Well, the cocoa from which the dark chocolate is made, has phenols (carbolic acid), which lowers blood pressure.
You can read about the studies the the Aug. 2003 issue of Nature magazine.
According to my chocolatier course teacher, the thing we should remember is that the darker chocolate is, the better.
We can find various kinds of dark chocolate, often marked with the percentage of "chocolate" in it. So if we buy a bar with 55% dark chocolate, what are the other 45%? The answer is sugar.
A 99% dark chocolate will have only 1% of sugar, and that is why it is healthier but less tasty, and I recommend eating it in very small pieces with a cup of coffee to balance the bitterness.
I really like 70% for eating and 85% for cooking.
Remember that when mixed with milk, the chocolate loses its antioxidant feature, so it is better not to mix. That is why milk chocolate isn't healthy at all.
White chocolate is the worse, because it doesn't have cocoa. Only cocoa fat, which is seperated from the cocoa itself.
Most important is to remember that even the healthy chocolate can make you fat, so despite the healthy features, eat moderately... :)
