Splenda and Leukemia

Artificial sweeteners, including sucralose (Splenda) continue to be studied for potential risks.

You may have your own favorite -- Sweet ‘n Low (saccharine), Equal (aspartame) or maybe Splenda (sucralose).

If it's early in the morning, perhaps you prefer your sweetener color-coded: the pink one, the blue one or the yellow one.

No scientific publication would ever phrase the question in this way, but…
Could artificial sweeteners like Splenda be killing us slowly?

Based on available evidence, it is not likely. However, there is at least some evidence that artificial sweeteners, including the sucralose in Splenda, may not be the best way to cut calories -- or still worse, may not be as inert or as harmless as believed. Scientists speculate about potential links between sweeteners and a variety of chronic diseases, but leukemia?

Recently, a group of investigators based in Italy studied sucralose in mice and found a significant link to leukemia, a cancer of the blood-forming cells. The relevance to human health is at this time unknown, but the makers of Splenda responded promptly and mounted a forceful defense.

Sucralose (Splenda) in the US and Canada

Sucralose has been in use in Canada and the US since about 2000 and in the EU since 2003, and it's now found in the sanitary wastewater in many parts of the world. It persists during sewage treatment -- so much so that scientists have considered using it as a marker for recent groundwater contamination by wastewater. Kind of creepy, but no inherent health risks, right?

Like saccharin, sucralose can inhibit gut bacteria, and some researchers say it may have an even more pronounced effect on gut bacteria than saccharin because about 65 to 95 of sucralose is excreted through the feces, unchanged.

When it comes to potential harm from sucralose, there are several theories, but little definitive evidence. One theory is that sucralose may impact gut bacteria in a way that could lead to digestive enzyme inactivation and problems with gut barrier function -- problems that have been hypothesized to explain the rising incidence of inflammatory bowel disease, or IBD.

Sucralose has been shown to reduce the overall number of gut bacteria, with significantly greater suppression for “good bacteria” -- for example, lactobacilli, bifidobacteria -- and less inhibition of more detrimental bacteria such as enterobacteria.

Since millions and millions of people use artificial sweeteners, any hint of increased cancer risk is also taken seriously; while no increased risk was found in the numerous studies leading to approval, risks continue to be investigated and monitored.

Sucralose and the Leukemia Link

In 2016, a research group based in Italy published results from a large study performed in mice, finding that a significant increase in leukemia and related blood cancers occurred in male mice that were exposed to sucralose throughout their lives, starting from before birth.

Previous industry-sponsored studies did not find a link with cancer. However, adopting a devil's advocate approach, reports on the newest study suggest past investigations may have tested fewer animals, started exposing the animals beginning at adolescence rather than in utero, and some of them may have come to an end earlier than the present study. Animals in the industry-sponsored studies were also reported to have had less body mass than controls, which can decrease rates of some types of cancer.

Italian Study in Mice

The Italian group used a mouse model and treated the mice from 12 days of gestation through the lifespan with sucralose mixed into the mouse feed: They made five different groups, giving each differing concentrations of sucralose, in parts per million (ppm): 0, 500, 2,000, 8,000, and 16,000 ppm.

They found a significant dose-related increase in males with malignant tumors and a significant dose-related increase of hematopoietic neoplasia (blood cancers) in males, in particular at the dose levels of 2,000 ppm and 16,000 ppm.

These findings need to be confirmed, and the risk in humans at feasible/conceivable doses would need to be established, but as the study's authors concluded -- using different words -- it would be a good idea to find out for sure, given that millions and millions are being exposed.

Splenda Responds

According to Fox News Insider, Splenda has responded to the researchers behind the study, saying that "poorly conducted and unscientific studies make bold headlines and stir up safety fears."

"Researchers have conducted more than 100 scientific studies on the safety of sucralose over the past 20 years," they said in a statement on their Facebook page.

"They’ve all declared sucralose safe to enjoy."

Center for Science in the Public Interest on Sucralose

“When sucralose was first being considered for approval by the FDA, the Center for Science in the Public Interest (CSPI) objected,” as reported in one CSPI online resource.

A study in rats had apparently indicated that the sucralose might cause premature shrinkage of the thymus gland, which is part of the immune system. A subsequent study did not find any problem, and industry studies designed to detect whether sucralose could cause cancer in lab animals did not find any problems.

“Several researchers contend that sucralose negatively impacts the gut, including changes in the microbiome and enzyme levels. That could have a range of consequences, including inflammatory bowel disease, how drugs and other chemicals are absorbed and metabolized by the body, and the regulation of body weight, possibly leading to obesity,” note CSPI sources.

CSPI recommends that consumers avoid sucralose, but also saccharin and aspartame. CSPI president Michael F. Jacobson put things in perspective as follows: “That said, the risk posed by over-consumption of sugar and high-fructose corn syrup, particularly from soda and other sugar-sweetened beverages, of diabetes, heart disease, and obesity, far outweighs the cancer risk posed by sucralose and most other artificial sweeteners."

The CSPI also notes that -- even setting aside these concerns -- young children could exceed the FDA's "acceptable daily intake" for sucralose (5 mg/kg), especially given sucralose's popularity -- more products containing sugar substitutes use sucralose than any other sweetener.

"For example, a 6-year-old child weighing 45 pounds would exceed the FDA limit by drinking two or three 12-ounce sodas containing the typical 40-60 mg of sucralose per can. In addition, sucralose passes into breast milk at detectably sweet levels."

View Article Sources