By Ronald Steriti, ND, PhD
L-theanine is a free (non-protein) amino acid found almost exclusively in tea. It is the predominant amino acid in green tea leaves, giving tea its characteristic umami or "5th taste". The calming effect of green tea may seem contradictory to the stimulatory property of tea's caffeine content but it can be explained by the action of L-theanine.
Research on human volunteers has demonstrated that L-theanine creates a sense of relaxation approximately 30-40 minutes after ingestion by at least two different mechanisms. First, L-theanine directly stimulates the production of alpha brain waves, creating a state of deep relaxation and mental alertness similar to what is achieved through meditation. Second, L-theanine is involved in the formation of the inhibitory neurotransmitter, gamma amino butyric acid (GABA). GABA influences the levels of two other neurotransmitters, dopamine and serotonin, producing a relaxation effect.
L-theanine has a significant effect on the release or reduction of neurotransmitters like dopamine and serotonin, resulting in improved memory and learning ability. L-theanine may also influence emotions due to its effects on the increased release of dopamine. L-theanine reduces brain serotonin concentration by either curtailing serotonin synthesis or increasing degradation in the brain.
Stress and anxiety are debilitating conditions that upset the balance of our hormones leading to a loss of our well-being, performance, and even lifespan. Stress impairs the immune system, leaving us vulnerable to opportunistic infections, and can cause depression. People under stress can mitigate many of the harmful effects of stress with L-theanine.
One of the greatest benefits of L-theanine is that you can use it without becoming sedated in the process. L-theanine doesn't make one drowsy, nor does it promote sleep because this amino acid does not produce theta waves in the brain.
L-theanine is extremely safe. There are no dietary limits on L-theanine intake by the Japan Food Additive Association. In 1964, the Japanese Ministry of Health and Welfare approved L-theanine for unlimited use in all foods, with the exception of infant foods.
L-theanine is most effective in the range of 50-200 mg, with the effect being felt within 30 minutes and lasting for 8-10 hours. Individuals with high stress levels may increase their dosage of L-theanine to at least 100 mg, with no more than 600 mg being taken in a six hour period. FDA recommends a maximum dose of 1200 mg daily, although the reason for this limit is not clear, due to its demonstrated safety.
There are no known adverse reactions to L-theanine and no drug interactions have been reported. L-theanine is not affected by food and may be taken anytime, as needed. Because it has a mild taste, capsules may be opened and dissolved in water. Although it is probably safe for pregnant women and nursing mothers, we discourage its use by them pending conclusive research
Juneja LR, Chu D-C, Okubo T, et al. L-theanine a unique amino acid of green tea and its relaxation effect in humans. Trends Food Sci Tech 1999; 10:199-204.
Kakuda T, Nozawa A, Unno T, et al. Inhibiting effects of theanine on caffeine stimulation evaluated by EEG in the rat. Biosci Biotechno Biochem 2000; 64:287-293.
Mason R. 200 mg of Zen; L-theanine boosts alpha waves, promotes alert relaxation. Alternative & Complementary Therapies 2001,April; 7:91-95
Yokozawa T, Dong E. Influence of green tea and its three major components upon low-density lipoprotein oxidation. Exp Toxicol Pathol 1997; 49(5):329-335.
The next step, after you have been diagnosed with a disease, is to find out what is the specific cause, and then choose supplements that address it. Phone consults are my specialty. Please call my at (239) 659-2684 to schedule a consultation.
I recommend that you make an informed choice, and the goal of this web site is to provide you with the information to make a wise choice when it comes to your health and wellness.
As you can see, I don't sell any vitamins on this web site. There are thousands of vitamin stores that will sell you whatever vitamin you want, and many of them offer discounts.
If you are interested in some high-quality basic nutritional supplements, I recommend visiting the Store You will find my recommendations for a multiple, tasty chewable fiber wafers, high-potency probiotics, and fish oils.
Good luck in your journey towards health and wellness!!
Unfortunately, that would be a clear violation of FDA regulations. Also, one of the most important aspect of naturopathy is: "Treat the person, not the disease". This is a profound statement, and many people have spent thousands of dollars on vitamins listed in books or web sites for a specific disease. This is what I call "vending machine medicine". It rarely works! The solution is to find a naturopathic physician, such as myself, to assist you.