he trend to reduce eggs in the diet comes from the American Heart Association (AHA) recommendation issued in 1972. It was then thought that cholesterol contained in food influenced elevated cholesterol levels in plasma. According to this belief, eggs containing 200-215 mg of cholesterol have been indexed as products that increase the risk of heart diseases and vascular diseases. According to the AHA recommendation, one should not consume more than three eggs a week. New scientific studies however have shown that this view is not correct. The World Health Organization and the American Heart Association report that current research shows no association between egg consumption and blood cholesterol levels. Although the AHA still recommends not exceeding 300 mg of cholesterol in a healthy daily diet, in 2006 it withdrew from the restrictions on the number of eggs consumed.
Moreover, studies conducted in the USA have shown the short- and long-term effects of several decades of reducing the consumption of eggs on human health. It was discovered that reducing eggs results in deficiency of choline, a vitamin-like substance that is extremely necessary for the proper functioning of the body. Its proper level reduces the risk of dementia and breast cancer, and also ensures the right functioning of the brain, the liver and the nervous system.
How is it possible though that an egg that contains 2/3 of the recommended daily dose of cholesterol can be consumed almost without restriction? Above all, the yolk, in addition to cholesterol constituting its 0.3%, is a source of 10-20% phospholipids that reduce the deposition of the cholesterol in the blood vessels. In addition, each of us produces about 3 grams of cholesterol daily, the equivalent of 15 eggs. Finally, one must not forget that cholesterol is essential for normal functioning of the body - it is a precursor of sex hormones, bile acids and vitamin D, as well as a component of cell walls and blood plasma. The problem of blood vessel obstruction is therefore not so much related to diet as with our internal metabolism.
The fact that cholesterol should be looked at more favorably is indicated by the experience of producing eggs with a reduced content of this substance. The use of appropriate methods of breeding and feeding chickens makes it possible to reduce the cholesterol content in eggs. However, studies have shown a significant reduction in hatching of these eggs. On this basis, it can be concluded that cholesterol plays an extremely important role in the development of the embryo. By improving nature, we may unnecessarily reduce the nutritional, health and biological value of eggs.
Consultancy related to the content: dr hab. Monika Michalczuk,
Department of Poultry Breeding, Faculty of Animal Science, WULS-SGGW