Green tea may help athletes to cheat...

A study in a test lab suggests that tea seems to reduce testosterone concentrations by up to 30 percent and appeared to work best when testosterone was only slightly higher than normal. Similar results have been found in rodent studies. The green tea contains catechins, also found in white tea, which seem to stop an enzyme involved in detecting testosterone. By preventing that enzyme from working, testosterone largely goes unnoticed in the body and doesn't get passed into the urine — where officials usually test for the hormone. Experts say athletes taking testosterone for doping purposes typically have 200 to 300 percent more in their bodies than normal. The study was a test in a lab dish so scientists aren't sure if the effects will be the same in people but some say the results are intriguing enough that Olympic testing could be updated to include that possibility.

The World Anti-Doping Agency, or WADA has tight controls on other commonly consumed substances like caffeine. It bans diuretics that could mask drug use and warns athletes about taking nutritional supplements which could be spiked with banned drugs. The researchers said it was too early to tell what the effect of green tea might be in humans, but said other beverages or foods likely produced similar effects. Olivier Rabin, scientific director of WADA said "We may need to adjust our steroid (test) to allow us to exclude whether a test is modified by food or training or disease, before we can say that it's doping. We might have to raise the normal threshold for what is a considered a legal amount of testosterone to allow for any such interference."

Some experts said the limited effects of foods like green tea on masking illegal drug use would be too small to help doping athletes. "You would probably need to drink the tea continuously to get any sustained but minor effect," said Andrew Kicman, head of research and development at the Drug Control Centre at King's College London, which is providing the anti-doping laboratory for the upcoming Olympics. "It would be a very foolish athlete who's thinking of doping with testosterone and thinks he could drink white or green tea to beat a drug test," he said. "And I personally wouldn't want to drink nine cups of tea on the day of a race."