Impact of Cocoa Drinks on Peripheral Artery Disease

Study Overview

Researchers conducted a study to investigate whether cocoa drinks can assist individuals with peripheral artery disease (PAD) in walking longer distances. PAD affects blood circulation in the lower body, complicating everyday tasks that require mobility, such as walking.

Understanding Peripheral Artery Disease

Individuals with PAD typically walk shorter distances compared to those without the condition, and this limitation often worsens over time. Previous research has indicated that certain components of cocoa, particularly flavanol, may enhance blood flow and muscle function in the legs.

Clinical Trial Details

A phase II clinical trial published in the journal Circulation Research evaluated the effects of a flavanol-rich cocoa drink consumed daily for six months. The study aimed to determine if this drink could improve the walking distance of participants with PAD compared to a control group that received a visually similar non-cocoa beverage.

Participants were tested on their walking ability over six minutes, which served as a measure of lower leg functionality. Some participants also provided calf muscle samples for further analysis of potential differences between the groups.

Trial Execution and Demographics

Conducted in Chicago, the trial included participants aged 60 and older. It was a double-blind study, meaning neither the researchers nor the participants knew who received the cocoa drink or the placebo until the trial concluded. In total, 23 individuals consumed the cocoa drink, while 21 received the placebo.

Findings and Results

At the six-month follow-up, participants who consumed the cocoa drink demonstrated a greater walking distance of approximately 42.6 meters over six minutes compared to the placebo group. This measurement was taken 2.5 hours after their final drink. The results remained significant even after adjusting for factors such as smoking status, race, and body mass index (BMI).

Calf Muscle Analysis

Analysis of calf muscle samples revealed minimal cellular differences between the two groups, although a slight increase in cytochrome c oxidase (COX) activity was observed in the cocoa group. Additional exploratory analyses indicated improvements in leg muscle health, such as increased capillary density among participants who consumed cocoa.

Conclusion and Limitations

Overall, the study concluded that cocoa drinks improved six-minute walking distances for individuals with PAD compared to those who consumed a non-cocoa beverage. The cocoa also appeared to offer cellular benefits, including enhanced enzymatic activity and capillary density.

The authors noted several limitations, including the pilot nature of the study, a relatively small sample size, variations in participant characteristics at the study’s outset (such as BMI, sex, and race), and the absence of dietary data collection.

Reference

McDermott MM et al. Cocoa to Improve Walking Performance in Older People With Peripheral Artery Disease: The Cocoa-Pad Pilot Randomized Clinical Trial. Circulation Research. 2020;0, 1–21. doi: https://doi.org/10.1161/CIRCRESAHA.119.315600.