Effect of Beet Juice Supplementation on Vascular and Inspiratory Muscle Function

May 12, 2026 updated by: University of Florida
Older adults with coronary artery disease (CAD) have impaired vascular and inspiratory muscle function. The overarching goal of this double-blind, randomized, crossover, placebo-controlled pilot trial was to inform the development of a fully powered trial to evaluate the effects of dietary nitrate supplementation in older adults with CAD. We aimed to address the following objectives: (a) assess the feasibility, tolerability, and safety of the study protocol; (b) gather preliminary evidence on the effects of nitrate-rich beetroot juice compared with nitrate-depleted beetroot juice (placebo), and estimate the effect sizes; and (c) determine if a full-scale definitive trial is justified.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
8

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • United States
    • Florida
      • Gainesville, Florida, United States, 32611
        • Integrative Cardiovascular Physiology Laboratory, University of Florida

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

60 years to 85 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Adults with coronary artery disease (CAD) based on an angiogram >50% stenosis in any major epicardial vessel or history of myocardial infarction or history of coronary revascularization.
  • Considered to have stable CAD on optimal medical therapy
  • 60 to 85 years of age
  • Males and females (females must be postmenopausal either natural or surgical)
  • Able to give consent

Exclusion Criteria:

  • Unstable angina, recent myocardial infarction or heart failure within 6 months
  • Coronary revascularization, including percutaneous coronary intervention and coronary artery bypass graft or thoracic surgery within 6 months.
  • Stroke, obstructive pulmonary disease, hepatitis B, C, HIV, seizures, or other relevant ongoing or recurrent illness
  • Individuals who have participated in respiratory training within the last 12 months or cardiac rehabilitation within the last 6 months
  • Uncontrolled hypertension
  • Use of tobacco products including smoking traditional or e-cigarettes
  • Use of hormone replacement therapy in women or men (e.g., estrogen, progesterone or testosterone)
  • Unwilling to stop using mouthwash at least 1 week before the start of the study and during study participation
  • Unwilling to remain weight stable during study participation

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Active Comparator: Nitrate rich beetroot juice
Dietary supplement: Nitrate rich beetroot juice
Participants will drink nitrate rich beetroot juice (2.4 floz ; Beet It Sport Nitrate 400 concentrated beetroot shot; James White Drink, ltd) twice daily for two weeks.
Placebo Comparator: Nitrate depleted beetroot juice
Dietary supplement: Nitrate depleted beetroot juice
Participants will drink nitrate depleted beetroot juice (2.4 floz ; Beet It placebo concentrated beetroot shot; James White Drink, ltd) twice daily for two weeks.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Change in endothelial function
Time Frame: Baseline up to following 2 weeks of experimental condition
Endothelial function will be determined using brachial artery flow-mediated dilation via high resolution duplex ultrasonography. Reactive hyperemia will be produced by inflating a forearm cuff to ~250 mmHg for 5 minutes followed by rapid deflation.
Baseline up to following 2 weeks of experimental condition
Change in inspiratory muscle function
Time Frame: Baseline up to following 2 weeks of experimental condition
Inspiratory muscle function including strength, power and endurance will be assessed using the POWERbreathe KH2 device
Baseline up to following 2 weeks of experimental condition

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Change in microvascular function
Time Frame: Baseline up to following 2 weeks of experimental condition
Microvascular function will be assessed using the forearm blood flow response to submaximal handgrip exercise. Brachial artery blood flow and diameter will be assessed using ultrasound.
Baseline up to following 2 weeks of experimental condition
Change in central arterial stiffness
Time Frame: Baseline up to following 2 weeks of experimental condition
The SphygmoCor XCEL device will be used to measure carotid to femoral pulse wave velocity.
Baseline up to following 2 weeks of experimental condition
Change in central arterial hemodynamics
Time Frame: Baseline up to following 2 weeks of experimental condition
The SphygmoCor XCEL device will be used to obtain central pulse wave analysis.
Baseline up to following 2 weeks of experimental condition
Change in functional capacity
Time Frame: Baseline up to following 2 weeks of experimental condition
Using the Duke Activity Status Index we will assess participants' ability to perform daily activities.
Baseline up to following 2 weeks of experimental condition

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University of Florida

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
November 12, 2021

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
August 28, 2025

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
August 28, 2025

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
May 27, 2021

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
June 3, 2021

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
June 10, 2021

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
May 14, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
May 12, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
May 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • IRB202100040

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

Cookie Settings

We use cookies to ensure that we give you the best experience on our website. For more details carefully read our Privacy and Cookies Policy. ...>>>You can change your preferences or withdraw your consent at any time by deleting the cookies from your website or computer as described in the policy. Please accept it and choose your preferences by ticking the corresponding boxes in the "Manage Settings" section below. Please carefully read our Terms of Service before you proceed with using any part of this website.
«Manage Settings