A New Natural Relaxant

Ever wonder why tea doesn’t give you the same buzz as coffee even though it has caffeine? The reason is scientific, dear Watson. Tea contains an amino acid known as theanine. Theanine is tea’s version of a relaxant. Think Japanese tea ceremony.

Calming effect

In Japan, stress is legendary– people literally die from overwork. It’s so bad that a Japanese doctor invented a name for it. “Karoshi” is death due to overwork. Anything that calms people down is very welcome in Japan. Tea, obviously, has been a part of Japanese culture for thousands of years. But it took a Japanese researcher to point out that caffeine ingested in tea has a different effect than the same amount ingested as pure caffeine. When researchers went to find out why, they discovered that theanine was offsetting caffeine’s hyper effect with a calming effect. This led to the manufacture of a new natural antidote to modern stress.

In 1964, Japan approved theanine’s use in all food, except baby food. In Japan, you can buy over 50 different food items that contain theanine. Japanese soft drinks are spiked with the relaxant, and it has been put into chewing gum.

The tranquilizing effects of theanine are not imaginary. Theanine readily crosses the blood-brain barrier of humans and exerts subtle changes in biochemistry. An increase in alpha waves has been documented, and the effect has been compared to getting a massage or taking a hot bath. Theanine is different than kava-kava in that it doesn’t cause drowsiness. And unlike tranquilizing drugs, it doesn’t interfere with the ability to think. Studies on rodents show just the opposite: theanine enhances the ability to learn and remember. By shutting down the “worry” mode, theanine increases concentration and focuses thought. This is the concept behind the Japanese tea ceremony which causes a person to focus on the moment. Consider this: the risk of mortality for Japanese women who practice tea ceremony is half of other Japanese women. The Japanese are already the longest-lived people on earth.

Theanine is a caffeine antagonist. It does the opposite. The effects can readily be seen in EEGs of rodents given caffeine, then theanine. One of the things that theanine changes is GABA, a brain chemical known for its calming effect. Theanine increases GABA, while caffeine decreases it. GABA doesn’t just relax, it also creates a sense of well-being. Theanine’s ability to increase this brain chemical can put you in a better mood by changing biochemistry. Theanine also increases levels of dopamine, another brain chemical with mood-enhancing effects.

Protect your ability to think

A very interesting feature of theanine, which is just now being investigated, is its ability to protect neurons. Theanine may protect against glutamate, an essential brain chemical that is toxic in high amounts. Although essential to brain chemistry, too much glutamate kills brain cells. The most common cause of glutamate overload is insufficient blood supply. If the brain doesn’t get adequate blood flow, glutamate surges, calcium increases, and free radicals damage cells.

“Cerebral vascular dementia” is dementia caused by insufficient blood flow due to bad blood vessels. Glutamate overload is one of the features. Theanine may protect against this type of dementia. In studies on neurons in cell culture, theanine significantly reverses glutamate-induced toxicity. In vivo studies show the same effect in rodents.

Theanine is structurally similar to the amino acid, L-glutamic acid. The similarity enables theanine to physically block glutamate (which is a version of glutamic acid). Although researchers aren’t positive how theanine works yet, they theorize that theanine blocks the NMDA receptor which is the doorway that glutamate uses to enter cells. Because of the similar structure, theanine can also fit in this doorway, blocking access to glutamate. But although it can fit in the doorway, theanine does not have the same effect on the cell as glutamate does. Rather than causing damage, theanine acts like a shield against damage.

Lowers blood pressure

High blood pressure is a feature of stress that can be lowered by lowering the stress. The simple act of drinking a cup of tea can lower blood pressure by forcing a person to slow down and relax. But there is evidence that tea exerts far more than just a psychological effect.

Chronically elevated blood pressure has been called America’s “silent killer” because many people don’t know they have it. Many others simply ignore it. Yet high blood pressure is a very strong indication that a person is destined for a heart attack or stroke.

Theanine and PMS

Premenstrual syndrome can interfere with a woman’s ability to get anything done. All kinds of symptoms are associated with the hormonal roller-coaster that causes PMS. Feelings can range from lethargy to homicide. Some women experience such bad symptoms that they’re put on drugs.

Many women (and the people around them) would welcome a non-toxic, safe supplement that would lessen PMS symptoms. Japanese researchers have discovered that theanine works for PMS. Using a distress questionnaire, they tracked the reactions of 20 women taking the new supplement for two months. Theanine caused documented reductions in mental, social and physical symptoms. Women who benefitted took 100 mg of theanine twice a day during the questionable days.

