When early research linked the widespread use of artificial sweeteners (saccharin) to bladder cancer in lab mice, concerns about artificial sweeteners (AS) and cancer in humans arose. This prompted the United States to issue cigarette-like warning labels on saccharin-containing products in the 1970s. In recent years, experts have largely dismissed studies in mice as unreliable. But results from subsequent carcinogenicity investigations on these AS have failed to show a clear link to cancer in humans. Similarly, no strong evidence of a link with cancer in humans has been found in investigations of other FDA-approved sweeteners.

Now, worrying data from human trials has been discovered by a recent study published in PLOS Medicine. The study is based on information from 102,865 people.
What does the research reveal?
The researchers searched through 102,865 French volunteers’ health records for over a decade. They found AS intake was connected with increased cancer risk. In particular, they discovered that people who consumed any type of artificial sweetener had about a 13% to 14% increased chance of developing cancer than those who did not.
Artificial sweeteners are chemicals with nearly no calories, making them appear to be a healthy sugar substitute in foods and beverages. Artificial sweeteners such as aspartame, saccharin, acesulfame potassium, and cyclamate are popular. Diet soda was created to replace the natural sugar used in Coca-Cola with a calorie-free alternative.
Six artificial sweeteners are approved by the FDA
Saccharin was found in 1879 and can still be found in fruit juices, sweets, jams, jellies, and cookies, particularly those products branded “low fat.”
Aspartame is the world’s second most used artificial sweetener. It’s in over 6,000 products, including powdered and carbonated soft drinks, chewing gum, hot cocoa, desserts, candies, tabletop sweeteners, yogurt, and vitamins and sugar-free cough drops from the pharmacy. It is consumed by about 200 million people globally. The FDA first approved the sweetener in 1974, and it has been in use for more than 30 years. Aspartame’s carcinogenicity has been studied. However, the results have been negative.

Approved in 1988, Potassium acesulfame is used to sweeten soft drinks and protein drinks and make medicines more palatable. Sucralose was approved in 1998 and used for many similar purposes as aspartame. Antvantam and Neotame were approved in 2002 and 2014, respectively, and are not used to the fullest. The first four are also legal in the European Union.
The study
Three common sweeteners were studied separately: aspartame, potassium acesulfame, and sucralose. Acesulfame Sunett and Sweet One are two brands of potassium marketed in the United States. Aspartame is sold as NutraSweet or Equal. Splenda is a brand name for sucralose.
The researchers used data from the NutriNet-Santé study, for which more than 170,000 French citizens agreed to submit information on their habits and health outcomes for decades, for researchers to extract correlations. The study began in 2009. The researchers looked at data from then until January 2021.
Volunteers were reminded to keep a food diary, write all of the foods and beverages they consume on a particular day, photographing containers to establish portion sizes. Hence, the scientists could compile a reasonable record of what people ingested on average and in what quantity.

The study results
Cancer rates were 15 percent higher for high aspartame consumers and 12 percent higher for lower consumers. More than others, aspartame intake was associated with an increased risk of breast cancer, with a 22% higher chance in the high-consuming group.
Higher potassium acesulfame consumers had a 13 percent cancer rate, whereas lower consumers had a 12 percent cancer rate. Sucralose appeared to have the least to do with cancer: Higher consumers had no higher rates while lower consumers had a 3% higher rate. Since the amount of artificial sweetener required for the desired sweetness varies widely, the scientists calculated distinct high and low measurements for each.
These numbers were adjusted to consider specific cancer risk variables, such as gender, age, and cigarette use, to ensure they represent the average French citizen.
Johns Hopkins Research on Saccharin
The moment Johns Hopkins University chemists discovered saccharin, the debate over the safety of artificial sweeteners began. Following the passage of the Clean Food and Drugs Act in 1906, amid fears of “falsification” of food, the newly established Food and Drug Administration considered a complete ban on saccharin. President Theodore Roosevelt intervened, calling his public health adviser “dumb” on the matter after going on a sugar-free diet.
Studies showing that saccharin caused bladder cancer in mice led to its labeling in the United States, a ban in Canada, and a worldwide reduction in its use. Since 1978, each pack of Sweet ‘N Low and countless diet Coke cans have included a warning that the beverage included a substance that could cause cancer in laboratory animals.
Scientists saw this reasoning as wrong, even panicked. The mechanism by which saccharin caused cancer in mice did not work in humans. To reach the doses given to laboratory mice, one would have to drink hundreds of diet soft drinks to consume the equivalent twelve ounces (340g) of saccharin daily to reach the same dose that the mice received. The United States removed the warning labels in 2000, and Canada reversed its ban in 2011.
According to researchers, “this is the first study to directly evaluate artificial sweeteners, not soda as a substitute.” They continued. “Research like this could settle the debate over artificial sweeteners, but they will probably rekindle it first.“
More research is needed
Considering the vast spectrum of artificial sweeteners and cancer, the connection between the two is a complicated research problem. Human evidence on artificial sweetener intake and cancer risk is limited. Given these limitations, further evidence from large clinical studies is needed to confirm the link between artificial sweeteners and cancer.