Is Splenda Really As Bad for You As Recent Research Suggests?

Fact checked by Nick Blackmer

Key Takeaways

• A recent study reported that sweetener ingredient sucralose-6-acetate (S6A) may damage DNA strands and impair gut barrier integrity.

• Splenda, a popular sweetener that uses sucralose, stated that their products do not contain S6A.

• More studies are needed to ascertain the potential health risks of artificial sweeteners.

Sucralose, a general-purpose sweetener approved by the Food and Drug Administration (FDA) in 1999, is currently facing scrutiny due to its potentially harmful impact on the body.

The popular sugar substitute, sold under the brand name Splenda, is about 600 times sweeter than table sugar. That means a smaller amount is needed to create the same level of sweetness.

In a recent study, researchers performed in vitro experiments exposing human blood cells to sucralose-6-acetate (S6A), a structural analog of sucralose. They found that the cells experienced DNA damage after being exposed, which points to it being genotoxic. The findings, published in Journal of Toxicology and Environmental Health, Part B, also reported that sucralose-6-acetate can impair that intestinal barrier integrity, causing a “leaky gut.”

Not long after the study was published, Splenda made it clear that their sweeteners use sucralose and do not contain the chemical compound S6A. “[T]he study never tested Splenda products and focused on a chemical compound that is not present in our products,” the company said in a press release.

Liz Weinandy, MPH, RDN, a registered dietitian at The Ohio State University Wexner Medical Center and instructor of practice in medical dietetics, told Verywell that while the study raises concerns about sucralose and S6A, it “doesn’t prove anything definitive since it was in vitro, taking place outside of a living organism.”

Related: Does Splenda Cause Cancer?

How Sucralose Differs From Sucralose-6-Acetate

Rafael Urrialde de Andrés, PhD, food safety and nutrition specialist and associate professor in Complutense University of Madrid’s Department of Genetics, Physiology and Microbiology, told Verywell that S6A is a metabolite from sucralose. That means it is a substance produced during metabolism. In other words, consuming S6A is not the same thing as consuming Splenda.

The aforementioned study referenced previous research in which rats were administered sucralose. Up to 10% of the dose came out as S6A in their fecal samples.

The findings from the rodent model suggests that only 10% of sucralose is metabolized to S6A. This is crucial to know when estimating the amount of the chemical compound that may be harmful for the body.

Only an Excessive Amount of Sucralose Can Reach Toxic Levels

According to the study, the lowest observed S6A concentration for genotoxicity—a type of genetic damage that is linked to cancer—was 707 micrograms per milliliter (µg/mL).

Based on a 2016 study, the concentration of sucralose in the blood can reach about 200 to 400 nanograms per milliliter (ng/mL) after drinking 250 milligrams (mg) of sucralose—the amount in four cans of diet soda. But for two participants, the concentration spiked even more, exceeding 1,500 ng/mL.

Even if your plasma sucralose concentration were to reach 1,500 ng/mL after drinking four cans of diet soda, you’d have to drink around 1,800 cans of diet soda to reach the lowest observed concentration for genotoxicity of S6A.

An older study from 2000 also looked at blood concentrations after a dose of sucralose. One hour after administering 10 milligrams per kilogram (mg/kg) of sucralose, the participants’ sucralose blood levels peaked and reached almost 600 µg/mL. The participants weighed between 126 to 176 pounds, and the dose of sucralose they received was the equivalent of about 47 to 66 packets of Splenda. The peak of 600 µg/mL still doesn’t reach S6A’s lowest observed concentration for genotoxicity.

The amount tested in the study is very high and its intake is impossible, Urrialde said. You would be consuming an excessive amount of sucralose before you reach the DNA damage threshold for S6A. Factoring in the estimate that only 10% of sucralose is metabolized to S6A, the consumption required to cross the threshold would be even higher.

Related: 5 Best Sugar Substitutes for People With Diabetes

Further Studies About Sweeteners Are Needed

The recent study says that consuming a genotoxic amount of S6A may produce DNA strand breaks. However, the bacterial reverse mutation tests reveal that sucralose and S6A are both non-mutagenic. The authors said that “DNA damage initiated by sucralose-6-acetate may not lead to permanent alterations in further generations of cells because it is not mutagenic.”

They also found that S6A induced expression of genes associated with inflammation, oxidative stress, and cancer in the intestinal epithelium. In animal models from earlier studies, the consumption of sucralose was indicated as a possible risk factor for colorectal cancer.

But further research is needed to understand how sucralose and S6A interact with the body. The study was conducted in vitro and is not comparable to in vivo research, Urrialde said. It can open the door to further studies, but should not necessarily be a cause for alarm, he added.

“It would be ideal for larger scale human studies to take place to get some more direction on this topic,” Weinandy said. Human trials are needed, "not just studies in rodents and in vitro.”

According to the FDA, an individual weighing 132 pounds can consume 23 packets of Splenda a day and still be within the safe level of consumption for sucralose.

That said, the continuous consumption of artificial sweeteners of any kind might not be as benign as initially thought. A study published last year in BMJ reported an association between higher artificial sweetener consumption and increased cardiovascular disease risk.

Moreover, the World Health Organization (WHO) recently recommended against the use of non-sugar sweeteners to control body weight because a review found that it doesn’t have any long-term benefit in reducing body fat. The organization also warned that a long-term use of sweeteners may have “potential undesirable effects” like the increased risk of type 2 diabetes, cardiovascular diseases, and mortality in adults.

“Since so many Americans use sugar substitutes and they are widespread in our foods, including many foods marketed towards children, we should be investing the money in research to ensure safety,” Weinandy said.

What This Means For You

Sucralose, as a food additive, is approved for consumption by the FDA. Although small amounts of the sweetener might not be genotoxic, more studies are ultimately needed to understand how it affects the body.