Higher levels of chocolate consumption were associated with a reduction of about a third in the risk of cardiometabolic disorders in our meta-analysis. This beneficial association was significant for any cardiovascular disease (37% reduction), diabetes (31% reduction, based on one publication), and stroke (29% reduction), but no significant association was found in relation to heart failure.
[however]...the high sugar and fat content of commercially available chocolate should be considered, and initiatives to reduce it might permit an improved exposure to the beneficial effect of chocolate. (doi: 10.1136/bmj.d4488 Published 29 August 2011).
In short, chocolate is good for you if it contains just a little bit of sugar and no added milk fat.
Though the history of drinking a cacao beverage goes back to 500 AD, today's solid chocolate is a fairly recent invention.
In 1828, Dutch chocolate maker Casparus J. van Houten patented an inexpensive method for pressing the fat from roasted cacao beans. Van Houten's machine -- a hydraulic press -- reduced the cocoa butter content by nearly half. This created a "cake" that could be pulverized into a fine powder known as "cocoa."
The introduction of cocoa powder not only made creating chocolate drinks much easier, but also made it possible to combine chocolate with sugar and then remix it with cocoa butter to create a solid. In 1849, English chocolate maker Joseph Storrs Fry produced what was arguably the world's first eating chocolate.It's interesting to observe the evolution of chocolate products and manufacturing processes. From a rare bitter drink to a popular sweet drink to a mass market packaged sugar+fat bar, with a wide variety of added ingredients.