More than a decade ago researchers discovered that some of the peoples of Panama, namely the Kuna, had very low blood pressure, even when elderly. The Kuna live on some small Caribbean islands and drink a fair amount of cocoa every day as a part of their spiritual rituals. And it was assumed that the cocoa drinking was the reason for the Kuna's lower blood pressure. In fact, Mars Inc funded a study investigating the benefits of cocoa, using the Kuna as the basis of their research. And the studies done found there were indeed health benefits to consuming cocoa and chocolate. Some years later, the results of various studies were touting the benefits of antioxidant flavanols found in raw cocoa beans, and therefore, placed chocolate in the list of beneficial super foods. Something people should be consuming several times a week.

Well, great! That's not bad news. Flavinols are good for us.... but, what are "flavanols"?
According to Wiki:
Flavonoids (specifically flavanoids such as the catechins) are "the most common group of polyphenolic compounds in the human diet and are found ubiquitously in plants".[47] Flavonols, the original bioflavonoids such as quercetin, are also found ubiquitously, but in lesser quantities. The widespread distribution of flavonoids, their variety and their relatively low toxicity compared to other active plant compounds (for instance alkaloids) mean that many animals, including humans, ingest significant quantities in their diet. Foods with a high flavonoid content include parsley,[48] onions,[48] blueberries and other berries,[48] black tea,[48] green tea and oolong tea,[48] bananas, all citrus fruits, Ginkgo biloba, red wine, sea-buckthorns, and dark chocolate (with a cocoa content of 70% or greater). Further information on dietary sources of flavonoids can be obtained from the US Department of Agriculture flavonoid database.[48] Also, the Peanut red skin.

And these flavaoids  have been shown to have a wide range of health benefits in vitro, a fancy term for in an artificial environment outside of the human body. Such benefits include: anti-allergic, anti-inflammatory, antioxidant, anti-microbial, antifungal, and antiviral, as well as anticancer and anti-diarrheal. It is important to note that none of the in vitro studies have involved human subjects, and so can not be relied on to prove that these flavaniods work just as well in humans. For our discussion, the most pertinent part of flavanols are the ones found in tea, coffee and chocolate. These are known as catechins
The catechins are abundant in teas derived from the tea plant Camellia sinensis, as well as in some cocoas and chocolates[2] (made from the seeds of Theobroma cacao). Catechins are also present in the human diet in fruits, vegetables and wine,[3] and are found in many other plant species, as well as cocoa.[4][5
You will note that these catechins are found mostly in tea, coffee and some cocoas. And the Kuna were using that kind of cocoa. So the scientists from Mars. Inc. took samples of the cocoa beans from around where the Kuna lived, ground the beans, and tested them. The results showed that indeed the cocoa beans had good supplies of flavanols, and therefore should be beneficial to people.
Sadly, that is not proving to be the case. The flavanols that are so apparent in raw cocoa beans are not there in cocoa or chocolate. Heating the beans, roasting them as is commonly done to make cocoa, destroys most of the flavinols. Our delicious superfood becomes simply a treat that has little nutrition and too much sugar.

So how did Mars Inc manage to get such good results from their tests with cocoa powder? That's apparently a secret. They also never told the public that.
But those flavanols largely disappear once the cocoa bean is heated, fermented and processed into chocolate. In other words, making chocolate destroys the very ingredient that is supposed to make it healthy.  
That’s why Small’s memory study used a highly concentrated powder prepared exclusively for research by Mars Inc., the chocolate company, which also partially funded the study. 
"It is not a commercially available product," said Catherine Kwik-Uribe, the scientific director at Mars Inc. "It’s actually very difficult for an average consumer today to get the flavanol levels that we see are needed in order to produce some of the effects."
This study and the lack of transparency has raised some disturbing questions about the role of private interests and companies who fund research, and just how much influence these companies have over not just the results, but the aims and focus of the research itself and what findings are published.   The other thing I should note is that since heat destroys flavanols, then all flavanols found in other sources, such as fruits and vegetables will be similarly destroyed by heating the veg or fruit. In other words...if you want the health benefits from flavanols, you have to eat your fruits and veggies raw and soon after picking. A general rule of thumb; any fruit or veggie should be eaten before they're two weeks old.

[ And as for Mars, Inc.? "how did Mars Inc. manage to get such good results from their tests with cocoa powder? That's apparently a secret. They also never told the public that."  Because, that is the way of science isn't it? Secrecy and not letting others test your results. And the company did not tell the public. Hmmm, they cannot be blamed but who told the public. Was it "scientists"? How do I know when a scientist is a scientist? When you think about it long enough you want to put a pox on Mars or a pox on science... or perhaps the media.  ...or piss on all of them because none adequately policed themselves in morality. ]