Whey contains all of the essential amino acids, or EAAs, your body needs but cannot produce itself. There are nine EAAs and each has its own function in the body. It's important to get enough EAAs each day, especially when trying to build and maintain lean muscle mass. According to the University of Illinois McKinley Health Center, whey protein is generally recognized as safe, but you should still consult your doctor before taking whey supplements.
Derived from cow's milk, whey protein goes through several manufacturer processes before it hits store shelves as a powder, bar or pre-mixed drink. It preserves its amino acid profile during these processes. Amino acids are building blocks of protein, and there are over 20 dietary amino acids. Your kidneys, liver, pancreas and other organs produce most of these amino acids, but not EAAs. Whey features the highest biological value, or BV, of any protein, which means the EAAs are absorbed and used more efficiently by your body compared to other sources of protein.
A particularly important set of EAAs, as it pertains to bodybuilders and anyone looking to build and maintain muscle mass, is branched-chain amino acids, or BCAAs. According to the U.S. Dairy Council, whey protein offers the highest concentration of BCAAs of any dietary source of protein at about 26 g of BCAAs per 100 g of protein. The three BCAAs include leucine, isoleucine and valine. BCAAs are proven to directly impact muscle growth and maintenance of existing lean muscle tissue.
Whey protein concentrate, or WPC, containing about 80 percent whey protein by weight is a commonly available type of whey supplement. It contains the following essential amino acid profile measured in mg/g of protein: leucine, 105 mg; lysine, 93 mg; tyrosine, 32 mg; cysteine, 21 mg; isoleucine, 63 mg; valine, 58 mg; threonine, 69 mg, tryptophan, 18 mg; histidine, 17 mg. Over 60 percent of the total protein in whey comes from EAAs, according to the U.S. Dairy Council.
The amino acids found in whey protein benefit the body in several ways. The high-concentration of leucine helps prevent breakdown of muscle tissue and promotes fat loss, according to McKinley Health Center. These amino acids also promote an increase in glutathione in the body, which is an antioxidant associated with boosting your immune system function.