Cholesterol: a fatty substance essential to the body
Cholesterol is a complex lipid essential to human life, both present in our diet – exclusively in animal products – and produced by our body (1200 mg of cholesterol per day is produced by the body) for many purposes. Cholesterol contributes to the construction of the membranes of our cells and the sheaths of our neurons. It is also a precursor of vitamin D and steroid hormones, including sex hormones. Health and fitness
Understanding Cholesterol: Role and Function
The majority of cholesterol is produced by the body and in particular by the liver, which also has the role of regulating it. Thus, cholesterol is transported to the cells by lipoproteins called LDL (low-density lipoprotein). The excess is excreted and brought back to the liver to be recycled there by the HDL lipoprotein (high-density lipoprotein). Commonly, it is said that HDL is the “good cholesterol” and that LDL is the “bad cholesterol”. We will see that everything is not white or black and that it is a little more complex than that. Always chose stayfreshtoday for your health and fitness.
The cholesterol transport system
We could think of this whole process of moving cholesterol and triglycerides (fats or lipids) through the body like a bus system with different routes and different buses carrying passengers along them. Buses carrying dietary fat and cholesterol (called chylomicrons) travel from the intestines to the liver, which is essentially the central bus station. Here, passengers get off the “chylomicron” bus and can board the VLDL (very low-density lipoprotein) buses where they are joined by new liver passengers. The VLDL bus makes stops throughout the body and ultimately has far fewer passengers. Along the way, it becomes the LDL bus, which continues on its lines before finally returning to the liver.
This is an oversimplification, as the lipoproteins in our bodies do much more than just shuttle fat and cholesterol, but at a basic level, this model describes how lipoprotein particles move and interact. If this system goes wrong, an excess of LDL cholesterol sent into the blood as well as a lack of cholesterol supposed to bring it back to the liver, can cause an accumulation of cholesterol in the arteries which gradually become clogged. The body must have a supply of cholesterol in favor of HDL. The consumption of alcohol and tobacco, and a diet high in sugars and refined foods hurt cholesterol levels.
The “bad” LDL cholesterol: more superhero than a supervillain
Most cells in our body can make some cholesterol from scratch, but they also rely heavily on the delivered supply of this molecule to build membranes and hormones. In the ovaries and testicles, for example, cholesterol delivered by LDL is needed to make the sex hormones estrogen and testosterone, which are crucial for libido and reproductive function. Without LDL, these hormones and many other steroids would not be made effectively.
LDL cholesterol also plays an important role in the immune system by taking part in our immune response to the onslaught of infectious invaders, as do many lipoproteins, including HDL. The bacteria that try to besiege us also secrete molecules that tell each other when it's the right time to divide and attack. This communication system is known as quorum sensing, and it's not good for our immune system. But the superhero LDL cholesterol can fight this battle again by binding these molecules together and helping to shut down such bacterial lines of communication.
For information, mice with experimentally increased levels of LDL are 8 times more resistant to endotoxin (poison from certain bacteria). Conversely, rats bred with very low LDL levels had much higher death rates and inflammation levels which could have been corrected by providing them with the extra LDL. Along with studies of LDL depletion in mice and rats, there is a known human condition in which total cholesterol is very low, due to a genetic mutation in the cholesterol synthesis pathway (Smith-Lemli-Optiz syndrome). ). Children born with this mutation are often stillborn, but those who survive to suffer from frequent and severe infections that are corrected with dietary cholesterol supplementation,
Saturated fats, cholesterol, and heart problems
Dietary fats are divided into 2: there are saturated fats and unsaturated fats. For the body, the treatment of either is identical and we need to eat saturated fat as much as unsaturated fat. Saturated fats are considered by the general public – but also by scientists, doctors, and nutritionists – to be bad fats, playing a role in overweight and heart health problems.
LDL cholesterol in heart problems and hypertension: criminal or savior?
LDL cholesterol, as we have seen, is a valuable particle in our blood and serves many indispensable roles. Isn't it a bit incongruous that nature would have designed something so precious, but also damages our arteries and causes heart problems and cardiovascular pathologies? That does not make sense! The answer is that LDL itself is not harmful, but in some situations it can be involved in the process of responding to injury and inflammation, making it seem like a bad actor. when he is simply present at the scene of the crime.
