Dietary Nitrate on Blood Pressure and Cardiovascular Disease Risk Factors

Study Overview
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Brief Summary
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The project aims to determine the effect of a high-nitrate dietary intervention on blood pressure and markers of vascular function compared to a low-nitrate intervention in people with elevated blood pressure. Half of the participants will receive the high-nitrate dehydrated vegetable intervention, while the other half will receive the low-nitrate dehydrated vegetable intervention.This project will advance the current hypothesis on the therapeutic link between dietary nitrate and high blood pressure, and potentially derive impactful recommendations for individuals at risk of hypertension.

Detailed Description
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Diets rich in fruits and in particular, vegetables, reduce blood pressure (BP) and the risk of cardiovascular events. Increasingly, attention is being given to high-nitrate containing vegetables, with emerging evidence that it might represent a source of vasoactive nitric oxide. Clinical data to date uniformly suggest an acute vasoprotective role of dietary nitrate administration and a BP-lowering effect. Whether the vascular effects extend to long-term intake and in individuals with elevated blood pressure is not well known. The investigators hypothesize that consumption of a dietary intervention high in nitrate from vegetable sources will have a greater effect on BP and related vascular parameters than a similar intervention that is low in dietary nitrates.

Official Title
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The Role of Dietary Nitrate on Blood Pressure and Cardiovascular Disease Risk Factors: a Randomized, Controlled Trial in Individuals With Elevated Blood Pressure

Conditions
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Hypertension, Blood Pressure, High

Intervention / Treatment
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* Other: High-nitrate dehydrated vegetable powder
* Other: Low-nitrate dehydrated vegetable powder


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: BMI 18.5-35 kg/m2 Seated systolic blood pressure ≥130 and <160 mmHg Exclusion Criteria: current use of antihypertensive agents history of major cardiovascular events in the last 1 year (stroke or myocardial infarction) stage II hypertension as per JNC7 criteria (systolic BP/ diastolic BP ≥160/100 mmHg) - angina pectoris gastrointestinal (i.e. inflammatory bowel disease, celiac), liver or kidney disease cardiac condition that compromises normal function (e.g. mitral valve disease, heart failure) serum triglyceride >4.5mmol/L major disability or disorder requiring continuous medical attention planned initiation in antihypertensive therapy herb or supplement use that may affect primary outcome consuming >3 servings of vegetables/day (based on semi-quantitative food frequency questionnaire) alcohol use >2 drinks/day chronic or prescribed use of medications including prescription NSAIDs, antacids, warfarin, medications affecting NO synthesis (ie. sildenafil, organic nitrates, etc) use of antibiotics within 3-months of the study start participants should also be willing to refrain from using mouthwash (ie chlorhexidine) for the duration of their participation in the study

Ages Eligible for Study
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Minimum Age: 30 Years
Maximum Age: 60 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: The study will be a randomized, double-blind, controlled parallel study. There will be two experimental arms of 16-week duration, in which participants are assigned to test or control arms under free living conditions in an outpatient setting.
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: High Nitrate Dehydrated Vegetables<br>Participants are given high-nitrate dehydrated vegetable powders contained in opaque sachets. Participants are advised to consume three sachets per day, over the course of three meals, for 16 weeks. | Other: High-nitrate dehydrated vegetable powder<br>* A mixed combination of vegetable powders that are naturally high in nitrate content, such as beet, spinach, and kale<br>|
| Active Comparator: Low-Nitrate Dehydrated Vegetables<br>Participants are given low-nitrate dehydrated vegetable powders contained in three opaque sachets. Participants are advised to consume three sachets per day, over the course of three meals, for 16 weeks. | Other: Low-nitrate dehydrated vegetable powder<br>* A mixed combination of vegetable powders that are naturally low in nitrate content, such as peas, tomato, broccoli, carrots, and brussel sprouts<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Systolic Blood Pressure | Change in systolic blood pressure vs. control at 16 weeks | Baseline, 8 and16 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Mean 24h and Daytime Ambulatory Systolic, Diastolic and Mean Arterial Blood Pressure | Change in mean 24h and daytime ambulatory systolic, diastolic and mean arterial blood pressure vs. control at 16 weeks | Baseline and 16 weeks | 
| Aortic Systolic and Diastolic Blood Pressure | Change in aortic systolic and diastolic blood pressure vs. control at 16 weeks | Baseline, 8 and 16 weeks | 
| Pulse Wave Velocity (PWV) | Change in PWV vs. control at 16 weeks | Baseline and 16 weeks | 
| Augmentation Index (AI) | Change in AI vs. control at 16 weeks | Baseline, 8 and 16 weeks | 
| High Sensitivity C-reactive protein (hs-CRP) | Change in hs-CRP vs. control at 16 weeks | Baseline and 16 weeks | 
| Plasma Lipids | Change in Total-C, LDL-C, HDL-C vs. control at 16 weeks | Baseline and 16 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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nitrate, vegetables