The Impact of Watermelon Juice on Blood Pressure

The Impact of Watermelon Juice on Blood Pressure in Young Healthy Adults

L-citrulline is found naturally in watermelon. Recently interest has increased for this amino acid due to potential health benefits. Notably, L-citrulline has the potential to lead to dilation of blood vessels due to its involvement in the production of nitric oxide.

The study will be an acute single blind, randomised controlled, crossover intervention study in healthy, young volunteers. Participants receive either the test watermelon drink or control drink (water). Blood samples and vascular measures (by a single-cuff based method) will be measured at baseline. Vascular measures will be repeated at 15-minute intervals between 0-2 hours and a second blood sample will be drawn at 1.5 hours to coincide with the estimated peak plasma L-citrulline. Citrulline, arginine and nitric oxide metabolites will be measured in the blood samples.

Study Overview

• Status: Active, not recruiting
• Conditions: Healthy Aging
• Intervention / Treatment: Other: Watermelon Juice; Other: Water

• Study Type: Interventional
• Enrollment (Actual): 10
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United Kingdom
  • UK
    • Reading, UK, United Kingdom, RG6 6AH
      • University of Reading

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 30 years (Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Males and females
• 18-30 years
• Healthy (as per exclusion criteria)
• Able to understand information sheet
• Willing to comply with the study protocol
• Able to give informed consent.

Exclusion Criteria:

• Medical history of myocardial infarction
• Medical history of angina
• Medical history of thrombosis
• Medical history of stroke
• Medical history of cancer
• Medical history of high cholesterol
• Medical history of liver diseases
• Medical history of renal diseases
• Medical history of respiratory diseases
• Medical history of bowel diseases
• Medical history of diabetes
• Medical history of other endocrine disorders
• BMI <18.5 kg/m2 or >25 kg/m2
• Blood pressure <90/60 or > 140/90 mmHg
• Current use of antihypertensive medication
• Pregnant or lactating
• Alcohol intake > 14 units/week
• Cigarette smoker (or quit within the last 6 months)
• Vigorous exercise > 3 times/ week

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: Active; Watermelon juice	Other: Watermelon Juice; 500 mL watermelon juice (What a Melon), containing ~1 g of L-citrulline.
Other: Control; Low nitrate water.	Other: Water; 500 mL low nitrate water

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in blood pressure	Blood pressure by automated device	At baseline (t= 0 hours) and 15 minute intervals until t= 2 hours.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in NOx (nitric oxide metabolites)	Plasma nitrate and nitrite concentration	At baseline (t= 0 hours) and t=1.5 hours.
Change in l-arginine	L-arginine concentration	At baseline (t= 0 hours) and t=1.5 hours.
Change in l-citrulline	L-citrulline concentration	At baseline (t= 0 hours) and t=1.5 hours.

Collaborators and Investigators

• Sponsor: University of Reading

Study record dates

Study Major Dates

• Study Start (Actual): January 8, 2020
• Primary Completion (Actual): December 30, 2022
• Study Completion (Estimated): December 30, 2024

Study Registration Dates

• First Submitted: January 7, 2020
• First Submitted That Met QC Criteria: March 29, 2020
• First Posted (Actual): March 31, 2020

Study Record Updates

• Last Update Posted (Estimated): November 22, 2024
• Last Update Submitted That Met QC Criteria: November 20, 2024
• Last Verified: January 1, 2024

More Information

Terms related to this study

• Keywords: Blood pressure; L-citrulline; Watermelon
• Other Study ID Numbers: 34/19

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
• product manufactured in and exported from the U.S.: No