps its contents into the bloodstream.
When this happens, the body tries to repair the damage of the plate, but the attempt is futile and all that achieves is a result ending in thrombus obstructing the artery. When this occurs in a coronary artery, we are confronted with a heart attack, if it occurs within the brain, a stroke.
Both sides
We can understand why it is important to keep cholesterol levels within acceptable (healthy, we can say).
What are these levels?
Well, that depends on which of the different types of cholesterol we are talking about.
As cholesterol is a fat molecule, and therefore is not soluble in water, to circulate in the blood should always be associated with another molecule which is given, say, personality.
Path through the blood
What mechanisms are activated in the body so that cholesterol levels are above those considered normal? What science gives the sinking?
Cells that feed cholesterol possess receptors that allow them to distinguish it from other molecules. When these receptors fail, cholesterol molecules cannot be captured by cells in the blood and roam the effect is the same as the production of cholesterol by the liver exceeds the demand of the cells.
Here comes the best scene in the movie: the molecules of high-density lipoprotein, or HDL (High Density Lipoprotein), popularly known as "good" cholesterol. When
for any of these reasons, the cholesterol molecules of LDL is not captured by the cells, says Dr. Ugarte, "can be transferred to other molecules, the HDL, which are responsible for traveling the reverse path, and return excess cholesterol to the liver."
"The different forms which acquires cholesterol are named according to the density of the molecules to which they are linked," says Dr. Ugarte.
Perhaps the best known and most feared-is the low-density lipoprotein or LDL (Low Density Lipoprotein) which the doctors called "bad cholesterol". This is the molecule responsible for transporting cholesterol that is produced in the liver on its journey to the different regions of the body.
Unfortunately, sometimes the molecules of LDL are not reaching their destination, and there begins the history of atherosclerosis.
The causes are not simple (see box), but the medicine has failed to clarify.
"If you ask me what is today the most effective antithrombotic drug, I would reply that the HDL cholesterol," said Dr. Valentin Fuster, director of cardiology at the prestigious May Clinic and former president of the American Heart Association, 3100 to 1700 of the cardiologists involved in the International Scientific Concurrent Events (ICSE 2003), which ended May 4 (2003) in Buenos Aires.
The comment is not minor: the role of antithrombotics is to prevent the formation of a thrombus inside the arteries, which occurs in the heart causing heart attack. And acquires more relevance when we are still trying to prevent is the leading cause of death not only in Argentina but throughout the Western Hemisphere.
In his lecture, Fuster presented recent studies showing that a significant increase in levels of HDL or "good cholesterol" does not only stop the development of atherosclerosis, but also the progress of the disease.
What are the acceptable or desirable in terms of cholesterol?
"When one speaks of total cholesterol, it is desirable to be less than 200 milligrams per deciliter (mg / dl)” replied the doctor. The limit values are entered 200 and 239 mg / dl, high cholesterol and talk about when it goes beyond the 240 mg / dl.
Spinning thinner, to read the analysis of cholesterol blood must be remembered that it is preferable that LDL levels are below 160 mg / dL for premenopausal women, and less than 130 mg / dl for men and women who have undergone menopause.
"To those people that have found evidence of arterial injury or who have diabetes are asked to keep their LDL levels below 100 mg / dL" says Ugarte.
With regard to HDL, complete this doctor nutritionist, "the desirable thing (for both men and women) is that it is above 40 mg / dl, and it is really beneficial from 60 mg / dl. In these cases, their presence is considered a factor for cardiovascular protection.
Finally, subtraction mentions other lipids: triglycerides. These are transported by third molecule, the very low density lipoprotein, or VLDL (Very Low Density Lipoprotein by).
"Although not an individual risk factor, if its presence in blood is high-this is 200 mg/dl- up while values are low HDL, the latter loses its protective function. "
To keep cholesterol under control, the first thing is to have a status of this potential enemy.
In healthy adults, the recommendation is making an analysis of cholesterol in blood and, if the values are normal, repeat five years later.
How to combat?
Now, if levels are to be outside what is considered healthy, control must be repeated annually.
What is the way forward in the latter case?
"First, we must take into account that while only a quarter of the cholesterol that circulates in the blood enters the body through food (the rest is produced by the same individual) The influence of diet remains very important," says Dr. Ugarte. When a person consumes a lot of calories and has some genetic predisposition, the high caloric intake promotes a high production of cholesterol. It in simple terms: for people with high cholesterol, the first recommendation is to not consume more calories.
"When a patient comes to my clinic with high cholesterol, the first thing I notice is if you are overweight, nearly so, the indication is to lose weight. If your weight is normal, it is advisable to make a predominantly vegetarian diet, because the plants contain no cholesterol."
Other measures to assist in the fight against high cholesterol are smoking cessation and activity physics, two decisive factors.
But if the modification of dietary behavior and the measures just mentioned cannot twist arm to the dreaded cholesterol.
Only then, drug is used to decrease levels in blood.
Not easy for a person with high cholesterol respect to the letter the instructions of your doctor. In a study of the Argentine Society of Cardiology, 43% of patients with hypercholesterolemia prescribed medication leaves to combat this condition that affects about 35% of Argentines, which is a major risk factor for myocardial infarction.
