Black and green have origin from the same evergreen bush tea tree Camellia sinensis. It’s an evergreen shrub-like tropical plant. The bushes are planted in large tea gardens. The Chinese have found that cultivation in different regions get different flavors of tea, depending on the technological process. Black tea leaves to be completely oxidized, while the leaves of green tea exhibited steam (in order to inhibit the enzymes of the fermentation), and then dried. Black tea is grown on plantations in India, Sri Lanka and Africa, and green in Japan and China. Of the total tea consumed about 78% are black tea, and green to about 20%.
Health benefits of black tea
Studies have shown that black tea considerably slows down the development of cancer. Scientists have conducted research on more than 500 people and proven that flavonoids in black tea reduce the production of harmful cholesterol, and thus markedly reducing the risk of stroke and heart attack. It also helps with diarrhea, improves the function of blood vessels, is used for headaches, improves mental ability, memory, learning, helps with kidney stones, keeps people awake, helps with weight loss when used with other products, reduces symptoms of the Parkinson disease.
Several studies claim that black tea can be helpful in the treatment of diabetes and diabetes-induced cataracts. Another extensive research says that there is clear evidence that drinking three or more cups of black tea a day reduces the risk for the occurrence of cardiovascular disease, which is linked to the action of polyphenols, antioxidants that this tea possesses.
Interesting health studies
One preliminary study found that black tea can have both positive and negative effects. Certain substances in black tea cause arterial stiffness, which increases the risk of hypertension, while other substances relaxes blood vessels. Haralambos Vlassopulos, from the University of Athens, Greece, believes that the caffeine in black tea causes arterial stiffness, while on the other side, flavonoids induce relaxation of arteries.
A study of people who drank large amounts of caffeine (an average of 560 mg of caffeine daily) showed that when they stopped to drank products with caffeine for two weeks, significantly was reduced the level of triglycerides by 25 %.
In contrast to a study that talks about the positive effects of black tea on recovery from stress, practical experience shows that there are people who have high levels of anxiety, or are very nervous, very sensitive to the effects of caffeine. Therefore, they should avoid all products which have caffeine. It increases gastric acid. And even moderated amounts of caffeine can enhance the symptoms of hypoglycemia. Because of that, people with low blood sugar should avoid products which have caffeine.
Side effects
Caffeine is one of the substances which scientists devote special attention because there are many side effects associated with it. So, referring to the caffeine content in the black tea, it was found that a cup of black tea contains about 40 – 42 mg of caffeine, green tea while, on the other hand, contains relatively low levels of caffeine. One cup of green tea has about 20-22 mg of caffeine. Overconsumption of caffeine by any of these two types of tea may cause many side effects such as restlessness, insomnia, headaches, frequent urination, nausea. So, to avoid these side effects, you should consequently limit the intake.
Precautions
The black tea and other teas need to be in the special containers, like the vessels of porcelain, glass or tin boxes. These containers are hermetically closed. Make sure you keep the tea in a cool and dry place without being affected by moisture (kitchen is a bad place for storing tea). And isn’t recommended to be kept for a long time because is losing much of quality.
Advised daily consumption
Three cups of the black tea every day have a protective effect against cardiovascular disease due to high concentrations of flavonoids, according to a study presented at the cardiology conference in Paris. According to various international studies published over the last years the black tea could play a role in preventing diabetes and obesity but also allow us to reduce the risk of various cardiovascular problems and diseases. According to the studies, the black tea could reduce the amount of cholesterol and triglycerides in the blood, but there is the question of adding sugar and milk which could delete or substantially reduce its use.