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Effect of Grape Seed Extract on Blood Pressure

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT00869193
Recruitment Status : Completed
First Posted : March 25, 2009
Last Update Posted : August 28, 2009
University of Edinburgh
Information provided by:
Unilever R&D

Brief Summary:
The purpose of this study is to determine whether an 8-week intervention with grape seed extract is effective in reducing daytime ambulatory blood pressure in male and postmenopausal female with elevated daytime blood pressure values.

Condition or disease Intervention/treatment Phase
Elevated Blood Pressure Dietary Supplement: Grape seed extract Dietary Supplement: Microcrystalline cellulose (placebo) Not Applicable

Detailed Description:

Background: High blood pressure is a major risk factor for morbidity and mortality from stroke, heart disease, and end-stage renal disease. Several studies have shown that dietary polyphenols derived from fruits and vegetables (including those from grape products) can lower blood pressure in both normotensive and hypertensive subjects.

Study objectives: Primary objective: To study, in subjects with elevated blood pressure levels, the effects of grape seed extract high in polyphenols, on daytime ambulatory systolic and diastolic blood pressure (SBP and DBP, respectively). Secondary objective: To explore mechanistic pathways responsible for the blood pressure lowering efficacy in case a blood pressure lowering effect is shown.

Study population: Each treatment group will consist of 35 men and postmenopausal women (35-75 years of age) with daytime SBP between 120 and 159 mmHg. The total number of subjects will be 70.

Study design: This study will have a randomized, double-blind, placebo-controlled parallel design with 2 treatments, a 1-week run-in period, and an 8-week intervention period. The 2 treatments will consist of placebo capsules and capsules with grape seed extract.

Study outcomes: Daytime ambulatory blood pressure (ABP) will be measured every 20 minutes for 2 x 12 hours at baseline and 2 x 12 hours at the end of intervention. Furthermore, before and after the intervention period, 24-hour urine will be collected and 2 blood samples will be taken in order to investigate mechanistic pathways and platelet function.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 70 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple (Participant, Investigator, Outcomes Assessor)
Official Title: Effect of Grape Seed Extract High in Polyphenols on Blood Pressure in Subjects With Elevated Blood Pressure Levels
Study Start Date : March 2009
Actual Primary Completion Date : July 2009
Actual Study Completion Date : July 2009

Resource links provided by the National Library of Medicine

Arm Intervention/treatment
Active Comparator: Grape seed
Grape seed extract
Dietary Supplement: Grape seed extract
Subjects will daily consume one capsule with grape seed extract for 8 weeks.
Other Name: Polyphenol

Placebo Comparator: Placebo
Microcrystalline cellulose
Dietary Supplement: Microcrystalline cellulose (placebo)
Subjects will daily consume one capsule with microcrystalline cellulose for 8 weeks.

Primary Outcome Measures :
  1. Difference between treatment and placebo in changes from baseline of ambulatory systolic and diastolic blood pressure [ Time Frame: 8 weeks of intervention ]

Secondary Outcome Measures :
  1. Difference between treatment and placebo in changes from baseline of mechanistic markers in plasma and/or urine (vasoactive factors and markers of polyphenol metabolism) and platelet function (only measured in case of a relevant BP-lowering effect) [ Time Frame: 8 weeks of intervention ]

Information from the National Library of Medicine

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, Learn About Clinical Studies.

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Ages Eligible for Study:   35 Years to 75 Years   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Male and postmenopausal female subjects in the age ≥ 35 and ≤ 75 at start of the study
  • BMI ≥ 18.5 and ≤ 30.0 kg/m2
  • Apparently healthy: no reported diseases that may affect study results and pre-selected blood parameters within normal range
  • Informed consent signed
  • Willing to refrain from supplements, food products, diets and drugs that may interfere with the outcomes of the study

Exclusion Criteria:

  • Mean of 6-hour ambulatory SBP < 120 mmHg, > 159 mmHg and/or DBP > 99 mmHg
  • 10-year risk mortality risk on CVD > 10% according to NHG standard M84. For subjects > 65 years of age and SBP ≥ 140 mmHg the study physician will assess eligibility
  • Irregular pulse or pulse < 50 or > 100 bpm
  • Intense exercise >10 h/w
  • Reported weight loss/gain > 10% of body weight in the 6 month preceding pre-study examination
  • The habit of smoking during the past year

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT00869193

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Unilever R&D Vlaardingen
Vlaardingen, Netherlands, 3133 AT
Sponsors and Collaborators
Unilever R&D
University of Edinburgh
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Principal Investigator: Rouyanne T Ras, Msc Unilever R&D Vlaardingen
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Responsible Party: Rouyanne Ras, Unilever R&D Vlaardingen Identifier: NCT00869193    
Other Study ID Numbers: 08050V
First Posted: March 25, 2009    Key Record Dates
Last Update Posted: August 28, 2009
Last Verified: August 2009
Keywords provided by Unilever R&D:
Blood pressure
Grape seed
Additional relevant MeSH terms:
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Vascular Diseases
Cardiovascular Diseases
Grape Seed Extract
Antineoplastic Agents, Phytogenic
Antineoplastic Agents
Molecular Mechanisms of Pharmacological Action
Protective Agents
Physiological Effects of Drugs