Blood Pressure Lowering Effects of Grape Juice

This study has been completed.
Sponsor:
Collaborator:
Welch's, Inc.
Information provided by:
Boston University
ClinicalTrials.gov Identifier:
NCT00302809
First received: March 13, 2006
Last updated: June 16, 2009
Last verified: June 2009
  Purpose

Recent studies suggest that a diet rich in fruit and vegetables can lower blood pressure, and a number of lines of evidence suggest that grape products may have such an effect. The purpose of this study is to determine whether consuming grape juice lowers blood pressure in individuals with pre-hypertension or stage I hypertension.


Condition Intervention
Hypertension
Dietary Supplement: Concord Grape Juice

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Crossover Assignment
Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
Official Title: Effect of Concord Grape Juice on Blood Pressure and Vascular Function in Subjects With Pre-Hypertension and Stage 1 Hypertension

Resource links provided by NLM:


Further study details as provided by Boston University:

Primary Outcome Measures:
  • Blood pressure measured by 24-hour recorder [ Time Frame: 8 weeks ] [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • Pulse wave velocity [ Time Frame: 8 weeks ] [ Designated as safety issue: No ]
  • Pulse amplitude tonometry [ Time Frame: 8 weeks ] [ Designated as safety issue: No ]
  • Blood pressure during mental tasks [ Time Frame: 8 weeks ] [ Designated as safety issue: No ]

Estimated Enrollment: 60
Study Start Date: March 2006
Study Completion Date: May 2009
Intervention Details:
    Dietary Supplement: Concord Grape Juice
    Approximately 16 oz of grape juice or placebo
Detailed Description:

Elevated blood pressure (BP) is among the most common and important risk factors for atherosclerosis. A number of non-pharmacological therapies have successfully been applied to prevent the development of elevated BP or reduce elevated BP. For example the DASH Study showed that a diet rich in fruits, vegetables and low fat dairy products, and reduced in saturated fat, total fat and cholesterol, substantially lowered blood pressure in normotensive and hypertensive individuals.

Within the past three years a number of small clinical trials have suggested suggest that drinking purple grape juice for a period of 6-12 weeks may lower blood pressure individuals with elevated blood pressure. Other clinical trials have shown that Concord grape juice improves the function of the vascular endothelium, possibly providing an explanation for the beneficial effect. However, there is a need for a prospective, controlled study to determine whether grape juice has a beneficial effect on blood pressure.

The present study will compare the effect of drinking Concord purple grape juice (7 ml/kg or about 16 oz/day for a 70 kg person) and the effect of calorie-matched placebo on 24-hour ambulatory blood pressure, blood pressure reactivity, and vascular function in men and women in the category of "pre-hypertension" (defined as blood pressure greater than 120/80, but less than 149/89 mmHg and Stage 1 hypertension (defined as blood pressure greater than 140/90, but less than 160/100). This study will specifically recruit patients with systolic blood pressure of 130-159 mmHg or diastolic blood pressure of 85-99 mmHg. The study will be double blind and have a crossover design with the order of treatment randomized (grape juice first or placebo first). A dietician will provide all subjects with formal instruction in a low salt diet, which is the current recommended initial therapy for patients with Stage 1 hypertension.

After a 1-week run-in period, subjects will consume each beverage for 8 weeks with a 4-week rest period between treatments. Blood pressure will be measured before and after each treatment period using a 24-hour ambulatory blood pressure recording. After each treatment period, we will measure changes in blood pressure induced by psychological challenge (mental arithmetic and computer tasks) and by the cold pressor test. In order to gain insight into the potential mechanisms of benefit, we will also examine the effects of beverage consumption on endothelial function, stiffness of the central aorta, fasting glucose and insulin, body weight, and markers of systemic inflammation, including CD40 ligand and C-reactive protein. Finally, we will store plasma samples for future investigation of other potential effects of grape juice on the cardiovascular system.

We hypothesize that Concord grape juice will have favorable effects on blood pressure compared to placebo.

  Eligibility

Ages Eligible for Study:   21 Years to 75 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  1. Adult males and females
  2. Body Mass Index (BMI) of less than 35.0 kg/m2
  3. Systolic blood pressure (130-159 mmHg) and/or diastolic blood pressure (85-99 mm Hg) on two screening visits
  4. Subject must be judged to be in good health on the basis of medical history; 5. Subject must not be taking any antihypertensive medications for at least one month prior to the Screening Visit

Exclusion Criteria:

  1. History of clinically defined coronary artery disease, peripheral artery disease, stroke, active gastrointestinal ulcers, renal, or hepatic disease;
  2. History of bleeding disorders or malabsorption syndromes;
  3. Taking drugs for regulating hemostasis, including stable-dose aspirin;
  4. History of active cancer
  5. Females who are pregnant or planning to become pregnant
  6. Use of weight-loss drugs (including over-the-counter and dietary supplements)
  7. Diagnosed diabetes mellitus
  8. Subjects who consume a vegetarian diet
  9. Recent history (within the past 6 months) of alcohol or substance abuse.
  10. Laboratory values outside the following ranges: serum potassium (3.5-5.1 mg/dl), creatinine (0.5-1.3 mg/dl), hematocrit (36-50%), white blood count (4.0-11.0 K/ul), platelet count (150-400 k/ul)
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT00302809

Locations
United States, Massachusetts
Boston Medical Center
Boston, Massachusetts, United States, 02118
Sponsors and Collaborators
Boston University
Welch's, Inc.
Investigators
Principal Investigator: Joseph A Vita, MD Boston University
  More Information

No publications provided by Boston University

Additional publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
Responsible Party: Joseph A. Vita, MD, Boston University
ClinicalTrials.gov Identifier: NCT00302809     History of Changes
Other Study ID Numbers: H-24568
Study First Received: March 13, 2006
Last Updated: June 16, 2009
Health Authority: United States: Institutional Review Board

Keywords provided by Boston University:
Flavonoids
Arterial stiffness
Blood pressure
Endothelium
Inflammation

Additional relevant MeSH terms:
Hypertension
Cardiovascular Diseases
Vascular Diseases

ClinicalTrials.gov processed this record on October 23, 2014