The lore surrounding chocolate -- from its use as an aphrodisiac among the Aztecs to its mood elevating properties -- can seem as complex and variable as the confection itself. Scientific studies, however, may provide a prudent excuse to indulge in the sweet treat.
Decades of research have shown that chocolate has several beneficial physiological effects, most notably on heart health.
A new study presented today at the International Headache Congress meeting in Philadelphia suggested that cocoa powder has a healing effect on inflamed cells related to migraine headaches in rats.
But many of the studies on chocolate are inconclusive, showing neither significant health advantages nor disadvantages. And the results of today's IHC study on cocoa powder contradicts previous theories that chocolate triggers migraines in some people.
While research continues, so does chocolate consumption. Parsing chocolate fact from fiction could be the key to guilt-free snacking.
"It's reasonable for a natural food, reasonably unrefined, to have some good qualities to it," said Keith-Thomas Ayoob, director of the nutrition clinic at the Albert Einstein College of Medicine in New York City. "Most people are probably already realizing these benefits."
Dark chocolate, which should be at least 60 percent cocoa by weight, is one of the richest sources of the bioflavonoid antioxidants that counteract cell damage.
Dr. David Katz, director of the Prevention Research Center at Yale University, said part of the reason why so many people love chocolate is because eating it stimulates the brain's pleasure centers. The xanthine compounds in chocolate -- a group of chemicals that includes caffeine -- aid that reaction.
"It's absolutely magic food," Katz said. "Because it's so good, it almost feels a little naughty."
Milk chocolate, which contains a much lower percentage of cocoa, confers less than half of the benefits of dark chocolate and white chocolate has no such health benefits because it lacks cocoa.
And there has been compelling evidence that eating dark chocolate has positive cardiovascular effects. Studies have found that chocolate can lower blood pressure, reduce the risk of blood clots and improve blood flow through veins and arteries in humans.
A study in the September issue of the Journal of Internal Medicine showed that heart attack survivors can reduce their risk of a second heart attack by eating chocolate several times per week.
But experts caution that if chocolate is eaten in large amounts, its fat and calorie content could negate the positive effects of its antioxidants and other chemicals.
"If we're going to make this a 'food as medicine' [issue], the public does need guidance," Katz said. "Some is good for you, more is bad for you ... there is a sweet spot in a certain range, like alcohol."
But some may continue to avoid chocolate due to its reputation for triggering migraines in some people who may be sensitive to the chemicals.