Health Effects of Matcha (Tencha Green Tea Powder)
Matcha, the vibrant green powdered tea used in traditional Japanese tea ceremonies, is considered the highest quality tea available in Japan. Matcha (sometimes spelled mat-cha) comes from the same Camellia sinensis plant as all other tea varieties including green, black, oolong, white and pu-erh tea. However, the growing and processing procedures used to make matcha are quite different from those of other teas. Not only do these procedures give matcha its subtle sweetness, they also contribute to the unique health benefits of matcha green tea powder.
The production of matcha involves covering the tea plants with bamboo mats a few weeks before the harvest in spring. The lack of light causes the tea leaves to turn dark green and to produce large amounts of the health promoting amino acid theanine. After harvesting, the dark green tea leaves are steamed and then laid out flat and left to dry. Once dried, the leaves are sorted for grade, and then destemmed and deveined. These dried green tea leaves, known as tencha (or ten-cha), can be used as such to brew high quality green tea, or they can be stone-ground to produce the fine, green tea powder we know as matcha. Grinding matcha is a time-consuming process, and it can take up to one hour to grind 30 grams of matcha.
While the unique procedures used to produce powdered tencha contribute to the health effects of matcha, they are not the only thing that sets matcha apart from other tea products in terms of health benefits. When matcha powder is used as a basis for tea or as an ingredient in smoothies, noodles or baked goods, the entire leaf is consumed. As a result, drinks and foods containing matcha are a more concentrated source of green tea polyphenols and nutrients than infused green tea. If you are interested in learning more about cooking with matcha, read our article on matcha uses.
To learn more about the health effects of matcha powder, continue reading. This article is structured along three sections:
Matcha contains L-theanine, commonly referred to as theanine, which is a health promoting amino acid found almost exclusively in tea plants (other foods that contain theanine include bay bolete mushrooms and certain flowering plants in the genus Camellia)1. Evidence suggests that theanine in tea plants may be able to boost immunity and prevent infections by improving the disease-fighting capacity of gamma delta T cells2.
Theanine is also responsible for the relaxing effects of matcha and green tea. These relaxing effects, which are usually experienced within 40 minutes after the ingestion of theanine, are largely attributed to the ability of theanine to directly stimulate the production of alpha brain waves. Generation of alpha brain waves is considered to be a sign of mental relaxation.3 Theanine also appears to play a role in the formation of gamma amino butrylic acid (GABA), which may further contribute to the relaxing effects of theanine-containing products such as matcha powder and brewed green tea. GABA is a neurotransmitter that has been shown to influence the release of the neurotransmitters dopamine and serotonin.4 In addition to facilitating relaxation, theanine in matcha powder may be able to decrease high blood pressure3, improve memory and learning ability5, and even help prevent Altzheimer's disease6.
One study that compared the theanine content of Japanese teas found very high levels of theanine in ceremonial-grade matcha made from Japanese gyokuro tea, with 100 grams of this type of matcha providing 2.41 milligrams of theanine (dry weight).4Continue to Part 2
1. Mason R (2001). 200 mg of Zen — L-theanine boosts alpha waves, promotes alert relaxation. Alternative Complementary Therapies, 7, 91-95
2. Kamath A, Wang L, Das H et al. (2003). Antigens in tea-beverage prime human Vgamma 2Vdelta 2 T cells in vitro and in vivo for memory and nonmemory antibacterial cytokine responses. Proceedings of the National Academy of Sciences USA, 100(10), 6009-14
3. Juneja LR, Chu DC, Okubo T, et al. (1999). L-theanine — a unique amino acid of green tea and its relaxation effect in humans. Trends in Food Science & Technology, 10(6-7), 199-204
4. Du Rand EE (2009). Identification of digallated and methylated catechins using UPLC/MS/MS and development of a rapid analysis method for theanine in tea [Camellia sinensis (L.) O. Kuntze) utilizing evaporative light scattering detection. University of Pretoria
5. Yamada T, Terashima T, Honma H, et al (2008). Effects of Theanine, a Unique Amino Acid in Tea Leaves, on Memory in a Rat Behavioral Test. Bioscience, Biotechnology, and Biochemistry, 72(5), 1356-1359
6. Kim T, Kee YK, Park SG, et al. (2009). L-Theanine, an amino acid in green tea, attenuates β-amyloid-induced cognitive dysfunction and neurotoxicity: Reduction in oxidative damage and inactivation of ERK/p38 kinase and NF-kB pathwaysFree Radical Biology and Medicine. Free Radical Biology and Medicine, 47(11), 1601-1610