Elevated blood cholesterol levels are upsetting the medical community. Studies advocate reducing the focus of attention on it.
At this point in the movie, we all know more or less about the "dreaded" cholesterol, that blood fat called an antihero and almost capable of causing cardiovascular or cerebrovascular infarcts by itself. Or at least that is what it seems, given the emphasis that continues to be made today in medical consultations and clinical practice guidelines with the recommendation that "cholesterol, the lower the better. "
Reality, as always, has a multitude of nuances. And cholesterol is not as bad as we have been told, nor is it as good as others would have us believe. Given that the bad names of "good cholesterol" and "bad cholesterol" are still used, it will also be necessary to clarify these concepts and know why they were invented and for what purpose.
For this reason, today we will try to explain what cholesterol is and what it is for, why it is given such importance in medicine, what concepts have changed about cholesterol over the years, and how it is sought to reduce it with and without drugs.
What is cholesterol and what is it for?
As we have already anticipated initially, cholesterol is a waxy substance, similar to fats or triglycerides, although chemically it is an alcohol (for this reason it was formerly known as “cholesterol” and later it was called “cholesterol”). Cholesterol has always been essential for life, just like fats. It is not possible to live without either substance.
In the specific case of cholesterol, most of it is produced endogenously, that is, it is created by the body itself specifically in the liver. In fact, more cholesterol is produced internally than is usually ingested with the diet: We synthesize around 10 mg per kilogram of body weight per day, while the dietary recommendations advise not to ingest more than 300 mg per day.
There are various subunits of cholesterol, depending on the type of transporter proteins that have it. Since cholesterol is not soluble in water, it requires these "transporters", lipoproteins. These include the Low-Density Lipoprotein (Low Density Lipoproteins) or LDL in the acronym, and High-Density Lipoprotein (High Density Lipoproteins) or HDL in its English acronym. The former, known as "bad cholesterol" or "LDL cholesterol" have the function of transporting cholesterol to the tissues so that it can be used, including the arteries; For its part, "good cholesterol" or "HDL cholesterol" has precisely the opposite function, collecting cholesterol from the tissues and transported to the liver to be eliminated by the bile.
There are many other cholesterol transporting subunits, but we will focus on these two as they are the most used in the medical field today.
In general, it is known that cholesterol as a molecule is necessary to be able to build the cell membranes of the human body, to make bile in the liver, and it is also part of several types of hormones, including sex hormones. Therefore, it is more than evident that living without cholesterol can be dangerous, although its excess is not adequate.
Why cholesterol is important in medicine
Currently the dietary recommendations advise not to exceed 200 mg / dl of blood cholesterol, and for this, various food groups have been advised and discouraged, some for good and others to reach a disastrous nutritional point.
Initially, all these recommendations stemmed from the obsession of an American physiologist, Ancel Keys, whose "study of the seven countries", among other related works, started the persecution against cholesterol and fats in general. Subsequently, in 1997, Keys himself rectified and even stated that "cholesterol in the diet has a limited effect in humans." But the damage was already done.
The reality is that the cholesterol consumed does not go directly to the arteries, nor does the consumption of dietary cholesterol have such a detrimental effect. In fact, as we have already mentioned, the same human liver is capable of synthesizing twice the cholesterol that is usually recommended to be ingested through the diet.
Supposedly, a level greater than 150 mg / dl of "LDL cholesterol" or a level less than 35 mg / dl of "HDL cholesterol" is harmful to health, and both at inadequate levels could increase the risk of suffering a cardiovascular heart attack. But the reality is far from being this way.
In studies between five and ten years ago it was seen, both in animals and in humans, that there is no such direct relationship between cholesterol consumed by diet and blood cholesterol levels: the reality is that the human body itself regulates cholesterol, since if too much is ingested, internal production is reduced, and vice versa.
On the other hand, there is the relationship between saturated fat and cholesterol, which continue to be prohibited in all current medical recommendations. However, as we already explained in Kitchens, neither fats in general are bad, nor saturated fats in particular are a direct path to premature death. In fact, eating saturated fat can increase bad cholesterol or LDL, but it also increases good cholesterol or HDL, while lowering the level of triglycerides in the blood. Therefore, there is something that does not add up.
Finally, we have the icing on the cake: high cholesterol increases cardiovascular risk, and it should be reduced even if it requires medication. Although these recommendations are medically official today, more and more studies that disagree with respect. One of many, striking for the number of individuals included, is the one published by the American Heart Journalin 2009: after analyzing more than 140,000 individuals admitted for a heart attack, it was detected that almost half of them had less than 100 mg / dl of bad cholesterol or LDL, and up to 75% of them had lower levels of 150 mg / dl. In other words, they suffered a cardiovascular event despite having adequate and even "very good" levels of bad cholesterol. Again, something is wrong, as other even older studies have shown, like the one published by JAMA in 1994 denying the relationship between cholesterol and mortality.
