TYROSINE is an aromatic non-essential amino acid produced from phenylalanine. It is a precursor of thyroid and adrenocortical hormones, as well as for norepinephrine and adrenaline. Tyrosine is also used to synthesize epinephrine and dopamine. Therefore, tyrosine is important to the functioning of the adrenal, thyroid, and pituitary glands. A lack of tyrosine triggers a deficiency of norephinephrine at a specific brain location, resulting in depression and mood disorders. Physiologically active neurons are highly responsive and will actively synthesize neurotransmitters from such substances as tyrosine and choline.
Tyrosine is also essential in the formation of adrenaline, thyroxine, and melanin (hair and skin pigment). It is involved in the initial breakdown of phenylalanine in the liver. Low plasma levels of tyrosine have been associated with hypothyroidism. It can also act as a mood elevator, supresses the appetite, and reduces body fat. Tyrosine has been used to assist in the withdrawal from drugs. It should be noted that tyrosine is not compatible with the taking of MAO drugs (monoamineoxidases). Interestingly, tyrosine has also been used to lower raised blood pressure and to raise lowered blood pressure as a result of trauma. Tyrosine has been helpful in treating some Parkinsons cases, as well as relieving depression in some patients. Deficiencies have been noted in Parkinson-type illnesses. Low levels can lead to an iron deficiency.
Therapeutic supplementation is more effective when taken with a high carbohydrate meal in relation to lower levels of competing amino acids. A high protein meal will increase blood and brain tyrosine somewhat, but not enough to affect neurotransmitter synthesis to any degree. There are few known side effects from taking large doses of tyrosine but it has been found to be more effective if used when there is evidence of a deficiency. In addition, small doses seem to be more effective than larger ones.
Food sources include almonds, avocados, bananas, dairy products, lima beans, pumpkin seeds, and sesame seeds.
Other names for tyrosine include: TYR, amino acid Y, and 2-amino-3-(4 hydroxy phenyl)propanoic acid.
Deficiency symptoms include: paleness, low body temperature, low blood pressure, “restless leg” syndrome, decreased skin melanin, and an overall decreased protein uptake.
Toxic reactions can occur if excessive doses are taken of it and/or of phenylalanine.