Green and white tea can block excreting testosterone in urine

Sportspersons become more and more sophisticated in administration of steroids. They study new ways to mask their intake of banned products. Several athletes spend time studying researchers’ conclusions that could help them to hide that they dope. Nowadays a way has been found: athletes may mask administration of testosterone by drinking of green tea.
Testosterone is a hormone which occurs in body naturally. So, it can be difficult for anti-doping organizations to determine that a person has administered testosterone. T: E ratio testing is commonly used by anti-doping agencies. Such tests can manifest unusual ratio of testosterone to epitestosterone in urine. But it doesn’t manifest difference between testosterone that has been created in body naturally and that introduced into body with the help of injections, creams, etc.
 Declan Naughton and his colleagues at Kingston University ( London) have discovered that green tea has such substances that are called “catechins”. They can inhibit the enzyme UGT2B17. This enzyme promotes attaching glucuronic acid to testosterone. If UGT2B17 is inhibited, less testosterone glucoronide is excreted in urine.  
Catechins, the compounds that can mask intake of testosterone, are contained in green and white tea. Black tea lacks such compounds.
Naughton and his colleagues have conducted some experiments. They claim that a cup of strong green tea hides usage of testosterone.
So, those athletes that apply testosterone may lower measures of testosterone excreting in urine by drinking of green or white tea. Green or white tea may block excretion of testosterone, increasing circulating levels of this hormone.
The World Anti-Doping Agency was informed about the findings by the experts. If this process occurs, it means that it is not worthy to apply urine tests. Blood tests should be performed in order to detect testosterone use.
Olivier Rabin, the WADA’s scientist, claims that regular checks of blood steroids will be added. Everything will be done by anti-doping agencies in order to avoid fooling of urine tests.