Phenylketonuria is a condition in which a genetic mutation results in the inability to synthesize the enzyme to digest the amino acid phenylalanine. As one of 20 amino acid units of proteins, phenylalanine is found in abundance in high-protein foods. Phenylketonurics who consume these foods are at risk of developing mental retardation, seizures, hyperactivity, stunted growth and skin rashes, among other health problems. Because phenylketonurics are unable to digest the phenylalanine in many protein food sources, the mainstay treatment for the condition is to limit intakes of high-protein foods.
Milk, Dairy Products and Eggs
Milk and dairy products such as cheese are particularly rich in protein, and so phenylketonurics must avoid these foods. Milk is a common ingredient in many baked goods, and so people with this condition must examine nutrition labels before eating prepared foods. Eggs are similarly protein-rich and dangerous for phenylketonurics.
Nuts and Soybeans
Nuts and nut products such as nut butters are also rich protein sources, and phenylketonurics should limit these foods in their diet. Soybeans are similarly protein-rich and inappropriate foods for phenylketonurics. Both nuts and soybeans are common ingredients in a variety of prepared foods, and so it is important to examine product nutrition labels when shopping.
Chicken, Beef and Fish
Chicken, beef and fish are all rich dietary sources of protein and can be dangerous for phenylketonurics to eat. Phenylketonurics should instead achieve their limited protein needs by consuming low-protein varieties of breads, cereals and pastas.
Diet Sodas
Many diet sodas are made with artificial sweeteners that release phenylalanine when metabolized. These sweeteners, including NutraSweet and Equal, should be strictly avoided by phenylketonurics.
Cautions
It is important to note that a low-protein phenylketonuria diet must be followed for life and not simply for a limited time. Keeping blood levels of phenylalanine low is vital in preventing cognitive and other developmental issues. Maintaining a strict low-phenylalanine diet will greatly improve attention span, concentration and memory, and is important for phenylketonurics of all ages.
