It is believed that dark chocolate has health benefits. Is it true, or just wishful thinking, promoted by market forces? Limited studies suggest that cocoa, an ingredient in chocolate, may have health benefits. Researchers in the United States are studying whether concentrated doses of cocoa flavanols can improve health. Thousands of participants are involved, in the study of how cocoa supplements affect everything from eye disease to heart health, cancer risk, and cognitive abilities. (Podcast source: NIH, US Dept of Health, Image courtesy: Wikimedia Commons)