Reduction of PMS Symptoms by Theanine

Adapted from the Proceedings of the Nogei Kagaku Kai, (Biosci Biotech Biochem 75, 166, March 2001, Kyoto) in cooperation with Taiyo Kaguku Co., Ltd., University of Shizuoka and The Family Planning Institute of Japan.


Remember karoshi? Most readers would assume that death by overwork would be caused by heart attacks. But it’s not. In Japan, high levels of stress and hypertension are not risk factors for heart attack and stroke. Salt isn’t either, and neither is smoking even though Japanese smoke more cigarettes than Americans. The reason is diet. Studies show that when Japanese adopt a Western diet, their risk of heart attack almost doubles, and Western risk factors then apply to them.

One of the protective factors in the Japanese diet is green tea. According to one study, drinking one or more cups of tea can almost halve the risk of heart attack. Green tea contains a much higher concentration of theanine than other teas. Theanine has been proven to lower blood pressure. It works through its GABA-enhancing effects. GABA lowers blood pressure. Genetically hypertensive rats taking 2000 mg/kg of theanine a day showed significant reductions in blood pressure. Green tea extract contains a phytochemical known as GMA that also lowers blood pressure. Combining them together may have significant effects.

Theanine has multiple beneficial effects. It’s like zen in a bottle, and its effects have been compared to tobacco or aromatherapy. Studies show that theanine is a non-toxic, highly desirable mood modulator that can be enjoyed by every adult.

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References

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Kakuda T, et al. 2000. Inhibiting effect of theanine on caffeine stimulation evaluated by EEG in the rat. Biosci Biotech Biochem 64:287-93.

Kakuda T, et al. 2000. Protective effect of -glutamylethylamide (theanine) on ischemic delayed neuronal death in gerbils. Neurosci Lett 289:189-92.

Kobayashi K, et al. 1998. Effects of L-theanine on the release of -brain waves in human volunteers. Nippon Noegik Kaishi 72:153-57.

Sadakata S, et al. 1992. Mortality among female practitioners of Chanoyu (Japanese “tea-ceremony”). Tohoku J Exp Med 166:475-77.

Sesso HD, et al. 1999. Coffee and tea intake and the risk of myocardial infarction. Am J Epidemiol 149:162-7. Simons LA, et al. 1992. Health status and lifestyle in elderly Hawaii Japanese and Australian men. Exploring known differences in longevity. Med J Aust 157:188-90.

Yokogoshi H, et al. 1998. Hypotensieve effect of -glutamylmethylamide in spontaneously hypertensive rats. Life Sci 62:1065-68.

Yokogoshi H, et al. 1995. Reduction effect of theanine on blood pressure and brain 5-hydroxyindoles in spontaneously hypertensive rats. Biosci Biotech Biochem 59:615-18.

Theanine Enhances Chemotherapy
And Reduces Side Effects

Cancer cells are good at getting rid of drugs designed to kill them. They use tiny pumps to expel what they don't like-such as doxorubicin (adriamycin), a drug used for chemotherapy.

For several years, researchers in Japan have been investigating the potential of an amino acid from tea to enhance the ability of doxorubicin to work. Known as theanine, this unique dietary supplement has already proved valuable in other areas of health. Early studies showed that if theanine is added to a regimen of doxorubicin, tumor weight could be halved compared to the effects of the drug alone. The experiments were repeatedly done, and every time theanine enhanced the killing capacity of doxorubicin. Researchers soon discovered why.

Theanine increases the amount of drug getting into tumors. What's exciting, though, is that while it increases the level of "dox" entering cancer cells, it doesn't increase those levels in healthy tissue. That means that theanine selectively enhances toxicity only where it's needed. This makes theanine different from the drugs presently being used to overcome "multi-drug resistance".

Those drugs work by suppressing a protein that enables cancer cells to resist chemotherapy. The problem is that the multi-resistance drugs suppress the protein all over the body, which causes toxicity. Theanine doesn't do this. Instead of suppressing a protein, theanine pretends to go along with the program, enters cells and then throws a monkey wrench in the works. The original studies showing these effects were published in Cancer Letters and Toxicology Letters.

Theanine protects healthy cells

Besides enhancing doxorubicin's cancer-killing effects without harming healthy tissue, theanine also keeps doxorubicin out of healthy tissue. This is a major added benefit since one of the drawbacks of doxorubicin is its toxicity to the heart.

