Dark Chocolate's Heart Health Benefits are Bittersweet

It's Valentine's Day, and chocolate is bound to be around us. We love the stuff, and recent studies suggest it may be one of the foods that loves us back.

In the past few years science has observed that people with a moderate intake of dark chocolate may reduce their risk for developing certain cardiovascular diseases by up to 37 percent. But there's a caveat, the "dark" in "dark chocolate" is not so easy to define. (So here comes the nerdy stuff -- if you just want the sweets, skip to the conclusion of this article.)

The Heart of the Matter:

It turns out the percentage of cocoa and the color of chocolate are only part of the story of "dark chocolate." The real benefit of dark chocolate is found in compounds called flavonols, which act as antioxidants in the body. Flavonols have a bitter taste and because of this they can be ruined, diminished or removed from much of the chocolate we consume. A particular flavonol, epicatechin, or EC, which is also found in red wine, is said to be responsible for much of dark chocolate's effects of increased blood circulation to the heart, extremities and brain.

This increased circulation to the blood vessels may be why we see a reduction in blood pressure in people diagnosed with hypertension. A study of the current research found the dosages of flavonols needed to reduce blood pressure varied widely from 30-1008 mg per day. While some scientists claim that chocolate can contain 500 mg of polyphenols per 100g of chocolate (the weight of a standard candy bar found in stores), there is question if the chocolate we buy in stores reaches this level.

A USDA study (which appears to be data from the Netherlands) listed the flavonoid content of foods and found 100g of pure cocoa beans contained 343 mg of flavonols (99 mg being EC), but dark chocolate only had an average of 53.5 mg of flavonols (41.5 mg of that being EC) and milk chocolate had an average of 8.38 mg (6.31 of EC). These are levels from Dutch chocolate, and I couldn't find data on whether American chocolate sources had more or less. Also, the percentage of cocoa in this dark chocolate wasn't stated in this data.

Dark chocolate's blood pressure-reducing effect may not be entirely from flavonols alone. The magnesium content (up to 300 mg per 100g of chocolate) according to one source may contribute to the reduction in blood pressure as well.

Conclusion:

I know, I know, that's a lot of chemistry and medical jargon... so what's the take-away message from all of this?

Emerging research suggests that chocolate may not be the junk food we once believed it to be. Consuming moderate amounts dark chocolate may have cardiovascular benefits, but the amount of beneficial flavonols in store bought chocolate is uncertain. The effects were not seen in people who ate similar amounts of milk and white chocolate, likely because these varieties don't have large enough amounts of flavonols left in them. Though I wouldn't classify it as a health food, eating moderate amounts of dark chocolate may be a better choice when replacing another high calorie treat, particularly another type of chocolate.

The statistics that show a decrease in cardiovascular diseases were made from observational studies. This means chocolate has not been proven to be the cause, but it is related in some way. Further research will be needed to determine if chocolate alone is responsible for the benefits.

To read more about foods we love that will love us back, see Dr. Katz's recent article on this very topic.

In Health,

Michael Stanclift, ND

Naturopathic Doctor - Carlsbad, California

*This post was originally published by the Huffington Post, by Dr. Michael Stanclift, ND