If you suffer from mood swings and constant stress you may want to consider phenylalanine and tyrosine, the amino acid precursors of neurotransmitters and neurohormones.
Phenylalanine is one of eight essential amino acids. Both phenylalanine and its derivative tyrosine, are precursors of the neurotransmitters dopamine, norepinephrine and epinephrine. These neurotransmitters are known as “catecholamines” because of their adrenaline-like effects in the brain and body. Dopamine mediates many forms of motivated behavior and motor function, while epinephrine and norepinephrine modulate the “fight-or-fight” mechanism.
Neurotransmitters are chemicals that are released at nerve endings in the brain where one nerve cell is close to another. They allow messages to pass from one cell to the next and are essential for communication between cells. A balance between neurotransmitters that excite and those that are calming maintains healthy brain function. Parkinson’s disease, for example, is caused by an imbalance of the neurotransmitter dopamine in specific areas of the brain.
Additionally, tyrosine functions as an “adaptogen” by relieving the physical symptoms of stress, such as high blood pressure, mood swings, and anxiety. In one study, 23 male U.S. Army personnel, aged 18-20 years were exposed to extreme weather conditions. On the first test day, half the group were supplemented with L-tyrosine while the other half got a placebo. On a second test day, the groups were switched so that the tyrosine supplemented group received a placebo. The other half of the group now received tyrosine. Tyrosine significantly reduced many of adverse behavioral effects produced by exposure to cold and lack of oxygen at high altitude. These included headache, coldness, distress, fatigue, muscular discomfort, and sleepiness.
