The Influence of Beetroot Juice on Racial Disparities in Vascular Health

Black adults are 30% more likely to die from cardiovascular disease (CVD) compared to White adults, and more than half of this racial disparity in cardiovascular mortality may be attributed to the substantially greater prevalence of high blood pressure and vascular dysfunction in Black adults. Nitric oxide (NO) is a potent signaling molecule and key regular of vascular function that is suspected to be reduced in black individuals, but can be enriched by dietary nitrate (e.g., arugula, spinach, beets). The purpose of this study is to test the hypothesis that increasing NO bioavailability via nitrate-rich beetroot juice (BRJ) will lower blood pressure and improve vascular health in Black adults.

Study Overview

• Status: Completed
• Conditions: Blood Pressure; Cardiovascular Risk Factor; Racial Disparities
• Intervention / Treatment: Other: Acute Beetroot Juice

Detailed Description

The investigators long-term research goal is to investigate mechanisms accounting for the higher prevalence of CVD and high blood pressure in Black individuals, and identify effective preventive strategies. Nitric oxide (NO) is a gaseous molecule that plays an essential role in the regulation of vascular tone and blood pressure regulation. Some, but not all, studies have observed reduced NO bioavailability in Black individuals, which may contribute to racial disparities in vascular health. Dietary nitrate supplementation using beetroot juice (BRJ) is demonstrated to increase circulating NO, lower blood pressure and arterial stiffness, and improve blood pressure regulation in clinical populations and health individuals. The central hypothesis is that increasing NO bioavailability by nitrate-rich BRJ supplementation will lower blood pressure and improve vascular health in Black adults. The investigators acknowledge that racial differences are not entirely driven by ancestry, and thus will assess and account for sociocultural factors and health behaviors (i.e., sleep, physical activity, and nutrition) that may contribute to racial health disparities.

• Study Type: Interventional
• Enrollment (Actual): 40
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Georgia
    • Savannah, Georgia, United States, 31401
      • Biodynamics and Human Performance Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 39 years (Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Between 18-39 years of age
• Body mass index (BMI) below 30 kg/m^2
• Free from signs or symptoms of neurologic, cardiovascular (e.g., heart attack, stroke, heart failure, arrhythmia), metabolic, and/or renal disease
• Have a blood pressure no lower than 90/50 mmHg
• Are not currently smoking, using smokeless tobacco, nor smoked within the past 12 months

Exclusion Criteria:

• Low blood pressure - less than 90/50 mmHg
• History of cardiovascular disease
• History of cancer
• History of diabetes
• History of kidney disease
• Obesity (BMI > 30 kg/m^2)
• Smoking or tobacco use
• Current pregnancy
• Nursing mothers
• Communication barriers

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Single

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Nitrate-rich beetroot juice (~12.8 mmol); Participants will have blood pressure, arterial stiffness, and blood samples (from venipuncture) assessed before and after the nitrate-rich beetroot juice (~12.8 mmol).	Other: Acute Beetroot Juice; Participants will ingest a beetroot juice supplement with and without inorganic nitrate to determine the effects of acute dietary nitrate ingestion on blood pressure and arterial stiffness
Placebo Comparator: Beetroot juice with nitrate removed; Participants will have blood pressure, arterial stiffness, and blood samples (from venipuncture) assessed before and after the beetroot juice with nitrate removed.	Other: Acute Beetroot Juice; Participants will ingest a beetroot juice supplement with and without inorganic nitrate to determine the effects of acute dietary nitrate ingestion on blood pressure and arterial stiffness

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Changes in nitric oxide (NO) metabolites	The investigators will use chemiluminescence detection to measure salivary and circulating NO metabolites (nitrate and nitrate).	Baseline and two hours after beetroot juice ingestion, both conditions (experimental and control)
Changes in blood pressure	The investigators will use the SphygmoCor XCEL system to assess pulse wave analysis (PWA), which will provide brachial and aortic blood pressures (mmHg).	Baseline and two hours after beetroot juice ingestion, both conditions (experimental and control)
Changes in arterial stiffness	The investigators will use the SphygmoCor XCEL system to assess pulse wave velocity (PWV). A high-fidelity strain-gauge transducer is used to obtain the pressure waveform at the carotid pulse. Distances from the carotid artery sampling site to the femoral artery (upper leg instrumented with a thigh cuff for oscillometric sphygmomanometry), and from the carotid artery to the suprasternal notch will be recorded. PWV will be expressed as m/s.	Baseline and two hours after beetroot juice ingestion, both conditions (experimental and control)
Changes in blood pressure responses to stress	The investigators will use the SphygmoCor XCEL system to assess pulse wave analysis (PWA) at rest and during handgrip exercise and after exercise during cuff occlusion.	Baseline and two hours after beetroot juice ingestion, both conditions (experimental and control)
Changes in arterial stiffness responses to stress	The investigators will use the SphygmoCor XCEL system to assess pulse wave velocity (PWV) at rest and during handgrip exercise and after exercise during cuff occlusion.	Baseline and two hours after beetroot juice ingestion, both conditions (experimental and control)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Objective sleep duration	ActiGraph GT9X accelerometers will be used to quantify sleep duration. Participants will wear the watch unit for 7 days. The investigators will assess qualitative sleep scores and cross-check actigraphy wear times with a sleep diary.	Baseline (pre-intervention)
Subjective sleep quality	The investigators will use the Pittsburgh Sleep Quality Index (0-21, higher value indicating worse sleep) to assess subjective indices of sleep health.	Baseline (pre-intervention)
Physical activity	Participants will wear an ActiGraph GT9X accelerometer for seven days to objectively quantify time spent in moderate-vigorous physical activity.	Baseline (pre-intervention)
Habitual dietary intake	The investigators will instruct participants to complete a diet log for three days which will be characterized with Nutrition Data System for Research (NSDR).	Baseline (pre-intervention)
Social determinants of health	The investigators will use the Perceived Ethic Discrimination Questionnaire (22-154, higher value indicating more experiences of ethnic discrimination/racism) to quantify social determinants of health.	Baseline (pre-intervention)
Economic determinants of health	The investigators will use the Socioeconomic Status (0-32, lower score indicating lower socioeconomic status) questionnaire to quantify economic determinants of health.	Baseline (pre-intervention)

Collaborators and Investigators

• Sponsor: Georgia Southern University
• Investigators: Principal Investigator: Gregory Grosicki, PhD, Georgia Southern University

Study record dates

Study Major Dates

• Study Start (Actual): November 1, 2021
• Primary Completion (Actual): May 1, 2023
• Study Completion (Actual): October 4, 2023

Study Registration Dates

• First Submitted: November 5, 2021
• First Submitted That Met QC Criteria: November 12, 2021
• First Posted (Actual): November 24, 2021

Study Record Updates

• Last Update Posted (Actual): October 5, 2023
• Last Update Submitted That Met QC Criteria: October 4, 2023
• Last Verified: October 1, 2023

More Information

Terms related to this study

• Keywords: blood pressure; nitric oxide; arterial stiffness; cardiovascular health
• Other Study ID Numbers: H22040

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: Data with all HIPAA identifiers removed may be shared in future collaborative efforts pending appropriate DMDA approvals
• IPD Sharing Time Frame: One year after completion of trial, indefinitely
• IPD Sharing Access Criteria: A formal plan identifying the intended use of the data and proper completion of a DMDA and MTA (if needed) with Georgia Southern University and the study PI.
• IPD Sharing Supporting Information Type: SAP

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No