GENERAL DESCRIPTION:
Phenylalanine is an essential amino acid,
which can be obtained from eating almonds, avocado, bananas, beans, brewer’s yeast, cheese,
corn, cottage cheese, dairy products, eggs, fish, legumes,
lima beans, meat, nuts, peanuts, pickled herring, pumpkin
seeds, seafood, seeds, sesame seeds, soy, whey, and whole grains. Once inside the body
phenylalanine is converted into the amino acid tyrosine,
which is then converted into the neurotransmitters L-dopa,
norepinephrine, and epinephrine. Phenylalanine governs the release of the hormone cholecystokinin (CCK) that signals the brain to feel satisfied after
eating.
ROLE FOR ANTI-AGING:
Phenylalanine is used to treat a variety of
medical problems. Because some antidepressants work by raising norepinephrine levels phenylalanine has been used to treat depression,
with varying degrees of success. D-phenylalanine has been suggested as a treatment for
chronic pain caused by rheumatoid arthritis, muscle pain,
and osteoarthritis, as It blocks
enkephalinase, an enzyme that may act to increase pain
levels in the body. There is some evidence to support
the use of phenylalanine to alleviate chronic pain, although it has not been clinically proven. Some studies have suggested that the various
forms of phenylalanine may be useful as a treatment for
vitiligo (a disease characterized by abnormal white
blotches of skin due to loss of pigmentation), when used in combination with UV light therapy.
DEFICIENCY SYMPTOMS:
Symptoms and signs of phenylalanine deficiency
include: low serum levels of essential blood proteins, apathy, loss of pigmentation in hair,
edema, lethargy, liver damage, muscle loss, fat loss, skin
lesions, weakness, and slowed growth in
children.
THERAPEUTIC DAILY AMOUNT:
When used as a treatment for depression, the
initial dose of L-phenylalanine is typically 500mg
per day; the dose is then gradually increased to
3-4g daily. However, some people may
suffer side effects at doses of 1.5mg and above.
D- or DL-phenylalanine can also be used as a treatment for depression, however the typical dosage
is much lower at 100-400mg per day For the treatment of
chronic pain doses of Dphenylalanine can be as high as
2.5g.
MAXIMUM SAFE LEVEL:
Not established, however doses of 1.5g and
above can cause side effects.
SIDE EFFECTS/CONTRAINDICATIONS:
Phenylalanine does not generally cause side
effects, however daily doses of approximately 1.5g and above have been reported to cause anxiety,
headaches, and mildly elevated blood pressure. People who suffer from the metabolic disease phenylketonuria (PKU) should avoid all forms of
phenylalanine (L-phenylalanine, Dphenylalanine, and
DL-phenylalanine). Phenylalanine can cause potentially
dangerous hypertension when taken with monoamine oxidase inhibitors (MAO’s). It should also
not be taken alongside the amino acid tyrosine.
There is some evidence to suggest that using
phenylalanine in combination with antipsychotic drugs may increase the risk of developing the
movement disorder tardive dyskinesia. As with other amino
acids, phenylalanine may interfere with the absorption and
action of the anti-Parkinson’s drug levodopa. People with kidney disease or liver disease should
consult their doctor before taking phenylalanine.