Dox-induced cardiac toxicity is associated with high levels of lipid peroxidation-free radicals. A study published in 1996 shows that theanine reverses lipid peroxidation in cardiac tissue which doxorubicin causes to double. In studies on rodents, complete reversal of lipid peroxidation was achieved with 100 mg/kg of theanine. One of the supplement's actions is to reverse the loss of glutathione peroxidase, an enzyme that is depleted by the extra free radicals.

Doxorubicin suppresses the ability of cancer to spread. When combined with theanine, it works even better. The same researchers conducted a study on the suppression of liver metastases in mice with ovarian sarcoma. Metastases were fewer than with dox alone.

Theanine makes chemotherapy work

In 1999, researchers did a study testing theanine in conjunction with a drug similar to doxorubicin known as idarubicin. Idarubicin has been tried against drug-resistant leukemia cells, but it causes toxic bone marrow suppression and can't be used.

Researchers wanted to see if theanine would make the drug work. In the first experiment, about one-quarter of the standard dose of idarubicin was used. At this dose, the drug doesn't usually work, and doesn't cause toxicity. When combined with theanine, however, idarubicin worked-without toxicity. Tumor weight was reduced by 49%, and the amount of drug in the tumors doubled. In the next experiment, theanine was added to the usual therapeutic dose. Theanine increased the effectiveness of the drug, and significantly lessened the usual bone marrow suppression. Leukocyte loss was reduced from 57% to 37%.

How does it work?

Glutamate is a multi-faceted amino acid. One of its jobs is to help create glutathione, an important detoxifier. Glutathione is the liver's first-line defense against drugs and chemicals. It is also one of the things cancer cells use against drugs and chemicals. Cancer cells use glutathione to detoxify doxorubicin and escort the drug out of cells. Theanine works because it interferes with the process.

Theanine is an amino acid which is structurally similar to glutamate. This is the key to its success. It is able to fool cancer cells into letting it in, but once inside this Trojan horse acts very differently. Glutamatic acid, or glutamate, is one of the components of glutathione, the drug detoxifier. Because it looks like glutamic acid, cancer cells take up and mistakenly use the theanine to create glutathione. But the glutathione they create with theanine does not detoxify like natural glutathione. Instead, this theanine-based glutathione appears
to block the ability of cancer cells to detoxify.

Researchers working with ovarian cancer have discovered that theanine lowers the amount of glutathione in cancer cells. Without this raw material, cancer cells can't run their detoxification system. They lose their ability to detoxify, and thus, doxorubicin becomes more toxic to them. Up to twice as much doxorubicin stays in cancer cells treated with theanine.

These findings on glutamate and this detoxification system in cancer cells is very important because most research on drug resistance in cancer cells has been focused on a different system altogether. By showing that a non-toxic, readily available dietary supplement can enhance the amount of a chemotherapeutic drug that gets into cancer cells, and at the same time reduce it in healthy cells, Japanese researchers have made a great leap forward. Theanine may be an ideal partner for doxorubicin chemotherapy.

Note: The human equivalent dose of theanine as a chemotherapy adjuvant with doxorubicin is 500 to 1,000 mg/day. Be aware that no human studies have been conducted.

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References

Sadzuka Y, et al. 1996. The effects of theanine, as a novel biochemical modulator, on the antitumor activity of adriamycin. Cancer Lett 105:203-209.

Sadzuka Y, et al. 2000. Improvement of idarubicin induced antitumor activity and bone marrow suppression by theanine, a component of tea. Cancer Lett 158:119-24.

Sadzuka Y, et al. 2001. Enhancement of the activity of doxorubicin by inhibition of glutamate transporter. Toxicology Lett 123:159-67.

Sadzuka Y, et al. Efficacies of tea components on doxorubicin induced antitumor activity and reversal of multidrug resistance. Toxicology Lett 114:155-62.

Sugiyama T, et al. 1998. Enhancing effects of green tea components on the antitumor activity of adriamycin against M5076 ovarian sarcoma. Cancer Lett 133:19-26.

Sugiyama T, et al. 1999. Combination of theanine with doxorubicin inhibits hepatic metastasis of M5076 ovarian sarcoma. Clin Cancer Res 5:413-16.

These statements have not been evaluated by the FDA. These products are not intended to diagnose, treat, cure, or prevent any disease