Leucine, Isoleucine, and Valine May Be Derived from Duck Feathers or Human Hair; Vegetable-Based Versions Available
by Jeanne Yacoubou, MS
VRG Research Director
In February 2011, The VRG received confirmation from major amino acid suppliers and manufacturers as well as from dietary supplement companies that the amino acids leucine, isoleucine, and valine, used today mostly in dietary supplements and nutraceutical products, may be derived from human hair or duck feathers. One large company reported this information to us based on an official statement received from its Chinese supplier. When manufactured with non-animal ingredients, companies report that “a microbial fermentation process using glucose from corn or soy” is implemented to manufacture all three of these amino acids. Companies also report that Brazil and China are usually the countries of origin for them.
One major manufacturer told us that leucine, isoleucine, and valine previously had been sourced mostly from human hair or duck feathers although he has noticed a change in the last year toward vegetable-based sources, at least in the case of leucine. He said that “customers are starting to ask for non-animal sourced material.” In fact, a leading amino acid supplier told us, based on an official Chinese statement, that the source of valine that he resells was “corn and glucose.” A few customer service representatives at dietary supplement companies reported that the leucine, isoleucine, and valine that they offer are vegetable-based fermentation products.
Leucine, isoleucine, and valine are essential amino acids that humans need for important metabolic functions such as building protein. They must be ingested because the human body cannot make them on its own. Leucine, isoleucine and valine are often grouped together as branched chain amino acids (BCAAs). They are called this because their chemical structure has a branch off the main segment of the amino acid. The correctly proportioned combination of these three amino acids is believed by some to enhance energy; increase endurance; and maintain, build, and repair lean muscle.
In July 2010, the United States Food and Drug Administration (FDA) announced that leucine manufactured by Ajinomoto AminoScience had been granted GRAS (Generally Recognized as Safe) status as the first amino acid that can be an ingredient in conventional foods and beverages. According to a company press release, this is a significant development in the food and beverage industry; previously leucine was only approved as a dietary or nutritional supplement.
Currently, according to the press release, this is the only leucine formulation with GRAS status. AjiGRAS-Leucine may be used as an ingredient in non-milk and milk-based meal replacements; sports and isotonic beverages; vitamin enhanced waters; and meal replacement bars among other foods and beverages.
Ajinomoto manufactures its leucine, isoleucine, and valine from all plant-based materials through a microbial fermentation process. Brands which carry Ajinomoto BCAAs may use the “AjiPure” logo on their labels which means that the amino acids are not from an animal source.
To purchase our Vegetarian Journal’s Guide to Food Ingredients, go to:
To support VRG’s research, please donate at: