Your body uses phenylalanine for many functions, but it is primarily used to make three vital chemical messengers in the brain. Because phenylalanine is an amino acid and comes from protein, it also helps your body grow and repair muscle and other tissue. A lack of phenylalanine can cause fatigue, confusion, depression and a lack of appetite. Most people get enough of this nutrient from a balanced diet, but if you feel you need to supplement phenylalanine, ask your doctor first.
Metabolic Role
Proteins are made up of long connected chains of chemicals called amino acids. Many amino acids exist, but the human body only uses 20 of them. Of these 20, your body must get nine through your diet. Phenylalanine is one that you need to eat in order for your body to have a sufficient amount. Once in the body, it is converted to another amino acid called tyrosine. Tyrosine is the basis of three main neurotransmitters, or chemical messengers, in the brain: levodopa, norepinephrine and epinephrine. This makes phenylalanine important in the study of disorders of the brain.
Uses
Phenylalanine studies have focused on depression, Parkinson's disease and chronic pain. D-phenylalanine is the type of this amino acid that is made in the laboratory, and it has shown promise in studies for depression. In the journal "Archiv fur Psychiatrie und Nervenkrankheiten" in 1979, D-phenylalanine was shown to be as effective as the antidepressant imipramine, according to NYU Langone Medical Center. The supplement L-phenylalanine, which is also available in food, was not studied in rigorous tests for depression, so no scientific results are available. D-phenylalanine also had mixed success in treating chronic pain in a study published in "Advances in Pain Research and Therapy" in 1983, and it showed some promise in animal studies into Parkinson's disease in the journal "Neurology" in February 1993, according to the University of Maryland Medical Center. No studies into these diseases were conducted with L-phenylalanine.
Sources and Dosage
Phenylalanine is found in most food sources that contain protein. Some foods that are high in this nutrient are beef, chicken, turkey, pork, eggs, milk and cheese, according to the University of Maryland Medical Center. Vegetarians can eat soy or soy products, nuts and seeds. Aspartame, a common artificial sweetener, also has phenylalanine. Adults should get 14 milligrams per kilogram of body weight per day. To get your weight in kilograms, divide your number by 2.2.
Phenylketonuria
Some people are born with a rare genetic disorder called phenylketonuria, in which an enzyme required to break down this amino acid is missing. About 1 in every 15,000 infants born in the U.S. has this genetic disorder, according to the University of Washington. If the levels of phenylalanine get too high, it can cause irreversible brain damage to the growing infant. For this reason, newborns are tested, and those with the trait are started on a low-phenylalanine diet. Following this diet, the person should have no side effects from having phenylketonuria.
Member Comments