U.S. sprinter Tyson Gay linked to anti-aging specialist

Gibson repeatedly emphasized that, "I don't carry anything that's not food-based." But when asked directly if he was saying that he does not refer patients to

U.S. sprinter Tyson Gay, who has the fastest time in the 100 this year, admitted on Sunday that he has tested positive for a banned substance / Getty Images

Gibson repeatedly emphasized that, "I don't carry anything that's not food-based." But when asked directly if he was saying that he does not refer patients to products containing testosterone, DHEA, or other products often used by anti-aging specialists and that are banned in track and field, he replied: "No, I'm not telling you that. It all depends."