This would suggest the cyclist took some extra testosterone, something Landis has denied.
But the New York Times quoted a source at the French national antidoping laboratory in Chatenay Malabry as saying one advanced test had already shown that Landis's testosterone was not naturally produced in his body.
The carbon isotope test showed that the hormone must have come from outside his body, according to the unnamed source cited by the newspaper.
This would be the correct test to run to prove such an allegation, said Dr. Richard Hellman, President Elect of the Board of Directors of the American Association of Clinical Endocrinologists.
The test uses a mass spectrometer to find out which isotope, or chemical variant, of carbon is in the testosterone. The body synthesizes hormones from the foods people eat.
"They can look at the ratio of carbon atoms in the testosterone and see whether it is likely to have come from testosterone produced in his body or came from outside," Hellman said in a telephone interview.
Carbon-13 comes from plants and levels of that would suggest that Landis's testosterone was natural. But if carbon-13 was scarce, that would suggest lab-produced hormone, Hellman said.
SKEWED RESULTS?
Several things can skew the results of the urine test, Hellman said. Poor handling, bacterial contamination, and alcohol use can all alter the testosterone/epitestosterone ratio.
Landis said that the night before the 17th stage he and his teammates were depressed and drank beer and whiskey.
"If a person drinks alcohol, there is a study by some Swedish researchers that shows if you give fairly large amounts of alcohol it would alter the T/E ratio," Hellman said.
If Landis did cheat, Hellman said it was not clear to him why. Landis was repeatedly tested throughout the race, so the high testosterone would have shown up earlier if he had either naturally high levels, as Landis has claimed, or if he had been taking the drug all along.
Testosterone doping helps athletes, male or female, build muscle, strength and endurance, but it must be done over time, said Hellman, an endocrinologist in North Kansas City, Missouri.
"The benefit for the next day would be questionable. It would not be something that I would think would be very smart for a cheater," Hellman said. "Certainly he must have known that for the next day he would have been detected."
Dr. Don Catlin, Director of the University of California Los Angeles Olympic Analytical Laboratory, said there has been speculation about the benefits of taking testosterone short-term.
"People have been talking for a year or two about a short-acting effect of testosterone," he said. "Where it relieves the aches and pains of heavy exercise ... it hastens recovery."
(With additional reporting by Gene Cherry in Los Angeles) |
