If you have the genetic disorder phenylketonuria (pKU), the pKU diet is a key treatment strategy. In this case, you lack an enzyme that allows the conversion of phenylalanine to tyrosine (two amino acids). Phenylalanine builds up in the brain, causing cognitive and/or behavioral problems.
One of the basic tenets of the pKU diet is to avoid protein-rich foods, as they are a major source of phenylalanine. Of course, your body still needs protein, so specially formulated medical foods can help fill that gap.
Following a low phenylalanine pKU diet will not cure the disease, but it will help you manage your symptoms.
Following the pKU diet will help you live your best life and prevent or reduce cognitive problems associated with illnesses such as memory problems, headaches, anxiety, depression, ADHD and mental illness.
A study published in the Journal of Genetic Metabolic Diseases examined the neurological and psychological functions of adults treated with a pku diet from an early age. The researchers found some deficits in nervous system and social function. However, these flaws are not obvious. Compared with healthy people, most adults have normal IQs and a good quality of life.
Because of rapid brain development, it is especially important for children with pKU to follow their diet carefully. High levels of phenylalanine can lead to seizures and irreversible brain damage that can lead to permanent intellectual disability.
Researchers found detrimental changes in white matter at different levels of phenylalanine in children's brains. Their study, published in Molecular Genetics and Metabolism, underscores the importance of strict adherence to the pKU diet, which cannot be relaxed with age.
Other side effects of uncontrolled phenylalanine levels at all ages include eczema, body odor and poor social skills.
How it works.
Phenylalanine is found in varying amounts in different foods. Protein foods are the highest sources and should be avoided. Other foods, such as grains, starches, regular vegetables, and some fruits, contain less phenylalanine and can be eaten in moderation.
To make up for the lack of protein and other nutrients in your diet, you need to add a phenylalanine-free medical nutraceutical. In fact, about 70 to 85 percent of your protein will come from this supplement, as Phenylalanine Free. The amino acids they provide oxidize very rapidly compared to amino acids in whole foods, so the protein requirements for those who rely on these medical foods for their protein are relatively high.
Children (age 4+) and adults need between 120% and 140% daily protein intake. Infants' protein needs depend on their age, but the average is about 2.5 grams per gram of body weight. For children under 4 years, the protein requirement is 1.5 to 2.1 grams per kilogram.
Your healthcare provider can tell you how much protein you need each day and what your daily phenylalanine goal is.
Aspartame. This artificial sweetener is made from phenylalanine and should be avoided. It is usually sold as fresh or Equal, but it is listed as aspartame, such as soft drinks, desserts, gelatin, pudding and yogurt.
Fruit. With the exception of raisins, most fresh or frozen fruits are low in phenylalanine, which should be limited due to their high phenylalanine content. Keep the weight of these items to less than half a cup and eat them in moderation. Keep in mind that if you eat sliced dried bananas (or most dried fruit), it's easy to eat a lot, so make sure you limit them to about half a cup.
Vegetables. Starchy vegetables, such as potatoes, potatoes, purple potatoes (and chips), winter squash, corn, and peas, should be eaten sparingly. With the exception of non-compliant vegetables, most other fresh or frozen vegetables are low in phenylalanine. Carrots, zucchini, and cauliflower contain moderate amounts of phenylalanine, but small amounts of cauliflower and rice make a good substitute for regular rice; spiral carrots or zucchini can replace pasta. If you buy frozen vegetables, make sure you don't have a creamy or cheese sauce that adds extra protein and phenylalanine.
Grain. Most baked goods made from common grains, bread, pasta, and wheat flour contain high amounts of protein and should only be eaten in moderation. Look for low-protein breads, cereals, pastas, and baked goods for better options. Ask your nutritionist for good resources.
Dairy products. Regular milk, cheese, yogurt and these foods are high in protein and phenylalanine, so we should choose non-dairy products. Use high-fat dairy products such as heavy cream or full-fat cream cheese as appropriate.
Nuts, nut butters, seeds. If you eat these things, even in moderate amounts, you will produce a lot of phenylalanine. Avoid peanut butter or other nut butters and limit to one if whole nuts or seeds are used. Ask your healthcare provider for more specific guidelines.
Condiments. Herbs, spices, salt, pepper, mustard, plain or flavored vinegar, soy sauce, sauces, and barbecue sauces are low in protein.