Carnitine, arginine and tryptophan: why are they so popular in amino acid food supplements?
Carnitine is an amino acid produced by the body from lysine and methionine. It plays an important role in transporting fatty acids into mitochondria. As this process enables energy to be produced from ATP, carnitine is considered essential for healthy muscle function.
The body is able to synthesise carnitine from food; rich sources include meat, especially red meat, dairy products, avocadoes and the soy product, tempeh. Though carnitine deficiency is uncommon, some people gain a variety of benefits from supplementation through the ingestion of natural amino acid supplements. Studies have shown that carnitine actually reduces muscle stress following exercise and increases sperm quantity and motility. Carnitine also has antioxidant properties.
Arginine is one of the 20 amino acids which builds proteins in the body. It is involved in various functions such as cell division, wound-healing, the immune system and muscle function.
Arginine is considered a ‘semi-essential’ amino acid because our bodies make enough for our needs. Nevertheless, serious infection and trauma can increase these requirements.
Which foods contain arginine?
Arginine is found in many foods such as pulses, red meat and nuts, in addition to amino acid food supplements. Studies have demonstrated that at certain doses, arginine improved erections, increased stamina and optimised immune response.
Ornithine is a non-essential amino acid produced from arginine. It is traditionally used to increase sports and athletic performance though studies appear to have produced inconsistent results.
Tryptophan (or l-trypophan) is an essential amino acid found in both plant and animal protein. A valuable dietary supplement, it has sedative effects, helps smokers quit, and is believed to help with insomnia and depression.