Researchers have found that L-theanine works by supporting the
formation of GABA (gamma-aminobutyric acid), an inhibitory
neurotransmitter that blocks the release of the
neurotransmitters dopamine and serotonin to promote a state of
deep relaxation and calm, while increasing sensations of
pleasure.
L-theanine has also been found to directly stimulate the
production of alpha brain waves, which are associated with deep
states of relaxation and enhanced mental clarity.
In a recent study, Japanese researchers also revealed that?in
addition to promoting a deep state of relaxation?L-theanine may
also support healthy blood pressure levels, enhance
concentration and learning, promote mental clarity and
strengthen the immune system.
In human studies L-theanine has been shown to exert profound
relaxing effects, 30 to 40 minutes after ingestion, including:
- Relaxation without drowsiness
- Generation of calming alpha-waves
- Improved learning ability, and
- Enhanced sensations of contentment and
pleasure
L-Theanine: How a Unique Anxiety
Reducer and Mood Enhancer Increases Alpha Waves and Alertness
Carolyn Perrini, CLS, CNC
Hundreds of studies exist showing the many health benefits of
green tea. But what makes it the most consumed beverage in the
world after water is its pleasant taste and relaxation effect.
Both of these qualities?and more?can be traced to a unique,
neurologically-active amino acid in tea called L-theanine
(gamma-ethylamino-L-glutamic acid).
L-theanine is a free (non-protein) amino acid found almost
exclusively in tea plants (Camellia sp.), constituting between 1
and 2-percent of the dry weight of tea leaves. It is the
predominant amino acid in green tea leaves, giving tea its
characteristic umami or 5th taste (besides the four traditional
tastes: sweet, salty, acid, and bitter). Attempts to isolate the
L-theanine, with its physical and neurological benefits, from
the tea leaves were once difficult, expensive, and inefficient.
Economically feasible methods of producing the identical L-theanine
now exist and do not require a mountain of tea leaves.
Physiological Effects The calming effect of green tea may
seem contradictory to the stimulatory property of teas caffeine
content but it can be explained by the action of L-theanine.
This amino acid actually acts antagonistically against the
stimulatory effects of caffeine on the nervous system. (1)
Research on human volunteers has demonstrated that L-theanine
creates a sense of relaxation in approximately 30-40 minutes
after ingestion via at least two different mechanisms. First,
this amino acid 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 the key relaxation effect. (2)
The brain emits weak electrical impulses (brain waves) that
can be measured on the surface of the head. The predominant
frequency of electrical impulses correlates with different types
of mental states and activities. Brain waves are classified into
four categories (delta, theta, alpha, and beta)?each with an
associated mental state (Fig. 1). Delta is seen only in the
deepest stages of sleep. Theta is seen in light sleep and
drowsiness. Alpha is present in wakefulness where there is a
relaxed and effortless alertness and Beta is seen in highly
stressful situations and where there is difficulty in mental
concentration and focus. It is well known that alpha brain waves
are generated during a relaxed state and therefore alpha waves
are used as an index of relaxation. Be sure
to check out Binaural
Beat Audio technology if your interested in altered states
and modulation of brain waves. http://web-us.com.

In one study of these mental responses to L-theanine, brain
wave topography showed that alpha waves were observed from the
back to the top of a persons head (occipital and parietal
regions of the brain) within approximately 40 minutes after the
subjects had taken either 50 or 200 mg of L-theanine. In a
separate study, the intensity of alpha waves were determined to
be dose dependent (with a 200 mg dose showing a significant
increase over controls) and detectable after 30 minutes. (2,3)
Additional
Benefits of L-Theanine
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.
The regulation of blood pressure is partly dependent upon
catecholaminergic and serotonergic neurons in both the brain and
the peripheral nervous system. Studies on spontaneously
hypertensive rats (SHR) showed an impressive blood pressure
lowering effect with L-theanine. The lowered blood pressure
effect was dose-dependent with the highest test dose creating
the most significant drop. L-glutamine was used as one of the
controls. Although L-glutamine is similar in chemical structure
to L-theanine, it did not exhibit an anti-hypertensive effect
(Fig. 2). (3)

Preliminary studies report that L-theanine has been found to
increase the anti-tumor activity of some chemotherapeutic agents
(doxorubicin and idarubicin) and to ameliorate some of the side
effects of these drugs. It appears to increase the inhibitory
concentration of these drugs in the tumor cells, although the
mechanism is not known. At the same time, L-theanine decreased
oxidative stress caused by these agents on the normal cells,
possibly due to its mild antioxidant activity. In this regard,
L-theanine has been shown to inhibit lipid peroxidation,
catalyzed by copper, in low-density lipoprotein (LDL) in vitro.
