Artificial Sweeteners and Cancer: Questions and Answers 

Key Points

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

Question 1). 

• There is no clear evidence that the artificial sweeteners on the market in the United 

States are related to cancer risk in humans (see Question 2). 

• Studies have been conducted on the safety of several artificial sweeteners, including 

saccharin, aspartame, acesulfame potassium, sucralose, neotame, and cyclamate (see 

Question 3). 

1. 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. 

2. 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

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not provided clear evidence of an association between artificial sweeteners and cancer in 

people. 

3. What have studies shown about a possible association between specific artificial

sweeteners and cancer? 

Saccharin 

Studies 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). More information about the 

delisting of saccharin is available at 

http://ntp.niehs.nih.gov/ntp/roc/eleventh/append/appb.pdf on the Internet. 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. 

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Recently, a laboratory experiment found more lymphomas and leukemias in rats fed very 

high doses of aspartame (equivalent to drinking 8 to 2,083 cans of diet soda daily) (1). 

However, there were some inconsistencies in the findings. For example, the cancers 

found in the treated rats were not specific to aspartame, and the number of cancer cases 

did not rise with increasing amounts of aspartame as would be expected. Subsequently, 

the NCI examined human data from the NIH-AARP Diet and Health Study of over half a 

million retirees. Increasing consumption of aspartame-containing beverages was not 

associated with the development of lymphoma, leukemia, or brain cancer (2). More 

information about aspartame can be found in the FDA Statement on Aspartame, which is 

available at http://www.cfsan.fda.gov/~lrd/tpaspart.html on the Internet. 

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. 

4. Where can people find additional information about artificial sweeteners? 

For more information about artificial sweeteners, contact the FDA at: 

Address: 5600 Fishers Lane 

Rockville, MD 20857 

Telephone: 1–888–INFO–FDA (1–888–463–6332) 

Internet Web site: http://www.fda.gov/ 

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Selected References 

1. Soffritti M, Belpoggi F, Esposti DD, et al. First experimental demonstration of the 

multipotential carcinogenic effects of aspartame administered in the feed to SpragueDawley rats. Environmental Health Perspectives 2006; 114(3):379–385. 

2. Lim U, Subar AF, Mouw T, et al. Consumption of aspartame-containing beverages 

and incidence of hematopoietic and brain malignancies. Cancer Epidemiology 

Biomarkers Prevention 2006; 15. 

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Related Resources

Publications (available at http://www.cancer.gov/publications) 

• What You Need To Know AboutTM Bladder Cancer 

• What You Need To Know AboutTM Brain Tumors

National Cancer Institute (NCI) Resources

Cancer Information Service (toll-free)

Telephone: 1–800–4–CANCER (1–800–422–6237) 

TTY: 1–800–332–8615 

Online 

NCI’s Web site: http://www.cancer.gov 

LiveHelp, NCI’s live online assistance: 

https://cissecure.nci.nih.gov/livehelp/welcome.asp

This fact sheet was reviewed on 10/5/06 

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