Ever since experts have realized the many negative health consequences of consistently consuming excessive added sugars (increased inflammation, altered gut microbiome health, overall increased chronic disease risk, etc.), we have had artificial sweeteners to help us have our (sugar-free) cake and eat it, too. These substances, which include aspartame, sucralose (Splenda), monk fruit, and stevia, provide a similar sweetness to sugar with little to no calories, and are found in a wide variety of packaged foods from diet sodas to protein powders.

But is the artificial stuff really better than plain ol’ sugar? That’s where things get a little sticky. According to Maya Feller, RD, CDN, Brooklyn-based registered dietitian and author of Eating from Our Roots, the data on artificial sweeteners is bittersweet. “We could all benefit from more research on artificial sweeteners,” Feller says. “This is required to definitively assess its impact on the body.” That said, nutrition science has uncovered some science on the subject. Ahead, Feller delves into what can potentially happen to your body (and gut) when—or if—you decide to cut back on artificial sweeteners.

The conflicting science around artificial sweeteners

The topic of artificial sweeteners is a hot-button issue in health and wellness spaces…but with scant amounts of definitive scientific backing, says Feller. Over the years, some research has suggested that certain types of artificial sweeteners may be associated with concerning health issues, including an increased risk of cancer, disrupted gut microbiome, and an increased risk of cardiovascular health problems including heart attack and stroke. However, other studies have concluded that artificial sweeteners are likely not linked to health issues like cancer…making things all the more confusing.

Then last year, the World Health Organization (WHO) added fuel to the fire last year when it recommended that people not use artificial sweeteners for weight management due to the potential of long-term health impacts. Yet the Food and Drug Administration (FDA) and other food safety authorities stand by the safety of aspartame and other artificial sweeteners. So…what gives?

Basically, we need more quality research. Despite being some of the “most-studied ingredients in our food supply,” says registered dietitian Kris Sollid, RD. “There is enough controversy surrounding the potentially beneficial and negative effects of low- and no-calorie sweeteners to warrant further study in the form of randomized control trials in multiple populations,” Feller adds.

But does artificial sweetener, or regular sugar for that matter, deserve the bad rap it often gets? Maybe, maybe not. Feller says although there’s been speculation that low- and no-calorie sweeteners could have negative implications on certain health outcomes, the data is still inconclusive. “Observational studies have shown associations between adverse health effects and the consumption of low- and no-calorie sweeteners,” she says. (Observational means that researchers collected data from participants or looked at pre-collected data and saw what people’s outcomes are.) But these associations haven’t been confirmed by randomized controlled trials (RCTs), aka the gold standard of research where specific interventions or treatments are tested directly on people picked at random.

“When rigorous intervention studies have been conducted to test potential adverse health effects of low- and no-calorie sweeteners…the randomized controlled trial evidence shows neutral and positive effects; not negative effects.” —Maya Feller, RD, CDN

In fact, Feller notes that evidence from other randomized controlled trials have shown the opposite effect. “In other words, when rigorous intervention studies have been conducted to test potential adverse health effects of low- and no-calorie sweeteners suggested in observational research, the RCT evidence shows neutral and positive effects; not negative effects,” she says. (Basically, in these trials, artificial sweeteners often have no effect or a positive impact on a person’s health.) “When it comes to connections between food and health, neutral shouldn’t be viewed as negative,” she says.

Feller says that conflicting data leads to more confusion—and further speculation—on the safety of artificial sweeteners. “IARC (International Agency for Research and Cancer) made a report stating that aspartame is possibly carcinogenic to humans, while the Joint FAO/WHO Expert Committee on Food Additives (JECFA) found that there was ‘no convincing evidence from experimental animal or human data that aspartame has adverse effects after ingestion,’” Feller says. And as mentioned earlier, the FDA, along with Health Canada and the European Food Safety Authority (EFSA) “have all noted that they do not have safety concerns when aspartame is used under approved conditions.”

“When it comes to connections between food and health, neutral shouldn’t be viewed as negative.”

So…is it “bad” to eat artificial sweeteners?

