Tea, green

The parent plant is the tea bush. Immediately after harvesting, the enzymes are inactivated by hot steam so that no fermentation takes place and the leaves remain green.

There are more than 1000 varieties of green tea. Apart from China, Japan is the main producer of green tea specialties. Well-known varieties in this area are Sencha, Bancha, Kukicha, Genmaicha and the absolute top quality, Gyokuro.

The young, unfermented leaves (green tea - Camelliae sinensis non fermentata folia), which are quickly stabilized by brief heating and then dried, are used phytotherapeutically.

Green tea has been known as a medicinal plant for more than 5,000 years. The oxidized leaves of the tea plant are used to produce an extract rich in active ingredients. The most important ingredient of tea is caffeine (formerly also called tein, teein or thein in connection with tea). Other constituents of tea leaves are catechins such as epicatechin, epicatechin gallate, epigallocatechin and epigallocatechin gallate. With 0,045-0,35% a relatively high aluminium content is found. This is biologically ineffective due to complex binding to catechins. Most of the health-promoting effects of green tea are attributed to the catechins (see below Condylomata acuminata). Catechins are the substances that give tea its bitter taste. They are potent antioxidants with photoprotective properties. They reduce UV-induced oxidative stress and inhibit various cytokines involved in the development of skin carcinomas. Green tea contains more tannins than black tea. Unlike black tea, the tea leaves are not fermented. Due to processing, Camellia sinensis leaves are preferred over the assamica variety for green tea, as the small-leafed, more delicate variety is more suitable. Green tea also differs from black tea in the preparation, taste, ingredients and effects of the infusion.

Caffeine (2 to 4%), theobromine (0.05%) and theophylline (traces); polyphenols (up to 30%): (-)-epigallocatechin-3-O-gallate (EGCG, up to 12%), (-)-epicatechin-3-O-gallate (ECG), catechin tannins, gallotannins, ellagitannins, flavonoids, phenolcarboxylic acids, theanine (amino acid), ascorbic acid, triterpene saponins, minerals and fluorides.

Green tea contains catechins (see below tannins), anti-inflammatory, antiviral (treatment option for condylomata acuminata 10-15% ointment), antimicrobial, antiproliferative and immunostimulant. The polyphenols contained have an antioxidant effect (atherosclerosis, coronary infarction). Green tea extracts are also described as liver protection and strengthening, as well as reducing insulin resistance in type 2 diabetics.

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