In a fast-paced and time-crunched society, it is no wonder that stress levels are high. Consumers are continually looking for quick and convenient ways to relax and reduce their stress. Enter L-theanine, an amino acid that research has proven to induce relaxation without causing drowsiness.

Found predominantly in tea plants, L-theanine contributes to the unique flavor and umami taste of green tea. Studies show that when consumed, L-theanine directly stimulates the production of alpha brain waves. These brain waves are associated with an awake, yet relaxed, state in humans. L-theanine also plays a role in the formation of gamma amino butyric acid (GABA). This inhibitory neurotransmitter is key for relaxation and works by inhibiting the release of dopamine and serotonin.

In addition to relaxation, L-theanine exhibits the potential to lower blood pressure and to improve learning ability and memory. In hypertensive rats, the administration of L-theanine resulted in a significant decrease in blood pressure. In Wistar rats, scientists observed relatively good reaction frequency in a series of memory and learning ability tests, with the administration of L-theanine.

These positive benefits help L-theanine prove itself to be a unique additive for dietary supplements and functional foods. Food scientists at Taiyo Kagaku Co. Ltd., Yokkaichi, Japan, developed an enzymatic process for the large scale production of L-theanine, which is offered under the name Suntheanineâ„¢ by Taiyo International Inc., Edina, Minn. A dose of between 50 to 200 mg of Suntheanine has been shown to produce relaxation, without inducing drowsiness. Taiyo's studies concluded that Suntheanine produces the relaxant effect within 30 to 40 minutes of ingestion.

L-theanine was approved in Japan in 1964 for unlimited use in all but infant foods. In 1994, following favorable toxicology studies, Suntheanine-containing products entered the Asian markets; they became available in the European markets in 1999. Dietary supplements with Suntheanine hit U.S. market shelves in 2000.

Presently, over 50 food products containing Suntheanine are being sold in Japan, Korea and Europe. In Japan, products include capsules, gum, chocolate, caramel, ice cream and beverages. In the U.S., most of the products are in capsule form.

According to the company, no degradation of L-theanine is noted in beverages heated at 121° C for 5 minutes. Suntheanine shows good stability in both neutral (pH 6.5) and acidic (pH 3.0) beverages during 12 months of storage at under 25° C. Unlike similar stress-reducing herbs and supplements, Suntheanine has no unpleasant flavor and is transparent in solution.

Suntheanine was awarded the Food Ingredient Research Award at the 1998 Food Ingredients Europe and the Best New Product of 2000 at Nutracon.

For a copy of the research, see:

Taiyo International Inc.