Dark Chocolate for Health

The aptly named Theobroma cocoa, or "food of the gods," is believed to have originated in the ancient cultures of Mesoamerica, perhaps dating back as far as 4,000 years. By the 17th century, Europeans were drinking chocolate beverages for nutritional and medicinal purposes. Scientific evidence reveals they may have been right. Several studies suggest that health benefits of dark chocolate may include increased insulin sensitivity, decreased blood pressure, cholesterol and emotional stress, and less chance of stroke.

Identification

Cocoa beans contain antioxidants called flavonols. Not all chocolates are created equal, though; the darker the chocolate, the higher the flavonol content. To be considered a dark chocolate, the product must contain 50 percent or more cocoa. Bittersweet chocolate contains more than 70 percent cocoa. Consumed in moderation, less than 3 oz. daily, dark chocolate containing at least 65 percent cocoa provides the most benefit. White chocolate, for clarification, contains cocoa butter, not cocoa solids, and is only considered chocolate if the product contains at least 20 percent cocoa butter. It does not have the flavonols of dark chocolate.

Insulin Sensitivity and Blood Pressure

A study published in the March 2005 issue of the "American Journal of Clinical Nutrition" compared the effects of dark and white chocolate consumption on blood sugar and blood pressure in 15 healthy participants. They found that only dark chocolate decreased blood pressure and improved insulin sensitivity. The authors suggest more research is needed to confirm their findings, but results are promising for the benefit of dark chocolate on the vascular system.

Cholesterol

The "American Journal of Clinical Nutrition" published an article in November 2001 on the effects of dark chocolate on cholesterol levels. Researchers randomly divided 23 healthy people into two groups eating separate diets. The first group was given 22 g of cocoa powder and 16 g of dark chocolate daily in addition to their normal diet. The second group continued their normal dietary intake without cocoa or dark chocolate. The two groups consumed their assigned diets for four weeks and then traded diets for another four weeks. Blood and urine samples were collected throughout the study, revealing that both groups, while consuming cocoa and dark chocolate, experienced lower levels of low-density lipoproteins, or bad cholesterol, thus reducing their risk for cardiovascular disease.

Stroke

In May 2010, researchers at Johns Hopkins discovered that a dark chocolate compound called epicatechin may increase the brain's own response for reducing damage after stroke. The study involved mice given epicatechin 3 hours prior to a lab-induced stroke and again 3 1/2 hours after the stroke. The mice suffered less brain damage than mice that did not receive the compound. Researchers reported that the compound was only beneficial when given within 2 to 3 hours of the stroke. Heat and light damage epicatechin, so not all dark chocolate contains the compound.

Emotional Stress

A clinical trial, published in November 2009 by EurekAlert.org, reported that participants rating themselves as highly stressed ate 1.5 oz. of dark chocolate daily for two weeks and showed decreased amounts of stress hormones. The researchers suggest that 40 g daily for two weeks may promote stress hormone balance in healthy adults.