Effect of a Polyphenol Rich Diet on Vascular and Platelet Function

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.

Conditions

• Hypertension

Interventions

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)

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.

Sponsors & Collaborators

• Belfast Health and Social Care Trust

  collaborator OTHER

• Queen's University, Belfast

  lead OTHER

Principal Investigators

• Pascal McKeown, MD · Belfast Health and Social Care Trust

• Jayne Woodside, PhD · Queen's University, Belfast

• Michelle McKinley, PhD · Queen's University, Belfast

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

SINGLE

Model

PARALLEL

Eligibility

Min Age

40 Years

Max Age

65 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2011-01-31

Primary Completion

2013-08-31

Completion

2015-08-31

Countries

• United Kingdom

Study Locations