Lecithin, also known as egg yolk, is a group of yellowish brown oily substances existing in animal and plant tissues and yolk. The components include phosphoric acid, choline, fatty acid, glycerol, glycolipid, triglyceride and phospholipid. It is an important component of cell membrane, alveolar surfactant, lipoprotein and bile. Lecithin has many benefits to human health. There is no age limit for lecithin supplementation, and it can be taken from children to the elderly.
Egg yolk is rich in lecithin. In addition, milk, animal brain, bone marrow, heart, lungs, liver, kidneys, soybeans and yeast all contain lecithin. Therefore, people are advised to take as many kinds of food as possible to supplement their nutrition. At present, lecithin tablets made from this ingredient extracted from eggs can be used for adjuvant treatment of liver diseases.
The discovery of lecithin
Lecithin was first isolated from egg yolk by French chemist and pharmacist Theodore Gobley in 1845. It can also come from soybean, milk, marine resources, rapeseed, cottonseed and sunflower.
It is composed of fatty acids, usually a mixture of stearic acid, palmitic acid and oleic acid diglyceride, which is linked to choline phosphate. Lecithin fats are amphiphilic, which means that they absorb both water and fatty substances (they are hydrophilic and lipophilic).
Lecithin can be used to make food smooth, dissolve powder (emulsify), homogenize liquid mixture and repel sticky substances. Lecithin can also be sold as an over-the-counter dietary supplement, which is said to help improve the strength and function of the heart, help cognitive functions such as memory retention and logical reasoning, and reduce inflammation and internal swelling.
In cosmetics and personal care products, the lecithin used is called hydrogenated lecithin. Hydrogenated lecithin is the product of controlled hydrogenation (hydrogen addition) of lecithin.
What is the safety of lecithin?
The Panel of Cosmetic Composition Review (CIR) has evaluated the safety of lecithin and hydrogenated lecithin. CIR expert group evaluated the scientific data and concluded that lecithin and hydrogenated lecithin can be safely used for washing products. However, CIR expert group limited the use of lecithin and hydrogenated lecithin in disposable products to a concentration less than or equal to 15%.
Because lecithin plays the role of penetration enhancer, it should be used with caution when mixed with other ingredients. (Because absorption through skin barrier may be harmful to human body)
The main function of lecithin is to provide energy, and it can be used as an emulsifier, which can improve cardiovascular and nervous system functions. However, large doses of lecithin can lead to gastrointestinal stress, sweating, salivation and loss of appetite.
Some people may be allergic to lecithin because it may come from soybeans, eggs and milk, which are common allergic foods. Foods that are highly sensitive to these foods may react to lecithin.