What is L-Theanine?
Theanine is derived from tea leaves. Tea is native to eastern Asia and is a member of the Theaceae family. This evergreen shrub or tree grows to over 9 m in height and is pruned from 60 cm to 1.5 m for cultivation. Its dark green, serrated-edged leaves are alternate and oval, while its white and fragrant blossoms appear singly or in clusters.
What is it used for?
Second only to water, tea is the most widely consumed beverage in the world. L-theanine was discovered as a constituent of green tea in 1949 and was approved in Japan in 1964 for unlimited use in all foods, including chocolates, soft drinks, and herb teas, except infant foods. It also provides a unique umami (brothy or savory) taste and flavor to green tea infusion.
L-theanine may help relieve stress by inducing a relaxing effect without drowsiness and may also possess immunologic attributes. Theanine may also have effects on the cardiovascular system and play a preventative role in cancer; however, limited clinical information is available to support these claims.
Few adverse reactions have been reported. Adverse reactions recorded in human studies using tea extracts include headache, dizziness, and GI symptoms.