Artificial sweetener: "Diet," "no-sugar-added," "sugar-free" soft drinks and packaged (tabletop) sweeteners.
Saccharin (one brand is Sweet 'N Low) is about 350 times sweeter than sugar and is used in diet foods and as a packaged (tabletop) sugar substitute. Saccharin is the original artificial sweetener, having been discovered accidentally in 1879 at Johns Hopkins University. Many studies on rodents have shown that saccharin can cause cancer of the urinary bladder, especially in males. In some animal studies, saccharin also caused cancer of the uterus, ovaries, skin, blood vessels, and other organs. Additional studies have shown that saccharin increases the potency of other cancer-causing chemicals. And the best epidemiology (human) study, which was conducted by the National Cancer Institute, found that the use of artificial sweeteners (saccharin and cyclamate) was associated with a higher incidence of bladder cancer. That said, other animal and human studies did not identify a cancer risk.
In 1977, the FDA proposed that saccharin be banned because of the studies showing that it causes cancer in animals. However, Congress intervened and permitted it to be used, provided that foods carried a warning notice. In 1997, the diet-food industry began pressuring the U.S. and Canadian governments and the World Health Organization to take saccharin off their lists of cancer-causing chemicals. The industry acknowledges that large amounts of saccharin cause bladder cancer in male rats, but argues that those tumors are caused by a mechanism that would not occur in humans. Some public health experts respond by stating that, even if that still-unproved mechanism was correct in male rats, saccharin could cause cancer by additional mechanisms and that, in some studies, saccharin has caused bladder cancer in mice and in female rats and other cancers in both rats and mice.
In May 2000, the U.S. Department of Health and Human Services removed saccharin from its list of cancer-causing chemicals. Later that year, Congress passed a law removing the warning notice.
Saccharin has been replaced in almost all foods by aspartame and other better-tasting sweeteners. Coca-Cola Company's Tab, one of the first diet sodas, still contains saccharin, but now also contains aspartame. In 2014, Health Canada lifted its decades-long ban on saccharin in foods, allowing it to be added to some beverages, canned fruits, frozen desserts, and other foods. Saccharin passes into the breast milk of nursing mothers.