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Effect of Grape Seed Extract on Blood Pressure

This study has been completed.
University of Edinburgh
Information provided by:
Unilever R&D Identifier:
First received: March 24, 2009
Last updated: August 27, 2009
Last verified: August 2009
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 Intervention
Elevated Blood Pressure Dietary Supplement: Grape seed extract Dietary Supplement: Microcrystalline cellulose (placebo)

Study Type: Interventional
Study Design: 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

Resource links provided by NLM:

Further study details as provided by Unilever R&D:

Primary Outcome Measures:
  • 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:
  • 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 ]

Enrollment: 70
Study Start Date: March 2009
Study Completion Date: July 2009
Primary Completion Date: July 2009 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
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.

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.


Ages Eligible for Study:   35 Years to 75 Years   (Adult, Senior)
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
  Contacts and Locations
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Please refer to this study by its identifier: NCT00869193

Unilever R&D Vlaardingen
Vlaardingen, Netherlands, 3133 AT
Sponsors and Collaborators
Unilever R&D
University of Edinburgh
Principal Investigator: Rouyanne T Ras, Msc Unilever R&D Vlaardingen
  More Information

Responsible Party: Rouyanne Ras, Unilever R&D Vlaardingen Identifier: NCT00869193     History of Changes
Other Study ID Numbers: 08050V
Study First Received: March 24, 2009
Last Updated: August 27, 2009

Keywords provided by Unilever R&D:
Blood pressure
Grape seed

Additional relevant MeSH terms:
Vascular Diseases
Cardiovascular Diseases
Grape Seed Extract
Antineoplastic Agents, Phytogenic
Antineoplastic Agents
Molecular Mechanisms of Pharmacological Action
Protective Agents
Physiological Effects of Drugs processed this record on August 21, 2017