Feel Good With Tyrosine - Amino Acids And Their Uses

What Is Tyrosine And What It Is Used For

Some experts consider tyrosine to be a non-essential amino acid, while others classify it as essential.  Technically, tyrosine is a non-essential amino acid because it is manufactured by the body.  However, it is produced by the essential amino acid phenylalanine, so indirectly it must be obtained through the diet.  It has many important functions and is contained within the structure of virtually every protein in the human body.

Tyrosine is the precursor for several mood-regulating neurotransmitters including serotonin, norepinephrine, epinephrine and dopamine.  It plays an important role in the function of the thyroid, adrenal and pituitary glands.  Tyrosine is also involved in the production of melanin, which is the pigment responsible for the color of skin and hair.

Best Natural Sources Of Tyrosine

Phenylalanine, the amino acid that is converted into tyrosine, is available in generous amounts in most foods.  A well-balanced diet that is high in protein will supply ample amounts of phenylalanine and therefore tyrosine.  It is plentiful in

• meats
• fish
• eggs
• milk products

Non-animal sources include:

• soy products
• bananas
• oatmeal
• avocados
• peanuts
• almonds
• pumpkin seeds

Tyrosine Benefits

Instrumental as they are in the production of mood enhancers serotonin and dopamine, phenylalanine and tyrosine are sometimes combined with various mood-elevating herbs for use as an alternative treatment for depression.  Sufferers of depression are frequently found to have low levels of several amino acids, including tyrosine. Therefore, ensuring that the diet contains adequate levels of these amino acids is a logical course of action in the fight against depression and other mood disorders including Alzheimer’s and dementia.  It has also been used to treat chronic fatigue.

Tyrosine, when used in conjunction with tryptophan, has been shown to have some success in the treatment of cocaine addiction and the depression that accompanies withdrawal.  Tyrosine is said to increase alertness and mental focus, and is sometimes used along with phenylalanine as an appetite suppressant.

Tyrosine Side Effects

Because tyrosine is made from phenylalanine, excess doses of phenylalanine can cause tyrosine toxicity.  Excess tyrosine can cause anxiety, insomnia, increased heart rate and heart palpitations.  Caffeine can increase these symptoms; users of tyrosine supplements would be wise to limit their intake of caffeine.

People who are prone to migraines should be aware that in some cases tyrosine can act as a trigger for these types of headaches.  Sensitivity to this amino acid can also cause gastrointestinal upset in some people.

Although it is suggested that taking tyrosine supplements can increase melanin production, and therefore offer extra protection from skin cancer, for the same reason tyrosine is not recommended to be taken by people who have skin cancer; its role in the production of melanin can accelerate the growth of existing melanoma.

Tyrosine is not recommended to be taken with the antidepressants known as Monoamine Oxidase Inhibitors (MAOIs) (isocarboxazid, phenelzine and tranylcypromine).  People who combine tyrosine with these drugs may experience a severe increase in blood pressure known as “hypertensive crisis” that can lead to a heart attack or stroke.  Anyone who already has high blood pressure should not supplement the diet with tyrosine for this reason.

Being a precursor to thyroid hormone, tyrosine may further raise the levels of thyroid hormones in people with Graves disease (hyperthyroidism), so anyone with this disorder should not take tyrosine supplements.  For the same reason, tyrosine should be avoided by anyone who takes synthetic thyroid hormones to treat hypothyroidism.

Is Tyrosine Deficiency Possible?

Restless leg syndrome, low blood pressure and low body temperature (cold hands and feet) can be symptoms of tyrosine deficiency.  Tyrosine deficiencies are rare as long as the diet contains adequate amounts of phenylalanine.  A poor diet that is deficient in protein may be lacking in phenylalanine, and therefore be lacking in tyrosine.

Some people are born with a genetic deficiency in which the enzyme that converts phenylalanine to tyrosine is absent.  This condition is known as phenylketonuria (PKU).  If untreated, PKU can cause brain damage and even death.  People with PKU must restrict or eliminate phenylalanine from the diet, so they usually need to take tyrosine supplements to avoid becoming deficient.

Tyrosine Supplementation

Tyrosine does not usually need to be taken alone as a supplement, except in cases of PKU, where the phenylalanine required to produce it is not present.  Supplements containing tyrosine can be found in abundance, usually as performance enhancing supplements.

Amino acid supplements are popular with athletes and bodybuilders because they are the basis for all proteins.  These supplements, referred to by some as natural alternatives to steroids, are said to increase stamina and improve athletic performance. Phenylalanine and tyrosine are key ingredients in many bodybuilding supplements.  Expert opinions differ as to the actual effectiveness of amino acid supplements in bodybuilding, but people who have been using them for extended periods of time usually attest that the supplements work very well.

Final Thoughts

Tyrosine supplements are commonly marketed as ‘wake-up’ formulas.  The advertised effects of these supplements are similar to those of amphetamines, which can make them subject to abuse by people looking for a quick energy fix.  Many people who take them are unaware that under certain circumstances they could be unsafe, because they are found on the same shelves as vitamins and other ‘natural’ supplements.  Remember that many pharmaceutical drugs also originate from natural sources.