This page was reviewed under our medical and editorial policy by
Maurie Markman, MD, President, Medicine & Science
This page was updated on August 2, 2023.
Artificial sweeteners are found in a wide variety of processed foods and drinks. The food industry uses these common ingredients to help people satisfy a sweet craving, while still helping them cut calories or manage their blood sugar. When consumed in moderation, artificial sweeteners may benefit those trying to lose weight or cut back on sugar. For decades, people have wondered about potential adverse health effects related to these sugar substitutes, but scientific literature largely doesn’t support these claims.
This guide will cover essential topics on artificial sweeteners and cancer risk, including:
Artificial sweeteners are sometimes called non-nutritive sweeteners, sugar substitutes or high-intensity sweeteners. These terms describe the chemical and plant-based compounds that are either synthesized or refined in a lab, and are used as an at-home replacement for sugar or to sweeten packaged foods and beverages. Below are some of the main types of artificial sweeteners and their associated brand names:
They are often found in products labeled as “diet,” “sugar-free” or “low-carb” because they provide a sweet taste with little to no calories from sugar. Most artificial sweeteners are between 200 times and 700 times sweeter than regular sugar. Because they are chemically different from sugar, artificial sweeteners generally don’t raise blood sugar levels.
Stevia is a sugar substitute, and considered by some an artificial sweetener due to its processing, even though it’s made from the stevia rebaudiana plant. Others consider it a “natural” alternative to other sugar substitutes. But stevia is highly processed.
Making stevia involves extracting sweet compounds from the leaves of the stevia rebaudiana plant and then refining and purifying them into a processed formula. The plant has to be processed in this way to be used as a food additive, because the U.S. Food and Drug Administration (FDA) hasn’t approved untreated or whole-leaf stevia for this use due to potential adverse effects. Purified stevia extracts have a GRAS (“generally recognized as safe”) designation from the FDA.
Like other sugar substitutes and artificial sweeteners, stevia has no calories and is much sweeter (roughly 200 to 400 times) than regular sugar. It’s used as an at-home sugar substitute and added to hundreds of processed products, including popular drinks. Stevia is also mixed with other sugar substitutes and some sugar alcohols in other products, such as certain sweeteners made by Truvia and Splenda.
Stevia may be helpful for blood sugar control and weight loss, although the evidence is limited. When consumed in moderation and according to nutrition labels, stevia is generally considered safe. Some individuals may experience mild discomfort after consuming stevia, such as nausea or fullness.
Below are some of the main types of plant- and fruit-based sweeteners and their associated brand names:
Sugar alcohols are a type of carbohydrate. They don’t contain sugar or alcohol, but their chemical structure is similar to both. Synthetic sugar alcohols may be manufactured in a lab, but the compounds also occur naturally in some plants. Below are some of the commonly used types of sugar alcohols:
Sugar alcohols aren’t in the same category as high-intensity, non-nutritive sweeteners because they contain calories and are not sweeter than regular sugar. However, they have fewer calories than sugar—about half as much, depending on the specific type. They also aren’t fully digested by the body and are absorbed at a slower rate than sugar. Sugar alcohols won’t cause sharp spikes in blood sugar or harm the teeth, but they may cause digestive issues such as bloating and diarrhea.
Sugar alcohols are common additives in products labeled “sugar-free,” “diabetic-friendly” or “low-carb.” Some believe the carbohydrates provided by sugar alcohols can be subtracted from the total carbohydrates in a food or beverage product because sugar alcohols are incompletely absorbed in the body. This practice is called calculating “net carbs,” and may be used by those following ketogenic or low-carb diets. However, the calculation of “net carbs” isn’t always accurate because the amount of calories in sugar alcohols depends on the type, and most food labels don’t include the specific types used. Those who need or want to control blood sugar levels, such as those with diabetes or on a ketogenic diet, should be aware that this method isn’t reliable or precise.
The nutritional information explains whether a product contains a sugar substitute. However, non-nutritive sweeteners are only included in the ingredients list, not the nutrition facts table. It may be difficult to spot these sweeteners because they have many different names and types. Determining how much sweetener a product has is another challenge. Sugar alcohols may be easier to identify because most types end with the letters “tol” and some ingredient lists specify the amount of sugar alcohols.
