Theanine is a free form amino acid that exists in tea and the Xerocomus badius species of mushroom. An average cup of tea has 20 to 60mg of theanine. Theanine is responsible for many of the benefits tea provides. Theanine supplement potential benefits include neuroprotection, better mood, decreased anxiety, increased ability to learn, lowered blood pressure, lowered cholesterol, antioxidant effects, anticarcinogenic effets, increased immunity, weight loss, and dealing with PMS symptoms.

Mood and Cognition Benefits: Theanine might improve mood and cognition. One study of 18 to 22-year-old females found 50 to 200mg of theanine improed feelings of awakeness, alertness, and relaxation within about half an hour of taking it. Rodent studies have found theanine to improve memory and learning test performance. Theanine is believed to counteract the stimulant effect of caffeine in tea accounting for tea’s relaxing capabilities. Theanine significantly improves dopamine levels. It might alsp effect other neurotransmitter levels, such raising and lowering serotonin and reducing norepinephrine.

Neuroprotection Benefits: Theanine’s neuroprotective capabilities have been demonstrate in rodent studies. This includes it preventing neurotoxicty in vitro. Theanine is also believed to account for tea drinkers having a lower risk of stroke. Thus theanine might help treat and prevent strokes. Animal studies show it improves nerve growth factor synthesis. The neuroprotective benefits of theanine are associated with its AMPA, NMDA, and antioxidant aspects.

Additional Benefits: Early animals studies have found theanine might lower blood pressure and improve other cardiovascular variables. Theanine can also improve immune system function. Theanine is also partially responsible for the well-known weight loss effects of green tea. Additionally, studies found it helped relieve premenstrual syndrome (PMS) symptoms in daily doses of 200mg.

Theanine has also been found to improve the effectiveness of anti-tumor drugs on tumors while also reducing their toxicity in other tissues. It can also slow tumor growth. Thus it is thought that drinking green tea can improve cancer patients life quality by improving the effectiveness of treatment and providing psychological benefits. (Posted on 2/20/11)