Phenylalanine

Some important facts about Phenylalanine:
Phenylalanine is an essential amino acid. This means that it must be obtained through the diet in adequate quantities to meet the body's needs.Phenylalanine has got immense metabolic role in the body. It is ketogenic as well as glycogenic. Phenylalanine is initially but irreversibly hydroxylated to tyrosine. Tyrosine then undergoes series of metabolic changes leading to the formation of hormones epinephrine, nor epinephrine, thyroxin and tri-iodothyronine. It is not synthesized in the body but in the microorganisms it is synthesized. Phenylalanine may undergo bacterial breakdown in the intestine by the bacterial enzyme with the formation of phenyl acetic acid. This phenyl acetic acid may be converted into benzoic acid. These toxic substances are absorbed and detoxicated in the liver. Like all other amino acids, phenylalanine also takes part in the synthesis of tissue protein.

Use of phenylalanine:
1. D-phenylalanine may help reduce chronic pain associated with certain health conditions by stimulating nerve pathways in the brain that control pain.
2. D-phenylalanine may improve rigidity, walking disabilities, speech difficulties, and depression associated with Parkinson's disease.
3. Evidence suggests that combining L-phenylalanine (oral and topical) with UVA radiation for people with vitiligo (a condition characterized by irregular depigmentation or white patches of skin) may lead to some darkening or repigmentation of the whitened areas, particularly on the face.
4. Phenylalanine is also used to give relief to the patients suffering from depression. This is thought to be due to enhanced production of brain chemicals such as dopamine and nor epinephrine.
5. Phenylalanine acts as an analgesic. It also acts as an appetite suppressant by administrating the release of an intestinal hormone that signals the brain to feel satiated after eating. As an analgesic, it has been shown to decrease back pain, toothaches, and pain associated with migraine headaches.
6. It has also been used to treat attention deficit disorder, fatigue, Parkinson's disease and premenstrual syndrome.
7. Phenylalanine serves in the body as a precursor to the catecholamine family of hormones. The catecholamines include adrenaline and noradrenaline, which are activating substance in the central and peripheral nervous systems as well being produced by the adrenal medulla (adrenal gland).
8. Therapeutic doses of phenylalanine may have useful roles in the management of blood pressure disorders and the control of certain forms of depression. Both low blood pressure and elevated blood pressure have been normalized by administration of therapeutic doses of phenylalanine and tyrosine to animals. Therapeutic doses used in humans range between 300 and 1,500 mg per day. It is best to administer these amino acids along with a carbohydrate source in the diet to facilitate absorption in the nervous system.
9. Contraindications of phenylalanine supplementation are in those individuals who display a hyper-functioning nervous state (anxiety) that may be aggravated by adrenaline. Supplementation with phenylalanine in these people can actually amplify the problem. Phenylalanine is known to be the antagonist of tryptophan. Whereas tryptophan has been used to induce sleep, phenylalanine has been used to increase states of arousal. Phenylalanine supplementation should be discontinued if headaches result.

Deficiency symptoms of phenylalanine:
Symptoms of phenylalanine deficiency include confusion, lack of energy, decreased alertness, decreased memory, and diminished appetite.
Its deficiency can also lead to stunted growth, apathy, muscle loss, and weakness.
A rare metabolic disorder called phenylketonuria (PKU) occurs in people who are missing an enzyme that is needed to properly metabolize phenylalanine. Symptoms of PKU, which tend to appear between three and six months of age, include eczema, developmental delay, an abnormally small head, and hyperactivity. If it is not treated before three weeks of age, PKU can cause severe, irreversible mental retardation.

Symptoms of high intake:
1. Doses in excess of 5,000 mg a day may be toxic and can cause nerve damage.
2. High quantities of DL-phenylalanine may cause mild side effects such as nausea, heartburn, and headaches.
3. Most consumers don't know that too much Phenylalanine is a neurotoxin and excites the neurons in the brain to the point of cellular death.
4. Emotional and behavioral disorders can all be triggered by too much Phenylalanine in the daily diet.
5. Phenylalanine can cause irreversible brain damage and death, especially when used in high quantities or during pregnancy.
6. Excessive amounts can also lead to hypertension and/or migraine headaches.

Other facts:
1. People with PKU and women who are lactating or are pregnant should not take phenylalanine supplements.
2. DL-phenylalanine may cause symptoms of anxiety, jitteriness, and hyperactivity in children. Children with ADHD may need to avoid foods containing aspartame, which is made from phenylalanine.
3. Patients already taking antidepressants should not supplement with phenylalanine.

Method of Action:
An inborn Phenylalanine can be converted to tyrosine by way of an enzyme called phenylalanine hydroxylase. This enzyme has been shown to be genetically impaired in some individual, resulting in a disorder called phenylketonuria. In these cases a phenylalanine restricted diet must be administered in infancy or mental retardation will result.
The sweetener aspartame contains phenylalanine as part of its chemical makeup. Feeding this sweetener at high levels to individuals with the tendency toward phenylketonuria can aggravate their problem.

Daily requirement:
Foods high in isoleucine include:
· Cottage cheese (dry) 2,300 mg/cup
· Cottage cheese (crmd) 1,647 mg/cup
· Fish & other seafoods 3,000-4,500 mg/lb
· Meats 1,000-4,500 mg/lb
· Poultry 2,000-4,500 mg/lb
· Peanuts, roasted w skin 3,500 mg/cup
· Sesame seeds 3,000 mg/cup
· Dry, whole lentils 2,500 mg/cup