Unraveling the Health Benefits of L-Theanine in Uji Matcha Tea

Posted on June 30 2023, By: Luke Alcock

Japanese tea setting with Uji Matcha and a book on L-Theanine benefits.

Unraveling the Health Benefits of L-Theanine in Uji Matcha Tea: A Scientific Perspective


Uji Matcha tea, a premium green tea variant originating from the Uji region of Japan, is celebrated for its robust flavor profile and a plethora of health benefits. A significant contributor to these benefits is L-theanine, a unique amino acid predominantly found in tea plants. This comprehensive article aims to demystify the science behind L-theanine, its health benefits, and its pivotal role in augmenting the value of Uji Matcha tea[1].

The Legacy of Green Tea and L-Theanine

Green tea, particularly Camellia sinensis, is a Chinese tea variant acclaimed for its health benefits and antioxidant properties. It has gained worldwide popularity due to its potential health benefits[1]. The tradition of tea drinking was first introduced by Chinese King Shen Nung in 2737 BCE when tea leaves accidentally fell into boiling water, resulting in a pleasant aroma[4].

Green tea leaves are rich in antioxidative catechins[5]. These catechins offer a multitude of health benefits, including anti-inflammatory, antiarthritic, anticarcinogenic, anti-cancerous, antimutagenic, antibacterial, antiviral, antifungal, anticoccidial, antiprotozoal, antiparasitic, anti-infective, hypocholesterolemic, resistant to capillary blood congestion, and hypolipidemic effects[6][7][8].

The Discovery of L-Theanine

L-theanine, also marketed as Suntheanine™, is a distinctive non-protein amino acid discovered in 1949 in the leaves of green tea, specifically Camellia sinensis[1]. This discovery underscored the unique attributes of L-theanine, which significantly contributes to the umami taste and unique flavor of green tea infusion[2]. It imparts a caramel flavor and an appealing aroma that helps mitigate the astringency of tea polyphenols and the bitterness of caffeine[3]. These characteristics are part of why L-theanine is often associated with the sense of relaxation that comes from drinking green tea[1].

Technical, safety, and toxicological evaluations have indicated that L-theanine is a safe and non-toxic photogenic food supplement. In fact, L-theanine was chemically synthesized for the first time from aqueous ethylamine and pyrrolidone carboxylic acid, further attesting to its safety and potential for use[4].

L-Theanine and Relaxation

L-theanine can reach the brain within 30 minutes without any metabolic change when administered to rats[1]. It acts as a neurotransmitter in the brain and can significantly decrease blood pressure in hypertensive rats[1]. The generation of alpha waves in the brain is considered an index of relaxation. In human volunteers, alpha waves were generated on the occipital and parietal regions of the brain surface within 40 minutes after the oral administration of L-theanine (50–200 mg), signifying relaxation without causing drowsiness[1].

L-Theanine and Stress Reduction

The oral intake of L-theanine could cause anti-stress effects via the inhibition of cortical neuron excitation[3]. L-theanine intake resulted in a reduction in heart rate and salivary immunoglobulin A responses to an acute stress task relative to the placebo control condition[3]. This suggests that L-theanine could have anti-stress effects[3].

Matcha tea cup and Uji leaves with L-Theanine chemical structure, showcasing the amino acid content.

L-Theanine in Uji Matcha Tea

L-theanine constitutes approximately 1 to 2% of the total dry weight of green tea leaves, with one cup of green tea containing about 8 to 30 mg of theanine [4]. This makes Uji Matcha tea a significant source of this beneficial amino acid.

Bioavailability and Absorption

Upon consumption, L-theanine is readily bioavailable and is quickly absorbed in the intestinal tract, followed by its metabolism in the liver[4]. The source of L-theanine and the matrix in which it is administered might impact its pharmacokinetics and absorption rate[4].

Synergistic Effects with Caffeine

In conjunction with caffeine, L-theanine may have a synergistic positive effect on attention[4]. This has been measured in EEG studies between 30 and 120 min, and in a behavioral study after 60 min following L-theanine plus caffeine consumption[4].

Image depicting the health benefits of L-Theanine with a meditative figure and scientific research symbols.

Health Benefits of L-Theanine

L-theanine has several bioactivities including anti-cerebral ischemia-reperfusion injury, stress-reducing, antitumor, anti-aging, and anti-anxiety activities[5][6]. It has influential effects on lifestyle-associated diseases, such as diabetes, cardiovascular disorders, hypertension, stress relief, tumor suppression, menstruation, and liver injury[6].

Antioxidant and Anti-inflammatory Effects

Various teas and herbs have been found to have antioxidant and anti-inflammatory effects[5]. L-theanine exhibits strong antioxidant-like properties and contributes to the favorable umami taste sensation[7].

Antimicrobial Activities

Tea polyphenols have been found to have antimicrobial activities[5]. Green, black, and herbal teas of Camellia sinensis have been found to have antioxidant and antibacterial properties[5].

Cognitive and Mood Effects

L-theanine and caffeine, both in isolation and in combination, have been found to have significant cognitive and mood effects[3]. The combination of L-theanine and caffeine led to faster simple reaction time, faster numeric working memory reaction time, and improved sentence verification accuracy[3]. 'Headache' and 'tired' ratings were reduced, and 'alert' ratings increased[3]. There was also a significant positive caffeine and L-theanine interaction on delayed word recognition reaction time[3].

The Production of L-Theanine

L-theanine can be obtained by chemical synthesis or isolation from tea[6][2]. However, the biological production of L-theanine has recently attracted much attention[2]. Four kinds of bacterial enzymes, including L-glutamine synthetase, γ-glutamylmethylamide synthetase, γ-glutamyltranspeptidase, and L-glutaminase, have been characterized to have L-theanine-producing ability[2].


The diverse health benefits of L-theanine provide a basis for designing in-depth studies related to the onset and progression of cognitive disorders, particularly in older individuals[8]. The effect of L-theanine on the autonomous nervous system and CNS under different stresses requires further investigation[8].

Uji Matcha tea, with its high content of L-theanine, offers a delicious and natural way to harness these benefits. Whether you're looking to enhance your cognitive function, manage stress, or simply enjoy a cup of high-quality green tea, Uji Matcha tea is a great choice.

The science of L-theanine and its health benefits is an exciting field of study. As we continue to learn more about this unique amino acid and its effects on human health, it's clear that Uji Matcha tea, with its high L-theanine content, is more than just a delicious beverage—it's a natural source of wellness and relaxation. Whether you're looking to enhance your cognitive function, manage stress, or simply enjoy a cup of high-quality green tea, Uji Matcha tea is a great choice[1][7][8][2][3][4][5][6].

Be sure to check out our YouTube video on this topic, and thanks for stopping by!

Subscribe to this blog's RSS feed using http://premium-health-japan.myshopify.com/blogs/news.atom


[1]: [Green tea, specifically Camellia sinensis](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2855614/)
[2]: [The unique properties of l-theanine](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3518171/)
[3]: [L-theanine and stress reduction](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4728665/)
[4]: [L-theanine in Uji Matcha tea](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4787341/)
[5]: [Health benefits of L-theanine](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4137549/)
[6]: [The production of L-theanine](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6366437/)
[7]: [Antioxidant and Anti-inflammatory Effects](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6528221/)
[8]: [Conclusion](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7023169/)