PHENYLALANINE

Written by Slawomir (“Swavak”) Gromadzki, MPH

Scientific research suggests Phenylalanine has potential to improve our mood and functioning of the brain and nervous system. Studies conclude that it may help improve concentration, memory, learning abilities, and enhance overall alertness.

Phenylalanine is one of essential amino acids (building blocks of proteins), meaning the body needs it from food or in the form of supplements as it cannot make it. Phenylalanine is required for the production of tyrosine (another amino acid), and neurotransmitters such as dopamine, epinephrine and norepinephrine.  Since norepinephrine positively affects mood, phenylalanine has been proposed to be helpful in helping those who are depressed. The body uses phenylalanine to make also other chemicals, including L-dopa and thyroid hormones.

FORMS OF PHENYLALANINE

There are three forms of Phenylalanine:

– L-phenylalanine, the natural form found in proteins.

– D-phenylalanine exactly the same as L-phenylalanine but made in a laboratory. D-phenylalanine has more pain-relieving effects than the L- form because it inhibits the enzyme that breaks down opioids.

– DL-phenylalanine, a combination of the 2 forms.

DEFICIENCY SYMPTOMS

Symptoms of phenylalanine deficiency include:  Lack of energy and fatigue, low mood or depression, memory problems, decreased alertness, etc.

HEALTH BENEFITS OF PHENYLALANINE

DOPAMINE LEVELS

Phenylalanine is the precursor of another amino acid tyrosine which is converted into dopamine. Dopamine has great influence on our mood, motivation, learning abilities and plays very important role in many different processes in the brain such as in pain perception and the reward system of the brain. Without enough dopamine we tend to be impatient and chose lower reward now instead of waiting for higher reward later. Increasing phenylalanine can indirectly raise not only dopamine but also noradrenaline and helps regulate adrenaline levels.

Some people try to take tyrosine supplements to increase dopamine and other neurotransmitters but the problem is that tyrosine does not dissolve well in water and for this reason its direct supplementation is not effective. Therefore, increasing phenylalanine concentrations is regarded as much better alternative to produce more dopamine in the body.

DEPRESSION

Some studies demonstrated that phenylalanine may be helpful as part of treatment for depression. People have reported that their mood improved as a result of taking phenylalanine supplements. Researchers believe this effects is caused by the fact that phenylalanine increases production of brain chemicals, such as dopamine and norepinephrine.

PAIN

Some studies appeared to show positive results in the ability of D-phenylalanine to reduce chronic pain.

PARKINSON’S DISEASE

One animal study suggests that D-phenylalanine may improve movement disabilities, depression and speech difficulties associated with Parkinson’s disease.

APPETITE CONTROL

Studies suggest that Phenylalanine may help suppress appetite by stimulating the production of hormone, cholecystokinin.

ALCOHOL WITHDRAWAL SYMPTOMS

When patients start alcohol-detoxification therapies, the stress associated with the withdrawal process results in lower dopamine levels. Phenylalanine can increase dopamine levels thus helping decrease various psychiatric symptoms.

VITILIGO

Preliminary studies suggest L-phenylalanine may lead to some darkening of the white patches on the skin of people suffering from vitiligo.

ADHD

Low dopamine levels are believed to play a role in ADHD. Therefore, it is suggested that increasing dopamine levels by phenylalanine supplementation should help reduce ADHD symptoms. In a study which involved 13 ADHD patients, those that took DL-phenylalanine supplements showed improvements in symptoms such as anger, restlessness, and focus. Unfortunately, three months after the experiment finished, the beneficial effects of taking this supplement disappeared and increasing the dosage showed no beneficial effect.

MENOPAUSE

Tyrosine may benefit menopausal women by regulating and balancing the neurotransmitters dopamine and norepinephrine in the brain.

DIETARY SOURCES

L-phenylalanine is found in most foods that contain protein, especially soy products (including soy soybean flour, and tofu), and certain nuts and seeds.

USAGE

Recommended dosages of phenylalanine vary depending on the health condition being treated. Speak to your doctor about what dose is right for you.

PRECAUTIONS

People with phenylketonuria (PKU), and women who are breastfeeding or are pregnant, should not take phenylalanine supplements. Aspartame, found in artificial sweeteners such as Nutrasweet, is a source of phenylalanine.

DL-phenylalanine should not be used in people taking antipsychotic drugs.

DL-phenylalanine may cause symptoms of anxiety and hyperactivity in children.

If you are currently being treated with medication you should not use phenylalanine without first talking to your health care provider.

REFERENCES

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– Russell AL, McCarty MF. DL-phenylalanine markedly potentiates opiate analgesia – an example of nutrient/pharmaceutical up-regulation of the endogenous analgesia system. Med Hypotheses. 2000;55(4):283-8.

– Dietary Guidelines for Americans 2005. Rockville, MD : US Dept of Health and Human Services and US Dept of Agriculture; 2005.

– Anjemo K, van Rijn M, Verkerk PH, Burgerhof JG, Heiner-Fokkema MR, van Spronsen FJ. PKU: high plasma phenylalanine concentrations are associated with increased prevalence of mood swings. Mol Genet Metab. 2011;104(3):231-4.

– Dillon EL, Sheffield-Moore M, Paddon-Jones D, Gilkison C, et al. Amino acid supplementation increases lean body mass, basal muscle protein synthesis, and insulin-like growth factor-I expression in older women. J Clin Endocrinol Metab. 2009 May;94(5):1630-7. Epub ahead of print.

– Kliegman R. Nelson Textbook of Pediatrics. 19th ed. Philadelphia, PA: Elsevier Saunders; 2011.

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– Szczurko O, Boon HS. A systematic review of natural health product treatment for vitiligo. BMC Dermatol. 2008 May 22;8:2. Review.

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Vockley J, Andersson HC, Antshel KM, et al. Phenlalanine hydroxylase deficiency: diagnosis and management guideline. Genet Med. 2014;16(2):188-200.

– Wissman P, Geisler S, Leblhuber F, Fuchs D. Immune activation in patients with Alzheimer’s disease is assocaitd with high serum phenylalanine concentrations. J Neurol Sci. 2013;329 (1-2):29-33.