All foods with protein contain the amino acid leucine. Obtained from hydrolysis of foods like milk, it is essential for optimal growth in infants and for nitrogen equilibrium in human adults. Leucine is a branched-chain amino acid (BCAA). It promotes the muscle building process as well as healing of bones, skin, and muscle tissue. Leucine must be balanced with isoleucine and valine. It remains unclear, however, if leucine compromises niacin status or metabolism.
One benefit of leucine is that it lowers
high blood sugar, but too much at birth creates leucine-induced
hypoglycemia. An infant suffering from leucine-induced
hypoglycemia will show signs of retarded growth, convulsions, and
symptoms similar to Cushing's syndrome. Because leucine is a
component of protein foods, a leucine-free diet cannot be used
for treatment. By manipulating the diet, a carefully monitored
child can survive until the disease runs its course, usually
within 5 to 6 years.