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

University of Leeds

Status and phase: Completed; Early Phase 1

Conditions: Diabetes; Hyperuricemia; Kidney Calculi; Cardiovascular Disease; Gout

Treatments: Dietary Supplement: Control; Dietary Supplement: Treatment

Study type: Interventional

Funder types: Other

Identifiers

NCT01881919

MEEC12-019

Details and patient eligibility

About

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.

Full 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.

Enrollment: 22 patients

Sex: Male

Ages: 19 to 65 years old

Volunteers: Accepts Healthy Volunteers

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

Trial design

Primary purpose: Basic Science

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: Double Blind

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22 participants in 2 patient groups, including a placebo group

Treatment

Experimental group

Description:

Daily intake of Quercetin supplement 500mg tablet for 28 days with meal (breakfast preferred.)

Treatment:

Dietary Supplement: Treatment

Placebo

Placebo Comparator group

Description:

Daily intake of Placebo (lactose) tablet for 28 days with meal (breakfast preferred)

Treatment:

Dietary Supplement: Control