Impact of Oranges on Cardiovascular Health

Phase 1

Completed

• Conditions: Blood Pressure; Endothelial Dysfunction; Cardiovascular Disease Risk Reduction
• Interventions: Dietary Supplement: Placebo; Dietary Supplement: Citrus supplement

• Registration Number: NCT01935362
• Lead Sponsor: University of Leeds

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

Detailed Description

Not available

Study Timeline

• Study Start: 2013-06
• Study First Submitted: 2013-08-20
• Study First Submitted QC: 2013-09-04
• Study First Posted: 2013-09-05
• Primary Completion: 2014-02
• Status Verified: 2014-03
• Study Completion: 2014-03
• Last Update Submitted: 2014-03-31
• Last Update Posted: 2014-04-01

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 25

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

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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

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Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
placebo	Placebo	Placebo administered to participant
Citrus supplement	Citrus supplement	Citrus supplement administered to participant

Primary Outcome Measures

Name	Time	Method
blood pressure	Baseline and 4 weeks	Change in systolic and diastolic blood pressure
An improvement in blood flow	Baseline and 4 weeks	Change in blood flow using Endo-PAT device

Secondary Outcome Measures

Name	Time	Method
blood glucose	Baseline and 4 weeks	Change in blood glucose level in plasma,
bioavailability of flavanones compounds	Baseline and 4 weeks	Change of urine flavanones from the baseline and after 4 weeks of each arm

Trial Locations

Locations (1)

School Of Food Science and Nutrition, University Of Leeds; 🇬🇧 Leeds, West Yorkshire, United Kingdom