Identification

Phenylalanine is an essential amino acid which affects neurological function. Phenylalanine cannot be made by the body, so it must be consumed in the diet. Dietary sources of phenylalanine include meat, fish, pork, dairy, walnuts, garbanzo beans and shrimp, as well as diet drinks with the artificial sweetener aspartame.

Theories/Speculation

Open studies by the University of Munich have found phenylalanine to be an effective antidepressant in patients suffering from depression. Its antidepressant effects were first discovered in a 1966 Parkinson's disease study, in which Parkinson's patients who were treated with phenylalanine experienced a sort of euphoria in response to the amino acid.

Disorders

Phenylketonuria, abbreviated PKU, is an inability to absorb phenylalanine, which causes a buildup of the amino acid in the body. Those who suffer from PKU must avoid products with aspartame, such as diet sodas and some artificial sweeteners. Since phenylalanine is present in meat, some people with PKU must also monitor their meat and protein intake in order to keep body levels of phenylalanine under control.

Effects on Children

Phenylalanine is produced naturally in the breast milk of mammals, but the amount of phenylalanine in breast milk is very low and is usually safe. Babies suffering from extreme cases of phenylketonuria may need to be placed on a phenylalanine-restricted formula if they have a reaction to the phenylalanine in breast milk. Nutrition companies such as Periflex manufacture phenylalanine-free formula for babies who are phenylketonuric (see Resources).

History

Phenylalanine was first discovered in 1961 by German biochemist J. Heinrich Matthaei and American biochemist Marshall Nirenberg. Nirenberg shared a 1968 Nobel Prize in Physiology and Medicine for his work in identifying the active chemicals of the nervous system.

Deficiency

Symptoms of a phenylalanine deficiency include disorientation, mental confusion, depression, memory problems, lack of physical coordination or the appearance of neurological dementia. Those who are of advanced age, vegetarians, chronic users of stimulants or hypothyroid patients are most at risk for phenylalanine deficiency and would benefit from its supplementation. Patients of multiple sclerosis and fibromyalgia may find that phenylalanine helps relieve some of the pain associated with those diseases.