Given the conflicting research and guidance from various health and governmental agencies, different experts have different opinions about whether or not to consume artificial sweeteners. In Sollid’s opinion—formed after looking into the research extensively—she says that they’re probably fine for many people in moderation. “People who consume them should be reassured that they are a safe option to help them reach their desired health goals, especially if that goal is to reduce the amount of added sugar they consume without sacrificing sweetness or enjoyment,” he says.

For Feller, the context of how these sweeteners are used is very important.“The use of a low- and no-calorie sweetener does not [necessarily] make something a healthy food and the presence of added sugar does not [necessarily] make something unhealthy,” she says. What’s more important is analyzing their effects on a case-by-case basis. “Context needs to be taken into consideration as well as quantity and regularity of consumption for both,” she says.

For folks in need of lowering added sugar intake, for example, consuming artificial sweeteners may be a good thing. That’s possibly a lot of folks—per the American Heart Association, the average American consumes 17 teaspoons of added sugar each day, which is two to three times higher than recommended intakes for men and women. “For some, replacing a low- or no-calorie sweetener in place of added sugars may be beneficial,” says Feller. “In fact, there may be a metabolic benefit for people who have or are at risk of developing cardiovascular disease, or for folks who live with type 1 or type 2 diabetes who may want to avoid added sugar for glucose reasons.”

Who shouldn’t consume artificial sweeteners? 

That said, Feller says that are two main groups who should avoid the consumption of artificial sweeteners whenever possible: people with phenylketonuria (PKU) and children under the age of two.

Feller recommends that aspartame intake should be limited by people with PKU, a rare genetic disease that makes an affected person unable to properly metabolize phenylalanine, one of the amino acids found in aspartame and many common foods like milk, cheese, nuts, and meat. “Individuals with PKU need to avoid or restrict their intake of phenylalanine from all sources. All packaged foods and beverages with aspartame as an ingredient are required by the FDA to have a statement on the label informing consumers of phenylalanine’s presence,” Feller says.

Meanwhile, Feller explains that the 2020-2025  Dietary Guidelines for Americans (DGA) does not recommend the consumption of low-calorie sweeteners or added sugars by children younger than the age of two. “This DGA recommendation is not related to body weight, diabetes, or the safety of added sugars or low-calorie sweeteners, but is instead intended to avoid infants and toddlers developing a preference for overly-sweet foods during this formative phase,” Feller says. (Exceptions can reasonably made for children with diabetes, Feller says, since their blood glucose management needs are very different.)

What happens to your body when you cut back on artificial sweetener

So, you cut back on artificial sweeteners because it’s right for you. Now, what can you expect? First and foremost, Sollid reiterates that the science is murky, at best. “How our body might react to cutting back is unclear—for some people, it might be a good idea, for others it may not. The answer is not simple and would likely depend on a number of factors—for example: How much is one cutting back? And from which foods and drinks? What is replacing it?” Sollid says. Here’s what we (kind of) know:

According to Feller, some observational research has found that low- and no-calorie sweeteners may change the composition of microbes found in the gut. Keep in mind, however, microbiome research is still in its infancy. “Regarding the gut specifically, currently, no standards exist to define a healthy human microbiome. There are significant differences among the microbiome profiles of different people,  and research has shown that the gut microbiome can quickly respond to normal changes in the diet,” Sollid says.

This makes it especially difficult to establish a baseline standard for adequate microbiome health. On the flip side, some research also indicates that artificial sweeteners may have the upper hand on sugar. “Alternatively, research has found that low- and no-calorie sweeteners can be a beneficial alternative to consuming added sugars [in some instances],” she says.

A few easy ways to cut back on artificial sweeteners

For those looking to reduce their low and no-calorie sweetener intake in the food supply, reading labels becomes important, Feller says. “Currently, there are six low and no-calorie sweeteners approved for use in the food supply; consumers can read ingredient labels and choose products without these additives,” she says. In the case of beverages, water is best. However, if plain water isn’t cutting it, Feller recommends sticking to 100 percent fruit juice, sparkling water with 100 percent fruit or vegetable juice, still or sparkling water with natural flavors, infused water, or teas like herbal, green, or black.