Good News For Dark Chocolate

Dark chocolate lovers rejoice. Researchers have found that eating dark chocolate may help people with peripheral artery disease (PAD) walk a little better. While the study was small with only 20 participants—14 men and six women—the results were clear. The eaters of the dark chocolate showed an 11% increase in their maximum walking distance compared to no change in those patients who ate the same amount of milk chocolate. The study was limited to patients with intermittent claudication (IC). IC involves impaired blood flow to the limbs, especially during exercise.

Salynn Boyles, a contributing writer for MedPage Today reported the study.

The lead researcher was Lorenzo Loffredo, M.D., of Sapienza University, Rome, Italy.   He reported on the study in the Journal of the American Heart Association. The goal of Loffredo’s work was to determine whether eating dark chocolate could improve walking autonomy in PAD patients with IC.

Researchers drew fasting blood samples from the participants at 8 am in the morning and also performed ankle brachial index (ABI) and flow mediated dilation (FMD) exams.   At 9 am the subjects performed a treadmill test and 2 minutes after completing the treadmill test the investigators measured the subject’s maximal walking distance (MWD) and maximal walking time (MWT). They also measured their ABI again.

At 9:25 am they gave the participants the chocolate (40 grams). The dark chocolate was 85% cocoa and the milk chocolate was 35% cocoa. They had 15 minutes to eat it. At 11:25 am the researchers drew blood samples again. At 11:30 am they performed a second ABI at rest and FMD, and at 11:50 am the participants underwent a second treadmill test. Once again, doctors performed an ABI two minutes after they measured MWD and MWT.

“This study has implications and limitations, ” the researchers wrote. “It should be considered a proof-of-concept study that is potentially useful to understand the mechanism of disease related to IC but not transferable to clinical practice because of small sample size and the disease of the study.”

Natalie Evans, M.D., of the Cleveland Clinic, who was not involved with the study, said “There is a huge population out there with peripheral artery disease, but only about 11% of them actually have intermittent claudication, ” she said. “I think it would be really interesting to find out what impact dark chocolate would have on [patients without this complication].”