How healthy is green tea?

Unclear. Green tea may have a significant amount of caffeine in it, which can cause elevated blood pressure or heart palpitations. However, it may provide some health benefits. There are no long term studies available yet about the health benefits of green tea, so proceed with caution.
Antioxidants. Tea is derived from the camellia sinensis tree. The leaves contain antioxidant polyphenols. Studies suggest green tea can assist with glycemic control, have an anti-carcinogenic effect as well as leading to a reduced heart disease death rate.