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

This study is ongoing, but not recruiting participants.
Sponsor:
Collaborator:
Belfast Health and Social Care Trust
Information provided by (Responsible Party):
Rebecca Noad, Queen's University, Belfast
ClinicalTrials.gov Identifier:
NCT01319786
First received: March 21, 2011
Last updated: June 3, 2013
Last verified: June 2013
  Purpose

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 Intervention
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.

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single Blind (Outcomes Assessor)
Primary Purpose: Treatment
Official Title: Effect of a Polyphenol Rich Diet on Vascular and Platelet Function- a Randomised Control Trial

Resource links provided by NLM:


Further study details as provided by Queen's University, Belfast:

Primary Outcome Measures:
  • Vascular function [ Time Frame: Measured at weeks 4 and 12 ] [ Designated as safety issue: No ]
    Pharmacological provocation of endothelium-dependent vasomotion.


Secondary Outcome Measures:
  • Platelet function, biomarkers of cardiovascular risk and heart rate variability [ Time Frame: Measured at weeks 0, 4 and 12 ] [ Designated as safety issue: No ]

Estimated Enrollment: 110
Study Start Date: January 2011
Estimated Study Completion Date: August 2015
Estimated Primary Completion Date: August 2013 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
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.

  Eligibility

Ages Eligible for Study:   40 Years to 65 Years
Genders Eligible for Study:   Both
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
  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: 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
  More Information

No publications provided

Responsible Party: Rebecca Noad, Professor Pascal McKeown, Queen's University, Belfast
ClinicalTrials.gov Identifier: NCT01319786     History of Changes
Other Study ID Numbers: QueensUBelfast
Study First Received: March 21, 2011
Last Updated: June 3, 2013
Health Authority: Northern Ireland: "Office for research ethics committees"
Northern Ireland: "Queen's University Belfast"
Northern Ireland: "Belfast Health and Social Care Trust"

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

Additional relevant MeSH terms:
Hypertension
Vascular Diseases
Cardiovascular Diseases

ClinicalTrials.gov processed this record on August 21, 2014