responses in experimental animals that may not be relevant to humans. For example,
the propensity of the widely used artificial sweetener saccharin to cause bladder cancer in rats
may not be relevant to humans at normal dietary intake rates. This is because mechanistic
studies have demonstrated that bladder cancer is induced only under conditions where
saccharin is at such a high concentration in the urine that it forms a crystalline precipitate
(Cohen, 1998). Dose–response studies suggest that such high concentrations
would not be achieved in the human bladder even after extensive dietary consumption.