What are lecithins?
Lecithins are chemical compounds belonging to the group of phosphatidylcholines. These are so-called phospholipids. These are composed of fatty acids, phosphoric acid, glycerol and choline.
The name lecithin comes from the Greek lekithos and means egg yolk. This name was chosen because lecithin was first isolated in 1846 from egg yolk. Only later was it found that the phospholipids are found in all animal organisms and also in many plants.
Function, effect & tasks
Lecithins carry out numerous functional tasks in the body. Their most important task is the structure formation in the body. The living cells in the human body are surrounded by a cell membrane. This protects the cell organelles and maintains the internal environment of the cell.
The cell membrane consists of a lipid bilayer. An important component of this lipid bilayer are the lecithins. Lecithins together with other phospholipids in the impermeable membrane form so-called hydrophilic windows. Through these windows, ions, water molecules and water-soluble substances enter the cell. The higher the lecithin content of the cell, the more active the cell membrane can act.
In nerves and brain, lecithin can be converted to acetylcholine in various chemical processes. Acetylcholine is one of the most important neurotransmitters in the human body. He is responsible, for example, for the transmission of nerve impulses to the heart. It is also the most important transmitter in the parasympathetic and sympathetic nervous systems.
Lecithin stimulates enzymes that can neutralize and eliminate free radicals. Free radicals are molecules that arise in many metabolic processes in the body. From a chemical point of view, they are incomplete. They lack an electron in their chemical structure. To compensate for this deficiency, they try to steal this electron from other structures in the body. In doing so, they damage the cell membranes and also the entire cells of the body. Free radicals are believed to play a crucial role in the development of cancer and other serious diseases.
Lecithins also play an important role in fat digestion. They act as an emulsifier of lipids in the blood. Only in emulsified form can the fats be utilized by the body. Cholesterol is also emulsified by lecithins. Thus, the cholesterol remains soluble in the gallbladder. Without this emulsification gallstones could form from the cholesterol. But lecithins can not only bind cholesterol, they can also activate enzymes that break down excess cholesterol. Thus, lecithins have a vascular protective effect.
Education, occurrence, properties & optimal values
In the body, lecithins are found in large part in the cell membranes. In particular in the liver, in the brain, in the lung, in the heart and in the muscle tissue high concentrations of lecithin are found. Lecithin can also be found in the blood plasma.
Some of the lecithins, the phosphatidylethanolamines and the phosphatidylcholines, are produced in the Kennedy pathway. It is a biochemical process that takes place in the nerve cells. However, lecithins can also be absorbed through food. The main source of lecithin is soy. But rape, sunflower oil and, of course, yolk also contain lecithin. Lecithin levels in blood plasma are not determined. Therefore, there are no reference values.
Diseases & Disorders
A lack of lecithins in the body can lead to a variety of symptoms. Lecithins play an important role in lipid metabolism. In one study, men and women were given intravenously normal levels of methionine and folic acid.
Throughout the study, the subjects developed a fatty liver and also the first signs of liver damage became clear. By regularly adding lecithin, these changes could be reversed. Lecithins bind portions of so-called VLDL particles. These are responsible for the transport of fats from the liver to the tissues. Without lecithins, the VLDL particles can no longer be produced. The fat accumulates in the liver and damages the tissue there.
Lack of lecithin appears to increase cell death rates within the liver. Studies show that liver cells induce programmed cell death, called apoptosis, when they lack lecithin. In rats, a diet-related lack of lecithins resulted in an increased incidence of liver cancer. Sensitivity to carcinogenic chemicals also increased with lecithin deficiency.
Lecithins also seem to play an important role in Alzheimer's disease. Alzheimer's disease (Alzheimer's disease) is a disease of the nervous system. It predominantly occurs in persons older than 65 years. Characteristic of the disease is a worsening of cognitive performance. The memory is limited, the spatial orientation decreases, the time experience is disturbed and the practical skills are limited. In addition, there are disturbances of the language, a restriction of spatial-constructive skills, a disturbance of the inner drive and a fluctuating emotional state.
The exact causes of Alzheimer's disease are still unclear. In the course of the disease, however, there is a lack of acetylcholine. The messenger substance is no longer produced in sufficient quantities. This leads to a reduced performance of the brain. In several studies, lecithin administration in Alzheimer's patients showed a slight improvement in memory performance. However, lecithins can not arrest or even cure the disease. Nevertheless, given the multiple effects of lecithin, care should be taken to ensure adequate supply of the phospholipids.