The article 'Dark Chocolate Health Benefits' written by Jason Katz published on the site 'Popcorn for the people' claims that Dark Chocolate has health benefits. The article uses a reliable source being that from Harvard: (https://hsph.harvard.edu/news/dark-chocolate-health-flavonoids/) which explains how dark chocolate could be a good choice for health but should not be an alternate for medication and should be eaten in moderation.
According to a long-running trial called, 'Cocoa Supplement and Multivitamin Outcomes' Study done at Brigham and Women's Hospital which is an affiliate of Harvard Medical School did a clinical trial with the Fred Hutchinson Cancer Research Center (Seattle,WA) where they randomized 21,442 men and women across the United states to participate in their research which investigated whether "taking daily cocoa extract supplements containing 500 mg/day cocoa flavanols or a common multivitamin reduces the risk for developing heart disease, stroke, cancer, and other important health outcomes." (https://cosmostrial.org/) They found out that while cocoa supplements didn't reduce heart attacks directly as whole they did reduce heart-disease related deaths.
The article by Harvard states that cocoa powder contains flavonoids, substances that are full of antioxidants and may help lower the risk of some chronic diseases and improve mental cognition and mood. This is true and can be backed up by NIH--"This is attributed to their anti-oxidative, anti-inflammatory, anti-mutagenic and anti-carcinogenic properties coupled with their capacity to modulate key cellular enzyme function. Research on flavonoids received an added impulse with the discovery of the low cardiovascular mortality rate and also prevention of CHD." (https://pmc.ncbi.nlm.nih.gov/articles/PMC5465813/)
Dark chocolate is also a great source for vitamins and has a lot of beneficial minerals like iron, magnesium, phosphorus, copper and zinc. However, to absorb the benefits of Dark Chocolate one must consume about 70-80% of cocoa and least amount of sugar. One of the flavonoids is epicatechin and this helps in combating diabetes, what it does is it protects cells and makes them stronger and supports the processes that help the body use insulin better. (https://www.hopkinsmedicine.org/health/wellness-and-prevention/the-benefits-of-having-a-healthy-relationship-with-chocolate#:~:text=Increases%20heart%20health%3A%20The%20antioxidants,and%20death%20from%20heart%20disease.)
Antioxidants that combat radicals are abundant in dark chocolate. In the fight against free radicals, antioxidants like vitamins and phytochemicals like flavonoids and polyphenols are very powerful. Jilian Levy, Senior Writer at Dr. Axe, claims that free radicals are extremely reactive chemicals that hasten the aging process. Additionally, they weaken the immune system, making it less effective at defending us against illnesses. (https://www.hopkinsmedicine.org/health/wellness-and-prevention/the-benefits-of-having-a-healthy-relationship-with-chocolate#:~:text=Increases%20heart%20health%3A%20The%20antioxidants,and%20death%20from%20heart%20disease.)
Flavanols assist reduce blood pressure in addition to increasing blood flow. This is due to the flavanol compound's ability to reduce and restrict LDL's (bad cholesterol) oxidation. In other words, it keeps harmful cholesterol from accumulating around the walls of arteries and obstructing blood flow. (https://www.bannerhealth.com/healthcareblog/teach-me/the-benefits-of-flavanols-in-your-diet#:~:text=Flavanols%20support%20your%20heart%20health,prevent%20cancer%20cells%20from%20surviving.)