Clinical trial NCT03410342: The Effects of Types of Fruits and Vegetables on Vascular Function
Official title: The Effects of Types of Fruits and Vegetables on Vascular Function in Prehypertensive Participants: a Pilot Study
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Blood Pressure
Vascular Stiffness
Cardiovascular Risk Factor
Keywords: Blood Pressure
Vascular Stiffness
Cardiovascular Risk Factor
Fruit and vegetable
Lead sponsor: University of Cambridge
Sponsor class: OTHER
Collaborators: name: Imperial College London
First posted: 2018-01-25
Enrollment: 36
Sex: ALL
Minimum age (years): 40
Maximum age (years): 65
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: PREVENTION

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.

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

Primary outcomes:
measure: Blood pressure
timeFrame: Measured on the morning after each of three recurring run-in periods and after each of three recurring 2-week intervention periods, 6 times total during 9 weeks
Secondary outcomes:
measure: Arterial stiffness
timeFrame: Measured on the morning after each of three recurring run-in periods and after each of three recurring 2-week intervention periods, 6 times total during 9 weeks
measure: Markers of cardiometabolic health measured in fasted blood samples
timeFrame: Measured on the morning after each of three recurring run-in periods and after each of three recurring 2-week intervention periods, 6 times total during 9 weeks
measure: Markers of endothelial function measured in fasted blood samples
timeFrame: Measured on the morning after each of three recurring run-in periods and after each of three recurring 2-week intervention periods, 6 times total during 9 weeks
measure: Markers of low-grade inflammation measured in fasted blood samples
timeFrame: Measured on the morning after each of three recurring run-in periods and after each of three recurring 2-week intervention periods, 6 times total during 9 weeks
measure: Urinary metabolic profiles
timeFrame: Measured on the morning after each of three recurring run-in periods and after each of three recurring 2-week intervention periods, 6 times total during 9 weeks
measure: Circulatory metabolic profiles
timeFrame: Measured on the morning after each of three recurring run-in periods and after each of three recurring 2-week intervention periods, 6 times total during 9 weeks
measure: Established objective markers of food intake
timeFrame: Measured on the morning after each of three recurring run-in periods and after each of three recurring 2-week intervention periods, 6 times total during 9 weeks
measure: Faecal microbiome composition
timeFrame: Measured on the morning after each of three recurring run-in periods and after each of three recurring 2-week intervention periods, 6 times total during 9 weeks
measure: Cognitive function
timeFrame: Measured on the morning after each of three recurring run-in periods and after each of three recurring 2-week intervention periods, 6 times total during 9 weeks
measure: Self-rated general health and mental well-being
timeFrame: Measured on the morning after each of three recurring run-in periods and after each of three recurring 2-week intervention periods, 6 times total during 9 weeks
Other outcomes:
Locations:
city: Cambridge
country: United Kingdom
facility: Cambridge Epidemiology & Trials Unit
city: London
country: United Kingdom
facility: Imperial/NIHR Clinical Research Facility
Study officials:
affiliation: MRC Epidemiology Unit, University of Cambridge
name: Linda Oude Griep, PhD
role: PRINCIPAL_INVESTIGATOR
References: