~46 spots leftby May 2026

Cocoa Flavanols for Peripheral Arterial Disease

(COCOA-PAD II Trial)

Recruiting at2 trial locations
Mary McGrae McDermott, MD ...
Overseen byMary McDermott, MD
Age: 18+
Sex: Any
Travel: May Be Covered
Time Reimbursement: Varies
Trial Phase: Phase 3
Recruiting
Sponsor: Northwestern University
Disqualifiers: Amputation, Critical limb ischemia, Wheelchair, others
Pivotal Trial (Near Approval)
Prior Safety Data

Trial Summary

What is the purpose of this trial?

Among people with peripheral artery disease (PAD) age 55 and older, the investigators will test the hypothesis that PAD participants randomized to cocoa flavanols will have greater improvement or less decline in six-minute walk distance at six-month follow-up, compared to those randomized to placebo. The study will randomize 190 participants with PAD age 55 and older to one of two groups for six months: cocoa flavanols vs placebo. Our primary outcome is change in six-minute walk distance at six-month follow-up. Secondary outcomes are Actigraph-measured physical activity, brachial artery flow-mediated dilation (FMD), gastrocnemius muscle biopsy measures of endothelial nitric oxide synthase (eNOS) and phosphorylated eNOS, gastrocnemius muscle perfusion (measured by magnetic resonance imaging (MRI)) and gastrocnemius muscle characteristics (measured by muscle biopsy). To achieve the specific aims, the study will randomize 190 participants age 55 and older with PAD to one of two groups: cocoa flavanols vs placebo. Participants will be followed for six months.

Will I have to stop taking my current medications?

The trial information does not specify whether you need to stop taking your current medications. However, it does mention that participants should not have taken cocoa supplements in the past three months and should avoid taking cocoa flavanol supplements during the study.

What data supports the effectiveness of the treatment Cocoa Flavanols for Peripheral Arterial Disease?

Research suggests that cocoa and its component epicatechin may help improve blood flow and muscle activity in people with peripheral artery disease (PAD). Additionally, a study on Annurca apple polyphenols, which are similar to cocoa flavanols, showed improved walking ability in PAD patients, indicating potential benefits of flavanol-rich treatments.12345

Is cocoa flavanol supplementation safe for humans?

Research on cocoa flavanols, often found in chocolate, suggests they are generally safe for human consumption, with studies showing no significant adverse effects on vascular function in people with coronary artery disease or diabetes.56789

How is the treatment of cocoa flavanols unique for peripheral arterial disease?

Cocoa flavanols are unique because they are derived from cocoa and may improve blood flow and muscle function in the legs, which is different from standard treatments that typically focus on medications or surgical interventions. This treatment leverages the natural compounds in cocoa to potentially enhance vascular health and walking performance.156910

Research Team

Mary McGrae McDermott, MD ...

Mary McDermott, MD

Principal Investigator

Northwestern University

Eligibility Criteria

The COCOA-PAD II Trial is for individuals aged 55 or older with peripheral artery disease (PAD), defined by specific diagnostic criteria. Excluded are those with severe cognitive impairment, current foot ulcers, recent major surgeries or cardiovascular events, certain allergies, and other serious health conditions that limit walking or life expectancy.

Inclusion Criteria

I am 55 years old or older.
I have been diagnosed with peripheral artery disease.

Exclusion Criteria

I do not speak English.
I haven't taken cocoa supplements or eaten dark chocolate regularly in the last 3 months.
I can walk less than 500 feet or more than 1600 feet in six minutes.
See 16 more

Trial Timeline

Screening

Participants are screened for eligibility to participate in the trial

2-4 weeks

Treatment

Participants are randomized to receive either cocoa flavanols or placebo for six months

6 months

Follow-up

Participants are monitored for safety and effectiveness after treatment, including assessments of six-minute walk distance and other secondary outcomes

6 months

Post-intervention Follow-up

Assessment of persistent effects on six-minute walk distance at two and four weeks after the study intervention is completed

4 weeks

Treatment Details

Interventions

  • Cocoa Flavanols (Flavanols)
  • Placebo (Placebo)
Trial OverviewThis trial investigates whether cocoa flavanols can improve walking distance over six months in PAD patients compared to a placebo. The study will enroll 190 participants who will be randomly assigned to receive either the cocoa flavanols or a placebo.
Participant Groups
2Treatment groups
Active Control
Placebo Group
Group I: cocoa flavanolsActive Control1 Intervention
Group II: placeboPlacebo Group1 Intervention

Find a Clinic Near You

Who Is Running the Clinical Trial?

