Products
Black tea is available in grocery stores and specialty stores in bags or open. Different varieties, names and countries of origin exist (e.g. Darjeeling, Ceylon, Pekoe, Assam, English Breakfast Tea, Five o’Clock Tea, Afternoon Tea). Black tea is mainly drunk in the West, while green tea and the semi-fermented oolong tea are more popular in Asia. It is often blended and flavored, such as Earl Grey with bergamot. Also from black tea, iced tea is prepared with lemons and sugar.
Stem plant
The parent plant is the evergreen tea plant of the tea shrub family (Theaceae), native to Asia. It grows into a shrub or a tree.
Medicinal drug
The black tea leaves (Theae nigrae folium) are used as medicinal raw material, the wilted, rolled, crushed, fermented (oxidized) and dried young leaves next to the leaf bud of . Green tea and white tea are not fermented and oolong tea is fermented for less time.
Ingredients
The ingredients of black tea include (selection):
- Methylxanthines: caffeine (formerly: “theine”), theobromine, theophylline.
- Polyphenols: Flavonoids: theaflavins and thearubigens, catechins.
- Tannins
- Phenolic carboxylic acids
- Flavoring agents
- Minerals (e.g. potassium), trace elements (e.g. fluoride) and vitamins
- Amino acids such as L-theanine
The caffeine content is lower than that of coffee:
Effects
Black tea has stimulating effects due to the caffeine it contains and it keeps you awake. It additionally also has antioxidant, astringent, antitumor, anticariogenic, antimicrobial, and other health-promoting properties and is considered healthy. Black tea can possibly help prevent cardiovascular disease, obesity and cancer.
Indications for use
- As a stimulant.
- As a stimulant against fatigue and drowsiness.
- For the treatment of diarrhea (tannins).
- For the supportive treatment of obesity (prepare without milk).
- For mouth rinses, for example, in case of inflammation of the oral mucosa.
- As a home remedy for conjunctivitis (compresses, washes).
Dosage
- As a stimulant, steep in hot water for two to five minutes (caffeine).
- For diarrhea, infuse in hot water for ten minutes (tannins).
Interactions
Black tea should not be consumed at the same time as medications, as it can reduce their absorption and thus bioavailability. A typical example of this interaction is the binding of iron.
Adverse effects
At a high dosage, the adverse effects of caffeine are observed. Other possible side effects include gastrointestinal symptoms such as constipation. Black tea is usually better tolerated than coffee.