Cholesterol and its news
Currently there are already several voices among experts who advocate minimizing the importance of cholesterol and saturated fats in medicine. For now, the United States has removed the recommendation to "consume less than 300 mg of cholesterol per day" from its official guidelines.
For their part, studios are beginning to see the other side of the coin. One of these studies, coming from the Carlos III National Center for Cardiovascular Research (CNIC) of Spain, published in the Journal of the American College of Cardiology in December 2017, again demonstrated that the levels of bad cholesterol or LDL are not a good indicative of cardiovascular risk: even with normal levels, without other risk factors, there may be atheroma plaques in the arteries. Once again, our knowledge of "fatty" plaques and cardiovascular risk is missing something.
Therefore, and after obtaining these data from another larger study called PESA (Progression of Early Subclinical Atherosclerosis in its English acronym), the researchers advocate the search for new cardiovascular risk markers as an alternative to cholesterol: up to 50% of individuals with normal bad cholesterol levels they had atheroma plaques, as the 2009 JAMA study stated.
Although, on the other hand, the same authors from the CNIC also suggest that the cut-off point for bad cholesterol or LDL levels that are currently being managed should be lowered; In other words, its reduction should be sought intensively, something that also does not quite fit with the other available studies.
Other researchers, for their part, suggest that it is better to change. A study published in Science, also in December 2017, opted to replace the LDL cholesterol parameter with apolipoprotein B or apoB, another molecule whose function is to transport LDL cholesterol and other low-density cholesterol molecules considered “harmful” in excess. Although theoretically there should be a correlation between LDL and apoB levels, given that one transports the other, this is not always the case: some studies suggest that not all LDL particles contain the same amount of cholesterol, something to take into account in clinical tests, which calculate LDL levels based on HDL levels and fats or triglycerides, indirectly, and not in a direct way.
How cholesterol is treated
Currently in medicine, drugs called statins are used, whose function is to reduce blood cholesterol levels when it exceeds the famous 200 mg / dl of total cholesterol, or when LDL cholesterol exceeds 150 mg / dl, as long as there are other factors associated risk, such as suffering from type 2 diabetes, obesity, hypertension, alcoholism or smoking, among others. In fact, depending on the associated risk factors, or if a heart attack or stroke has already been suffered, medical clinical guidelines advocate a more abrupt reduction in total cholesterol in general, and LDL cholesterol in particular, reaching suggest that the latter be less than 70 mg / dl in some cases. For its part, it is often advocated for an increased HDL cholesterol, although there are currently no specific drugs for this purpose. In fact, some recent studies claim that too much good cholesterol or HDL would increase the risk of infections and premature death.
Without associated risk factors, the advice is usually to carry out a healthy diet, and without more.
While it is true that statins lower cholesterol, which implies that they are effective in their goal, the fact that they reduce mortality is not so clear. According to a 2011 meta-analysis, statins would be useless to reduce the risk of death in individuals without previous cardiovascular disease, so I would not advise their use in this type of individuals, no matter how high their cholesterol.
However, these drugs, like any other, are not without side effects, which can vary according to age: cognition and memory problems, muscle cramps (the most typical side effect), increased resistance to antibiotics, and an increased risk of diabetes. In fact, from the ages of 80-85, they are beginning to stop being recommended, as "high cholesterol" at these ages seems to provide a protective factor against dementia.
How should cholesterol be treated
Although medical and nutritional recommendations advocate the cessation of certain foods, the reality is that they are becoming obsolete. Some of the "not recommended foods" are fatty cheeses, or eggs, both foods high in saturated fat and cholesterol, factors that we have already explained do not have as direct an effect on blood cholesterol as used to be thought.
In fact, recent work not only states that eating more than one egg a day is not harmful, but that even consuming one egg a day would protect the heart.
For their part, given that nuts are rich in fat, they have also been in the spotlight of official recommendations to reduce their consumption, but today we know that they are beneficial and increase the feeling of satiety. The danger comes when they are consumed salty or fried, because not only do we consume an excess of them (any excess, even of good foods, is harmful), but we also consume a higher caloric density thanks to the super-added fried.
On the other hand, the most recent studies suggest that we should not give so much importance to atheroma plaque or fatty accumulation in the arteries, since we still have a lot to learn about it and know when and how it can harm us. In fact, a 2017 study showed that performing intense exercise doubles the number of fatty plaques, when physical exercise supposedly has a protective role; the researchers suggested that what exercise really does is "stabilize the plates," although more needs to be done.
For their part, statins have also been shown to cause a "halo effect" on their users: "as I take the pill, I can eat worse, it will not raise my cholesterol." And cholesterol, by itself, is not responsible for all the ills of modern medicine.
The reality is that diet and physical exercise, in short, a healthy lifestyle in general, would be more powerful by themselves than any drug we want to use. Already in 2009, a study published in Circulation affirmed it: diet surpasses any drug as a prevention factor for cardiovascular risk. And it is not just about eating healthy (with the vaunted " real food "), but also in the right amounts: a good diet, but hypercaloric, is also harmful.