Watermelon and Beetroot Products on Endothelial Function

Effect of Watermelon and Beetroot Products on Endothelial Function in Young and Older Adults

Cardiovascular disease is the main cause of death worldwide. Endothelial dysfunction is the first step to development of cardiovascular diseases. Endothelial dysfunction occurs due to reduction in nitric oxide, a molecule that plays an important role on vascular health. Due to important role of nitric oxide in endothelial function, several studies have evaluated the effect of its precursors, such as L-citrulline and nitrate on endothelial function parameters. The present study will evaluate the effect of L-citrulline and nitrate derived by watermelon and beetroot products, respectively, on endothelial function of young and older participants. Furthermore, we will evaluate the plasmatic amino acids, nitrate, glucose and insulin in response to ingestion of these products.

Study Overview

• Status: Completed
• Conditions: Healthy Young; Older People With Cardiovascular Disease Risk
• Intervention / Treatment: Dietary supplement: Watermelon; Dietary supplement: Beetroot; Dietary supplement: Watermelon + beetroot; Dietary supplement: Placebo

• Study Type: Interventional
• Enrollment (Actual): 12
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Brazil
  • Rio De Janeiro
    • Macaé, Rio De Janeiro, Brazil, 27979-000
      • Universidade Federal do Rio de Janeiro

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 14 years to 81 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria for healthy young participants:

• Age between 18-35 years;
• Triglycerides ≤ 150 mg/dL
• HDL-cholesterol ≥ 50 mg/dL for women and ≥ 40 mg/dL for men;
• Waist circumference ≤ 102 cm for men and ≤ 88 cm for women).

Inclusion Criteria for older people with cardiovascular risk:

• Age ≥ 60 years;
• Elevated triglycerides ≥150 mg/dL;
• Reduced HDL-cholesterol ≤ 50 mg/dL for women and ≤ 40 mg/dL for men;
• Elevated waist circumference ≥102 cm for men and ≥ 88 cm for women).

Exclusion Criteria:

• Elevated fasting glucose (≥100 mg/dL);
• Smoking;
• Beetroot or watermelon allergy;
• Unwillingness to avoid beetroot or watermelon products during the entire study;
• Other chronic diseases (diabetes, liver disease, etc.) or acutely ill

Study Plan

How is the study designed?

Design Details

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

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: Placebo; Maltodextrin	Dietary supplement: Placebo; A single dose of maltodextrin
Active Comparator: Watermelon; Watermelon powder containing 3 g of L-citrulline.	Dietary supplement: Watermelon; A single dose of watermelon powder containing 3g of L-citrulline
Active Comparator: Beetroot; Beetroot powder containing 8 mmol of nitrate.	Dietary supplement: Beetroot; A single dose of beetroot powder containing 8 mmol of nitrate
Active Comparator: Watermelon + beetroot; Watermelon powder containing 3 g of L-citrulline and Beetroot powder containing 8 mmol of nitrate.	Dietary supplement: Watermelon + beetroot; A single dose of watermelon and beetroot powder containing 3g of L-citrulline and 8 mmol of nitrate

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Flow-mediated dilation (FMD)	This measure will be evaluate before the nutritional intervention
Flow-mediated dilation (FMD)	This measure will be evaluate 60 minutes after the nutritional intervention
Flow-mediated dilation (FMD)	This measure will be evaluate 120 minutes after the nutritional intervention
Muscle oxygen saturation	This measure will be evaluate before the nutritional intervention
Muscle oxygen saturation	This measure will be evaluate 30 minutes after the nutritional intervention
Muscle oxygen saturation	This measure will be evaluate 60 minutes after the nutritional intervention
Muscle oxygen saturation	This measure will be evaluate 90 minutes after the nutritional intervention
Muscle oxygen saturation	This measure will be evaluate 120 minutes after the nutritional intervention

Secondary Outcome Measures

Outcome Measure	Time Frame
Plasmatic amino acids	This measure will be evaluate before the nutritional intervention
Plasmatic amino acids	This measure will be evaluate 30 minutes after the nutritional intervention
Plasmatic amino acids	This measure will be evaluate 60 minutes after the nutritional intervention
Plasmatic amino acids	This measure will be evaluate 90 minutes after the nutritional intervention
Plasmatic amino acids	This measure will be evaluate 120 minutes after the nutritional intervention
Plasmatic glucose	This measure will be evaluate before the nutritional intervention
Plasmatic glucose	This measure will be evaluate 30 min after the nutritional intervention
Plasmatic glucose	This measure will be evaluate 60 min after the nutritional intervention
Plasmatic glucose	This measure will be evaluate 90 min after the nutritional intervention
Plasmatic glucose	This measure will be evaluate 120 min after the nutritional intervention
Plasmatic insulin	This measure will be evaluate before the nutritional intervention
Plasmatic insulin	This measure will be evaluate 30 min after the nutritional intervention
Plasmatic insulin	This measure will be evaluate 60 min after the nutritional intervention
Plasmatic insulin	This measure will be evaluate 90 min after the nutritional intervention
Plasmatic insulin	This measure will be evaluate 120 min after the nutritional intervention

Collaborators and Investigators

• Sponsor: Universidade Federal do Rio de Janeiro
• Investigators: Principal Investigator: Thiago Alvares, PhD, Universidade Federal do Rio de Janeiro

Publications and helpful links

General Publications

• Volino-Souza M, de Oliveira GV, Conte-Junior CA, Alvares TS. Effect of microencapsulated watermelon (Citrullus Lanatus) rind on flow-mediated dilation and tissue oxygen saturation of young adults. Eur J Clin Nutr. 2022 Sep 15. doi: 10.1038/s41430-022-01200-8. Online ahead of print.

Study record dates

Study Major Dates

• Study Start (Actual): March 1, 2021
• Primary Completion (Actual): June 30, 2022
• Study Completion (Actual): July 31, 2022

Study Registration Dates

• First Submitted: February 23, 2021
• First Submitted That Met QC Criteria: March 1, 2021
• First Posted (Actual): March 4, 2021

Study Record Updates

• Last Update Posted (Actual): December 22, 2022
• Last Update Submitted That Met QC Criteria: December 21, 2022
• Last Verified: December 1, 2022

More Information

Terms related to this study

• Keywords: nitric oxide; endothelial function; nitrate; L-citrulline
• Additional Relevant MeSH Terms: Cardiovascular Diseases
• Other Study ID Numbers: E-26/202.905/2019

Drug and device information, study documents

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