Saccharin

In February 1974, Canada’s Health Protection Branch — FDA’s counterpart there — began a major rat study to resolve the scientific uncertainties surrounding saccharin. The Canadian project, in which parent rats and their offspring were exposed to saccharin, focused on the effects of the suspect impunity in saccharin, orthotoluenesulfonamide (OTS). In early 1977, the study demonstrated that neither OTS nor other alleged culprits–bladder parasites and bladder stones–were causing the tumors. The substance responsible was saccharin.

Public clamor over the proposed ban erupted at once, fueled by mention in the agency’s announcement that the rats in the Canadian study were fed the equivalent of 800 cans of diet soda a day. High does of suspect carcinogens are used in feeding.

FDA contracted with the National Academy of Sciences for these studies. The first NAS report, in November 1978, concluded that saccharin was a carcinogen in animals, although of low potency; that it was a potential cancer-causing agent in humans; that the impurities in saccharin were not the carcinogenic agents; and that saccharin seemed to promote the cancer using effects of other carcinogenic agents that might be concerned with it.

Cyclamate

At FDA’s request, the National Academy of Sciences/National Research Council undertook an independent review of the carcinogenicity data. On June 10, 1985, the NAS panel of scientists issued a report that concluded that the scientific evidence did not indicate that cyclamate or its major derivative, cyclohexylamine, was carcinogenic. However, the NAS committee recommended repeating animal studies that suggested that cyclamate may act as a tumor promotor–that is, as a substance that may cause the development of tumors when used with a carcinogen. The NAS panel acknowledged, however, that scientists were uncertain about how such findings might apply to humans. “If the findings (of tumor promotion) are confirmed, uncertainty would still exist about the assessment of risk of cyclamate use for humans…, ” the NAS report noted.

Aspartame

Approval of aspartame for use in carbonated beverages followed in July 1983. By the end of 1990, FDA had approved aspartame’s use as a sweetener in 21 food categories. Breath mints, ready-to-drink iced tea, gelatin dessert, and fruit toppings are just a few of the products in which aspartame may be found. Aspartame’s use as an “inactive ingredient” in human drug products was approved by FDA in January 1987.

Aspartame’s widely publicized approval for use in carbonated drinks also was accompanied by an increasing number of complaints from consumers about headaches, dizziness, and a wide variety of other symptoms they attributed to consuming aspartame-containing products.

After evaluating the complaints, CDC reported in November of 1984, that although some individuals may have an “unusual sensitivity” to aspartame products, the data obtained “do not provide evidence for the existence of serious, widespread, adverse health consequences attendant to the use of aspartame.”

Acesulflame K

Like the new kid on the block, acesulfame K (“K” is the chemical symbol for potassium) the latest artificial sweetener on the market, was approved by FDA in July 1988 as a calorie free sugar substitute in packets or tablets and as an ingredient in chewing gum, dry drink mixes, gelatins, puddings, and nondairy creamers.

Acesulfame K is not metabolized–that is “burned” or changed in the human body–so it contributes no calories. Soluble in water, it is stable at normal temperatures.

Beginning in 1982, Hoechst Celanese Corporation, the manufacturer of acesulfame K, submitted to FDA animal feeding studies on the safety of the sweetener. The agency was provided with data from four long-term studies–a two-year toxicity study in beagle dogs, a carcinogenicity study in mice, and two long-term rat studies.

In its evaluation of all the data, FDA found that the safety studies did not show any toxic effects that could be attributed to the sweetener. The agency applied a 100-fold safety factor in making its safety assessment–that is, the agency found that the maximum amount consumed by humans would be less than one-hundredth of the amount that caused no toxic effect when fed to animals.

Data from population studies do not provide evidence of a clear relationship between artificial sweeteners and cancer in humans.

National Women’s Health Information Center
Office of Women’s Health
Department of Health and Human Services