Blueberries for Improving Vascular Endothelial Function in Postmenopausal Women With Elevated Blood Pressure

Summary

Postmenopausal women are at an increased risk of developing cardiovascular disease (CVD) largely due to accelerated aging-related modifications to vascular health following menopause. The vascular endothelium is responsible for producing chemicals that are essential for proper vasodilation and blood flow and therefore is involved in maintaining normal blood pressure. A major modification that occurs during aging and is accelerated during menopause is termed vascular endothelial dysfunction which is characterized by impaired endothelium-dependent dilation. This can lead to increased blood pressure, atherosclerosis, and increased risk of CVD and death. Nitric oxide (NO) is a chemical produced by the endothelium and is essential for normal endothelial function and cardiovascular health. Vascular endothelial dysfunction is primarily caused by reduced NO bioavailability secondary to excessive oxidative stress. Approximately 3/4 of postmenopausal women have elevated blood pressure or hypertension which further worsens endothelial function and increases CVD risk through increased oxidative stress and inflammation. Blueberries are rich in phytochemicals including anthocyanins, phenolic acids, and pterostilbene. These phytochemicals and their metabolites are known to attenuate oxidative stress and inflammation. The overall goal of the current study is to assess the efficacy of blueberries to improve vascular endothelial dysfunction in this high-risk population and to gain insight into underlying mechanisms. 58 postmenopausal women with elevated blood pressure and stage 1-HTN will be asked to consume 22 grams freeze-dried blueberry powder or placebo powder per day for 12 weeks. Vascular endothelial function will be assessed at baseline and 12 weeks. Measurements indicative of vascular nitric oxide production, oxidative stress, inflammation, cardiometabolic health, cognitive function, and blueberry phytochemical metabolism will be measured at baseline and 12 weeks. Blood pressure will be assessed at baseline and 4, 8, and 12 weeks.

Conditions

• Menopause
• Elevated Blood Pressure
• Hypertension
• Endothelial Dysfunction

Interventions

DIETARY_SUPPLEMENT

Blueberry Powder

22 g/day freeze-dried blueberry powder for 12 weeks

DIETARY_SUPPLEMENT

Placebo Powder

22 g/day placebo powder for 12 weeks

Sponsors & Collaborators

• U.S. Highbush Blueberry Council

  collaborator OTHER

• Colorado State University

  lead OTHER

Principal Investigators

• Sarah A. Johnson, PhD, RDN · Department of Food Science and Human Nutrition, Colorado State University

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

TRIPLE

Model

PARALLEL

Eligibility

Min Age

45 Years

Max Age

65 Years

Sex

FEMALE

Healthy Volunteers

No

Timeline & Regulatory

Start

2017-12-02

Primary Completion

2021-09-30

Completion

2021-09-30

Countries

• United States

Study Locations