What is phenylketonuria (PKU) and why is there a statement regarding PKU on products sweetened with aspartame?
Phenylketonuria (PKU) is a rare inherited disease that prevents the essential amino acid phenylalanine from being properly metabolized. (An essential amino acid is required for normal growth, development, and body functioning and must be obtained from the diet, as the body cannot make it.) Because those with PKU cannot metabolize phenylalanine, it can accumulate in the body and cause health problems including mental retardation. In the U.S. and many other countries, routine screening for PKU is required for all newborns. In the U.S., about 1 in 15,000 babies is born with PKU. People with PKU are placed on a special diet with a severe restriction of phenylalanine from birth to adolescence or after. Women with PKU must remain on the special diet throughout pregnancy. Since individuals with PKU must consider aspartame as an additional source of phenylalanine, aspartame-containing foods must state “Phenylketonurics: Contains Phenylalanine” in the U.S.
