Clinical trial NCT01935362: Impact of Oranges on Cardiovascular Health
Official title: Bioavailability of Flavanones Compounds and Their Impact on Cardiovascular Health
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE1
PHASE2
Conditions: Blood Pressure
Endothelial Dysfunction
Cardiovascular Disease Risk Reduction
Keywords: Flavanones
Bioavailability
Blood vessel health
Blood glucose
Lead sponsor: University of Leeds
Sponsor class: OTHER
Collaborators: name: Dr Andrea Day and Prof Gary Williamson
First posted: 2013-09-05
Enrollment: 25
Sex: ALL
Minimum age (years): 30
Maximum age (years): 60
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: PREVENTION

Brief summary: Cardiovascular disease (CVD) is the leading cause of deaths in the Western world. Established risk factors include high LDL cholesterol, high blood pressure and diabetes. Poor blood vessel health is considered a predictor of future CVD risk, but can be reversed. Several different measurements can be used to determine blood vessel health; such as blood pressure (BP), and newer techniques which measure blood flow through the arteries after a blood pressure cuff restricts blood flow for a few minutes in one arm.

Flavonoids are compounds found in plant-based foods, and are associated with a reduced risk of CVD. From the previous studies, there is strong evidence that orange juice and citrus foods which have higher amount of specific citrus flavonoids improved cardiovascular risk factors such as BP and blood vessel health. Absorption of citrus flavonoids occurs in the colon after bacteria breakdown the forms found in food. After the flavonoids are absorbed into the blood they are modification by liver enzymes before they are excreted in the urine. A large range of citrus flavonoid have been found excreted in the urinary, ranging anywhere from 0-57% of the dose. Variation in the potential health effect may reflect the level of the citrus flavonoid absorbed, and this is not often considered in human studies.

This study is a 4-week double-blinded, randomized, cross-over intervention trial using a commercially-available orange juice supplement and a placebo control. The aims of the study are to determine whether orange juice supplements reduce blood pressure and improve blood vessel health after 4 weeks. Furthermore, to determine if there is a relationship between absorption of flavonoids (as measured by urinary excretion) and changes in blood pressure or blood vessel health.

The participants will need to attend 4 sessions on 4 separate study days, every 4 weeks for 12 weeks. On each study day they will have their weight, height, waist circumference, and blood pressure measured. A finger-prick blood sample, using a single-use lancet (Accu-Chek Safe T Pro Plus), will be taken to check the fasting blood glucose level. Blood flow in fingertips will be monitored before and after reducing blood flow in your forearm using a blood pressure cuff (called an EndoPAT). Participants will be asked to collect urine for 24 hr on each of the study days, and to consume the supplements provided daily for two sets of 4 weeks (there will be 4 weeks in the middle without any supplements).

An improvement in blood pressure and/or blood flow will provide evidence that blood vessel health has improved through short-term (4 week) use of a citrus flavonoid supplement


Eligibility criteria: Inclusion Criteria:

* No known cardiovascular disease or diabetes
* Age between 30-60 years
* Heavier than average (Body mass index, BMI ≥ 25 kg/m2)
* Currently non smoker
* Willing to consume orange juice supplements for 2 months
* Male and female are equally eligible as not mentioned on advert

Exclusion Criteria:

* Those who Taken any antibiotics in the 2 months prior to the study
* Those who consume dietary or herbal supplements
* previous surgery on gastrointestinal tract
* Those who currently taking medication
* Current smokers, or ex-smokers ceasing \< 3 months ago
* pregnant or breast feeding
* Those with known allergies to the intervention treatment

Primary outcomes:
measure: blood pressure
timeFrame: Baseline and 4 weeks
measure: An improvement in blood flow
timeFrame: Baseline and 4 weeks
Secondary outcomes:
measure: blood glucose
timeFrame: Baseline and 4 weeks
measure: bioavailability of flavanones compounds
timeFrame: Baseline and 4 weeks
Other outcomes:
Locations:
city: Leeds
country: United Kingdom
facility: School Of Food Science and Nutrition, University Of Leeds
state: West Yorkshire
Study officials:
affiliation: University of Leeds
name: Abdurrahman M Sweidan
role: PRINCIPAL_INVESTIGATOR
References: