There are lots of medications out there to help us or our kids feel better. But for a large number of people they are not as useful as had hoped.

But just by making sure we get enough amino acids in our diet or through supplementation is the first step to treating low moods, anxiety, irritability, poor cognitive function or just simply improving our overall mental wellbeing.

Amino acids

Amino acids are often described as the building blocks of life, by forming structures such as muscle, skin, and hair but they also form enzymes which are needed to make sure that processes within the body happen at the right pace. More importantly they are essential in the production of neurotransmitters, which are chemicals in the brain that either excite or inhibit neurons. This means they play a key role in the regulation of central neurotransmission, cognitive performance and attention and mood. If certain amino acids are either elevated or lowered, this can have a significant impact on brain function and behaviour. Here are four amino acids that are particularly important when it comes to your brain health and mood:


Tryptophan is the rarest of the essential amino acids found in food and is the precursor of serotonin. Serotonin is important for providing a feeling of calm and well-being. This is why tryptophan is often prescribed to induce restful sleep. A deficiency of serotonin can result in depression, anxiety, insomnia, excessive anger and mood swings. It can also alter other behavioural factors such as alertness, ability to concentrate and pain sensitivity. A series of studies conducted in several laboratories examined the effects of specially formulated tryptophan-free meals on mood state. They demonstrated that single meals that are deficient in tryptophan have substantial acute effects on self-reported levels of depression. Tryptophan-deficient meals also affected levels of aggression displayed. The studies found that administration of a high-tryptophan meal to such individuals decreases aggressive mood and behaviour. Tryptophan-rich foods include turkey (which is why there is a race to the couch after holiday dinners), soy/whey protein, quinoa, flaxseeds and lentils.


Another amino acid that has been extensively researched for behavioural effects is tyrosine, the precursor of three neurotransmitters: norepinephrine, dopamine and epinephrine. Collectively these molecules are referred to as catecholamines and are important for maintaining a sense of well-being and energy and promote a healthy nervous system. Tyrosine is not considered essential as it can be produced from another amino acid called phenylalanine, however some studies suggest that the brain may not be able to synthesise sufficient amounts from phenylalanine to meet its needs. Both norepinephrine and dopamine are believed to play a critical role in the brain’s response to acute stress. Neurons involving norepinephrine are critical for regulating attention, arousal level and mood state.


Dopamine, the “feel good” neurotransmitter helps to produce feelings of optimism and enthusiasm. It also helps to reduce fatigue and keep energy levels constant. Epinephrine, also known as adrenalin, helps sustain blood sugar, and both noradrenalin and adrenalin are very anti-inflammatory which is crucial to a healthy brain and nervous system. Whilst protein deficiency and by default, tyrosine deficiency is rare, there is a significant difference in simply having enough to avoid clinical symptoms and achieving optimum results by increasing levels. Protein-rich foods such as fish, legumes, nuts and seeds can be helpful in achieving this.


Another amino acid making it to the list is L-Carnitine. Acetyl-L-Carnitine is a more bioavailable synthesised form of L-Carnitine as it is able to more efficiently cross the blood brain barrier. Although Acetyl-L-Carnitine and its sister compound called L-Carnitine are manufactured in the body from amino acids, they are actually much closer in structure to a B-vitamin, and like the other B-vitamins, play critical roles in our energy, metabolism and nervous system. They also work as antioxidants and promote the production of glutathione, a free radical scavenger, in cells.

The effects of Acetyl-L-Carnitine in the brain include improved memory, increased mood and a sense of motivation and a boost in concentration. It also assists in reducing oxidative stress and has the ability to directly affect the mitochondria which are responsible for generating energy at a cellular level. In addition, Acetyl-L-Carnitine has been shown to increase the levels of the neurotransmitters noradrenaline and serotonin, which marks Acetyl-L-Carnitine as a potential effective supplement for depression.


Most people think of body building when they hear of glutamine, however some of its greatest benefits are to do with brain health. Glutamine increases energy, stamina and focus, improving overall cognitive function. It appears to have a role in the production, or more accurately, the “recycling” of glutamate and GABA, two neurotransmitter compounds. Glutamate is the most abundant neurotransmitter in the human body and is believed to be heavily involved in memory and learning processes. Glutamine is also believed to remove metabolic residue in the brain, acting as a detox and hence improving brain function. It is a common ingredient in brain health supplements and has been used as a treatment for ADHD, anxiety and depression. Good sources include fish, poultry, tomatoes and citrus.


  1. Lieberman, Harris R. (1999). Amino Acid and Protein Requirements: Cognitive Performance, Stress, and Brain Function. In The Role of Protein and Amino Acids in Sustaining and Enhancing Performance (pp. 289-307). Washington, D.C: National Academy Press.
  2. Biggs, John. (2014, September 12). Top Amino Acids for Brain Function [Blog post]. Retrieved from