(4)
Stress Relief 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. In 1998, pharmaceutical
sales of anti-anxiety drugs totaled over 700 million dollars,
while sales of antidepressants totaled close to 5 billion
dollars! People under stress can mitigate many of the harmful
effects of stress with L-theanine without becoming sedated in
the process. L-theanine doesnt make one drowsy, nor does it
promote sleep because this amino acid does not produce theta
waves in the brain. It should be noted that if an individual
were already relaxed, taking L-theanine would not produce
further relaxation.
Status and Usage L-theanine has just recently been introduced
to the U.S. market. Japan is credited with most of the clinical
studies and information we possess thus far on L-theanine but
research is ongoing. We do know that it is absorbed from the
small intestine via a sodium-coupled active transport process.
It crosses the blood-brain barrier, as evidenced by the mental
effects. L-theanine competes for absorption in the intestinal
tract and the brain with the amino acids found in the methionine
group (leucine, isoleucine, and valine), however the
concentrations of amino acids are unchanged by simultaneous
ingestion of L-theanine.
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.
The intended use of L-theanine is that of a mental and
physical relaxant that does not induce drowsiness. Although
there is no set schedule for taking L-theanine, it may generally
be taken at the first signs of stress. Based on the results of
the clinical studies, 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.
Conclusion Research into L-theanine derived from the
contradictory observation that green tea, with its high caffeine
content, produces a very calming effect. The seemingly
multi-dimensional reasons for this relaxation effect will
continue to be studied. Current areas of ongoing research
include using L-theanine as an alternative to Ritalin in
children and adults, as a treatment for PMS, in controlling
certain conditions of high blood pressure, in sharpening mental
acuity and concentration, and as an anti-cancer agent alone and
in synergy with other cancer-fighting agents. L-theanine may
find another area of application for its use as a supplement in
reducing the negative side effects of caffeine brought on by the
over-consumption of coffee, soft drinks, or other
caffeine-containing substances.
L-Theanine, the tea-derived substance known to act as an
anti-anxiety agent, also improves immunity, according to a
recent study.
Researchers conducted the study to see how L-Theanine
affected T-cells, the white blood cells that help the body
resist viral, bacterial, fungal and parasitical infections.
T-Cells also defend the body from tumor cells. Bacteria, viruses
and other harmful organisms as well as non-invading, healthy
cells all have antigens, cellular nametags that T-Cells use to
determine if the cells are foreign invaders or natural
inhabitants. Tea and other plant compounds also produce
antigens.
Researchers exposed T-cells both in vivo and in vitro to tea
with L-Theanine. They then exposed the cells to bacteria. They
discovered that treating the cells with L-Theanine caused the
cells to have a better immune response once the cells were
exposed to the bacteria. The cells treated with L-Theanine were
better able to recognize the foreign antigens. L-Theanine also
triggered the release of virus-destroying lactoferrin in the
cells.
Highly recommended
source of nutrients and supplements.
How did we
qualify VRP?
Reference: Kamath AB, Wang L, Das H, Li L, Reinhold VN,
Bukowski JF. Antigens in tea-beverage prime human Vgamma 2Vdelta
2 T cells in vitro and in vivo for memory and nonmemory
antibacterial cytokine responses. Proc Natl Acad Sci U S A. 2003
May 13;100(10):6009-14.
L-Theanine has been a popular product, and with good reason.
Theanine is well recognized for its ability to promote a
restful, relaxed state and to relieve nervousness, simple
tension and irritability.
Much of L-Theanine?s popularity has resulted from research
studies conducted by Taiyo Corporation, one of the world?s
largest producers of green tea and other natural ingredients.
Taiyo is the most active theanine researcher, and currently
holds 17 patents for Suntheanine?, its unique
pharmaceutical-grade theanine.
For proper effectiveness is must be pure
using L
References: 1. 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.
2. Mason R. 200 mg of Zen; L-theanine boosts alpha waves,
promotes alert relaxation. Alternative & Complementary Therapies
2001,April; 7:91-95
3. 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.
4. 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.