The Impact of Inorganic Nitrate-rich Beetroot Juice on Microvascular Blood Flow and Cognitive Function

Not Applicable

Completed

• Conditions: Post Menopausal
• Interventions: Dietary Supplement: Concentrated beetroot juice; Dietary Supplement: Nitrate depleted beetroot juice; Dietary Supplement: Nitrate depleted beetroot juice + potassium nitrate (KNO3)

• Registration Number: NCT05810974
• Lead Sponsor: University of Reading

Brief Summary

Cardiovascular disease (CVD) is one of the leading causes of mortality worldwide. Inorganic nitrate found in beetroot and green leafy vegetables has been demonstrated to reduce cardiovascular disease risk factors including reducing blood pressure and the stiffness of blood vessels by increasing levels of a compound called nitric oxide. Much of the research to date has focused on the large blood vessels, and little is known about the impact of inorganic nitrate on smaller blood vessels which could be related to cognitive function.

The majority of beneficial effects with inorganic nitrate have been observed within young healthy populations. However, it is known that after the menopause women are at an increased risk of cardiovascular disease and have reduced levels of nitric oxide in their body; this could also contribute to the cognitive decline also observed post-menopause. This trial will investigate the impact of inorganic nitrate from beetroot juice on the blood flow in small blood vessels and on cognitive function in postmenopausal women. The hypothesis of the study is that the nitrate in beetroot juice will increase circulating nitric oxide that will then increase blood flow in small blood vessels and improve cognitive function.

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2023-02-08
• Study Start: 2023-03-14
• Status Verified: 2023-04
• Study First Submitted QC: 2023-04-11
• Study First Posted: 2023-04-13
• Primary Completion: 2023-07-07
• Study Completion: 2023-08-07
• Last Update Submitted: 2024-11-20
• Last Update Posted: 2024-11-22

Recruitment & Eligibility

• Status: COMPLETED
• Sex: Female
• Target Recruitment: 20

Inclusion Criteria

• Apparently healthy post-menopausal women (age over 45)
• Able to understand information sheet and willing to comply with the study protocol and able to give informed consent
• Not having menstrual period for 12 months

Exclusion Criteria

• Blood pressure <90/60 or > 140/90 mmHg
• Medical history of myocardial infarction, angina, thrombosis, stroke, cancer, high cholesterol, liver, renal, respiratory or bowel diseases or diabetes or other endocrine disorder
• BMI>30
• Any tobacco and/or nicotine users (or quit within the last 6 months)
• Current use of antihypertensive medication
• Alcohol intake > 14 units/week
• Vigorous exercise > 3 times/ week
• Antihypertensive medication users
• People who have had hysterectomy
• Currently taking hormone replacement therapy or selective oestrogen receptor modulator

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Concentrated beetroot juice	Concentrated beetroot juice	-
Nitrate-depleted beetroot juice	Nitrate depleted beetroot juice	-
Nitrate depleted beetroot juice + potassium nitrate (KNO3)	Nitrate depleted beetroot juice + potassium nitrate (KNO3)	-

Primary Outcome Measures

Name	Time	Method
Change from baseline endothelial dependent microvascular function as laser Doppler imaging (LDI) with iontophoresis	At baseline (t= 0.5 hours) and t= 3 hours	Measurements will be taken by LDI with iontophoresis of endothelium-dependent (acetylcholine (ACh))
Change from baseline cognitive function. Domain: Executive function 2	At baseline (t= 0 hours) and t=2.5 hours	-Stroop Task
Change from baseline endothelial independent microvascular function as laser Doppler imaging (LDI) with iontophoresis	At baseline (t= 0.5 hours) and t= 3 hours	Measurements will be taken by LDI of endothelium-independent (sodium nitroprusside (SNP))
Change from baseline cognitive function. Domain: Episodic memory	At baseline (t= 0 hours) and t=2.5 hours	-Rey Auditory Verbal Learning Test (RAVLT) task; Cognitive domains will be assessed by using the Gorilla online research tools.
Change from baseline cognitive function. Domain: Executive function 1	At baseline (t= 0 hours) and t=2.5 hours	-Digit Span Task

Secondary Outcome Measures

Name	Time	Method
Change in blood pressure	[Time Frame: At baseline (t= 0 hours) and 15 minute intervals until t= 2.5 hours.]	Systolic and Diastolic Blood pressure measurement by automated device

Trial Locations

Locations (1)

University of Reading; 🇬🇧 Reading, UK, United Kingdom