Effect of a Polyphenol Rich Diet on Vascular and Platelet Function (PPhIT)
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.
|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 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|
- Vascular function [ Time Frame: Measured at weeks 4 and 12 ]Pharmacological provocation of endothelium-dependent vasomotion.
- Platelet function, biomarkers of cardiovascular risk and heart rate variability [ Time Frame: Measured at weeks 0, 4 and 12 ]
|Study Start Date:||January 2011|
|Study Completion Date:||August 2015|
|Primary Completion Date:||August 2013 (Final data collection date for primary outcome measure)|
|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.
Please refer to this study by its ClinicalTrials.gov identifier: NCT01319786
|Belfast Health and Social Care Trust|
|Belfast, United Kingdom, BT12 6BJ|
|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|