Health Glossary - For Everyone

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What is l-theanine?

L-theanine is an amino acid which is predominantly found in the green tea plant (Camellia sinensis), making up about 50% of the amino acid content in the tea plant.

The l-theanine content in green tea contributes to the main flavour of it.


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Important l-theanine facts

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Why l-theanine is important

L-theanine possesses strong antioxidant properties and has demonstrated in various studies that it has anti-cancer properties as wel as being ale to positively enhance the activity of some anti-cancer drugs and decreased tumour size more than just in experiments with the anti-cancer drugs alone.

L-theanine's effect on certain neurotransmitters could be a reason why it is thought to be able to regulate mood.

A recent study on lab rats demonstrated that even high doses of L-theanine administered at repeated intervals did not cause any toxic effects.

Other research suggests that L-theanine naturally stimulates activity in the brain known as alpha waves, which are associated with a relaxed yet alert mental state.


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Last reviewed: 30 September 2007 || Last updated: 14 March 2010


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More information

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NOTE: Mega doses of any type of vitamin, mineral, amino acid or herbal supplement cannot cure illnesses and in fact can be very dangerous and produce toxic side effects and interfere with medicine you are taking. Always ensure you consult your doctor before taking any type of complementary supplements.
Disclaimer: This guide is not intended to be used for diagnostic or prescriptive purposes. For any treatment or diagnosis of illness, please see your doctor.


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