Aspartame and sucralose, sold under the brand name Splenda, are two varieties of commonly used artificial sweeteners. These sweeteners do not contain any calories, but they have a sweetening power far greater than that of sugar. The Food and Drug Administration has approved these sweeteners for consumers. However, there is some evidence that points to potential dangers, based largely on animal studies, of both sucralose and aspartame. No human studies have found any safety issues with these artificial sweeteners.
According to the National Cancer Institute, over 100 studies have shown sucralose to be a safe substance that poses no health risk to humans. NYU Langone Medical Center reports that sucralose underwent over 20 years of scrutiny by regulatory agencies before it was deemed safe.
Potential Risks of Sucralose
A recent study cited by the Center for Science in the Public Interest, which found a link between sucralose and leukemia in mice, prompted the center to change its safety rating of sucralose from "Safe" to "Avoid." Still, to date, no human studies have demonstrated any clear links between sucralose and cancer. A study published in 2008 in the "Journal of Toxicology and Environmental Health" did find, however, that sucralose reduced beneficial gut bacteria in rats.
An article published in "Regulatory Toxicology and Pharmacology" in 2002 reviewed the safety of aspartame. The authors concluded that the safety testing of aspartame had gone well beyond the required level. According to the article, the evidence, when examined as a whole, clearly indicated that aspartame is safe.
Potential Risks of Aspartame
The National Cancer Institute notes that although some reports suggested a possible link between brain tumors and aspartame, inconsistencies in the data led the institute to conclude, after review, that there was no clear link. A 2005 lab study found that rats fed very high doses of aspartame had a higher incidence of certain cancers. This study also had inconsistencies, which prevented clear conclusions from being drawn. A study published in "Environmental Health Perspectives" in 2007 found that long-term exposure to low doses of aspartame increased cancer in rats.
Sucralose, Aspartame and Weight Gain
Although the primary purpose of artificial sweeteners is to reduce calorie consumption, some research shows that they may do just the opposite. A paper published in the "Yale Journal of Biology and Medicine" in 2010 examined the effect that artificial sweeteners have on pleasure centers in the brain. According to the researchers, noncaloric sugar substitutes, including aspartame and sucralose, do not satisfy the brain in the same way that real sugar does. This can lead to overeating and potentially to obesity. The paper refers to several large-scale studies that found links between use of artificial sweeteners and weight gain. The researchers also noted that artificial sweeteners can actually encourage sugar cravings and sugar dependence.