We are no researchers in the medical field and highly recommend you to rely on professional sources for the health-benefits of tea. The information published here is mostly coming from the following website: http://www.teahealth.co.uk

" ... Research is now suggesting that antioxidants, such as those found in both green and black tea, may have a protective role to play in certain conditions such as heart disease, stroke and some cancers ..." . There is also a speculation that green tea has a positive role in the skin care , weight loss and oral health, but for these further research are still needed for a confirmation.

As to the question "which tea is best" it seems that the benefits of either green, oolong and black teas are comparable, with maybe a little favor for green tea. The choice is more a matter of taste, but obviously here too further research is still needed.

But one thing is certain: the better the quality of the tea, the better for you!