The main reason green tea has such great health benefits, is believed to be because of a type of antioxidant present in it called a Catechin. The specific Catechin present in green tea is one called epigallocatechin-3-gallate (or EGCG for short). This is a very potent antioxidant found in high amounts in green tea but is not found in black tea. This is because black tea is quite highly processed unlike green tea, and during this production process the Catechins in black tea are converted to other things, therefore removing much of the health benefit that's associated with green tea.
Green tea has shown in research to be protective against cardiovascular diseases such as stroke as well as showing it may be protective against neurodegenerative diseases such as Alzheimer's and Parkinson's disease. Many studies have also shown that its consumption could decrease the risk or reduce progression of a variety of cancers too.
For all those of you watching their weight or wanting a nutritional help to weight loss, green tea has shown in many studies to be effective in aiding weight loss as it is shown to increase energy expenditure as well as aiding actual fat loss.
There may even be some hope for people suffering from chronic fatigue syndrome (CFS) with studies showing that green tea could well be effective in helping relieve symptoms of CFS such as tiredness and muscle ache. However so far this benefit has only been shown in mice and not humans, but there is certainly no detrimental effect in its consumption if you are affected by Chronic Fatigue Syndrome.
We do however need to make sure we are drinking enough of it to get these health benefits though, and although an optimal dose has not yet been set, most of the research studies show benefits from drinking 2-3 cups of green tea every day. So get that kettle on and start drinking the green stuff!!!