Casein

Milk contains two types of protein - casein and whey protein. The percentage of casein in milk protein is 80% and whey protein’s share is 20%. Casein is a slowly digestible fraction of the milk protein which contains all the essential amino acids the human body needs. The amino acid profile of casein includes a higher percentage of the amino acids histidine, methionine and phenylalanine, while whey protein contains more from the branched chain amino acids (BCAAs) leucine, isoleucine and valine. This amino acid profile is responsible for the casein’s weak effect on protein synthesis and its strong effect on preventing protein breakdown in the muscle cells. The slow release of the amino acids in casein combined with its specific amino acid profile make it indispensable for taking before going to sleep or as a protein substitute for those of the main meals, after which a long meal pause is expected. Consumed during these periods casein exhibits anti-catabolic function, which reduces muscle breakdown and helps the body to recover during the long meal pause during sleep or when it is impossible to achieve a sufficient number of meals during the day.