Phenylalanine is an essential amino acid that is transformed into the related tyrosine in the body. It is one of the three so-called aromatic amino acids - tryptophan and tyrosine are the two others. Like tyrosine, phenylalanine is the precursor of the formation of the neurotransmitters such as dopamine, epinephrine and norepinephrine, and tyramine and the very essential catecholamines. Phenylalanine is also a component in the psychotropical substances such as mescaline, papaverine, and codein.
Even though phenylalanine plays an overwhelming and multi-faceted role in the biochemistry of the brain, it is not present in its free form here. However, it is part of numerous other active substances - such as neuropeptides - which are of great importance to primarily the functions of the central nervous system and the mental processes.
Phenylalanine is normally broken down in the liver by the enzyme phenylalanine hydroxylase and is thereby transformed into tyrosine. The synergetic nutrients in the metabolism of phenylalanine are the vitamins B3 (niacin), -B6 (pyrodoxine) and -C, and folic acid plus the minerals iron and copper. Due to a hereditary enzyme defect this transformation does not take place in patients with the disease phenylketonuria = PKU.
The government of the USA has established the mean average need of phenylalanine of an adult to be about 1 g. Leading scientists in the area of orthomolecular psychiatry, however, have pointed to the fact that normal, healthy individuals consume about 5 g. a day and actually require about 8 g. They recommend that the total daily consumption of phenylalanine should be an average of 16 g. However, it should be noted that consumption of phenylalanine will increase the body's depots of tyrosine while the consumption of tyrosine will not increase the concentration of phenylalanine.
The foods that are richest in phenylalanine are meat proteins (which is the case for most amino acids). Wheat germ, however, is an exception. The highest concentration by far can be found in venison.
All naturally occurring phenylalanine is L-phenylalanine. However, DL-phenylalanine is a very frequently used substance in aiding to pain alleviation in certain diseases. The unusual thing about the D-forms of both phenylalanine and tyrosine is that - contrary to the D-forms of most other amino acids - they are not transformed into L-forms in the liver. The D-forms of other amino acids have sometimes turned out to be not only useless but harmful to the immune reaction and in some cases even toxic.
A deficit in catecholamines in the central nervous system has, for more than a generation, been considered the cause of certain kinds of depression. By supplying the biochemical precursor to the catecholamines - i.e. phenylalanine sufferers may be able to lift their mood. L-tyrosine and L-dopa are also precursors but phenylalanine is the precursor to all.
DL-phenylalanine has an outstanding ability of blocking certain enzymes in the central nervous system that normally break down the naturally occurring, pain relieving, morphine-like, hormones that our own body produces. By preventing the break-down of these hormones and thereby increasing their concentration in the tissues, the body's own pain defence is enhanced.
The tyramines are metabolization products of tyrosine, dopa, or dopamine. Their function is partly unknown. Combined with the type of antidepressants that are designated monoamine oxidase inhibitors (= MAOIs) they can cause headaches and violent increases in blood pressure. Even without medication, foods containing tyramine - such as strong cheese, chocolate, liver, red wine, bananas, curdled milk products, nuts, vanilla, and soy sauce - can cause headaches or migraines in predisposed persons.
DL-phenylalanine (synthetic phenylalanine)
stimulates the central nervous system’s ability to block pain. It should not be taken during pregnancy or by people suffering from phenylketonuria, skin cancer, or an elevated blood pressure.
It is recommended to supplement with acupuncture since this combination procedure has a higher success rate. A lot of patients who do not really react to conventional analgesics react very positively to DL-phenylalanine. After obtaining favourable results, the dose can be moderated to the minimum that suffices.
Please note!
Not to be taken during pregnancy and not by patients suffering from phenylketonuria, skin cancer, or an elevated blood pressure. It must not be taken together with MAOIs such as Marplan, Sinemet, Eldepryl, or the like. Patients suffering from an elevated blood pressure should consult their physician before taking this amino acid.
