Black tea is the same as green tea except that the black tea has been allowed to oxidize. This oxidation does cause it to have different effects as a supplement. This is the common tea that in Texas we use as ice tea, but it is also commonly used for a hot tea.
A. Black tea for energy and alertness
Black tea is well attested to as a supplement for alertness and energy. This attestation has been validated by scientific research. It works in this regard because it contains a large supply caffeine. Depending on conditions it may even have more caffeine than coffee.
This tea also has theophylline, which does some stimulating also. In combination of caffeine and theophylline black tea can increase up your heartbeat and also affect more alertness.
B. Black tea as an Antioxidant
Now we are talking polyphenols. Black tea is stuffed full of these healthy elements. These substances, antioxidants, are good for protecting your cells, especially your DNA from damage.
Scientific researchers think that the kind antioxidants we see in black tea, which includes polyphenols and catechins, can aid in preventing some types of cancer. Consider this; the research points us to the conclusion that women who regularly drink black tea manifest a sharply lower risk of ovarian cancer compared to women who do not.
This may not apply to other cancers risk, but that is just to say that that research has has not been done or I have not noticed it yet in my searchings.