Effect of a Polyphenol Rich Diet on Vascular and Platelet Function

NCT01319786 | Completed

• 1 other identifier: QueensUBelfast
• Study Type: interventional
• Target: 104
• Locations: 1 country
• Sites: 1

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.

Conditions

Hypertension

Keywords

Hypertension; Microvascular function

Outcome Measures

Primary Outcomes (1)

• Vascular function

  Pharmacological provocation of endothelium-dependent vasomotion.

  Measured at weeks 4 and 12

Secondary Outcomes (1)

• Platelet function, biomarkers of cardiovascular risk and heart rate variability

  Measured at weeks 0, 4 and 12

Study Arms (2)

Low- polyphenol diet

OTHER

Other: Two portions of fruit and vegetables per day (excluding berries and dark chocolate)

High-polyphenol diet

ACTIVE COMPARATOR

Other: Six portions of fruit and vegetables per day (one of which must be berries) and 50g dark chocolate.

Interventions

Two portions of fruit and vegetables per day (excluding berries and dark chocolate) OTHER

Two portions of fruit and vegetables per day (excluding berries and dark chocolate)

Low- polyphenol diet

Six portions of fruit and vegetables per day (one of which must be berries) and 50g dark chocolate. OTHER

Six portions of fruit and vegetables per day (one of which must be berries) and 50g dark chocolate.

High-polyphenol diet

Eligibility Criteria

• Age: 40 Years - 65 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

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

You may not qualify if:

• 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

Sponsors & Collaborators

• Queen's University, Belfast: lead
• Belfast Health and Social Care Trust: collaborator

Study Sites (1)

Belfast Health and Social Care Trust

Belfast, BT12 6BJ, United Kingdom

Location

Related Publications (1)

• Noad RL, Rooney C, McCall D, Young IS, McCance D, McKinley MC, Woodside JV, McKeown PP. Beneficial effect of a polyphenol-rich diet on cardiovascular risk: a randomised control trial. Heart. 2016 Sep 1;102(17):1371-9. doi: 10.1136/heartjnl-2015-309218. Epub 2016 May 10.

  PMID: 27164919 DERIVED

MeSH Terms

Conditions

Hypertension

Condition Hierarchy (Ancestors)

Vascular Diseases; Cardiovascular Diseases

Study Officials

• Pascal McKeown, MD

  Belfast Health and Social Care Trust

  PRINCIPAL INVESTIGATOR

• Jayne Woodside, PhD

  Queen's University, Belfast

  STUDY DIRECTOR

• Michelle McKinley, PhD

  Queen's University, Belfast

  STUDY DIRECTOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: OUTCOMES ASSESSOR
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor Pascal McKeown

Study Record Dates

• First Submitted: March 21, 2011
• First Posted: March 22, 2011
• Study Start: January 1, 2011
• Primary Completion: August 1, 2013
• Study Completion: August 1, 2015
• Last Updated: October 28, 2015

Record last verified: 2015-10

Locations

GB (1)