Northwestern University

Lead Sponsor

Trials
1,674
Recruited
989,000+
Dr. Jeffrey Sherman profile image

Dr. Jeffrey Sherman

Northwestern University

Chief Medical Officer

MD from Northwestern University

Dr. Alicia Löffler profile image

Dr. Alicia Löffler

Northwestern University

Chief Executive Officer since 2010

PhD from the University of Massachusetts at Amherst, post-doctoral training at Caltech

National Institute on Aging (NIA)

Collaborator

Trials
1,841
Recruited
28,150,000+

Dr. Richard J. Hodes

National Institute on Aging (NIA)

Chief Executive Officer since 1993

MD from Harvard Medical School

Dr. Marie Bernard

National Institute on Aging (NIA)

Chief Medical Officer

MD from Harvard Medical School

University of Minnesota

Collaborator

Trials
1,459
Recruited
1,623,000+
Shashank Priya profile image

Shashank Priya

University of Minnesota

Chief Executive Officer since 2023

PhD in Materials Engineering from Penn State

Charles Semba profile image

Charles Semba

University of Minnesota

Chief Medical Officer since 2021

MD from the University of Minnesota Medical School

University of Chicago

Collaborator

Trials
1,086
Recruited
844,000+
Pete Salzmann profile image

Pete Salzmann

University of Chicago

Chief Executive Officer since 2018

MD from University of Chicago’s Pritzker School of Medicine, MBA from Stanford University’s Graduate School of Business

Anh Nguyen profile image

Anh Nguyen

University of Chicago

Chief Medical Officer

MD from Rutgers New Jersey Medical School, MBA from University of Chicago

Findings from Research

In a phase II clinical trial involving 44 participants with peripheral artery disease (PAD), a cocoa beverage containing epicatechin significantly improved walking distance by 42.6 meters after 6 months compared to a placebo, indicating potential therapeutic benefits for PAD patients.
Cocoa consumption also enhanced calf muscle mitochondrial activity and capillary density, suggesting that its mechanism of action may involve improved muscle perfusion and energy production, although further studies are needed to confirm these effects.
Cocoa to Improve Walking Performance in Older People With Peripheral Artery Disease: The COCOA-PAD Pilot Randomized Clinical Trial.McDermott, MM., Criqui, MH., Domanchuk, K., et al.[2021]
In a large study involving 21,442 older adults, cocoa extract supplementation did not significantly reduce total cardiovascular events, but it was associated with a 27% reduction in cardiovascular death, suggesting potential benefits for heart health.
The study found no safety concerns with cocoa extract, and per-protocol analyses indicated a lower risk of total cardiovascular events, highlighting the need for further research to explore its effects on clinical outcomes.
Effect of cocoa flavanol supplementation for the prevention of cardiovascular disease events: the COcoa Supplement and Multivitamin Outcomes Study (COSMOS) randomized clinical trial.Sesso, HD., Manson, JE., Aragaki, AK., et al.[2023]
Regular consumption of flavanol-rich cocoa products can significantly lower systolic blood pressure, with a study showing a mean reduction of 5.8 mmHg in a population with mild hypercholesterolemia.
Human dietary intervention trials indicate that flavanol-containing foods, like cocoa, improve endothelial and platelet function, supporting their potential cardiovascular benefits.
Effects of cocoa flavanols on risk factors for cardiovascular disease.Erdman, JW., Carson, L., Kwik-Uribe, C., et al.[2008]

References

Cocoa to Improve Walking Performance in Older People With Peripheral Artery Disease: The COCOA-PAD Pilot Randomized Clinical Trial. [2021]
Dark chocolate and vascular function in patients with peripheral artery disease: a randomized, controlled cross-over trial. [2015]
Does epicatechin contribute to the acute vascular function effects of dark chocolate? A randomized, crossover study. [2018]
Effect of Annurca Apple Polyphenols on Intermittent Claudication in Patients With Peripheral Artery Disease. [2019]
Effect of cocoa flavanol supplementation for the prevention of cardiovascular disease events: the COcoa Supplement and Multivitamin Outcomes Study (COSMOS) randomized clinical trial. [2023]
Effects of cocoa flavanols on risk factors for cardiovascular disease. [2008]
Acute and chronic effects of flavanol-rich cocoa on vascular function in subjects with coronary artery disease: a randomized double-blind placebo-controlled study. [2015]
The science of cocoa flavanols: bioavailability, emerging evidence, and proposed mechanisms. [2023]
Acute Effects of Cocoa Flavanols on Blood Pressure and Peripheral Vascular Reactivity in Type 2 Diabetes Mellitus and Essential Hypertension: A Protocol for an Acute, Randomized, Double-Blinded, Placebo-Controlled Cross-Over Trial. [2021]
10.United Statespubmed.ncbi.nlm.nih.gov
Sustained benefits in vascular function through flavanol-containing cocoa in medicated diabetic patients a double-masked, randomized, controlled trial. [2022]