Dark chocolate has recently been touted for having many health benefits and researchers from the American Heart Association have just added another one to the already long list. They found that people with peripheral artery disease (PAD) can delay the onset of pain and walk a little farther by regularly eating dark chocolate or anything made from cocoa.

The small study was conducted on 20 PAD patients (14 men and 6 women), aged between 60 and 78 years. The participants were given 40 gm of milk chocolate and dark chocolate on alternate days. Every morning they were made to walk on a treadmill so that researchers could keep a record of their time and speed. On days that the participants ate dark chocolate, they walked 11 percent farther and 15 percent longer. No such improvement was seen on days they ate milk chocolate.

So what makes dark chocolate so beneficial? It's the presence of a compound called polyphenols, which is found in abundance in cocoa products. This compound is known to reduce oxidative stress and improve blood flow in peripheral arteries.

"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," American Heart Association spokesperson Dr. Mark Creager said in a press statement. "We know from other studies of antioxidants -- vitamin C and vitamin E for example -- that these interventions have not gone on to show improvement in cardiovascular health."

This is not the first study that has highlighted the benefits of dark chocolate for arteries. A previous study also found that dark chocolate can reduce plaque buildup in the arteries among other heart benefits. It increases the flexibility of arteries and also prevents white blood cells from sticking to the walls of blood vessels.

Another study also highlighted that the flavanols in dark chocolate have anti-obesity and anti-diabetic properties. Hence, health experts often advise people with these conditions to increase their intake of cocoa products.

But as they say, too much of anything is bad. To reap the maximum benefits of any food item, it is important to know the quantity in which it should be consumed. According to recommendations from the American Heart Association, men should not consume more than 150 calories of added sugar per day. For women, it is 100 calories a day. Therefore, it is essential to keep a check on the amount of processed dark chocolate you consume so that you don't suffer from negative effects.

The study was published in the Journal of the American Heart Association.