Dark Chocolate Might Help Artery Disease Patients Walk Longer, Farther

A new study suggests that dark chocolate might benefit those suffering from Peripheral Artery Disease (PAD). Compounds in dark chocolate, researchers said, improve blood flow to the legs, helping patients to walk longer and farther.

Peripheral Artery Disease (PAD) is a condition where plaque builds up in arteries that carry blood from heart to brain, other organs and limbs. PAD usually affects the arteries in legs. People suffering from the condition feel numbness or pain in legs and find it difficult to walk. 

The study, conducted by researchers at the Sapienza University in Rome, was based on a small set of 20 patients suffering from PAD. The group had 14 men and six women aged between 60-78 years.

For the study, participants were asked to walk on a treadmill. They were then given 40 grams of either dark or milk chocolate. Two hours later, they were asked to walk on the treadmill again. The amount of chocolate given to each patient was the same as a regular bar of American chocolate.

The treadmill was set at 2.2 miles per hour and a 12-percent grade, and participants were asked to walk for as long as they could, Reuters reports.

The team found that patients who ate milk chocolate showed no improvement in their walking ability. However, people who ate dark chocolate could walk for a longer duration and to a farther distance than before, suggesting that compounds in the chocolate were improving blood circulation.

The difference in walking ability was modest, but researchers said that eating dark chocolate might improve walking ability of PAD patients.

"Polyphenol-rich nutrients could represent a new therapeutic strategy to counteract cardiovascular complications," said Francesco Violi, M.D., study senior author and professor of internal medicine at the Sapienza University of Rome, according to a news release. The dark chocolate used in the study had more than 85 percent of cocoa.

According to the team, levels of nitric oxide - a gas linked to better blood flow - were higher in patients who ate dark chocolate. Also, other signs of oxidative stress were lower in the group which consumed dark chocolate as compared to the group which ate milk chocolate. Researchers believe that nitric oxide might be dilating the blood vessels in the legs, improving blood flow.

Don't take the study results as an excuse to eat high amounts of chocolate. The American Heart Association maintains that chocolate increases calories in the diet. The association recommends that men should get only 150 calories per day and women 100 calories per day from added sugar.

Cloves, dried peppermint, celery seed, capers and hazelnuts are some other foods that have high levels of polyphenols and far lower levels of sugar and fat than chocolate.

"Other investigations have shown that polyphenols including those in dark chocolate may improve blood vessel function. But this study is extremely preliminary and I think everyone needs to be cautious when interpreting the findings," said Dr. Mark Creager, who is director of the Vascular Center at Brigham and Women's Hospital and an AHA spokesperson. 

The Sapienza University of Rome funded the study and it is published in the Journal of the American Heart Association.