Tyrosine is one of 20 different amino acids which are used by cells in the human body to synthesize proteins, building blocks of muscles and other organs. It is a nonessential amino acid, which means that it is manufactured in the body from other essential amino acids. Amino acids are those molecules which must be received from nutrients, digested and cannot be made from within the body.
Tyrosine is also a precursor of several neurotransmitters, including dopa, dopamine, norepinephrine and epinephrine. Through the effect on neurotransmitters researchers believe that tyrosine effect several health conditions, including Parkinson’s disease, depression and other mood disorders which rely on dopamine and l-dopa. Preliminary findings from several studies have indicated that individuals experience a beneficial effect of taking supplemental tyrosine, along with other amino acids, in the treatment of depression, dementia and Alzheimer’s disease. It is also believed that tyrosine may help ease the adverse effects of chronic environmental, psychosocial and physical stress on the body.
If the levels of neurotransmitters are insufficient, the individual often feels sadness, anxiety, irritability and frustration. In addition, dopamine will often help suppressing appetite and reduce body fat so people who have insufficient levels of the neurotransmitter may find they gain weight or struggle to lose it. Another use of tyrosine in the body is to convert the thyroid home hormone to adrenaline during times of stress. This means that individuals who are chronically stressed have depleted levels of tyrosine which may affect their neurotransmitters and weight loss.
Tyrosine is used by the body in the skin cells to convert to melanin which is the dark pigment that protects the skin against the harmful rays of ultraviolet light. Melonin is the pigment in the skin that turns color during the summer time and creates a tanned effect on the skin. Interestingly, thyroid hormones also contain tyrosine as part of their structure.
Babies born without the ability to metabolize phenylalanine, the essential amino acid from which tyrosine is derived, have resulting mental retardation and other severe disabilities. This disease is called phenylketonuria (PKU) and is screened for by mandatory screening process for all babies born in US hospitals. With simple phenylalanine dietary restrictions these problems are prevented.
Tyrosine is found in dairy products, meat, fish, wheat and Oates and most other protein containing foods. Practitioners have used it in the treatment of depression with some success and as an herbal supplement for individuals who are going through alcohol withdrawal and in the treatment of Parkinson’s disease.
Most individuals should not supplement with tyrosine. Although severe side effects have not been reported it is not known about the long-term use particularly in large amounts. For this reason any supplementation should be monitored by a physician. There are certain medications and over the counter drugs that can interact with tyrosine and individuals who are considering this supplementation should have a discussion with their pharmacist to identify which medications, if any, that they are already taking that may interact with tyrosine.