Does Splenda Cause Cancer?

Artificial sweeteners are everywhere - but are they a better substitute than sugar? Does the artificial sweetener Splenda (sucralose) cause cancer? Is it a safe substitute for sugar in a cancer-prevention diet?

The answers may be confusing. Some articles quote studies that found leukemia in mice and say yes. In contrast, you may read that Splenda does not increase cancer risk and is considered safe, even in pregnant and breastfeeding women. With so many conflicting answers and lots of research for each answer, it can be hard to figure it out.

Read on to get some explanations.

Packages of Splenda and Equal
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What Is Splenda (Sucralose)?

Splenda, whose generic name is sucralose, is a non-nutritive sweetener 600 times sweeter than sugar (sucrose). It was first approved in 1998 as a table-top sugar substitute, and in 1999 it was approved as a general-purpose sweetener. Splenda is now estimated to be present in more than 4,000 products, from dessert mixes to syrup, and is available in more than 80 countries.

Sucralose is made from real sugar. The difference is that, in the artificial sweetener, three hydrogen-oxygen bonds are replaced with three chlorine atoms. Sucralose interacts with nerve cells (chemoreceptors) in the digestive tract that play a role in our brain's interpreting a sweet taste sensation.

The Controversy Over Artificial Sweeteners

There has been controversy surrounding sugar substitutes. The cancer stigma surrounding artificial sweeteners is believed to stem from the 1970s when lab rats developed bladder cancer during a saccharin trial. Although no case of cancer in a human has been linked to saccharin, the stigma remains and has continued with the approval of aspartame (sold as Equal or NutraSweet), which is likely of more concern than Splenda.

On the other side of the equation is a large amount of sugar the average American consumes—reportedly 22 teaspoons daily—combined with rising rates of obesity and diabetes.

Below, we'll look at Splenda alone and what we have learned about whether it may cause cancer or lead to health problems that increase cancer risk.

Sucralose and Cancer

It's essential to begin with the regulatory committee's decision on whether Splenda can cause cancer. Based on more than 110 studies, the FDA has approved the use of sucralose in the consumer market without restrictions.

In addition, studies evaluating metabolites—the products of sucralose as it is broken down and metabolized by the body—were also found to have no carcinogenic potential.

Overall, sucralose has been found to have no potential for carcinogenicity or genotoxicity, even at high doses.

Carcinogenicity vs. Genotoxicity

Carcinogenicity refers to the ability of a substance to cause cancer. Genotoxicity refers to the ability of a substance to damage genes. Genotoxicity (the ability to damage genes) usually makes a substance carcinogenic.

What the Research Says

Most studies have not shown any increase in cancer risk with Splenda, except for a 2016 Italian study. In this study, which looked at the effect of sucralose in Swiss mice, it was found that the male mice exposed to high doses of sucralose had an increased risk of developing leukemia. A follow-up study by the manufacturer failed to show this association. But what did the study actually test?

The sucralose and leukemia study looked at mice who were given sucralose in three different doses beginning in utero (prenatally) and throughout their lifespan. There was no increased risk of leukemia at doses equivalent to ordinary human doses. There was, however, an association at doses roughly equivalent to four times the recommended daily intake in humans when used throughout the mouse lifespan.

A study such as this is difficult to interpret. Certainly, most adults will not use four times the recommended maximum amount of sucralose every day of their lives. But what amount is safe? In general, it's thought that there is no safe limit to a carcinogen. This is also only one study conducted on animals—though it was relatively large compared to other studies.

Compared to many risk factors in our lives, if this does mean an increased cancer risk, it is probably small relative to other risk factors we are exposed to daily. For example, it's thought that home exposure to radon causes 21,000 lung cancer deaths annually, but many people don't take the time to purchase a 10-dollar test kit to find out if their home has a problem.

Other Health Effects

Sucralose has also been found to have a few actions of concern in the digestive tract. In other words, it is not "inert" or completely inactive. Some of this could have implications for the formation of cancer.

Splenda (sucralose) appears to decrease the number of "good" bacteria in the gut. Having enough good bacteria in the gut is as important or more important than having "bad" bacteria in the gut. It's not certain if this has any significance or if this is related to another finding—that sucralose is a risk factor for inflammatory bowel disease.

