Effect of Quercetin Supplements on Healthy Males: a Four-Week Randomized Cross-Over Trial

A Double-Blind, Cross-Over, Placebo-Controlled Study Evaluating the Effect of Quercetin 500 mg Tablets on Blood Uric Acid in Healthy Males

The purpose of this study was to test the effect of chronic consumption of Quercetin 500 mg tablets on blood uric acid and other biomarkers in adult males.

Study Overview

• Status: Completed
• Conditions: Kidney Calculi; Cardiovascular Disease; Diabetes; Hyperuricemia; Gout
• Intervention / Treatment: Dietary supplement: Treatment; Dietary supplement: Control

Detailed Description

The main goal of the research is to determine the long term effects of daily supplementation of quercetin, a compound naturally and normally present in food, on the chemical composition (uric acid ii and glucose) of blood and urine and on blood pressure, of healthy males.

Six of the volunteers will collect urine after consuming a standard meal made from fresh onion and after quercetin supplement intake, in the same way, with 3 days washout before each. The urine collected here will be analysed to check that the supplement is equivalent to the food. Stage 2 will only be conducted with supplement and placebo.

Healthy male volunteers with higher (than average) blood uric acid will be selected and will be asked to consume a standard supplement/placebo added to their own diet for 4 weeks per phase. Two arms are separated by 4 weeks resting period: quercetin supplement and placebo. Blood and urine samples will be taken every other week to detect any changes of uric acid and other biomarkers.

----- i) Quercetin is found in a variety of foods including apples, berries, brassica vegetables, capers, grapes, onions, shallots, tea, and tomatoes, as well as many seeds, nuts, flowers, barks, and leaves.

ii) Uric acid, a compound found in both in the human body and urine, is produced by the breakdown of purines, which are nitrogen-containing compounds in substances such as nucleic acids (DNA). They enter the circulation from digestion of certain foods, drinks (alcoholic beverages like beer and wine) or from normal breakdown and turnover of cells in the body. Most uric acid is removed by the kidneys and disposed of in the urine; the remainder is excreted in the stool.

• Study Type: Interventional
• Enrollment (Actual): 22
• Phase: Early Phase 1

Contacts and Locations

Study Locations

• United Kingdom
  • West Yorkshire
    • Leeds, West Yorkshire, United Kingdom, LS2 9JT
      • School of Food Science and Nutrition

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 19 years to 65 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: Male

Description

Inclusion Criteria:

• Written informed consent
• Plasma Uric Acid > 300 micro Mole/L
• Generally Healthy

Exclusion Criteria:

• Body Mass Index (BMI) ≥ 30 kg/m² or <18.5 kg/m²
• Unable or unwilling to comply with the protocol, or likely to leave the study before its completion.
• Who would undertake important change in physical exercise or vigorous sport competitions during the study period.
• regularly drink more than 3 units of alcohol every day
• smokers
• have history of treated hyperuricemia, gout and/ or kidney stone
• have intestinal disorders

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Treatment; Daily intake of Quercetin supplement 500mg tablet for 28 days with meal (breakfast preferred.)	Dietary supplement: Treatment; Address: Nature's Best, Century Place, Tunbridge Wells, Kent, TN2 3BE Phone:+44(0)1892 552030 Email:info@naturesbest.co.uk; Other Names: Quercetin dihydrate 500 mg tablet; Brand: Nature's Best; Batch Number:114501; Serial Number: 5055148404901
Placebo Comparator: Placebo; Daily intake of Placebo (lactose) tablet for 28 days with meal (breakfast preferred)	Dietary supplement: Control; Address: Fagron GmbH&Co. KG, 22885 Barsbuttel, Germany Phone: +49(0)4067067680; Other Names: Placebo: lactose tablet; Brand: Fagron; Serial Number: PZN-0921071; Batch Number:1208D001A

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Risk of getting hyperuricemia assessed by the measure of plasma uric acid.	The change of plasma uric acid level from day 1 on day 15 and day 29 of each arm.	Fasting blood samples are taken on day 1, day 15 and day 29 of each arm

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Kidney excretion of uric acid: urinary uric acid level	Difference in 24-h urinary uric acid level at 14 days and 28 days between arms	24 h urine samples are collected on day 14 and 28 of each arm and volume is recorded
Blood pressure	To monitor the compliance of subject.	Blood pressure is measured on day 1 and 29 of each arm
Blood glucose	The change of plasma glucose level from the baseline at day 15 and day 29 of each arm.	Fasted blood samples are collected on day 1, 15, 29 of each arm
Metabolomic and metabonomic profiling of blood plasma	1H NMR (proton nuclear magnetic resonance )	Fasting blood samples are taken on day 1, day 15 and day 29 of each arm

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Urinary excretion of quercetin	To monitor the compliance of subject.	24 h urine will be collected on day 14 and 28 of each arm and volume is recorded
Subject Body Weight	To monitor the compliance of subject.	weight is measured on day 1 and 29 of each arm
Subject Height	To monitor the compliance of subject.	Height is measured on day 1 and 29 of each arm
Life style maintenance	To monitor the compliance of subject.	Recall Questionnaires about the past 28 days are required on day 1 and 29 of each arm.
Primary health assessment	To set baseline for maintaining lifestyle and routine medicine for the study.	Recall Questionnaires about history of certain disease, routine medication / supplements, allergies and exercise/diet practice at enrollment

Collaborators and Investigators

• Sponsor: University of Leeds
• Investigators: Study Chair: Gary Williamson, PhD, University of Leeds; Principal Investigator: Yuanlu Shi, PhD Candidate, University ofLeeds

Publications and helpful links

Helpful Links

• Information Sheet for Volunteers

Study record dates

Study Major Dates

• Study Start: February 1, 2013
• Primary Completion (Actual): April 1, 2014
• Study Completion (Actual): November 1, 2014

Study Registration Dates

• First Submitted: June 7, 2013
• First Submitted That Met QC Criteria: June 17, 2013
• First Posted (Estimate): June 20, 2013

Study Record Updates

• Last Update Posted (Estimate): March 24, 2015
• Last Update Submitted That Met QC Criteria: March 20, 2015
• Last Verified: March 1, 2015

More Information

Terms related to this study

• Keywords: Functional Food
• Additional Relevant MeSH Terms: Pathologic Processes; Kidney Diseases; Urologic Diseases; Pathological Conditions, Anatomical; Urolithiasis; Urinary Calculi; Cardiovascular Diseases; Calculi; Kidney Calculi; Nephrolithiasis; Hyperuricemia; Physiological Effects of Drugs; Molecular Mechanisms of Pharmacological Action; Protective Agents; Antioxidants; Quercetin
• Other Study ID Numbers: MEEC12-019