In addition to relaxation, research suggests that L-theanine may have application in the following:
L-theanine also adds unami (a brothy or savory) taste when added to water, coffee, tea, etc. Decreases bitter taste when added to coffee, tea, and other beverages and foods. Takes effect within 30 minutes after consumption. No known cautions or drug interactions
Stress and Anxiety
Stress and anxiety are debilitating conditions that can shorten life span while lessening performance, well being, and the enjoyment of life. Stress can impair the ability to perform mentally. It may result in reactions to situations that cause enhanced frustration, hostility or even injury. Stress slowly destroys the immune system, lowering resistance to disease and thus allowing degenerative and opportunistic diseases to occur. Stress is a cause of depression. The entire population is subjected to stress. In a 1998 survey, nearly 65 percent of the adult population indicated that they were under great stress. More than 23 million Americans suffer from anxiety illness.
PMS
Studies in cooperation with Taiyo Kagaku Co., The University of Shizuoka, and The Family Planning Institute of Japan have shown that women taking 200 mg L-theanine daily have lower incidence of PMS symptoms. These symptoms include physical, mental, and social symptoms. Overall, a significant alleviation of PMS symptoms by L-theanine was observed.
Brain Chemical May Thwart Ravages of Aging Study
L-theanine appears to have a role in the formation of the inhibitory neurotransmitter Gamma Amino Butyric Acid (GABA). GABA blocks release of the neurotransmitters dopamine and serotonin, playing a key role in the relaxation effect.
By Keith Mulvihill
[Info about GABA]
SOURCE: Science 2003;300:812-815.
NEW YORK (Reuters Health) - A shot of a brain chemical called GABA essentially turned back the clocks in the brains of older monkeys, whose brain function briefly operated at levels normally seen in monkeys less than half their age.
The finding may one day help scientists reverse similar age-related deterioration in the brains of people, according to the report published Friday in the journal Science.
GABA, or gamma-aminobutyric acid, is a messenger chemical that is essential for optimizing how brain cells transmit messages to each other and acts to put a damper on unwanted brain signaling activity, explained the study's lead author Dr. Audie G. Leventhal at the University of Utah School of Medicine in Salt Lake City.
Although GABA's age-related decline has not been documented in humans, a host of studies in mammals, including other primates, suggests that a similar process is at work in people, explained Leventhal.
L-theanine Documented Safety
L-theanine is considered to be safe based on its historical use as a component of tea and on favorable toxicology studies. Tea is the most consumed beverage worldwide after water, and has been consumed for thousands of years by billions of people. It is estimated that a heavy tea drinker (6-8 cups daily) will consume between 200 to 400 mg of L-theanine daily.
Dosage:
100 to 200 mg 1 to 3 times daily or as needed depending on stress and anxiety levels. Based on the results of clinical studies, it has been established that L-theanine is effective in single dosages in the range of 50-200 mg. It is suggested that subjects with higher levels of anxiety take a dose at the higher end of the effective range (100 - 200 mg) for best results.
