PKU is the abbreviation used for the medical diagnosis of phenylketonuria. This is a metabolic disorder in which a portion of a protein molecule, called phenylalanine, is not processed correctly during metabolism. When the phenylalanine level gets too high in the blood stream, it damages the brain and leads to mental retardation in children. The genetic disorder is treatable with an altered diet when found early. All babies born in the United States must now be screened for PKU.
Formula
Phenylalanine is a substance found in most protein rich foods. The safe amounts will differ for each person; however, individuals who suffer from PKU require a restricted diet for life. In order to receive protein necessary for the growth and development of cells, manufacturers have produced specific formulas that are free of phenylalanine and designed specifically for individuals to consume throughout their lives, according to MayoClinic.com. Infants may be given small amounts of breast milk to supplement the formula, while older children and adults must continue to drink several glasses of formula each day in order to receive enough protein to support cell growth.
Allowed Foods
Specific foods allowed for individuals who suffer from PKU are those that do not include large amounts protein, according to the Utah Department of Health. Foods allowed in moderate amounts include fruits such as apples, oranges, bananas, great, great fruits, peaches and strawberries. Vegetables allowed in moderate amounts include certain beans, carrots, cauliflower, celery, cucumbers, lettuce and tomatoes. While most sugars and sweets are not encouraged in the nutrition of the average individual, these foods are considered "free" foods for an individual who suffers from PKU. Foods such as sugar, molasses, frosting, popsicles, lard and bacon drippings, apple juice, Gatorade, Kool-Aid and lemonade can all be eaten freely without fear of building up phenylalanine in the bloodstream. However, although allowed in the diet because they do not cause a build-up of phenylalanine, they continue to have significant negative health effects and should only be taken in small amounts.
Restricted Foods
Both children and adults must restrict the amount of phenylalanine entering their bodies. According to the March of Dimes, until the 1980s, health care providers believed that children with PKU could alter their diets to include restricted foods after the age of 6 because brain growth had been completed. However, subsequent studies found that when the diet was discontinued before age 8, the children suffered from reduced IQ scores and when discontinued after age 12, it could lead to learning disabilities. Restricted foods include potato chips, potatoes, broccoli, peas, spinach, corn on the cob, certain cereals, white or brown rice, snack foods and some cookies and desserts, according to the Utah Department of Health.
Prohibited Foods
It is crucial for individuals who suffer from PKU to avoid all high protein foods, according to MayoClinic.com. These foods include meats, eggs, cheese, nuts, soybeans, chicken, beans, beef products, fish, chocolates and peas. While soda may be included in the diet, any diet sodas or medications made with aspartame must be avoided. Aspartame will release phenylalanine as it is digested in the body. The Utah Department of Health also includes all dairy products, legumes, breads, nuts and seeds on the list of foods that are not allowed.
