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

Colorado State University58 enrolled

Overview

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.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

TRIPLE

Enrollment

Conditions

Hypertension Aging

Eligibility

Sex: MALEMin age: 45 YearsMax age: 70 YearsHealthy volunteers:

Medical Language ↔ Plain English

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

Outcomes

Primary Outcomes

Reactive hyperemia index

Endothelial function assessed as reactive hyperemia index using peripheral arterial tonometry (EndoPat)