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Effect of Tea Consumption on Steroid Profile in Healthy Volunteers

Effect of Tea Consumption on Steroid Profile in Healthy Volunteers. Pilot Study

Status
Completed
Phases
Phase 1
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT02779361
Enrollment
29
Registered
2016-05-20
Start date
2016-01-31
Completion date
2017-02-14
Last updated
2017-07-28

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Doping in Sports, Healthy Volunteers

Keywords

green tea, steroid profile

Brief summary

Open label phase I clinical trial in healthy volunteers designed to assess changes on steroid profile after green tea consumption.

Detailed description

Anabolic androgenic steroids are included in the list of banned substances in sports by the World Anti-Doping Agency (WADA) because of its ability to improve the performance of athletes. Testosterone glucuronization by UGT2B17 isoenzyme (Uridine Diphosphate Glucuronyltransferase 2B17) is inhibited in vitro by green tea flavonols like epicatechin, epigallocatechin gallate (EGCG) and catechin gallate. Therefore a diet rich in green tea could interfere in androgens' glucuronization and cause a change on the steroid profile of the athletes that could be considered a false positive. A clinical trial designed to assess changes on steroid profile in healthy volunteers after green tea consumption will be conducted. Subjects with different UGT2B17 genotype will be recruited (10 of each type: ins/ins, ins/del, del/del) to study if the genotype can modulate the results obtained. Urine samples obtained before and during 7 days of green tea consumption will be used to compare steroid profile. Blood samples will be also collected to assess EGCG pharmacokinetics.

Interventions

DIETARY_SUPPLEMENTGreen tea

Lipton pure green tea, 5 teas on the first 6 days, and 9 teas on the day 7. Teas will be ingested at 08:00 am, 10:30 am, 13:00 pm, 15:30 pm, 18:00 pm days 1-6, and 08:00 am (\*), 10:30 am, 13:00 pm (\*), 15:30 pm, 18:00 pm (\*), 20:30 pm on day 7. One bag of tea will be used to prepare the beverages with exception of some beverages on day 7 that will be prepared with two bags (\*).

Sponsors

World Anti-Doping Agency
CollaboratorOTHER
Parc de Salut Mar
Lead SponsorOTHER

Study design

Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
BASIC_SCIENCE
Masking
NONE

Eligibility

Sex/Gender
MALE
Age
18 Years to 50 Years
Healthy volunteers
Yes

Inclusion criteria

* Understand and accept the study's procedures and sign an informed consent form * Body mass index (BMI=weight/heigth2) between 19 and 27 kg/m2, weight between 50 and 100 kg. * No evidence of somatic or psychiatric disorders as per past medical history and physical examination * EKG, blood and urine tests taken before entry into the study within the normal range. Minor and transient abnormalities may be acceptable if, according to the Principal Investigator's criterion and the state of the art, they are felt to have no clinical relevance, entail no danger to the participant, and don't interfere with the product's assessment. These abnormalities and their non-relevance must be specifically justified in writing)

Exclusion criteria

* Evidence of a preexisting condition (including gastrointestinal, liver, or kidney disorders) that may alter the absorption, distribution, metabolism or excretion of the drug or symptoms suggestive of drug-induced gastrointestinal irritation * Previous psychiatric disorders, alcoholism, abuse of prescription drugs or illegal substances or regular consumption of psychoactive drugs * Having donated blood or having participated in this same study in the preceding 8 weeks, or having participated in any clinical trial with drugs in the preceding 12 weeks * Having had any somatic disease or having undergone major surgery in the 3 months prior to inclusion in the trial * Individuals intolerant or having experienced a severe adverse reaction to green tea or caffeine * Having regularly taken medication in the month before the trial, except for vitamins, herb-based remedies, dietary supplements that if, according to the Principal Investigator or his appointed collaborators' opinion, they pose no threat to the subjects and they won't interfere with the study's objectives. Single doses of symptomatic drugs taken during the week before the experimental session will not constitute an exclusion criterion if it can be assumed that it has been completely eliminated on the day of the experimental session * Smokers of \>10 cigarettes/day * Consumption of \>40 g/day of alcohol * Daily consumption of less than one xanthine-containing beverages per day * Hepatitis B, hepatitis C or human immunodeficiency virus-positive individuals * Vegetarian subjects or with aberrant diets

Design outcomes

Primary

MeasureTime frameDescription
Steroid profile in urineFrom 3 days before consumption (day -3,-2,-1) till day 8 (day 1-8) after consumption24 hours urine will be collected.

Secondary

MeasureTime frameDescription
Epigallocatechin gallate (EGCG) blood concentrationsBaseline and day 7One sample before tea administration (day -1) and 3 samples on day 7 (before, 1hour and 2 hours after first tea on day 7).
Serious and non serious adverse eventsFrom inclusion till day 9 (final visit)Adverse events reported by subjects and interrogated by investigators will be collected.
UGT2B17 GenotypeBaselineSample for pharmacogenetics will be obtained before tea administration

Countries

Spain

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Feb 4, 2026