Nitrate and Vitamin C on Vascular Health Oxidative Stress

NCT ID: NCT04283630

Last Updated: 2020-02-25

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 23 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2018-02-05
• Study Completion Date: 2019-12-13

Brief Summary

The objective of this study is to examine whether the co-administration of dietary nitrate combined with vitamin C for 4 weeks in patients at risk for CVD would yield robust effects on endothelial function using blood measures and a non-invasive technique (Peripheral Artery Tonometry) compared to dietary nitrate supplementation alone.

Detailed Description

This is a 10 week randomized, cross-over, double-blinded, placebo-controlled study. This study was designed to compare the magnitude changes in RHI (primary outcome), plasma NO metabolites (nitrate and nitrite), and plasma vitamin C, plasma oxidized LDL, and blood (secondary outcome) following treatment with inorganic nitrate and vitamin C placebo (N) and inorganic nitrate combined with vitamin C (NC). Following baseline testing, eligible subjects were randomized to receive either treatment (N) or treatment (NC) for 4 weeks (period1), and participants were then crossed over to the alternate treatment for another 4 weeks (period 2). There was a 2-week washout at crossover.

Conditions

Endothelial Dysfunction

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: CROSSOVER
• Primary Study Purpose: TREATMENT
• Blinding Strategy: DOUBLE

Study Groups

Randomization and Dietary supplement Interventions

The dietary nitrate supplement was provided in the form of commercial beetroot juice (Sport Beet IT shot, Heartbeet Ltd) for all participants, whereas vitamin C and the placebo were provided as supplement capsules. Participants were asked to consume one dose/shot of sport Beet IT (70ml) that delivers on average 300-400mg of inorganic nitrate every day in the morning during the four-week study period, except for the test days and washout weeks. Accordingly, the participant were asked to consume the concentrated beetroot juice with breakfast meals, and then the vitamin C supplement (1000 mg)or placebo at the same time one-hour post beetroot juice supplementation

Group Type: ACTIVE_COMPARATOR

Dietary nitrate in the form of beetroot juice for all participnats

Intervention Type: DIETARY_SUPPLEMENT

participants asked to consume dietary nitrate in the form of beet juice everyday in the morning and then one hour later, the vitamin C capsules.

Nature Made vitamin c 1000 mg

Intervention Type: DIETARY_SUPPLEMENT

vitamin C and the placebo were provided as supplement capsules. Participants were asked to consume one dose/shot of sport Beet IT (70ml) that delivers on average 300-400mg of inorganic nitrate every day in the morning during the four-week study period, except for the test days and washout weeks. Accordingly, the participant were asked to consume the daily vitamin C supplement (1000 mg) or placebo one-hour post beetroot juice supplementation.

Placebo

Vitamin C placebo was matched with the active vitamin c capsules in shape, color, and size.

Group Type: PLACEBO_COMPARATOR

Dietary nitrate in the form of beetroot juice for all participnats

Intervention Type: DIETARY_SUPPLEMENT

participants asked to consume dietary nitrate in the form of beet juice everyday in the morning and then one hour later, the vitamin C capsules.

Placebo

Intervention Type: DIETARY_SUPPLEMENT

Vitamin C matched Placebo capsules that made from starch.

Interventions

Dietary nitrate in the form of beetroot juice for all participnats

participants asked to consume dietary nitrate in the form of beet juice everyday in the morning and then one hour later, the vitamin C capsules.

Intervention Type: DIETARY_SUPPLEMENT

Nature Made vitamin c 1000 mg

vitamin C and the placebo were provided as supplement capsules. Participants were asked to consume one dose/shot of sport Beet IT (70ml) that delivers on average 300-400mg of inorganic nitrate every day in the morning during the four-week study period, except for the test days and washout weeks. Accordingly, the participant were asked to consume the daily vitamin C supplement (1000 mg) or placebo one-hour post beetroot juice supplementation.

Intervention Type: DIETARY_SUPPLEMENT

Placebo

Vitamin C matched Placebo capsules that made from starch.

Intervention Type: DIETARY_SUPPLEMENT

Other Intervention Names

Sport Beet IT shot

Eligibility Criteria

Inclusion Criteria

• Age: between 50 and 70 years
• Body mass index (BMI) of 18.5-34.9 kg/m2
• Reactive hyperemia index (RHI) of < or equal to 2
• High cholesterol levels with LDL concentrations (>130 mg/dL)
• Not receiving any lipid lowering therapy.
• Non-smokers

Exclusion Criteria

• Evidence of overt atherosclerotic disease (i.e., documented medical history of coronary artery disease, peripheral artery disease, cardiovascular disease, and stroke).
• Any surgery or medical history that could confound study results, such as a history of bowel resection, rheumatoid arthritis, inflammatory bowel disease, celiac disease, diabetes, uncontrolled hypertension (systolic blood pressure >160 mm Hg or diastolic blood pressure >100 mm Hg), controlled hypertension on clonidine medication.
• Participants were ineligible if they had been diagnosed with the following medical conditions such as active cancer, severe anemia (Hb < 10mg/dL), hepatic or renal disease, heart failure, or finger deformities.
• HIV-positive patients on combination antiretroviral therapy because of potential pharmacokinetic interactions with beetroot juice were excluded.
• Participants were also excluded if they reported taking any form of hormone replacement therapy (estrogens, progesterone, and testosterone), multivitamin supplements that provides >100% of RDA, or any of the following medications that attenuate nitrate conversion to NO: proton pump inhibitors (PPI) and antibiotics.
• Participants who consumed greater than 6 drinks of alcohol (any form) per week, performed structured resistance or aerobic training for more than 1-hour four times per week, or participated in other clinical intervention within the previous 30 days were excluded from the study.
• Eligible subjects were asked to avoid using the mouthwash before and throughout the study duration. In addition, enrolled participants were advised to consume low- vitamin c diet throughout the study. They were provided at the beginning of the study with a list of high vitamin C foods/fortified foods to avoid during the study.

• Minimum Eligible Age: 50 Years
• Maximum Eligible Age: 70 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

David Travis Thomas

OTHER

Sponsor Role: lead

Responsible Party

David Travis Thomas

Associate Professor

Responsibility Role: SPONSOR_INVESTIGATOR

Locations

University of Kentucky

Lexington, Kentucky, United States

University of Kentucky

Lexington, Kentucky, United States

Countries

United States

References

Basaqr R, Skleres M, Jayswal R, Thomas DT. The effect of dietary nitrate and vitamin C on endothelial function, oxidative stress and blood lipids in untreated hypercholesterolemic subjects: A randomized double-blind crossover study. Clin Nutr. 2021 Apr;40(4):1851-1860. doi: 10.1016/j.clnu.2020.10.012. Epub 2020 Oct 14.

Reference Type: DERIVED

PMID: 33115598 (View on PubMed)

Other Identifiers

17-0412-F3R

Identifier Type: -

Identifier Source: org_study_id