The leaves of camellia sinensis – a perennial evergreen shrub are allowed to dry and oxidize and black tea is made out of these dried leaves. Tea has a long history and served as a part of various ceremonies. Many people use tea to stay alert and awake as it contains caffeine that is a stimulant. Black tea is a good source of caffeine, depending on the strength and size of a cup, approximately 1 cup tea contains 50 milligrams of caffeine. Caffeine a methylxanthine is a potent diuretic, stimulates the heart, stimulates central nervous system, and relaxes smooth muscles in the airways to the lungs. Tea plant is native to Southeast Asia and maintained at a height of two to three feet by regular pruning but it has an ability to grow up to forty feet.
India and Sri Lanka are the primary producers of black tea.
Health and black tea
Black tea contains tannins, trace elements, polyphenols like catechins, anthocyanins, phenolic acids, and certain vitamins. The following health benefits are based on many unclear scientific evidences; however more research is needed in all these areas to prove its efficacy.
Caffeine present in black tea helps to improve airflow into the lungs (bronchodilator), but its benefits for asthma cure in patients remains unclear.
The polyphenols present in tea have antioxidant properties that helps fight cancer tumors. But it is a subject of controversy as some research also proves that some components of black tea can be carcinogenic.
Black tea may reduce the risk of platelet aggregation or endothelial dysfunction and may prove beneficial for patients with heart diseases and can be used for heart attack prevention.
Black tea can be used as a mouthwash for prevention of dental carries. It may also improve oral leukoplakia and prevent oral carcinoma.
Prolonged use of black tea may help to improve bone mineral density in older women.
Studies on black tea side effects are limited; the ones that are reported are with multiple reactions due to caffeine in tea.
Tannins in tea inhibit iron absorption and can lead to iron deficiency and may have carcinogenic effects. Tannins can also lead to constipation in some individuals.
Black tea should be used with a word of caution for pregnant and nursing ladies as caffeine tends to cross the placental barriers and is associated with spontaneous abortions or birth defects; it also passes through breast milk leading to insomnia, tremors and heart rhythm abnormalities. Conception may also be delayed if high levels are consumed.
High levels of caffeine can cause psychological dependence, increase the blood sugar levels, can cause insomnia, increase stomach acidity worsening ulcer symptoms, increase heart rate and blood pressure.
Black tea should be taken under recommended doses as higher doses can be fatal. Talk to a health care professional before starting it as it may also cause interaction with certain drugs, herbs or other dietary supplements.