Black tea or green tea- which is healthier?

Black tea is more oxidized than the green, oolong tea. Black tea is generally stronger flavor and contains more caffeine than the less oxidized tea.
Actually in China, black tea is known as red tea, not a black tea.

Until recently, tea research has focused on green tea. Green tea is loaded with the compound epigallocatechin gallate ,a powerful anti-oxidant. Since the fermentation process used to make black tea converts EGCg into other compounds, researchers assumed black tea had less health benefits than green tea. However, recent studies indicate the compounds contained in black tea do more than contribute to its dark color and distinctive flavor. They also provide health benefits originally attributed solely to green tea.

What are benfits about black tea?

Black tea has a lot of polyphenols, so it can make people younger than now, and black tea can protect our body from several diseases, like heart attack, immune system disease and several cancer. In addition, black tea can reduced risk of stroke because health benefits of foods contain high flavonoids which were obtained from fruits and vegetables, seventy percent came from black tea. Finally, black tea can help our diet. Black tea is low calories, and they offer essential nutrient like vitamins and essential amino acids.