Phenylketonuria is a genetic condition characterized by the inability to break down a certain type of protein called phenylalanine. Phenylalanine can then build up in the bloodstream, leading to a number of health conditions, including brain damage and mental retardation. All babies born in hospitals in the U.S. are screened for PKU, facilitating early diagnosis and treatment of this medical condition. A specialized diet that limits phenylalanine intake is the primary method of treating and managing PKU throughout life.
Foods to Avoid
People with PKU cannot properly digest phenylalanine, so it is important to limit dietary intake of phenylalanine. Phenylalanine is found in protein-rich foods, including meat, poultry, fish, beans, soybeans, nuts, nut butters, seeds, milk, yogurt, cheese and eggs. Breast milk and standard infant formulas also contain phenylalanine. Aspartame, an artificial sweetener often found in diet soda and some medications, should also be avoided because it is broken down into phenylalanine in the body. It is important to eliminate phenylalanine-containing foods from your child's diet as soon as PKU is diagnosed, and continue a phenylalanine-restricted diet throughout your child's lifetime to avoid health complications from this medical condition.
Foods to Eat
Fruits, vegetables, juices, and low-protein breads and pastas are healthy choices for people with PKU. Potatoes, peas, pasta, bread and corn contain small amounts of phenylalanine, but can often be safely incorporated into a phenylalanine-restricted diet when eaten in moderation. Your child's doctor can help you determine how much phenylalanine your child can tolerate based on blood tests and growth and weight gain trends. The amount of phenylalanine your child can tolerate may change throughout her lifetime, especially during times of rapid growth in puberty and pregnancy.
Nutritional Formulas
Protein is required for proper growth and development, as well as muscle, skin and tissue production and maintenance. Because a phenylalanine-restricted diet limits protein-rich foods, specialized nutritional formulas have been developed for infants, children and adults with PKU to provide essential protein, free of phenylalanine.
Professional Resources
If you have questions about a phenylalanine-restricted diet for your child with PKU, consult a registered dietitian. Dietitians are trained to assess nutritional status and can help you design an eating plan tailored to meet your child's needs. A dietitian will take into consideration all of your child's medical conditions when determining and appropriate diet. A dietitian can help monitor your child's growth and weight gain, and can help you determine the amount of phenylalanine-free formula your child needs to drink each day.
