Sugar substitutes have come under fire in the past few years after being linked to a slew of potential health issues. Now, there’s another one to add to the list: They may interfere with your liver’s ability to detoxify your body.
That’s the major takeaway from new research presented at the American Society for Biochemistry and Molecular Biology’s annual meeting. The study specifically looked at the impact of two sugar substitutes—acesulfame potassium and sucralose—on liver cells and cell-free assays, which allow scientists to study cellular processes.
The researchers discovered that the sweeteners disrupted the function of a protein called P-glycoprotein (PGP), which works to help rid your body of toxins, drugs, and drug metabolites (i.e. byproducts that are formed when your body breaks down a drug).
“We think that it might interfere with the efficiency of medication or chemotherapy and increase toxicity,” says lead study author Stephanie Olivier Van-Stichelen, Ph.D., an assistant professor of biochemistry at Medical College of Wisconsin. “That’s where we’re putting our research right now.”
Olivier-Van Stichelen points out that while artificial sweeteners will show up on food nutrition labels, the actual amount isn’t listed. “We don’t usually know how much sweeteners we consume,” she says. “It’s not listed on labels for yogurts and diet soda and it's hard for people to know how much they’re having.”
How worried about this should you be? Experts break it down.
What are sugar substitutes?
Sugar substitutes, aka non-nutritive sweeteners or artificial sweeteners, are substances that give you a sweet taste with little or no calories, according to the Food and Drug Administration (FDA).
Both sucralose, which has the brand name Splenda, and acesulfame potassium (aka Sweet One), are approved by the FDA for use as food additives.
How your liver detoxifies your body
Your liver is an organ that regulates most chemical levels in your blood and excretes a product called bile that helps carry away waste products from the liver, according to Hopkins Medicine.
All of your blood that leaves your stomach and intestines passes through your liver, which processes and balances the blood. It also metabolizes drugs into forms that are easier for the rest of your body to use or that are nontoxic, Hopkins Medicine says.
“The liver is the main—but not only—detoxifying organ in your body,” says Jamie Alan, Ph.D., Pharm.D., associate professor of pharmacology and toxicology at Michigan State University. (Your kidneys, lungs, and lymphatic system also play a role in detoxifying your body, along with other organs.) When something interferes with your liver’s function, it “may shift metabolism to another non-toxic product and you might not notice anything,” Alan says. But, she adds, “you may build up the active compound or build up a toxic metabolite and then serious side effects or consequences may occur.”
Your liver plays a crucial role in the detoxification process, though. “Your liver is essential for breaking down and clearing waste products from normal metabolism, as well as chemicals, toxins, and medications from your body,” says Rebecca Mason, R.D.N., manager of clinical nutrition at Spectrum Health. “Limiting your liver’s capacity to do this could mean increased levels of toxins remaining in your system or impairments to metabolism.”
In the case of these sugar substitutes, Olivier-Van Stichelen says that more work is needed to understand what the findings mean. "We're trying to understand if this is anything to be concerned about," she says.
Is it OK to have some sugar substitutes?
In addition to the latest findings, animal studies have linked sugar substitutes to a range of potential health issues, including weight gain, bladder cancer, and tumors. But the findings have been in animals, not humans, and the National Cancer Institute (NCI) says that studies of FDA-approved artificial sweeteners “have not demonstrated clear evidence of an association with cancer in humans.”
Jessica Cording, R.D., author of The Little Book of Game-Changers, says that she generally recommends that her patients try to minimize the use of non-nutritive sweeteners. “You have to look at them on the same playing field as sugar,” she says. “A little goes a long way, and less is more. Definitely use them sparingly.”
If artificial sweeteners are an occasional part of your diet, like having a diet soda here and there, Cording says it’s “not a cause for concern.” But, if you’re having non-nutritive sweeteners regularly, she recommends looking for alternatives that don’t contain the sweeteners.
Artificial sweeteners are also incredibly sweet, and that can “condition people to crave really sweet foods,” Cording says. “They can really drive sugar cravings,” she adds. “That’s the main reason I recommend using them sparingly.”
But Liz Weinandy, a registered dietician nutritionist at The Ohio State University Wexner Medical Center, cautions against putting too much stock into this particular study. "While these findings are interesting, we need to keep in mind they are preliminary and we need much more research to see if these artificial sweeteners or sugar substitutes disrupt the liver’s ability to detoxify," she says.
Mason agrees that it’s important to limit your use of artificial sweeteners. “Moderation is key when it comes to processed goods, including sugar substitutes,” she says. “While using substitutes can be a good way to cut back on calories from sugar, many people find greater satiety and satisfaction when mindfully enjoying a small portion of their favorite—regular sugar—treats.”