In addition, vegetarians are also far from immune to heart problems and high blood pressure. They too show levels equivalent to the general population despite lower average levels of LDL. Yet they do not eat animal products and therefore no saturated animal fats. In fact, could there be another guest in the game, who could play his part in the problems we have just stated? Knowing that vegetarians have a hyper-carbohydrate diet, their insulin level could well be the cause.
(Saturated) fats: victims of the sugar propaganda
It is now very clearly established that sugar is the main factor in the problems of being overweight, high blood pressure, and cardiovascular disease, even if saturated fats remain the culprits in the eyes of people since we have been told for decades that fat makes you fat. In reality, it is sugar (carbohydrates) that makes you fat, because the 3 macronutrients (carbohydrate, fat, and protein) it is the only one to cause the secretion of insulin. And insulin is the hormone responsible for storing and releasing energy. In other words, if insulin is not stimulated, there is no storage possible because there is no other way for the body to store fat. When we consume fats (animal or vegetable, saturated or unsaturated) and proteins, it is simply not possible to gain “fat”. This energy is on the contrary either used directly or made available by the body in the blood, the muscles, or organs like the liver.
So why are we being told – public health agencies, doctors, scientists, nutritionists, journalists – that fat makes you fat and is bad for heart and body health? That cholesterol is bad and you shouldn't eat saturated fats? This is, among other things, because for more than half a century, and until very recently with a study published in 2004, The China Study by Dr. Campbell, fats, but also meat and salt have been made, wrongly and voluntarily, guilty of all evils. Even though voices have been raised throughout this time and reviews have been published, including a very widespread one published in 2014 by Denise Minger, Death by food pyramid, correcting decades of lies and propaganda in the collective consciousness takes time. Especially when the global health and nutrition agencies don't go along with it.
Natural saturated fats are good for cholesterol
Saturated fats are generally in solid form at room temperature and of animal origin. It is found in abundance in meat, fatty fish, cheese, dairy butter, egg, cocoa butter, and coconut oil. Above all, we must not eliminate them from our plates. Saturated fats of natural origin play important roles in our metabolism, especially in cholesterol, and they are excellent sources of energy. In contrast, processed fatty acids are unsaturated fats, but they are artificial and therefore dangerous. They serve our health instead of serving it. The best way to avoid them is to not buy processed or prepared foods, and to check labels that say "partially hydrogenated."
Furthermore, saturated fats are more stable and less sensitive to heat than unsaturated fats. They are the ones to use for cooking. On this point, we can distinguish between saturated medium-chain fats – MCTs – present in coconut oil and clarified butter (ghee butter). These MCTs are assimilated faster than longer-chain fats and appear to promote thermogenesis and fat utilization. We will therefore favor coconut fat and ghee butter for cooking (especially at high temperatures), and possibly olive oil for gentle cooking only (even if it is preferable to consume it cold) because it rapidly degrades.
Omega-6 and cholesterol, we are not told everything?
The modern diet is very rich in omega-6 with an average ratio of 20:1 against omega-3. However, a high ratio of omega-6 seems to activate inflammatory reactions. Yet omega-6s belong to polyunsaturated fats, called "good" according to global nutritional guidelines. Things are therefore not so simple, in the sense that everything is not white or black. Refined and processed vegetable oils, cereals (wheat, corn, spelled, etc.), seeds (nuts), and prepared meals are very rich in omega-6 (therefore in polyunsaturated fats) and represent the highest proportion. important in the Western diet. Yet officials from nutrition and health agencies put grains (and seeds) front and center.
However, most pathologies and diseases are of inflammatory origin. Having a pro-inflammatory diet, ie mainly composed of omega-6 does not play in favor our health. On the contrary, this ratio must be reversed by giving the advantage to omega-3 fats and above all by greatly reducing the consumption of sources of omega-6. For sources of omega-3, it is more interesting that they are of animal origin: oily fish, shellfish and crustaceans, raw organic dairy products, fermented milk, chicken eggs (fed with flaxseed is still better), grass-fed livestock (grazing ruminants).