The fats we consume with food are a heterogeneous group of substances composed mainly of triglycerides (that is, fatty acids linked together), but also cholesterol, sterols, and phospholipids. All of them fulfill important functions in the human being: they serve as an element to store energy, as fuel to produce energy, they are part of cell membranes, they participate in the synthesis of hormones and bile acids , and they participate in the aggregation of platelets. and in the activation of coagulation.
Therefore, the diet must include fats in its composition. There are several types of fats of interest in cardiovascular risk:
They are triglycerides that contain “simple” fatty acids (without any double bond in their chemical structure) have unfavorable effects on health by increasing blood levels of LDL cholesterol or “bad” cholesterol , raising blood pressure figures, increase the risk of thrombosis and increase the risk of cardiovascular disease.
They are present in all fats of animal origin (red meat, milk and derivatives); but there are also saturated fats of vegetable origin . Palmitic (palm and palm kernel oil) and lauric (coconut oil) acids are saturated fats of vegetable origin, and are also unfavorable for cardiovascular health. Generally, these fats appear on the labels of the products that contain them (pastry products, industrial pastries and pre-cooked foods) as “vegetable oil”. On the other hand, stearic acid, present in chocolate, and which is also a saturated fatty acid, behaves in a beneficial way on cardiovascular health given its metabolization in the body to oleic acid (monounsaturated).
They are triglycerides that contain fatty acids in whose structure there is a single double bond. This includes the fatty acids of the omega 9 (n-9) family, whose main representative is oleic acid, present in olive oil and nuts. These fats significantly improve cardiovascular risk. They slightly lower LDL cholesterol or “bad” cholesterol and slightly increase HDL cholesterol or “good” cholesterol ; LDL cholesterol is also less harmful to the arterial wall. In addition, monounsaturated fats would improve blood pressure, blood thrombosis capacity, inflammation in the arterial wall, and metabolic control of type 2 diabetes mellitus.
These are triglycerides whose fatty acids contain two or more double bonds in their chemical structure. Two families are included: omega 6 (n-6) fatty acids, from vegetables, and omega 3 (n-3) fatty acids, found in fish and shellfish and nuts. They are very beneficial, especially omega 3, for cardiovascular health.
N-6 fatty acids
The n-6 fatty acids are represented by linoleic acid , which we find in vegetable oils (sunflower, corn, soybean) and in nuts. They have a lowering effect on LDL cholesterol and HDL cholesterol. Their role by themselves in the prevention of cardiovascular disease is not clear. But, instead, if they replace saturated fats, they do reduce the risk of cardiovascular disease .
N-3 fatty acids
The n-3 fatty acids are found in fish (especially oily fish) and shellfish; its representatives are eicosapentaenoic acid and docosahexaenoic acid. They are also in vegetables (soybean oil, canola-rapeseed oil, green leafy vegetables and nuts); the representative is alpha linolenic acid. n-3 fatty acids produce numerous beneficial effects: decrease blood concentration of triglycerides and increase HDL cholesterol, reduce blood pressure, prevent arterial thrombi, reduce the incidence of ventricular arrhythmias after myocardial infarction, and reduce the risk of sudden death in previously healthy individuals . In short, they clearly reduce the incidence of cardiovascular disease or its recurrence or death from it in individuals who consume them.
Hydrogenated fats or trans fats
These are fats not present in nature until their appearance in the human food industry. They originate from unsaturated fatty acids by a hydrogenation process. Hydrogenation consists of adding, at high temperatures, hydrogen atoms to unsaturated fatty acids (generally monounsaturated acids). Thus, from a liquid fat (monounsaturated) a more solid fat is formed which can be said to be “of vegetable origin”, and which, in addition, makes the products made with it last longer, maintain for longer desired consistency and taste better. For all these reasons, these fats are ideal in industrial pastries and in the production of margarines with a hard consistency. However, despite being “vegetable”, trans fats have harmful effects on blood fats, increasing LDL cholesterol values and reducing HDL cholesterol values, they have a enhance inflammation on the arterial wall , increase the risk of developing type 2 diabetes mellitus and increase the risk of cardiovascular disease, even more than saturated fats. The more liquid the margarine is, the less trans fatty acids it contains.
Interestingly, cholesterol from food does not have a major effect on blood cholesterol . This is true for the majority of individuals, but we also find some individuals who greatly change blood cholesterol compared to any change in the amount of cholesterol in the diet; They are called “high responders” or “hyperresponders.” Another important aspect to take into account is the relationship between dietary cholesterol and the risk of cardiovascular disease; the results are not conclusive in this sense, there are studies in favor and others against. But, in these studies that find a causal relationship between dietary cholesteroland the appearance of cardiovascular disease, the risk is very low. Cholesterol is only found in foods of animal origin , such as meat, organ meats, sausages, whole dairy products (milk, cheese, butter), eggs, fish, and shellfish. But since many of these foods also contain saturated fat in their composition, it is not advisable to consume them in excess. On the other hand, it is important to note that the frequent indication in processed products of “does not contain cholesterol” does not presuppose that they are healthy, since they may contain saturated fats. In this sense, the recommendations on eggs is a moderate consumption (2-3 eggs a week).
There is scientific evidence of the implication of the quality and quantity of fats consumed in human health, either in the development (saturated fatty acids and trans acids) or in the prevention (monounsaturated acids and omega-3 acids) of cardiovascular diseases . We must take fats, but not of any type and in any amount. It is recommended that of the total energy that is incorporated with food, around 30-35% comes from fat: less than 7% in the form of saturated fat, 7-10% as polyunsaturated fat, and 15-20% as monounsaturated fat.