<P> Protein deficiency has been shown to affect all of the body's organs and many of its systems, including the brain and brain function of infants and young children; the immune system, thus elevating risk of infection; gut mucosal function and permeability, which affects absorption and vulnerability to systemic disease; and kidney function . The physical signs of protein deficiency include edema, failure to thrive in infants and children, poor musculature, dull skin, and thin and fragile hair . Biochemical changes reflecting protein deficiency include low serum albumin and low serum transferrin . </P> <P> The amino acids that are essential in the human diet were established in a series of experiments led by William Cumming Rose . The experiments involved elemental diets to healthy male graduate students . These diets consisted of cornstarch, sucrose, butterfat without protein, corn oil, inorganic salts, the known vitamins, a large brown "candy" made of liver extract flavored with peppermint oil (to supply any unknown vitamins), and mixtures of highly purified individual amino acids . The main outcome measure was nitrogen balance . Rose noted that the symptoms of nervousness, exhaustion, and dizziness were encountered to a greater or lesser extent whenever human subjects were deprived of an essential amino acid . </P> <P> Essential amino acid deficiency should be distinguished from protein - energy malnutrition, which can manifest as marasmus or kwashiorkor . Kwashiorkor was once attributed to pure protein deficiency in individuals who were consuming enough calories ("sugar baby syndrome"). However, this theory has been challenged by the finding that there is no difference in the diets of children developing marasmus as opposed to kwashiorkor . Still, for instance in Dietary Reference Intakes (DRI) maintained by the USDA, lack of one or more of the essential amino acids is described as protein - energy malnutrition . </P>

What are the 10 non essential amino acids