Over the past decade or so, scientific evidence linking chocolate with health benefits have trickled out in scientific journals and made the news. Here are some of the purported benefits and links to some of the research.
Generally, Dark Chocolate has more of the benefits and fewer of the additional unnessecary ingredients that are believed to be less healthy.
Chocolate is rich in "catechins, which are polyphenols of the flavanol group".  These flavanols may lower blood pressure and reduce cholesterol. There is also some evidence that chocolate may lower your risk of cancer or stroke.
- Some people have allergic reactions to chocolate.
- Chocolate contains phenylethylamine, theobromine, and caffeine. Theobromine can be poisonous to dogs and cats.
- Chocolate is often mixed with less healthy ingredients such as sugar, fat and high frutose corn syrup.
- Chocolate's Potential Health Benefits – and its Effect on Chronic Fatigue Syndrome Patients by Patti Schmidt, includes references to scientific journal articles
- Chocolate & Cocoa: 'Healthy' Benefits, or Negative Health Effects?, considers which studies were funded by chocolate interest groups
- Sweet Science: The Health Benefits of Chocolate By Rachael Rettner
- WebMD on Dark Chocolate Is Healthy Chocolate: Dark Chocolate Has Health Benefits Not Seen in Other Varieties By Daniel J. DeNoon