White tea is a more delicate and smoother version of green tea. This is the famous 'slimming tea' that we sometimes hear of. It is slimming because it slightly raises the metabolic rate but tea also causes fat to be stored differently within the body.
White tea is, of course calorie free because it is drunk without milk. An additional advantage is that it has powerful anti cancer properties. All tea is good against cancer- but milk tends to neutralise the good effects so white and green teas are far more healthy than black.
Do not expect miracles from white tea- and do not pay too much for it! There are some people selling green tea as a miracle cure and it is certainly not that.
White tea is only really useful if you stick at it.