What is L-theanine?
L-theanine is a natural amino acid commonly known as Suntheanine or simply Theanine, with L representing its chemical structure. It was discovered in 1949 and is an herbal extract gained of green tea, but is also found in certain edible mushrooms. It is commonly processed in foods (e.g. chocolates, beverages etc.) throughout the world. In the USA, the FDA has approved L-Theanine to be generally safe for use as dietary supplement. Although it is primarily known to relieve stress, there are studies which suggest the supplement as a nootropic. Such studies have reported the benefits of theanine in cognition enhancements and mood improvements.
While green tea only contains small amounts of Theanine, capsulated or powdered forms can contain Theanine equal to hundreds of cups of green tea.
How does L-theanine work?
Due to its ability to penetrate the blood-brain-barrier L-Theanine supplement is known to relieve stress without tranquilizing or causing drowsiness. While absorbed by the brain, Theanine acts as an analog to the neurotransmitter glutamate. Therefore, after entering the brain, Theanine is capable of regulating the production of glutamate. By reducing the excess amount of glutamate, harmful effects of stress hormones are minimized. This way, Theanine virtually acts as an anti-depressant, because all anti-depressants aim at reducing stress hormones. The supplement has been shown to relieve not only mental but also physical stress.
Alzheimer disease, brain stroke, alcohol abuse, memory loss for example, are all conditions due to disturbance of the glutamate level in the brain which activate signals. If there were an adequate amount of Theanine within the bloodstream, damage by strokes could be reduced significantly. In a research study including 14,000 people, it was reported that drinking tea (including Theanine and other constituents) can reduce the risk of a stroke by nearly 40%. One could conclude that regulation of the glutamate level with the help of theanine improves memory as well as learning capabilities by providing neuroprotection from degenerative processes.
Effects of L-theanine
Numerous studies were performed to establish the use of Theanine in humans. It is shown that Theanine is capable of increasing and smoothing alpha brain waves, which represents a calming state of the brain along with silent alertness. Moreover, its use increases levels of certain beneficial neurotransmitters e.g. serotonin, dopamine, GABA etc. Its consumption along with caffeine has been shown to be synergizing. One can choose to get only the desirable affects of caffeine; energy and motivation, without getting undesirable anxieties. This is because the addition of Theanine cancels out the negative aspects associated with caffeine.
Side-Effects of L-theanine?
Consumption of Theanine can be considered to be just as safe as green tea, but only in appropriate dosages. Special care must be taken when ingesting Theanine with other drugs. Predictively Theanine may tend to decrease blood pressure, thus when taking medications for lowering blood pressure it is not advised to combine them with Theanine. A physician’s consultancy is always crucial prior to using and selecting a Theanine dose and schedule.
Recommended Dosage / Usage instructions
Recommendations vary, however most sources suggest 200-500mg per day. To ensure the mildest forms of side-effects, if any, it is advised to start with smaller doses and to gradually increase until the personal optimum is reached.