Usual doubts and fears of patients before any treatment which in theory should be for life, was added a year and half ago, the specter of Lipobay.
When the pharmaceutical Bayer decided to withdraw the drug market for its adverse effects, the physicians were overwhelmed by calls from anxious patients taking this or any other medicine to control cholesterol levels.
Are they safe and effective drugs currently used to combat cholesterol? If the experts consult this agreeing. Of course, like any medicine, here too there are side effects that discourage their use without medical indication and supervision.
But if what we want is to keep cholesterol levels within healthy limits, it is always good to remember that medications are not the only tool available to the doctors to do so, nor the first to which should be used. There are dietary supplements such as soybean lecithin and Chitosan that has proved useful in regulating cholesterol levels. The chitosan is a 100% natural fiber derived from the carapace of crustaceans that possesses the ability to absorb fat. Lecithin is derived from oil extracted from soybeans. The Soya Lecithin acts as emulsifies in the body due to the nature of the molecule, which may involve water and fat. A portion of the molecule attracts grease and also attracts water. This feature is crucial in the transport of cholesterol through the arteries and prevents plaque formation (which reduced the light of the artery produced as atherosclerosis and stroke).
"Half of people with high cholesterol could benefit simply by changing their life style: changing diet, losing weight and exercising would resolve many of the cases of hypercholesterolemia, "said Dr. Alejandro Ugarte, head of the Diabetes and Nutrition Section of the Center for Clinical Medical Education and Research (CEMIC).
"When a patient comes to my clinic with high cholesterol, the first thing I notice is if is overweight, if so, the indication is to lose weight” explained Dr. Ugarte. “If your weight is appropriate, the desirable is a predominantly vegetarian diet, because the plants contain no cholesterol."
Firstly, it should be clear when one can begin to talk about high cholesterol, because the analysis that quantify the presence of lipids in the blood tend to make many variables: total cholesterol, LDL, HDL and triglycerides.
- Total cholesterol: what is desirable is that it is under 200 milligrams per deciliter (mg / dl). Between 200 and 239 mg / dl is the limit with high cholesterol that begins beyond the 240 mg / dl.
- LDL or bad cholesterol: it must be less than 160 mg / dL for premenopausal women and less than 130 mg / dl for men and women who have undergone menopause. In people with evidence of diabetes or arterial injury are lost values below 100 mg / dl.
- HDL or good cholesterol: is it desirable that more than 40 mg / dl, while above 60 mg / dl becomes a protective factor for cardiovascular health.
- Triglycerides (TG): are recommended values less than 150 mg / dl.
Combinations can give rise to these different forms of lipids that are those that will determine what treatment to follow. But, as we mentioned, the drugs are not the first.
Beyond reducing calorie intake, and replacing animal fat by vegetable, there are certain foods that are very good allies of all who seek to control their cholesterol levels.
"There are margarines, yogurts and milk fortified with plant sterols which are a natural product of the plant to reduce cholesterol” said Dr. Alfredo Lozada, head of the Center for Lipids and Prevention, Cardiovascular Institute of Buenos Aires (ICBA). “On the other hand, cold-water fish contain omega 3, a substance that helps to reduce triglyceride levels."
Adopt a routine of physical exercise-especially aerobic and leave the other bad habits, change that collaborate in the fight against high cholesterol.
Therapeutic Alternatives
When the proposed changes do not prove sufficient to twist the arm to cholesterol, only then resort to drugs. The choice of appropriate therapy depends on the lipid profile of the patient.
For those in whom LDL cholesterol is the problem, the therapy of choice is statins. "These drugs regulate LDL receptors, stimulating their uptake by the liver," explained Dr. Lozada. "Their side effects are very rare," added Dr. Ugarte; “can cause elevated liver enzymes or muscle, can cause liver inflammation or muscle."
It is why when one follows the medical treatment with statins frequently to monitor the behavior of these enzymes. Still, both experts agree, these are drugs with decades of use in humans that support their safety.
When you are out of control are the triglycerides are used fibrates. "These drugs act on the molecules that carry triglycerides, reducing its presence in the blood," said Ugarte. "Its most common side effect is the formation of gallstones," Lozada completed.
Sometimes, high levels of LDL cholesterol and triglyceride levels may coexist on the same person. "In that case, first shown statins because of high doses not only reduced LDL, but also a little lower triglycerides. When this is not combining statins and fibrates, but with much vigilance, because the combination increases risk of adverse effects of both drugs," said Ugarte.
"A most unusual case is having to deal with very low levels of HDL, which sometimes occurs in people who smoke, who are very overweight or who do not exercise” said Lozada."In these cases you can use a vitamin, nicotinic acid, which also raise the good cholesterol, lowers triglycerides and bad cholesterol." Of course it also has its unwanted side: "It raises the sugar, uric acid and raises the heat that is similar to the menopause.
The list of medications to treat high cholesterol does not end here; more soon Argentina will reach a new drug-the-ezetimide that further expanded the therapeutic arsenal. But what must be borne in mind is that "taking a medication does not relieve a person with high cholesterol but to carry out a proper diet that enhances the desired effect," said Ugarte.
Source: The Nation and own