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

Early Phase 1

Completed

• Conditions: Hyperuricemia; Gout; Kidney Calculi; Diabetes; Cardiovascular Disease
• Interventions: Dietary Supplement: Control; Dietary Supplement: Treatment

• Registration Number: NCT01881919
• Lead Sponsor: University of Leeds

Brief Summary

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.

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 Timeline

• Study Start: 2013-02
• Study First Submitted: 2013-06-07
• Study First Submitted QC: 2013-06-17
• Study First Posted: 2013-06-20
• Primary Completion: 2014-04
• Study Completion: 2014-11
• Status Verified: 2015-03
• Last Update Submitted: 2015-03-20
• Last Update Posted: 2015-03-24

Recruitment & Eligibility

• Status: COMPLETED
• Sex: Male
• Target Recruitment: 22

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 & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Placebo	Control	Daily intake of Placebo (lactose) tablet for 28 days with meal (breakfast preferred)
Treatment	Treatment	Daily intake of Quercetin supplement 500mg tablet for 28 days with meal (breakfast preferred.)

Primary Outcome Measures

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

Secondary Outcome Measures

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

Trial Locations

Locations (1)

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