Most of the health benefits associated with dark chocolates lie in their rich concentration of flavanols. Cocoa contains flavanols that are also naturally found in other foods like teas, red wines, fruits, spices, and nuts. Flavanols have antioxidant properties that promote heart health and reduce your risk of stroke and heart disease. They also reduce oxidative stress in your system.  

According to a 2017 study published in The Journal of the American Heart Association, consuming almonds, dark chocolate, and cocoa was linked with lowering bad cholesterol or low-density lipoproteins (LDL). Cocoa consumption was tied to reducing your risk of diabetes in another 2017 study published in Appetite. 

Additional benefits of consuming dark chocolate have to do with warding off cancer and boosting brain health. A 2018 study published in The Federation of American Societies for Experimental Biology Journal found that eating dark chocolate with 70% cacao was linked with a positive influence on stress levels, inflammation, mood, memory, and immunity. The magnesium and flavonoid epicatechin found in dark chocolates are also thought to help combat cancer. Observational, yet interesting, studies involving an isolated tribe off the Caribbean Coast of Panama, called the Kuna Indians, are also referred to concerning dark chocolate. According to the senior scientific director of epidemiology research at the American Cancer Society, Marji McCullough who visited the tribe, this group of people consumes four cups of cacao mixed with water and a bit of sugar every day (via BBC). They had low blood pressure, few cases of heart attacks, strokes, diabetes, and cancer, and no early death.