Matcha powder is extremly popular today and is used in various beverages, desserts, soups and dressings. It is obtained from leaves of the tea tree plant (Camellia sinensis) and is considered the most aromatic of green teas. The tea plant from which the powder is made is grown in the shade and therefore has a higher concentration of therapeutic components such as theanine, chlorophyll and viramin C than green tea. 
Matcha powder is rich in numerous antioxidans such as catechins, caffeine, phenolic acid, rutin, quercetin, vitamin C and chlorophyll. The amino acid theanine is also found in the powder. Caffeine and catechins neutralize free radicals and increase the activity of enzymes: glutathione peroxidase, catalase and glutathione reductase. Caffeine and phenolic acid are anti-inflammatory agents, phenolic acid also shows hypoglycemic effects. Quercetin has neuroprotective effects, and vitamin C improves the body’s immune system. Due to the plants growth in the shade it contains an increased concentration of chlorophyll and theanine1. Theanine together with arginine reduces stress symptoms. 
Matcha powder and SARS-CoV-2
Experiments have shown that epigallocatechin gallate, theasinensin A and theaflavins found in the tea tree plant reduce the infectivity of SARS-CoV-2 virus. These results show the potential benefit of tea in preventing person to person transmission of the virus. However to confirm the significance of these findings for humans further studies need to be conducted, especially since it has already been established that intestinal microflora metabolises catechins and flavins so the absorption to the bloodstream is minimal. 
Do cookies with matcha powder reduce stress?
The positive stress reducing properties of matcha drinks have already been determined, since nowadays matcha powder is added to various desserts researchers were curious to see whether matcha cookies show the same stress reducing effect. Study participans consumed three cookies per day for a period of 15 days and already then were the positive effects of matcha cookies in reducing stress and anxiety evident. 
The health benefits of matcha powder have been scientifically proven and its usage is safe, however it should be noted that the beneficial effects depend on the quality of the powder. The powder is rich in caffeine, so the usual caution is recommended for pregnant women, nursing mothers and children.
Translated by Patricia Štriga
2. Unno K, Furushima D, Hamamoto S, Iguchi K, Yamada H, Morita A, Horie H, Nakamura Y. Stress-Reducing Function of Matcha Green Tea in Animal Experiments and Clinical Trials. Nutrients, 2018, 10, 1468.
3. Ohgitani E, Shin-Ya M, Ichitani M, Kobayashi M, Takihara T, Kawamoto M, Kinugasa H, Mazda O. Significant Inactivation of SARS-CoV-2 In Vitro by a Green Tea Catechin, a Catechin-Derivative, and Black Tea Galloylated Theaflavins. Molecules, 2021, 26, 3572.
4. Unno K, Furushima D, Hamamoto S, Iguchi K, Yamada H, Morita A, Pervin M, Nakamura Y. Stress-reducing effect of cookies containing matcha green tea: essential ratio among theanine, arginine, caffeine and epigallocatechin gallate. Heliyon, 2019, 5, e01653.