Artificial or non-nutritive sweeteners have a leg up on table sugar in three main ways:
However, there is some variability between different types of artificial sweeteners and other sugar substitutes. For example, stevia has many of the same benefits as artificial sweeteners. Sugar alcohols aren’t non-nutritive because they contain calories, but they still have less effect on blood sugar levels compared to regular sugar. Sugar alcohols also don’t harm teeth.
Non-nutritive sweeteners may be helpful for those who are cutting calories to lose weight or managing diabetes or other health concerns. Replacing sugar with artificial sugars allows people to satisfy their sweet tooth without taking in calories or spiking blood sugar. However, research on the efficacy of artificial sweeteners for weight loss is inconclusive. Studies suggest that artificial sweeteners may be useful for short-term weight loss in some cases, but these benefits do not seem to persist or lead to sustained improvements. Other studies have suggested that artificial sweeteners may hinder weight loss progress by altering the balance of healthy bacteria in the gut. Much of the research has been done in animals or small samples of humans and isn’t robust enough to draw any definitive conclusions.
Those trying to lose weight or control blood sugar should focus on making healthy food choices and speak to a doctor before using sugar substitutes.
Concerns about potential health consequences have followed sugar substitutes for decades. The current body of research has not identified a clear link between artificial sweeteners and cancer in humans. Below is a summary of the research on saccharin, aspartame and sucralose, three of the six FDA-approved artificial sweeteners.
Saccharin: Preliminary studies found a link between saccharin consumption and bladder cancer in laboratory rats. However, subsequent human studies haven’t established a relationship between saccharin and bladder cancer or any other cancer in humans, according to the National Cancer Institute (NCI). Researchers have also demonstrated that the mechanism by which saccharin may cause bladder cancer in rats is specific to their biology and doesn’t apply to humans.
Aspartame: Aspartame was approved by the FDA in 1981, after early studies in laboratory animals found no link between aspartame and cancer risk. Safety concerns emerged in 2005, when a study of lab rats suggested that high doses of aspartame taken over a long period of time may be associated with lymphoma and leukemia in rats. However, upon review, the FDA and other regulatory bodies found significant issues with the study design and data, and the findings were dismissed. Some subsequent studies haven’t found a consistent association between aspartame and cancer in humans, including a 2006 study published in Cancer Epidemiology, Biomarkers and Prevention of more than 500,000 individuals and a 2013 review of multiple investigations published in Food and Chemical Toxicology. However, a 2022 study of 102,865 people in France who were followed over an eight-year period found that those who consumed aspartame were found to have a higher risk for developing cancer.
Sucralose: The FDA approved sucralose in 1999 based on evidence from more than 110 studies that demonstrated its safety. In 2016, concerns emerged after a new study suggested that mice may be at greater risk of blood cancer after consuming high doses of sucralose for an extended time. However, the study was conducted by the same laboratory that published a debunked 2005 study on aspartame, and the FDA again disputed the scientific rigor and legitimacy of the data.
Three other artificial sweeteners approved by the FDA are:
Before authorizing each of these sweeteners, the FDA examined several studies and found no evidence of health risks, including cancer. The FDA also sets an “acceptable daily intake” for each approved sweetener, which designates the maximum daily dose that can be safely consumed. At these levels, the evidence suggests that artificial sweeteners are generally safe.
The general consensus among food safety experts and major health agencies, such as the NCI and FDA, is that the evidence doesn’t support a link between most artificial sweeteners and adverse health outcomes, including cancer. However, research is ongoing, and the relevant agencies continue to review new evidence and adjust their recommendations accordingly. For instance, in July 2023, the World Health Organization noted that aspartame is "possibly carcinogenic to humans" and advised that an acceptable daily intake of aspartame is 40 milligrams per kilogram of body weight.
People who are concerned about the effects of artificial sweeteners and other sugar substitutes should consult their health care team or oncologist.