Fatty acids are aliphatic monocarboxylic acids that have an unbranched carbon chain. According to their natural occurrence or chemical structure, saturated or unsaturated fatty acids can be distinguished.
What are fatty acids?
Based on their different chain lengths, fatty acids can be divided into lower, middle, and higher fatty acids, respectively. Natural fatty acids are normally composed of an even number of carbon atoms and have no branches. A carbon chain must have at least four carbon atoms. The simplest natural fatty acid is butyric acid. Unsaturated fatty acids have double bonds that are cis-configured. If there are several double bonds, they are separated by a CH2 group. Unsaturated fatty acids have two to eight hydrogen atoms less than saturated fatty acids. Fatty acids that have two hydrogen atoms less are called monounsaturated fatty acids. Polyunsaturated fatty acids, on the other hand, have four to eight fewer hydrogen atoms. Saturated or some unsaturated fatty acids can be broken down or converted by the body. This is not the case with polyunsaturated fatty acids, which is why they must be supplied through the diet and are therefore also referred to as essential fatty acids. The so-called essential fatty acids are needed by the organism, but it is not able to produce them itself. For humans, these are linolenic acid or linoleic acid. A special form is trans fatty acids, which are formed when polyunsaturated fatty acids are heated. In the food industry, fatty acids are mainly used as raw materials for various emulsifiers, and they are also used as release agents, carriers or as coating agents.
Function, effect and tasks
In the adipose tissue, fatty acids are stored as triglycerides, where lipolysis also occurs when needed. In the bloodstream, the free fatty acids are then transported to those cells that require energy. The body stores the energy in depots, and in the event of prolonged deficiencies it then has the opportunity to draw on these reserves. Fatty acids are essential components of dietary fats. Along with carbohydrates and proteins, fat is one of the basic nutrients. The intake of fat provides the body with essential fatty acids and energy. Essential fatty acids are important for cell structure and for various metabolic processes. They can be used to control fat absorption from the intestine, regulate fat metabolism and lower cholesterol levels. In addition, fat is important for the absorption of fat-soluble vitamins such as vitamin K, vitamin E, vitamin D or vitamin A. However, self-synthesis depends on the diet. If a lot of carbohydrates and few saturated fatty acids are consumed, fatty acid synthesis increases. However, if too much protein and fat are consumed, the formation of important fats is inhibited and more storage fat is stored. Cell membranes thus lose function, suppleness and reactivity, and saturated fats also increase the stickiness of blood platelets and the tendency to inflammation. As a further consequence, blood vessels also constrict.
Formation, occurrence, properties, and optimal values
Many fatty acids are found in the seed oils of the plant kingdom, some of which also represent developmental relationships. These include, for example, tariric acid, petroselinic acid, cyclopentene fatty acids, erucic acid, and cyclopropene fatty acid. Saturated fatty acids are mainly found in animal foods such as sausages, meat, butter, lard, cream or cheese. Unsaturated fatty acids or polyunsaturated fatty acids are found in fish or plant foods such as walnut oil, linseed oil, olive oil or rapeseed oil. Linolenic and linoleic acids, on the other hand, are found in sunflower seed oil, corn oil, soybean oil, nuts and in fish such as salmon, mackerel or herring. Trans fatty acids are found, for example, in shortenings, margarine, cookies, puff pastry or potato chips. Polyunsaturated fatty acids can be divided into omega-3 fatty acids and omega-6 fatty acids. Here, omega-3 fatty acids are distinguished between:
- Alpha-linolenic acid: Occurs in nuts, dark green leafy vegetables, walnutl, soybean oil, rapeseed oil or linseed oil.
- Docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA): found in fish such as tuna, salmon or mackerel.
Omega-6 fatty acids can be distinguished between the following groups:
- Linoleic acid: Contained in grape seed oil, corn oil, pumpkin seed oil, safflower oil or sunflower oil.
- Arachidonic acid: Can be found in egg yolks, butter, offal or meat.
Diseases and disorders
Unsaturated and saturated fatty acids are good suppliers of energy. They have a positive effect on the immune system and other metabolic processes. However, unsaturated trans fatty acids are quite unfavorable for cholesterol levels, as they increase LDL cholesterol. They also increase the risk of sudden cardiac death or coronary heart disease (CHD). It is therefore important to be able to assess which fats or how much fat is being consumed. However, a completely fat-free diet is not advisable, as some components of fat have important functions. One third of the fat consumed should consist of saturated fatty acids and two thirds of unsaturated fatty acids. If too many omega-6 fatty acids are consumed, this promotes the formation of so-called eicosanoids, which promote inflammation. To counteract this, sufficient vitamin C, A and E should always be taken in, as they are able to convert omega-6 fatty acids and reduce the concentration of eicosanoids. Basically, however, essential fatty acids are very important because their intake lowers blood lipid levels and reduces the risk of cardiovascular disease. A deficiency of essential fatty acids can lead to the following diseases:
- Weakened immune system
- High blood pressure
- Dyslipidemia
- Skin lesions
- Kidney diseases
- Decreased liver function
- Symptom aggravation of allergies, arthritis, thrombosis or eczema.
