All participants consumed their respective beverages three times a day for six months. Participants’ walking performance was measured at the beginning of the study and at the six month mark. There were at least two measurements of 6-minute walking: 2.5 hours after consuming the drink and at 24 hours after consumption.
The study saw those who consumed a drink with flavanol-rich cocoa could walk as far as 42.6 meters more in a 6-minute walking test than the placebo group, who drank the same number and kind of beverage that did not contain cocoa.
Additionally, people who drank the flavanol-rich cocoa had better blood flow to their calves and some better muscle function compared to the group who didn’t drink cocoa-containing drinks. Compared to their baseline results, their walking distance declined at 24.2 meters 2.5 hours after the last study beverage. That’s consistent with other studies that found people with PAD who don’t get treatment have declines over time in how far they can walk in six minutes.
“While we expected the improvements in walking, we were particularly pleased to see that cocoa treatment was also associated with increased capillary density, limb perfusion, mitochondrial activity, and an additional measure of overall skeletal muscle health,” said lead study author Mary McDermott, M.D. “If our results are confirmed in a larger trial, these findings suggest that cocoa, a relatively inexpensive, safe and accessible product, could potentially produce significant improvements in calf muscle health, blood flow, and walking performance for PAD patients.
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McDermott is the Jeremiah Stamler professor of medicine and preventive medicine at the Feinberg School of Medicine at Northwestern University in Chicago.
In addition to the increased walking distance, researchers also found those who drank cocoa beverages had muscle health improvements including increased mitochondrial activity and increased density of the blood vessel branches.
Still, the study acknowledges some limits, such as its small size and the lack of balance among the groups when it came to sex, race and body mass index. There was also deficient data for general dietary consumption.
“We know that exercise therapy helps people with PAD walk farther, and this early study suggests that cocoa may turn out to be a new way to treat people with PAD. We will need larger studies to confirm whether cocoa is an effective treatment for PAD, but maybe, someday, if the research supports it, we may be able to write a prescription for chocolate for our patients with PAD,” said Naomi Hamburg, M.D., FAHA, Chair of the American Heart Association’s Peripheral Vascular Disease Council. She is also author and author of an editorial on the PAD and cocoa study.