This report reviews the experimental and epidemiologic data related to the carcinogenicity of saccharin. The results of animal studies suggest a species and organ effect. In single-generation studies in rats, mice, hamsters, and monkeys, saccharin did not induce cancer in any organ. In two-generation studies involving rats, however, there was evidence that the incidence of bladder tumors was significantly greater in saccharin-treated males of the second generation than in controls; the development of bladder tumors in rats seems to be a species- and organ-specific phenomenon for which there is currently no explanation. In humans, available evidence indicates that the use of artificial sweeteners, including saccharin, is not associated with an increased risk of bladder cancer. Until there is firm evidence of its carcinogenicity in humans, saccharin should continue to be available as a food additive, and reports of adverse health effects associated with its use should be monitored.
SaccharinReview of Safety Issues. JAMA. 1985;254(18):2622–2624. doi:10.1001/jama.1985.03360180126039