Phenylketonurics

"Phenylketonurics" is a mandatory warning label found on food products in the United States. This label indicates that the product contains phenylalanine, an amino acid. Phenylalanine is a natural building block of proteins and is also released when the artificial sweetener aspartame is digested.

The "Phenylketonurics" label itself is not an ingredient used in food manufacturing; it is a regulatory requirement. This warning appears on foods that contain phenylalanine, most commonly from the artificial sweetener aspartame. Aspartame is used to provide sweetness without calories in products like sugar-free chewing gum and diet sodas.

This warning is critical for individuals with phenylketonuria (PKU), a rare genetic disorder where the body cannot properly process phenylalanine. For these individuals, consuming phenylalanine can lead to severe health issues. For the general population without PKU, phenylalanine is a normal dietary component and is considered safe. Aspartame, a common source of phenylalanine in processed foods, is approved by the FDA as a general-purpose sweetener. JECFA has evaluated aspartame and set an acceptable daily intake; in 2023, IARC classified aspartame as possibly carcinogenic to humans (Group 2B), while JECFA maintained its existing acceptable daily intake, stating there was no convincing evidence of harm at typical consumption levels.