L-Theanine (delta-glutamylethylamide) is an amino acid found in green tea. Was first isolated in the 1940s. This amino acid, is able to cross the blood-brain barrier and is considered to be psychoactive. Possesses neuroprotective, mood-enhancing, and relaxation properties. Theanine appears to have a role in the formation of the inhibitory neurotransmitter Gamma Amino Butyric Acid.
Klonopin, Valium, and Ativan are commonly prescribed anti-anxiety medicaments. But, long term use of this class of drugs named benzodiazepines, can lead to physical and psychological dependence, and like all drugs, they have the risk to damage the liver with extended use. Clinical findings show that l-theanine may help reduce stress and promote relaxation.
L-Theanine for Anxiety and Depression
Research on human volunteers has demonstrated that theanine creates a sense of relaxation approximately 30 minutes after ingestion by two different mechanisms. 1-Theanine directly stimulates the production of alpha brain waves, creating a state of deep relaxation and mental alertness similar to what is achieved through meditation.2- Theanine is involved in the formation of the inhibitory neurotransmitter, gamma aminobutyric acid (GABA). Gamma-aminobutyric acid is an important neurotransmitter that is abundant and widely distributed throughout the central nervous system. Low levels or decreased GABA function in the brain is associated with different neurological and psychiatric problems, but most primarily depression, anxiety, insomnia and epilepsy. According to a 2006 info in the “Journal of Herbal Pharmacotherapy“, L-theanine not only increases GABA levels in the brain, it also increases serotonin and dopamine levels. Theanine may alleviate anxiety by inhibiting the barrage of brain excitation associated with anxiety states, according to a study reported in the January 2007 Biological Psychology journal.
The human brain generates various types of weak electric pulses that are classified as alpha, beta, delta and theta waves. Each of these waves are associated with particular physiological activity e.g. theta waves are associated with drowsiness while alpha waves are associated with relaxation. Clinical studies have shown that L-theanine powerfully activates alpha waves and induces relaxation in test subjects. A study reported in Trends in Food Science and Tech found electroencephalographic evidence on how l-theanine affects the brain. L-Theanine increases the alpha brain frequency which means relaxes the mind without causing drowsiness. A study reported in 2008 in “Asia Pacific Journal of Clinical Nutrition” found that 50 mg of l-theanine significantly increases alpha brain wave activity within 40 to 90 min of ingestion.
L-Theanine Dosage for Anxiety
L-theanine supplements are taken in doses ranging from 200 mg to 800 mg per day. In a monograph reported by Alternative Medicine Reviews in 2010, the recommends taking 200 mg twice or three times daily to treat anxiety. (The approximate 1 cup of green tea is estimated to contain 20 mg of L-theanine). Though there are no reported side effects, the Food and Drug Administration (FDA) recommends that people do not take more than 1,200 mg daily. Suntheanine®, a pure form of L-Theanine, is a patented supplement and a registered trademark of Taiyo International.