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Effect of a Polyphenol Rich Diet on Vascular and Platelet Function (PPhIT)

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ClinicalTrials.gov Identifier: NCT01319786
Recruitment Status : Completed
First Posted : March 22, 2011
Last Update Posted : October 28, 2015
Sponsor:
Collaborator:
Belfast Health and Social Care Trust
Information provided by (Responsible Party):
Rebecca Noad, Queen's University, Belfast

Brief Summary:

Previous work has shown that increasing fruit and vegetable intake in patients with high blood pressure improves cardiovascular function. Research indicates that this may be partly owing to compounds called polyphenols, which are found in abundance in fruits and vegetables and other foods such as wine, tea and dark chocolate. The investigators now wish to test if consuming fruits and vegetables (including berries which are very rich in polyphenols), as well as dark chocolate, has further benefits for cardiovascular function. A total of 110 subjects with high blood pressure will be recruited and asked to follow a low polyphenol diet (2 portions of fruit and vegetables daily and no berries or dark chocolate) for four weeks (a washout period). They will then be randomised to continue this diet or to consume 6 portions of fruits and vegetables (to include 1 portion berries) and 1 portion of dark chocolate daily for 8 weeks. The fruit, vegetables and dark chocolate will be provided free of charge and delivered to the homes of the participants who are randomised to the high fruit and vegetable arm of the study.

Assessment of microvascular and platelet function will be undertaken before and after consuming this diet. Improvements in these tests of cardiovascular function have previously been linked to reduced risks of heart disease in people with high blood pressure. This study will provide evidence as to whether or not a polyphenol rich diet can reduce the risk of developing heart disease.


Condition or disease Intervention/treatment Phase
Hypertension Other: Two portions of fruit and vegetables per day (excluding berries and dark chocolate) Other: Six portions of fruit and vegetables per day (one of which must be berries) and 50g dark chocolate. Not Applicable

Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 104 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single (Outcomes Assessor)
Primary Purpose: Treatment
Official Title: Effect of a Polyphenol Rich Diet on Vascular and Platelet Function- a Randomised Control Trial
Study Start Date : January 2011
Actual Primary Completion Date : August 2013
Actual Study Completion Date : August 2015

Arm Intervention/treatment
Low- polyphenol diet Other: Two portions of fruit and vegetables per day (excluding berries and dark chocolate)
Two portions of fruit and vegetables per day (excluding berries and dark chocolate)
Active Comparator: High-polyphenol diet Other: Six portions of fruit and vegetables per day (one of which must be berries) and 50g dark chocolate.
Six portions of fruit and vegetables per day (one of which must be berries) and 50g dark chocolate.



Primary Outcome Measures :
  1. Vascular function [ Time Frame: Measured at weeks 4 and 12 ]
    Pharmacological provocation of endothelium-dependent vasomotion.


Secondary Outcome Measures :
  1. Platelet function, biomarkers of cardiovascular risk and heart rate variability [ Time Frame: Measured at weeks 0, 4 and 12 ]


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Ages Eligible for Study:   40 Years to 65 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • Age 40-65 years old
  • Systolic blood pressure 140-179 mmHg or diastolic blood pressure 90-109 mmHg

Exclusion Criteria:

  • diabetes mellitus
  • an acute coronary syndrome or transient ischaemic attack within the past 3 months
  • special dietary requirements, food sensitivities or vegetarian/vegan diet by choice
  • oral anticoagulation therapy
  • body mass index greater than 35kg/m2
  • excessive alcohol consumption (defined as > 28 units/week in men and 21 units/week in women)
  • fasting triglyceride concentration > 4 mmol/l
  • pregnancy/lactation
  • taking antioxidant supplements
  • medical conditions or dietary restrictions that would substantially limit ability to complete the study requirements

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 ClinicalTrials.gov identifier (NCT number): NCT01319786


Locations
United Kingdom
Belfast Health and Social Care Trust
Belfast, United Kingdom, BT12 6BJ
Sponsors and Collaborators
Queen's University, Belfast
Belfast Health and Social Care Trust
Investigators
Principal Investigator: Pascal McKeown, MD Belfast Health and Social Care Trust
Study Director: Jayne Woodside, PhD Queen's University, Belfast
Study Director: Michelle McKinley, PhD Queen's University, Belfast

Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
Responsible Party: Rebecca Noad, Professor Pascal McKeown, Queen's University, Belfast
ClinicalTrials.gov Identifier: NCT01319786     History of Changes
Other Study ID Numbers: QueensUBelfast
First Posted: March 22, 2011    Key Record Dates
Last Update Posted: October 28, 2015
Last Verified: October 2015

Keywords provided by Rebecca Noad, Queen's University, Belfast:
Hypertension
Microvascular function

Additional relevant MeSH terms:
Hypertension
Vascular Diseases
Cardiovascular Diseases