Effect of a Polyphenol Rich Diet on Vascular and Platelet Function

NCT ID: NCT01319786

Last Updated: 2015-10-28

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 104 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2011-01-31
• Study Completion Date: 2015-08-31

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

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: SINGLE

Study Groups

Low- polyphenol diet

Group Type: OTHER

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

Intervention Type: OTHER

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

High-polyphenol diet

Group Type: ACTIVE_COMPARATOR

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

Intervention Type: 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)

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

Intervention Type: 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.

Intervention Type: OTHER

Eligibility 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

• Minimum Eligible Age: 40 Years
• Maximum Eligible Age: 65 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Belfast Health and Social Care Trust

OTHER

Sponsor Role: collaborator

Queen's University, Belfast

OTHER

Sponsor Role: lead

Responsible Party

Rebecca Noad

Professor Pascal McKeown

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Pascal McKeown, MD

Role: PRINCIPAL_INVESTIGATOR

Belfast Health and Social Care Trust

Jayne Woodside, PhD

Role: STUDY_DIRECTOR

Queen's University, Belfast

Michelle McKinley, PhD

Role: STUDY_DIRECTOR

Queen's University, Belfast

Locations

Belfast Health and Social Care Trust

Belfast, , United Kingdom

Countries

United Kingdom

References

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.

Reference Type: DERIVED

PMID: 27164919 (View on PubMed)

Other Identifiers

QueensUBelfast

Identifier Type: -

Identifier Source: org_study_id