L-theanine is an amino acid found in green tea.
It is extremely rare.
To date it has been identified in tea (Camellia sinensis) and in a mushroom (Xerocomus badius, the Bay Bolete).
There are higher amounts in gourmet green tea (look for younger leaves and buds, mountain grown green tea), with lower amounts in oolong and black tea.
The amount will also vary with climate.
Human research has shown improvements in mental performance, with simultaneous improved focus and a general calming effect.
Other preliminary studies have shown potential enhancement of the immune system, including multiple cancer studies.
Here are some of them:
Reducing beta amyloid damage for Alzheimer's Disease
Dopamine research including 5 cups of green tea daily for increased well-being and improved memory
Increased serotonin in the brain with potential anti-depressant activity without side effects
Preliminary cancer studies show reduced liver cancer, breast cancer, colon cancer, ovarian cancer, and prostate cancer
Non-small cell lung cancer suppression of carcinoma growth and migration
Improving potency of chemotherapy while diminishing cellular damage side effects
Flu vaccine effectiveness for elderly patients
Green tea varieties: Dragon Well | Mao Feng | Matcha | Gunpowder Green | Pi Lo Chun | Gyokuro | Lu Shan Yun Wu | Japanese Sencha | Lu An Melon Seed | Jasmine | Blooming Tea | Chun Mee | All Flavored | Organically Grown | Premium Estates
How much caffeine in a cup of green tea? | Which green tea has more caffeine? | How to choose your caffeine level | 21 tips for choosing caffeine levels | What about decaffeinated green tea? | Effects of caffeine: positive and negative | Is caffeine dangerous?
This page was last updated by Sharon Jones on August 25, 2012.
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