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CompletedNCT04781595Updated Dec 22, 2022

Watermelon and Beetroot Products on Endothelial Function

An interventional study of Watermelon and Beetroot in Healthy Young and Older People With Cardiovascular Disease Risk, sponsored by Universidade Federal do Rio de Janeiro. Completed at 1 site in Brazil. Open to participants aged 18 Years to 85 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2022-12-22.

Sponsored by Universidade Federal do Rio de Janeiro · Not applicable, Interventional, and Prevention

Phase
Not applicable
Study type
Interventional
Enrollment
12
Allocation
Randomized
Ages
18 Years to 85 Years
Sex
All
01

Study summary

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.

02

Conditions studied

  • Healthy Young
  • Older People With Cardiovascular Disease Risk

Keywords

  • endothelial function
  • L-citrulline
  • nitrate
  • nitric oxide
03

In context

Cardiovascular Diseases

4,904 studies on the registry are indexed under Cardiovascular Diseases; 919 are open to participants now.

This study's enrollment of 12 is below the median of 100 across 2,738 interventional studies indexed under Cardiovascular Diseases.

Browse Cardiovascular Diseases studies →

Lead sponsor

Universidade Federal do Rio de Janeiro is the lead sponsor of 120 studies on the registry; 11 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years to 85 Years
Sexes eligible
All
Accepts healthy volunteers
Yes

Inclusion criteria

  • 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

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
05

Study design

Phase
Not applicable
Primary purpose
Prevention
Allocation
Randomized
Intervention model
Crossover assignment
Masking
Double (Participant, Investigator)
Enrollment
12 participants (actual)

Study arms

  • Active comparator
    Watermelon

    Watermelon powder containing 3 g of L-citrulline.

    Dietary Supplement: Watermelon

  • Active comparator
    Beetroot

    Beetroot powder containing 8 mmol of nitrate.

    Dietary Supplement: Beetroot

  • Active comparator
    Watermelon + beetroot

    Watermelon powder containing 3 g of L-citrulline and Beetroot powder containing 8 mmol of nitrate.

    Dietary Supplement: Watermelon + beetroot

  • Placebo comparator
    Placebo

    Maltodextrin

    Dietary Supplement: Placebo

Interventions

  • Dietary supplementWatermelon

    A single dose of watermelon powder containing 3g of L-citrulline

  • Dietary supplementBeetroot

    A single dose of beetroot powder containing 8 mmol of nitrate

  • Dietary supplementWatermelon + beetroot

    A single dose of watermelon and beetroot powder containing 3g of L-citrulline and 8 mmol of nitrate

  • Dietary supplementPlacebo

    A single dose of maltodextrin

06

What researchers measure

Primary outcomes

  1. Flow-mediated dilation (FMD)

    Time frame: This measure will be evaluate before the nutritional intervention

  2. Flow-mediated dilation (FMD)

    Time frame: This measure will be evaluate 60 minutes after the nutritional intervention

  3. Flow-mediated dilation (FMD)

    Time frame: This measure will be evaluate 120 minutes after the nutritional intervention

  4. Muscle oxygen saturation

    Time frame: This measure will be evaluate before the nutritional intervention

  5. Muscle oxygen saturation

    Time frame: This measure will be evaluate 30 minutes after the nutritional intervention

  6. Muscle oxygen saturation

    Time frame: This measure will be evaluate 60 minutes after the nutritional intervention

  7. Muscle oxygen saturation

    Time frame: This measure will be evaluate 90 minutes after the nutritional intervention

  8. Muscle oxygen saturation

    Time frame: This measure will be evaluate 120 minutes after the nutritional intervention

Secondary outcomes

  1. Plasmatic amino acids

    Time frame: This measure will be evaluate before the nutritional intervention

  2. Plasmatic amino acids

    Time frame: This measure will be evaluate 30 minutes after the nutritional intervention

  3. Plasmatic amino acids

    Time frame: This measure will be evaluate 60 minutes after the nutritional intervention

  4. Plasmatic amino acids

    Time frame: This measure will be evaluate 90 minutes after the nutritional intervention

  5. Plasmatic amino acids

    Time frame: This measure will be evaluate 120 minutes after the nutritional intervention

  6. Plasmatic glucose

    Time frame: This measure will be evaluate before the nutritional intervention

  7. Plasmatic glucose

    Time frame: This measure will be evaluate 30 min after the nutritional intervention

  8. Plasmatic glucose

    Time frame: This measure will be evaluate 60 min after the nutritional intervention

  9. Plasmatic glucose

    Time frame: This measure will be evaluate 90 min after the nutritional intervention

  10. Plasmatic glucose

    Time frame: This measure will be evaluate 120 min after the nutritional intervention

  11. Plasmatic insulin

    Time frame: This measure will be evaluate before the nutritional intervention

  12. Plasmatic insulin

    Time frame: This measure will be evaluate 30 min after the nutritional intervention

  13. Plasmatic insulin

    Time frame: This measure will be evaluate 60 min after the nutritional intervention

  14. Plasmatic insulin

    Time frame: This measure will be evaluate 90 min after the nutritional intervention

  15. Plasmatic insulin

    Time frame: This measure will be evaluate 120 min after the nutritional intervention

07

Study locations

1 site
  • Universidade Federal do Rio de Janeiro
    Macaé, Rio De Janeiro 27979-000, Brazil
08

References and documents

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. 2023 Jan;77(1):71-74. doi: 10.1038/s41430-022-01200-8. Epub 2022 Sep 15. PubMed 36109652 ↗
09

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Dec 22, 2022, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT04781595
Lead sponsor
Universidade Federal do Rio de Janeiro
Responsible party
Thiago Alvares (Principal Investigator, Universidade Federal do Rio de Janeiro) — Principal investigator
First posted
Mar 4, 2021
Start date
Mar 1, 2021
Primary completion
Jun 30, 2022
Completion
Jul 31, 2022
Last update
Dec 22, 2022

Study contacts

Thiago Alvares, PhD
principal investigator · Universidade Federal do Rio de Janeiro

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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