We know that inflammatory bowel disease raises colon cancer risk. In addition, some treatments for IBD elevate cancer risk.

Many studies have looked at artificial sweeteners for weight loss, but Splenda (sucralose) has increased appetite in at least one study. Since obesity is a strong risk factor for cancer and diabetes, this is an important topic.

The finding that sucralose may increase appetite is fairly ironic, given that the compound is often used to avoid sugar-related calories. However, an equally serious concern is that the average American consumes too much sugar, while obesity has become nearly epidemic.

Safety studies have looked at sucralose's effects and stability under normal use conditions. However, some researchers have examined what happens when sucralose is exposed to heat, such as cooking. There is a bit more concern in this setting (even with mild heating). Cooking sucralose at high temperatures generates potentially toxic compounds called chloropropanols.

Since sucralose gets into the water supply and is present in groundwater, scientists have been trying to study what—if any—effect this may have ecologically. At this time, we simply aren't sure.

If you wish to avoid this potential risk, do not cook or bake with Splenda.


At the present time, there is little evidence that sucralose—used in normal amounts and not heated—contributes to cancer risk. Following the "everything in moderation" rule, a little Splenda is probably not worth fretting over for those who crave sweetener.

It's important to note that while many people are concerned about what we still don't know about artificial sweeteners, there are probably many other risks in our lives that may be more deserving of our focus.

A Word From Verywell

If you're concerned about your risk of cancer from Splenda, talk with your healthcare provider. Knowing your health history, they can discuss their thoughts about your risks in using the sugar substitute and whether they have any other suggestions you can use instead.

Frequently Asked Questions

  • What artificial sweeteners can cause cancer?

    Saccharine and cyclamate were both found to cause cancer, but saccharine was only found to cause cancer in rats. The effects did not transfer over to humans.

  • What are the dangers of sucralose?

    As stated in the article, there were higher rates of certain cancers found in mice. It also has been found to increase appetite, decrease good bacteria in the gut, and when heated at high temperatures, it can break down into possibly toxic compounds.

  • What is the safest artificial sweetener to use?

    Aspartame seems to be an extremely safe artificial sweetener, with no associations with cancer or other adverse health effects.

11 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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  2. Code of Federal Regulations. Food additives permitted for direct addition to food for human consumption; sucralose.

  3. Food & Drug Administration. Additional information about high-intensity sweeteners permitted for use in food in the  United States.

  4. M S, M P, E T, et al. Sucralose administered in feed, beginning prenatally through lifespan, induces hematopoietic neoplasias in male swiss mice. Int J Occup Environ Health. 2016;22(1):7-17. doi:10.1080/10773525.2015.1106075

  5. US Environmental Prrotection Agency. Health risk of radon.

  6. Ruiz-ojeda FJ, Plaza-díaz J, Sáez-lara MJ, Gil A. Effects of Sweeteners on the Gut Microbiota: A Review of Experimental Studies and Clinical Trials. Adv Nutr. 2019;10(suppl_1):S31-S48. doi:10.1093/advances/nmy037

  7. Qin X. Etiology of inflammatory bowel disease: A unified hypothesis. World J Gastroenterol. 2012;18(15):1708‐1722. doi:10.3748/wjg.v18.i15.1708

  8. Wang QP, Lin YQ, Zhang L, et al. Sucralose Promotes Food Intake through NPY and a Neuronal Fasting Response. Cell Metab; 24(1):75-90.

  9. de Oliveira DN, de Menezes M, Catharino RR. Thermal degradation of sucralose: a combination of analytical methods to determine stability and chlorinated byproducts. Sci Rep. 2015;5:9598. doi:10.1038/srep09598

  10. Sang Z, Jiang Y, Tsoi YK, Leung KS. Evaluating the environmental impact of artificial sweeteners: a study of their distributions, photodegradation and toxicities. Water Res. 2014;52:260-74. doi:10.1016/j.watres.2013.11.002

  11. National Cancer Institute. Artificial sweeteners and cancer.

Additional Reading
Originally written by Lisa Fayed