The Effects of Types of Fruits and Vegetables on Vascular Function

NCT ID: NCT03410342

Last Updated: 2022-03-22

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 36 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2017-09-04
• Study Completion Date: 2021-06-21

Brief Summary

The CIRCUS study is a randomised controlled, cross-over trial to evaluate the effects of increased intakes of citrus fruits and cruciferous vegetables on vascular function in 36 untreated, prehypertensive participants.

Detailed Description

The study comprises three 14-day dietary intervention periods, preceded by one week run-in period and separated by one week wash-out periods, 9 weeks in total. The diet will be fully controlled and provided by the researchers. Participants will receive in random order three interventions:

• 1 portion of fruits plus 1 portion of vegetables, of commonly consumed types per day. Intakes are at 25th percentile of UK consumption and will exclude citrus fruits, cruciferous and allium vegetables.
• 4 portions of fruits plus 4 portions of vegetables, of commonly consumed types per day excluding citrus fruits, cruciferous and allium vegetables.
• 4 portions of citrus fruits plus 4 portions of cruciferous vegetables per day.

Conditions

Blood Pressure; Vascular Stiffness; Cardiovascular Risk Factor

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: CROSSOVER
• Primary Study Purpose: PREVENTION
• Blinding Strategy: NONE

Study Groups

Low Fruits and Vegetables (LFV)

1 portion of fruits plus 1 portion of vegetables, of commonly consumed types per day.

Intakes are at 25th percentile of UK consumption (NDNS) and will exclude citrus fruits, cruciferous and allium vegetables.

Group Type: PLACEBO_COMPARATOR

LFV

Intervention Type: OTHER

1 apple/banana/small bunch of grapes per day plus 1 portion of carrot/pepper/tomato per day

High Fruits and Vegetables (HFV)

4 portions of fruits plus 4 portions of vegetables, of commonly consumed types per day excluding citrus fruits, cruciferous and allium vegetables.

Group Type: EXPERIMENTAL

HFV

Intervention Type: OTHER

4 portions of fruits (apples, bananas, grapes, pears) plus 4 portions of vegetables (carrots, cucumber, sweet peppers, tomatoes), of commonly consumed types per day excluding citrus fruits, cruciferous and allium vegetables.

High Citrus fruits and Cruciferous vegetables (CC)

4 portions of citrus fruits plus 4 portions of cruciferous vegetables per day excluding any other types of fruits and vegetables including allium vegetables.

Group Type: EXPERIMENTAL

CC

Intervention Type: OTHER

4 portions of citrus fruits (clementines, grapefruits, lemons, oranges) plus 4 portions of cruciferous vegetables (broccoli, brussels sprouts, cauliflower, kale, savoy cabbage) per day.

Interventions

LFV

1 apple/banana/small bunch of grapes per day plus 1 portion of carrot/pepper/tomato per day

Intervention Type: OTHER

HFV

4 portions of fruits (apples, bananas, grapes, pears) plus 4 portions of vegetables (carrots, cucumber, sweet peppers, tomatoes), of commonly consumed types per day excluding citrus fruits, cruciferous and allium vegetables.

Intervention Type: OTHER

CC

4 portions of citrus fruits (clementines, grapefruits, lemons, oranges) plus 4 portions of cruciferous vegetables (broccoli, brussels sprouts, cauliflower, kale, savoy cabbage) per day.

Intervention Type: OTHER

Eligibility Criteria

Inclusion Criteria

• 40 - 65 years
• Average systolic blood pressure of 125-140 mmHg at 2 measurements separated by >30 minutes
• No use of antihypertensive medication
• No reported current or previous diabetes mellitus, (secondary) hypertension, or metabolic, cardiovascular, renal, liver, thyroid, gastrointestinal diseases
• Body Mass Index between 20 - 35 kg/m2
• Non-smoker
• Average fruit and vegetable consumption of <4 portions per day (UK average, 40-65 years), or willing to reduce habitual daily fruit and vegetable intake.

Exclusion Criteria

• Any medication likely to interfere with energy metabolism, appetite regulation and hormonal balance.
• Excessive alcohol intake of > 21 units per week (females) or >28 units per week (male) and not willing to limit alcohol intake to maximum of 1 unit/day
• Physical activity of >=10 hours/week of moderate to vigorous physical activity
• Weight loss or gain of >=3 kg in the preceding 3 months
• Use of dietary supplements or unwilling to stop supplement use >= 2 weeks before enrolment and during intervention
• Pregnancy or lactation
• Intervention specific factors, including:

• Unable or unwilling to consume provided diets during the intervention
• Unsufficient storage space for provided diets
• Food sensitivities or vegetarian/vegan diet by choice
• Participation in another intervention study at the same time
• Living > 15 miles from the Imperial/NIHR Clinical Research Facility at Hammersmith Hospital
• No signed informed consent

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

Sponsors

Imperial College London

OTHER

Sponsor Role: collaborator

University of Cambridge

OTHER

Sponsor Role: lead

Responsible Party

Linda Oude Griep

Senior Research Associate

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Linda Oude Griep, PhD

Role: PRINCIPAL_INVESTIGATOR

MRC Epidemiology Unit, University of Cambridge

Locations

Cambridge Epidemiology & Trials Unit

Cambridge, , United Kingdom

Imperial/NIHR Clinical Research Facility

London, , United Kingdom

Countries

United Kingdom

Provided Documents

Document Type: Study Protocol

View Document

Document Type: Statistical Analysis Plan

View Document

Other Identifiers

Research Ethics Committee

Identifier Type: REGISTRY

Identifier Source: secondary_id

17HH3878

Identifier Type: -

Identifier Source: org_study_id