The Kuna are a group of indigenous people living along the coast of Panama who for the most part live as their ancestors did, hunting and fishing. However, some have moved to Panama City. The Kuna stand out in the medical literature because they have no age-related increase in blood pressure; 60-year-olds have the same blood pressure as 20-year-olds - that is, as long as they stay out of Panama City.
In 2006, Harvard researchers explained the Kuna's apparent "immunity" to hypertension. Island-dwelling Kuna drink large quantities of flavanol-rich cocoa on a daily basis (5 cups or more) and incorporate it into numerous recipes. On the other hand, Kuna who live in the city consume far less cocoa, and what they do consume is commercially produced and thus has little flavanol content.

Chocolate also decreases blood markers of vascular inflammation and improves cholesterol levels. A 2008 paper published in the Southern Medical Journal reported that after one week of eating a daily dose of chocolate providing 700 mg of flavanols, subjects' low-density lipoprotein cholesterol levels (the "bad cholesterol") fell by 6 percent and their high-density lipoprotein cholesterol (the "good cholesterol") rose by 9 percent.

But wait, there's more. London researchers gave chocolates to 30 healthy volunteers, half of whom ate a high-flavanol chocolate while the others ate a low-flavanol chocolate. A minimal erythema dose (MED), a measurement of how much sun exposure it takes to trigger a sunburn reaction, was calculated at the start of the experiment and again three months later. Volunteers who ate the regular chocolate had no change in sun sensitivity. But in those who ate the high-flavanol chocolate, the length of time it took for their skin to start to "burn" more than doubled. In other words, they could tolerate twice the sun exposure without burning as before they started eating the chocolate.

Two major companies claim to have figured out how to preserve the flavanols in chocolate. One is the Belgium chocolate manufacturer Barry Callebaut, who has developed a special refining process marketed under the brand name Acticoa. This brand of chocolate has been used in most of these recent research papers. Callebaut does not currently sell its chocolate in North America, though a rumor hints that it will introduce it to the U.S. market this summer.

The other company marketing high-flavanol chocolate is part of the Mars candy company and sells their product under the brand name CirkuHealth. This product line replaces Mars' older specialty brand called CocoaVia, which was manufactured and sold for about 10 years, but discontinued in 2009.]