Vascular diseases linked to atherosclerosis are today the leading cause of death in rich countries. In Italy they are responsible for 44% of deaths. If some of the deaths are acute (from acute myocardial infarction-AMI or stroke), the remainder are the consequence of disease progression, which affects survivors from the acute event after a low-quality life, full of suffering and physical limitations.
These diseases are actually the manifestation of a single disease, arteriosclerosis, the process that gradually damages the arterial walls, with the deposit of fats, blood cells and fibrous tissue, causing the formation of arteriosclerotic plaque and thus hindering the flow of arterial blood. Arteriosclerosis, which compromises the flow of blood to vital organs, is a progressive and inexorable process, and it shows signs of itself only when the situation precipitates with the occlusion of the vessel. Hence the onset of a heart attack, if a coronary artery is blocked, or a cerebral stroke, if an artery that carries blood to the brain is blocked, or gangrene in a limb, if an artery in a leg is blocked.
The ways in which this occlusion appears, and its consequences, depend on the type of arteriosclerotic plaque: there are in fact 2 types of plaque, the “stable” plaque and the “unstable” plaque, both made up of lipids, blood cells and a layer of fibrous tissue (the “fibrous hood”).
In the “stable” plaque, the fibrous cap is thick and solid, so that the plaque continues to grow until it becomes occlusive by itself or because the slowing of the flow is such that at some point a small thrombus forms which completes the occlusion of the ‘artery. This type of plaque, however, precisely because its growth is very slow, gives time to the circulation of that area to “reorganize”, with the strengthening of a parallel circulation, so-called “collateral”. If this circulation is effective, then the occlusion of the vessel affected by the plaque can even go asymptomatic, because the blood flow is still guaranteed to the area by the collateral circulation. Exercise promotes the development of collateral circulation,
The so-called “unstable” plaques, on the other hand, are relatively small plaques, also formed by a lipid “core”, but have a thin fibrous cap. These plaques, while not significantly compromising circulation due to their size, are the most dangerous, because they are easy to break the fibrous cap. When the material contained within the plaque (the lipid “core”) enters into communication with the blood, a process is rapidly triggered that leads to the formation of a thrombus. If the vessel is very small (such as in the vessels of the heart) or the thrombus is large, the vessel closes quickly. Since these plaques are usually small in size, they do not cause the development of collateral circulation, and
It has been estimated that, while only 10% of AMIs would be caused by “stable” plaques, the remaining 90% would be attributable to rupture of “unstable” plaques. These plaques are almost always asymptomatic, until they become complicated, and are usually not recognizable in the angiographic study. 40% of cases of AMI occur in people who have never had any disorder before, and 1/3 of all heart attacks cause sudden death.
Therefore, the prevention of heart attack does not pass only through the recognition and surgical treatment of the obstructions caused by the large “stable” plaques, but above all through the offensive to the “unstable” plaques. This attack strategy recognizes as the main tool the lowering of total cholesterol and LDL cholesterol levels, which are directly related to the fats contained in the “core” of the plaque. The level of 200 mg / dL of total cholesterol, indicated as the normal limit, is considered by many scholars to be too high and therefore responsible for underestimating and under-treatment of subjects at coronary risk.
In fact, in the famous Framingham Study, as many as 35% of heart attacks occurred in subjects with cholesterol levels between 160 and 200 mg / dL. It is therefore the opinion of many authoritative researchers that the cholesterol level above which the risk must be placed is 150-160 mg / dL: many populations of the planet that have cholesterol values below this limit have an incidence of very low coronary events.
To achieve this goal, changes in some lifestyle habits (TLC, Therapeutic Lifestyle Changing), such as diet, exercise, are recognized as first choice by authoritative international organizations (NCEP, National Cholesterol Education Program, and AHA, American Heart Association). physical and smoking.
As far as dietary measures are concerned, it is known that saturated fats and transhydrogenated fats, in addition to food cholesterol, are responsible for the increase in LDL-cholesterol levels in the blood. Eliminating these fats, replacing them with mono and polyunsaturated fats leads to dramatic reductions in total cholesterol and LDL-cholesterol values. If the optimal amount of total fat in the diet is still the subject of controversy (the associations mentioned above indicate a maximum limit of 30% of total calories, which by many authors is considered too high a limit, especially when you want to obtain plaque regression ), however, there is full agreement on the importance of limiting saturated fat and cholesterol in the diet.
Unfortunately, the international guidelines, such as those issued by the American NCEP and AHA and also taken up in Italy, do not provide clear instructions on this subject. On the other hand, it is imperative that any information message addressed to the population and aimed at the prevention and treatment of arteriosclerosis should provide detailed instructions that can be used by ordinary people, including information that could allow them to pass responsibly and knowingly from theory (reduce fat .. ., to reduce blood cholesterol) to practice (these fats are contained in the following foods …, which should therefore be limited to the maximum / eliminated, while these foods should be privileged …). Limit yourself to advising to include in the diet abundant quantities of whole grains, legumes, vegetables and fruit is not enough if, on the same level and therefore with the same media value, the list of recommended foods also includes, without the suggestion of limiting them or rather considering them as optional, foods such as lean meats and dairy products. Including these foods among those allowed, in a cultural context in which these foods unfortunately represent the cornerstone of the diet of rich countries and are responsible for the cardiovascular disease epidemic that we face, actually means preventing the population from being able to reach “safe” cholesterol levels in the absence of pharmacological support. The pharmacological treatment of hypercholesterolemia certainly constitutes a therapeutic option, but the patient must choose it,
The optimal diet for the prevention and treatment of coronary heart disease consists of whole grains, legumes, vegetables and fruit, consumed as close as possible to their natural state (“as cultured”), ie avoiding the consumption of processed foods, especially industrial foods . All sources of saturated, transhydrogenated fats and cholesterol, such as butter, margarine, lard, cheese, eggs, whole milk, meat and sausages, and some vegetable oils (palm, coconut, unspecified vegetable oils, even if not transhydrogenated ) should be limited as much as possible, if not completely banned. To provide an optimal amount of omega-3 fatty acids, it is not necessary to take fish, but the intake of 2 servings per day of plant foods rich in these fatty acids (1 serving is equivalent to 1 tablespoon of ground flaxseed, or 1 teaspoon of flaxseed oil, or 4 tablespoons of walnuts). While some fish are a good source of omega-3 fatty acids, due to environmental toxicants that contaminate fish meat, both farmed and marine, it is considered safer to use plant sources of these fatty acids. While for the prevention of atherosclerosis 25% of the total calories from fat should not be exceeded, the best clinical results in the regression of coronary heart disease were obtained by adopting a diet with a fat content equal to or less than 15% of the total calories.
While some fish are a good source of omega-3 fatty acids, due to environmental toxicants that contaminate fish meat, both farmed and marine, it is considered safer to use plant sources of these fatty acids. While for the prevention of atherosclerosis 25% of the total calories from fat should not be exceeded, the best clinical results in the regression of coronary heart disease were obtained by adopting a diet with a fat content equal to or less than 15% of the total calories. While some fish are a good source of omega-3 fatty acids, due to environmental toxicants that contaminate fish meat, both farmed and marine, it is considered safer to use plant sources of these fatty acids. While for the prevention of atherosclerosis 25% of the total calories from fat should not be exceeded, the best clinical results in the regression of coronary heart disease were obtained by adopting a diet with a fat content equal to or less than 15% of the total calories.
This type of diet, combined with the abolition of cigarette smoking and the practice of regular exercise, has been shown to be useful and effective in the prevention, arrest and regression of coronary arteriosclerosis, as shown by some of the studies which will be presented in this section.
