Wild Blueberries and Cardiovascular Health in Middle-aged/Older Men and Postmenopausal Women

NCT ID: NCT04530916

Last Updated: 2025-11-17

Basic Information

• Recruitment Status: ACTIVE_NOT_RECRUITING
• Clinical Phase: PHASE1/PHASE2
• Total Enrollment: 58 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2020-01-01
• Study Completion Date: 2025-12-31

Brief Summary

Cardiovascular disease (CVD) is the leading cause of morbidity and mortality worldwide. Aging is the primary risk factor for CVD, in large part due to adverse modifications to the arteries. These modifications include vascular endothelial dysfunction and arterial stiffness. Vascular endothelial dysfunction is an initiating step in atherosclerosis, and is primarily caused by reduced nitric oxide (NO) bioavailability secondary to excessive superoxide-driven oxidative stress and inflammation. Endothelial dysfunction leads to arterial stiffness and the development of hypertension (HTN) which further increases CVD. Greater than 2/3 of the US population has elevated blood pressure or stage 1-HTN. As such, interventions that improve vascular endothelial dysfunction by increasing NO bioavailability and mitigating excessive oxidative stress and inflammation are needed. Blueberries are rich in bioactive compounds including flavonoids, phenolic acids, and pterostilbene. These compounds and their metabolites have been shown to attenuate oxidative stress and inflammation. The primary goal of this study is to assess the efficacy of blueberries to improve reduce blood pressure and improve vascular endothelial dysfunction and arterial stiffness in middle-aged/older men with elevated blood pressure or stage 1-HTN.

Conditions

Hypertension; Aging; Endothelial Dysfunction; Men

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: BASIC_SCIENCE
• Blinding Strategy: TRIPLE

Study Groups

Blueberry

22 g blueberry powder per day

Group Type: EXPERIMENTAL

Blueberry Powder

Intervention Type: DIETARY_SUPPLEMENT

22 g/day wild blueberry powder

Control

22 g placebo control powder per day

Group Type: PLACEBO_COMPARATOR

Placebo Powder

Intervention Type: DIETARY_SUPPLEMENT

22 g/day placebo powder

Interventions

Blueberry Powder

22 g/day wild blueberry powder

Intervention Type: DIETARY_SUPPLEMENT

Placebo Powder

22 g/day placebo powder

Intervention Type: DIETARY_SUPPLEMENT

Eligibility Criteria

Inclusion Criteria

• Men and postmenopausal women
• Aged 45-70 years
• Elevated blood pressure or stage 1-Hypertension
• Ability to provide informed consent

Exclusion Criteria

• Have had a menstrual cycle within the past year
• Blood Pressure < 120 (systolic BP) or ≥ 140/90 mm Hg
• Reactive hyperemia index > 3.00%
• Taking > 1 antihypertensive medication, taking 1 antihypertensive medication more than 1 time per day, and/or taking the antihypertensive medication for < 3 months
• Diagnosed cancer, cardiovascular disease, diabetes, or gastrointestinal, kidney, liver, lung, and/or pancreatic disease
• Triglycerides > 350 mg/dL, low-density lipoprotein cholesterol (LDL-C) ≥ 190 mg/dL, hemoglobin A1c ≥ 6.5%, and/or taking a lipid-lowering or glucose-lowering medication
• Testosterone or estrogen replacement therapy use 6 months prior to study start
• Weight change ≥ 3 kg in the past 3 months, actively trying to lose weight, or unwilling to remain weight stable throughout the study
• Current smokers or history of smoking in the past 12 months
• Binge and/or heavy drinker (>3 drinks on any given occasion and/or >7 drinks/week for women, and >4 drinks on any given occasion and/or >14 drinks/week for men)
• Body mass index < 18.5 or > 40 kg/m2
• Antibiotic therapy within past two months
• Allergies or contraindication to study treatments or procedures

• Minimum Eligible Age: 45 Years
• Maximum Eligible Age: 70 Years
• Eligible Sex: MALE
• Accepts Healthy Volunteers: Yes

Sponsors

Colorado State University

OTHER

Sponsor Role: lead

Wild Blueberry Association of North America

OTHER

Sponsor Role: collaborator

Responsible Party

Responsibility Role: SPONSOR

Locations

Food and Nutrition Clinical Research Laboratory

Fort Collins, Colorado, United States

Countries

United States

References

Johnson SA, Figueroa A, Navaei N, Wong A, Kalfon R, Ormsbee LT, Feresin RG, Elam ML, Hooshmand S, Payton ME, Arjmandi BH. Daily blueberry consumption improves blood pressure and arterial stiffness in postmenopausal women with pre- and stage 1-hypertension: a randomized, double-blind, placebo-controlled clinical trial. J Acad Nutr Diet. 2015 Mar;115(3):369-377. doi: 10.1016/j.jand.2014.11.001. Epub 2015 Jan 8.

Reference Type: BACKGROUND

PMID: 25578927 (View on PubMed)

Other Identifiers

1775

Identifier Type: -

Identifier Source: org_study_id