Can Cocoa Flavanols Protect Endothelial Function During Prolonged Sitting in Healthy Older Adults?

NCT07265869 | Completed

• 1 other identifier: ERN_19-0851B
• Study Type: interventional
• Target: 20
• Locations: 1 country
• Sites: 1

Brief Summary

Sitting time is high in older adults and has been shown to temporarily impair endothelial function and blood pressure. Flavanols, plant-derived compounds, acutely enhance endothelial function and reduce Blood pressure in older adults. The aim of this study is to investigate whether acute ingestion of cocoa flavanols can improve peripheral endothelial function and blood pressure during prolonged sitting in healthy older adults. In a randomised, double-blinded, cross-over, placebo-controlled human study, 20 healthy older adults will consume either a high-flavanol (695 mg) or low-flavanol (5.6 mg) cocoa beverage immediately before a 2-hour sitting bout. Flow-mediated dilation (FMD) of the superficial femoral (SFA; primary outcome) and brachial (BA) arteries, and blood pressure, were assessed before and after sitting. Microvasculature haemodynamics were assessed in the gastrocnemius before, during, and after sitting. It is hypothesized that the high flavanol cocoa will prevent declines in brachial and superficial femoral Flow-mediated dilatation post sitting.

Conditions

Ageing; Healthy

Keywords

vascular function; endothelial function; flow-mediated dilatation; flavanols; cocoa; flavonoids; polyphenols; sitting; sedentary; ageing; older adults; functional Near-Infrared Spectroscopy

Outcome Measures

Primary Outcomes (1)

• Flow-mediated dilatation of the superficial femoral artery

  Flow-mediated dilatation (FMD) of the superficial femoral artery. Expressed as percent FMD: change in brachial diameter from baseline to peak dilation following 5 minutes of arterial occlusion. Brachial artery diameter and blood flow will be measured using Doppler ultrasonography (uSmart 3300, Terason).

  Change from pre-intervention baseline to 2 hours post intervention /2 hours post sitting

Secondary Outcomes (12)

• Flow-mediated dilatation of the brachial artery

  Change from pre-intervention baseline to 2 hours post-intervention/ 2hours post sitting

• Tissue oxygenation index (TOI) of Gastrocnemius skeletal muscle

  Change from pre-intervention baseline to 2 hours post-intervention / 2 hours of sitting

• Normalized haemoglobin index (nTHI) of the gastrocnemius skeletal muscle

  Change from pre-intervention baseline to 2 hours post-intervention/2 hours sitting

• Tissue oxygenation index (TOI) of Gastrocnemius skeletal muscle during 2 hours of sitting

  Post-intervention time points considered during sitting were 0 , 10 , 60 and 120 minutes.

• Normalized haemoglobin index (nTHI) of Gastrocnemius skeletal muscle during 2 hours of sitting

  Post-intervention time points considered during sitting were 0 min , 10 min, 60 min and 120 min.

Study Arms (2)

High-flavanol cocoa powder

EXPERIMENTAL

12 g of fat-reduced natural cocoa powder containing 695 mg of total flavanols, including 150 mg (-)-epicatechin

Dietary Supplement: High-flavanol cocoa powder

Low-flavanol cocoa powder

PLACEBO COMPARATOR

12 g of fat-reduced alkalized cocoa powder containing 5.6 mg of total flavanols

Dietary Supplement: Low-flavanol cocoa powder

Interventions

Low-flavanol cocoa powder DIETARY_SUPPLEMENT

12 g of a fat-reduced alkalized cocoa powder containing 5.6 mg of total flavanols

Low-flavanol cocoa powder

High-flavanol cocoa powder DIETARY_SUPPLEMENT

12 g of a fat-reduced natural cocoa powder containing 150 mg of (-)-epicatechin, and 695 mg of total flavanols

High-flavanol cocoa powder

Eligibility Criteria

• Age: 65 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Older Adult (65+)

You may qualify if:

• Males and females
• aged 65 or more

You may not qualify if:

• history or symptoms of cardiovascular, renal, pulmonary, metabolic, or neurologic disease, hypertension (blood pressure higher than 140/90 mm Hg, based on recent guidelines), diabetes mellitus, anaemia, asthma, immune conditions, or high cholesterol.
• smoker
• individuals who were on weight-reducing diets
• individuals taking anticoagulants,
• had recently undergone prolonged bed-rest periods
• have been on antibiotics in the previous 3 months
• have an infection at present (e.g. cold) or viral infection

Sponsors & Collaborators

• University of Birmingham: lead

Study Sites (1)

School of Sport, Exercise & Rehabilitation Sciences, University of Birmingham

Birmingham, West Midlands, B15 2TT, United Kingdom

Location

MeSH Terms

Conditions

Sedentary Behavior

Condition Hierarchy (Ancestors)

Behavior

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: TRIPLE
• Who Masked: PARTICIPANT, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: PREVENTION
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: November 19, 2025
• First Posted: December 5, 2025
• Study Start: August 2, 2022
• Primary Completion: August 24, 2023
• Study Completion: August 24, 2023
• Last Updated: December 5, 2025

Record last verified: 2025-10

Data Sharing

• IPD Sharing: Will not share

Locations

GB (1)