Fat metabolism, also known as lipid metabolism, refers to all metabolic processes that involve absorption and utilization of various lipids. This includes the digestion of fats and fat-like substances, and also the conversion of fats into energy.
What is lipid metabolism?
The central site for the breakdown and breakdown of fats is the liver. Fats and fat-like substances ingested through food are first emulsified and partially broken down in the stomach. This complex process continues in the liver, intestine, muscles and fatty tissue. The central site for the breakdown and breakdown of fats is the liver. Lipid metabolism consists of an exogenous and an endogenous metabolism. Both serve to supply the organism with triglycerides and cholesterol. In exogenous lipid metabolism, fats enter the bloodstream as chylomicrons, which are lipoprotein particles, via the lymph. Triglycerides split off from these and are taken up by muscle and adipose tissue. The remaining chylomicrons migrate to the liver. During endogenous lipid metabolism, complicated transport and remodeling processes take place. One group of lipoproteins, VLDL, Very Low Density Lipoprotein, serve to transport triacylglycerides, phospholipids, and cholesterol to tissues. VLDL is transformed into intermediate density lipoproteins, so-called IDL, which are poorer in triglycerides and richer in cholesterol. In parallel, they also give rise to low-density lipoproteins, LDL, which are also poor in lipoprotein triglycerides but rich in cholesterol lipoproteins. Special receptors are used to shuttle LDL into the tissues. The cholesterol delivered there, along with other fat-soluble substances, is responsible for the synthesis of steroid hormones and vitamin D. Excess LDL is reabsorbed by the liver. High-density lipoproteins, called HDL, are also important for protecting the heart and blood vessels from too much cholesterol. Special transport proteins pick up the excess.
Function and role
Unlike glucose, which plays a central role as an energy supplier for all cells, lipids are needed as a basic supply by only a minimal number of cells. The main task of lipids is therefore storage. What the body does not need is stored in the depot. If there is a shortage of food, the required fats can be retrieved by the organism thanks to lipid storage. In this respect, fats are essential for a well-functioning organism. Lipids provide high-quality energy and heat and thus supply muscles, cells and organs. Fats have a variety of tasks and functions. They serve as energy stores for all processes in the body that require energy. As building blocks, they form the basic structure for all cellular membranes. These thin tissue layers of lipids and proteins seal themselves off from external influences in order to maintain the internal milieu. Fats also serve as synthesis precursors for a large number of biologically active compounds. These include hormones and hormone-like substances. Triglycerides, cholesterol and fatty acids are absorbed through the diet. Triglycerides are the actual, important blood lipids that mainly provide energy for fat and muscle cells. They are found in vegetable oils and animal fats. Cholesterol is found mainly in foods of animal origin. Strictly speaking, cholesterols are fatty substances and not fats. Cholesterol also provides energy to fat and muscle cells, and also serves as a building block for cell walls, is involved in the building of nerves, in the formation of sex hormones, in cortisone production and heart stimulating substances, contributes to vitamin D synthesis and is an important factor in the formation of bile acids. These play a central role in fat digestion and excretion. Fatty acids, which include both saturated and unsaturated ones, are found mainly in vegetable fats. They provide energy, support the immune system, are involved in numerous other metabolic processes and can alleviate depression. Lipids also play their part in enzymatic reactions.
Diseases and ailments
Lipid metabolism disorders are widespread in the Western world. Reasons are an unhealthy lifestyle and a diet high in fat and sugar. However, genetic predisposition also plays a role. In industrialized countries, vascular diseases and cardiovascular diseases occur in particular.The causes here are a diet too rich in calories, combined with a lack of exercise. Lipid disorders can be identified by an increase in blood lipid levels. A lipid metabolism disorder occurs when the transport, processing and production of lipids no longer function properly. A lipid disorder is divided into two categories, the primary and secondary forms. The primary form is a genetically determined disorder. In the case of congenital lipid metabolism disorder, fat deposits in the skin can already be observed in childhood. Cholesterol levels are significantly elevated and patients develop vascular calcifications already in childhood. In the secondary form, underlying diseases such as diabetes, obesity, stress or thyroid dysfunction are usually present. The consequences are the same for those affected by both forms. There is an increase in the total fat content of the blood, a disturbance in transport and blood fat processing. An increase in blood lipid levels is one of the most common lipid disorders and is further divided into two categories: high cholesterol levels and high triglyceride levels. Unlike triglyceride, the body produces its own cholesterol and is therefore hardly dependent on food intake. However, due to the large number of cholesterol-containing foods, intake has risen sharply and the excess can no longer be broken down. The primary, genetically determined lipometabolic disorder usually results in an increase in cholesterol. While the secondary form results in an increase in triglyceride levels.
