Quite the cure: dark chocolate

The “chocolate cure” for emotional stress is getting new support from a clinical trial published online in ACS’ Journal of Proteome Research. It found that eating about an ounce and a half of dark chocolate a day for two weeks reduced levels of stress hormones in the bodies of people feeling highly stressed. Everyone’s favorite treat also partially corrected other stress-related biochemical imbalances.

Sunil Kochhar and colleagues note growing scientific evidence that antioxidants and other beneficial substances in dark chocolate may reduce risk factors for heart disease and other physical conditions. Studies also suggest that chocolate may ease emotional stress. Until now, however, there was little evidence from research in humans on exactly how chocolate might have those stress-busting effects.

In the study, scientists identified reductions in stress hormones and other stress-related biochemical changes in volunteers who rated themselves as highly stressed and ate dark chocolate for two weeks. “The study provides strong evidence that a daily consumption of 40 grams [1.4 ounces] during a period of 2 weeks is sufficient to modify the metabolism of healthy human volunteers,” the scientists say.

Also, dark chocolate may stave off artery hardening in smokers, and a few squares every day could potentially cut the risk of serious heart disease, finds a small study in Heart.Researchers compared the effects of dark (74% cocoa solids) and white chocolate on the smoothness of arterial blood flow in 20 male smokers.

In smokers the activity of both endothelial cells, which line the artery walls, and platelets, which are involved in the formation of blood clots, are continuously disrupted, making the arteries susceptible to the narrowing and hardening characteristic of coronary artery disease. Before eating 40 g of chocolate (about 2 oz), smokers were first asked to abstain from other foods rich in antioxidants, such as onions, apples, cabbage, and cocoa products for 24 hours. After two hours, ultrasound scans revealed that dark chocolate significantly improved the smoothness of arterial flow, an effect which lasted for eight hours. Blood sample analysis also showed that dark chocolate almost halved platelet activity. Antioxidant levels rose sharply after two hours. White chocolate had no effect on endothelial cells, platelets, or antioxidant levels.