Artificial Sweeteners and Cancer

by National Cancer Institute

Key Points

Artificial sweeteners are regulated by the U.S. Food and Drug Administration.

There is no clear evidence that the artificial sweeteners on the market in the United States are related to cancer risk in humans.

Studies have been conducted on the safety of several artificial sweeteners, including saccharin, aspartame, acesulfame potassium, sucralose, neotame, and cyclamate.

What are artificial sweeteners and how are they regulated in the United States?

Artificial sweeteners, also called sugar substitutes, are substances that are used instead of sucrose (table sugar) to sweeten foods and beverages. Because artificial sweeteners are many times sweeter than table sugar, smaller amounts are needed to create the same level of sweetness. Artificial sweeteners are regulated by the U.S. Food and Drug Administration (FDA). The FDA, like the National Cancer Institute (NCI), is an agency of the Department of Health and Human Services. The FDA regulates food, drugs, medical devices, cosmetics, biologics, and radiation-emitting products. The Food Additives Amendment to the Food, Drug, and Cosmetic Act, which was passed by Congress in 1958, requires the FDA to approve food additives, including artificial sweeteners, before they can be made available for sale in the United States. However, this legislation does not apply to products that are "generally recognized as safe." Such products do not require FDA approval before being marketed.

Is there an association between artificial sweeteners and cancer?

Questions about artificial sweeteners and cancer arose when early studies showed that cyclamate in combination with saccharin caused bladder cancer in laboratory animals. However, results from subsequent carcinogenicity studies (studies that examine whether a substance can cause cancer) on these sweeteners and other approved sweeteners have not provided clear evidence of an association between artificial sweeteners and cancer in people.

What have studies shown about a possible association between specific artificial sweeteners and cancer?

Saccharin

tudies in laboratory rats during the early 1970s linked saccharin with the development of bladder cancer. For this reason, Congress mandated that further studies of saccharin be performed and required that all food containing saccharin bear the following warning label: "Use of this product may be hazardous to your health. This product contains saccharin, which has been determined to cause cancer in laboratory animals." Subsequent studies in rats showed an increased incidence of urinary bladder cancer at high doses of saccharin consumption, especially in male rats. However, mechanistic studies (studies that examine how a substance works in the body) have shown that these results apply only to rats. Human epidemiology studies (studies of patterns, causes, and control of diseases in groups of people) have shown no consistent evidence that saccharin is associated with bladder cancer incidence.

Because the bladder tumors seen in rats are due to a mechanism not relevant to humans, and because there is no clear evidence that saccharin causes cancer in humans, saccharin was delisted in 2000 from the U.S. National Toxicology Program's Report on Carcinogens, where it had been listed since 1981 as a substance reasonably anticipated to be a human carcinogen (a substance known to cause cancer). The delisting led to legislation, which was signed into law on December 21, 2000, repealing the warning label requirement for products containing saccharin.

Aspartame

Aspartame, distributed under several trade names (e.g., Nutrasweet® and Equal®), was approved in 1981 by the FDA after numerous tests showed that it did not cause cancer or other adverse effects in laboratory animals. Questions regarding the safety of aspartame were renewed by a 1996 report suggesting that an increase in the number of people with brain tumors between 1975 and 1992 might be associated with the introduction and use of this sweetener in the United States. However, an analysis of then-current NCI statistics showed that the overall incidence of brain and central nervous system cancers began to rise in 1973, 8 years prior to the approval of aspartame, and continued to rise until 1985. Moreover, increases in overall brain cancer incidence occurred primarily in people age 70 and older, a group that was not exposed to the highest doses of aspartame since its introduction. These data do not establish a clear link between the consumption of aspartame and the development of brain tumors.

Acesulfame potassium, Sucralose, and Neotame

In addition to saccharin and aspartame, there are three other artificial sweeteners currently permitted for use in food in the United States. Acesulfame potassium (also known as ACK, Sweet One®, and Sunett®) was approved by the FDA in 1988 for use in specific food and beverage categories, and was later approved as a general purpose sweetener (except in meat and poultry) in 2002. Sucralose (also known as Splenda®) was approved by the FDA as a tabletop sweetener in 1998, followed by approval as a general purpose sweetener in 1999. Neotame, which is similar to aspartame, was approved by the FDA as a general purpose sweetener (except in meat and poultry) in 2002. Before approving these sweeteners, the FDA reviewed more than 100 safety studies that were conducted on each sweetener, including studies to assess cancer risk. The results of these studies showed no evidence that these sweeteners cause cancer or pose any other threat to human health.

Cyclamate

Because the findings in rats suggested that cyclamate might increase the risk of bladder cancer in humans, the FDA banned the use of cyclamate in 1969. Upon the reexamination of cyclamate carcinogenicity and the evaluation of additional data, scientists concluded that cyclamate was not a carcinogen or a co-carcinogen (a substance that enhances the effect of a cancer-causing substance). A food additive petition is currently filed with FDA for the reapproval of cyclamate. The FDA's concerns about cyclamate are not cancer related.

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