L-theanine (N-ethyl-L-glutamine) is a non-proteinaceous amino acid that is found in high amounts almost exclusively in tea (Camellia sinensis). In fact, L-theanine accounts for around 50 % of the amino acids in tea leaves. L-theanine is structurally similar to glutamic acid. L-theanine is of interest nutritionally because it appears to have an ability to increase calmness and focus in humans and this relates to the way it interacts with the brain. L-theanine is able to cross the blood brain barrier and here it can interact with neurones such as the N-methyl-D-aspartate (NMDA) receptor to antagonise its activity. This reduces the excitability of the brain and therefore explains the calming effects of the amino acid. L-theanine also appears to be able to increase synthesis of a number of neurotransmitters including GABA, serotonin and dopamine, and this may have particular mood-elevating effects. Drinking tea has been shown to have these effects, but L-theamine can also be taken as a supplement in powder form.
Eat Well, Stay Healthy, Protect Yourself
RdB
